EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3. Production of Oil and Gas Facilities Available
3.1 Process Description After completion of drilling up to the target depth, well logging operations were undertaken to estimate the resource present. After that perforation job was carried out in the final casing and production testing will be done to estimate the reservoir potential and rate of production. Finally depending upon the rate of return expected from the well it will be either put on production or the same may be abandoned. The potential wells which are capable of producing Oil & Gas will be connected to the existing nearby production facility (GGS/ EPS/ WHI) through flow line or will be transported by tankers. The details of facilities available with Cambay sub asset with respect to the fields mentioned in these projects is given below in Table.
Table 3.1 Production of Oil and Gas Facilities Available
S. Field/ Area Expected Planned Oil& Gas handling Produced potential for locations facility available water handling o. each well facility (MT/d) 1. Akholjuni 80 4 EPS Akholjuni Mobile ETP 2. 150 15 WHI (Crude to be ETP Kathana transported to Anklav Kathana GGS through tankers) 3. Chaklasi 15 3 GGS Kathana ETP Kathana 4. Kathana 24 3 GGS Kathana ETP Kathana 5. 3 1 WHI (Crude to be ETP Kathana transported to Mahi High Kathana GGS through tankers) 6. Padra 144 18 GGS Padra CETF Padra 7. 27 9 WHI (Crude to be ETP Kathana transported to Siswa Kathana GGS through tankers) 8 15 7 WHI *(Crude to be ETP Kathana transported to Nadiad Kathana GGS through tankers) 9 330 48 EPS* ( 3 nos. ETP* with proposed at Vadatal Water Injection Vadtal 1,3 & 5) Facility ( 3 nos. proposed at Vadatal 1,3 & 5)
3 1
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
* Proposed Facilities
In the above table all other installations were established well before
WHI, EPS and ETP for Nadiad & Vadtal Field will be established in near future after establishment of substantial wells in the field. Flow lines of 4”/8”dia will be laid as per requirement of respective field for transportation of crude oil depending on production from wells.
The installed capacity of the Production Installation mentioned above w.r.t handling of oil and gas is given below. It could be observed that there is enough capacity for handling the additional production.
Table 3.2 Present ProductionInstallations of Oil and Gas And Handling Capacity
S. Oil& Gas Installation Installed Present Processing Present Present Processing o Capacity Processing after ETP processing after . (m3/d) ( m3/d) Expected capacity of addition of Additional produced Expected Production (m3/d) water Produced ( m3/d) (m3/d) water(m3 Oil Gas Oil Oil Gas /d)
1. Akholjuni EPS 300 50,000 137 231 120 69 116 2. Kathana GGS 500 (Presently, oil from Anklav, Chaklasi,Mahi
high, Siswa, Nadiad and Vadatal ( Totaling 349 459 250 175 230 to 280 m3)is being processed at Kathana GGS along with the oil of Kathana field. 3. Padra GGS 500 50,000 186 319 150 93 150
• Considering 50% watercut 3.2. Process Description of GGS/ EPS The general process involved in any oil& gas process installation is given below along with brief description. The capacity of EPS is lesser than capacity of GGS and accordingly the number of separators and other utilities varies. The general accessories associated all the process facility and there functions are as below:
3 2
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Well Fluid Manifold Well header manifold is a combination of flow lines and control valves. A header has production and testing valves to control the flow of each well, thus directing the produced fluids to production or testing separators. The wells are connected to header manifold by their individual/combined flow lines at GGS/EPS. This manifold facilitates to divert the well fluids to any one of the separators. Separators Separators a vessel used to separate oil, gas and water coming directly from an oil or gas well, or a group of wells (i.e., a "production" separator). A separator is primarily used to separate a combined liquid gas stream into phases that are relatively free of each other. Separators are generally classified as two phase separator and three phase separator.Two phase separators achieve only vapour liquid separation, while three phase separators also remove free water from the crude oil. Test Separator Any well can be diverted from well fluid manifold to test separator for periodical testing and assessing individual well potential. After separation of liquid and gas, liquid is flown to 2nd stage test separator and further to storage tanks. Gas from test separator is sent to consumers through M/S. GAIL and LP gas is sent to consumers through LP gas scrubber, excess gas is flared through knock out drum (KOD). Scrubber Scrubbers a vessel normally (but not necessarily) more efficient than conventional separators in removing small liquid drops from a gas phase. Scrubbers are often used ahead of compressors, glycol and amine units, and they are often applied downstream of field separators to remove entrained and/or condensed liquids. A scrubber is a separator specifically designed for streams with unusually high GLR ratios, so it is not intended to handle large slugs of liquid. Knock Out Drum Knock out drum is used to separate liquid phase from a combined gas, hydrocarbon liquid. The total liquid knockout is often used to remove liquids from a high pressure gas stream. This vessel usually is used with a cold separation unit.One knock out drum is placed upstream of flare stack, in the installation to remove liquid particles from flare gas. KOD liquid is drained into surface pit for further recovery.
Oil Storage Tank Storage tank is a container used to store produced crude oil from wells. There are number of horizontal/vertical cylindrical tank, each having a capacity of 45 m3. After settling crude oil is further collected in oil storage tanks. From storage tanks, oil is transported to GGS/EPS. The processed oil is pumped to Gujarat refinery Vadodara through 10” trunk line.
Flare Stack Flare stack is an elevated vertical stack which is used for burning off excess gas from production handling system. Low pressure gas from 2nd stage separator and LP separator and excess gas from 1st stage separator’s is flared through a flare stack of 30 m height and 4” diameter flare header (2 nos – LP/HP) provided with pilot and burner. Process Flow Diagrams of Existing of typical Installation is shown below:
3 3
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 4
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 5
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 6
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3.4 Process Description of Effluent Treatment Plant
The water separated from the oil at GGS /EPS is collected in effluent storage tank/pit. The effluent is then further pumped to the effluent treatment plant
Untreated effluent is received in raw water tank. Oil particles, if any, is skimmed off to slop oil sump & from there is pumped to slop oil tank.
Effluent is pumped from raw effluent tank to flash mixer I. Lime solution is added to the tank to maintain the effluent pH at about 7.5 (Lime is added only when the effluent pH is below 7.1). The effluent and lime solution are well mixed by an agitator rotating at 100 RPM. The effluent from flash mixer I flows by gravity to flash mixer II where it is treated with alum. Mixing is achieved through an agitator rotating at 100 RPM.
Then effluent flows by gravity into the flocculation zone of the clariflocculator. The floc grows in size. The flocculated water flows into the clarifier section where large flocs settle easily to the bottom. The bottom is slopped towards center and settled sludge flows to sludge drying bed. Filtered water from the bottom of the drying bed collects in a sump (OWS)and is pumped back to Flash mixer tank.
Over flow from the clariflocculator is fairly clean water and flows by gravity to a Filter feed sump. From this sump, clarified water is pumped to dual media filters. Water flows from top to bottom and filtered water is collected in treated water storage tank of approximate capacity of 1300 m3 (2 tanks).Provisions for adding conditioning chemicals such as Corrosion inhibitor, Oxygen scavenger and Bactericide for minimizing corrosion, erosion and bacterial growth prior to injection of treated effluent are also available.
The treated water is pumped with high pressure pumps through which it is injected into effluent disposal wells. The above process and complete facilities were designed to treat and inject maximum quantity of 1400 m3 / day (ETP NRM) + 500 m3 / day (ETP KMP).
The maximum limits of the effluent parameters fixed by MOEFCC / GPCB for injecting into abandoned wells below 1000m are as under :
(i) TSS (Total Suspended Solids) ≤100 ppm (ii) Oil & Grease ≤ 10 ppm
3 7
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 8
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 9
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3.5 Details of proposed Installations and proposed flow lines.
S. No. Installation proposed Location of Installation
1 Early Production system (EPS) Vadatal 1
2 Early Production system (EPS) Vadatal 3
3 Early Production system (EPS) Vadatal 5
4 Effluent Treatment Plant (ETP) Vadatal 1
5 Effluent Treatment Plant (ETP) Vadatal 3
6 Effluent Treatment Plant (ETP) Vadatal 5
7 Well Head Installations (WHI) Nadiad 1
3 10
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 11
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 12
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 13
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 14
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Schematic Diagram of Early Production System at Vadatal-1
GAS TO LP COMPRESSOR/FLARE
PG PC SCRUBBER STORAGE TANKS 200 m3 × 2 H TEST HEADER MP HEADER 1 STAGE P LP HEADER HP HEADER CHANGE OVER HEADER PC GAS TO COMPRESSOR DRAIN TO SUMP
M
P TG DRAIN TO SUMP
PC
GAS TO FLARE L P
LP SEPARATOR
DRAIN TO SUMP PUMP OIL DISPATCH
TEST TANK PC GAS
OIL TO PUMP DRAIN TO SUMP
BATH HEATER SEPARATOR BATTERY
3 15
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Schematic Diagram of Early Production System at Vadatal-3
GAS TO LP COMPRESSOR/FLARE
PG PC SCRUBBER STORAGE TANKS 200 m3 × 2
H TEST HEADER MP HEADER 1 STAGE P LP HEADER HP HEADER CHANGE OVER HEADER PC GAS TO COMPRESSOR DRAIN TO SUMP
M
P TG DRAIN TO SUMP
PC
GAS TO FLARE L
P
LP SEPARATOR
DRAIN TO SUMP PUMP OIL DISPATCH
TEST TANK PC GAS
OIL TO PUMP DRAIN TO SUMP
BATH HEATER SEPARATOR BATTERY
3 16
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Schematic Diagram of Early Production System at Vadatal-5
GAS TO LP COMPRESSOR/FLARE
PG PC SCRUBBER STORAGE TANKS 200 m3 × 2 H TEST HEADER MP HEADER 1 STAGE P LP HEADER HP HEADER CHANGE OVER HEADER PC GAS TO COMPRESSOR DRAIN TO SUMP
M
P TG DRAIN TO SUMP
PC
GAS TO FLARE L P
LP SEPARATOR
DRAIN TO SUMP PUMP OIL DISPATCH
TEST TANK PC GAS
OIL TO PUMP DRAIN TO SUMP
BATH HEATER SEPARATOR BATTERY
3 17
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03nos.of EPS,01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Schematic of Proposed WHI at Nadiad-1
Gas to Flare
Changeover Header
Group Header Test Header Storage Tank 45m3
Test tank Storage Tank 45 m3 45m3 PG TG
Drain to Sump
PC Gas
Mobile Separator
Drain to Sump
Details of scheme of oil collection system (Flow line and Pipeline diagrams) :
Map – 1, Map 2, Map – 3 are existing flow line, pipe line diagrams connected to Kathana GGS, Padra GGS, Akholjuni EPS of Cambay Asset respectively.
Map – 4 to 12 are proposed flow line diagrams of Akholjuni, Anklav, Chaklasi, Kathana, Mahi high, Siswa, Padra, Vadtal, Nadiad respectively.
3 18
Map - 1
Map – 2
Map - 3
T ROAD
CANAL
ASPHALT ROAD OIL & NATURAL GAS CORPORATION LIMITED SCALE:- 1 : 10000 LEGEND:- MAP-4 MAP-4 CAMBAY SYMBOL DESCRIPTION SYMBOL DESCRIPTION TOPOGRAPHICAL MAP SHOWING AKHOL JUNI FIELD
XãBLIM%8
DRAIN ASPHALT ROAD
CANAL
AK#2N XãBLIM%25 XãBLIM%22
GUDEL PRAVISHAKHA
ASPHALT ROAD ASPHALT ROAD
ASPHALT ROAD
AK#2N -PROPOSED FLOW LINE (TENTATIVE)
XãBLIM%4 ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
GUDEL PRAVISHAKHA
XãBLIM%32
ASPHALT ROAD
XãBLIM%9
ASPHALT ROAD AK#3N
XãBLIM%29
ASPHALT ROAD AK#4N ASPHALT ROAD ASPHALT ROAD ASPHALT ROAD
AK#3N -PROPOSED FLOW LINE (TENTATIVE) XãBLIM%24
ASPHALT ROAD XãBLIM%31
XãBLIM%26
ASPHALT ROAD ASPHALT ROAD ASPHALT
XãBLIM%27
ASPHALT ROAD
AK#4N -PROPOSED FLOW LINE (TENTATIVE)
GUDEL PRAVISHAKHA
AK#1N AK#1N -PROPOSED FLOW LINE (TENTATIVE) XãBLIM%28 ASPHALT ROAD XãBLIM%6
XãBLIM%7
JUNI AKHOL EPS
ASPHALT ROAD
ASPHALT ROAD
XãBLIM%23 LIBNCIBU"QIBTFãJ"H/J/E/D/ ASPHALT ROAD )LIBNCIBU*
SALT WASTE DRY
ASPHALT ROAD
XãBLIM%21
SALT WASTE DRY ASPHALT ROAD
OIL & NATURAL GAS CORPORATION LIMITED SCALE:- 1 : 10000 KHEDASA SUBMINOR LEGEND:- CAMBAY MAP-5 SYMBOL DESCRIPTION SYMBOL DESCRIPTION TOPOGRAPHICAL MAP SHOWING ANKLAV FIELD
ASPHALT ROAD SW#9N
ASPHALT ROAD AN#3N AN#15N AN#13N ASPHALT ROAD
ASPHALT ROAD TJTX%9
ASPHALT ROAD BLMW%3
ASPHALT ROAD
ASPHALT ROAD AN#14N
AN#12N AN#10N
ASPHALT ROAD AN#11N
ASPHALT ROAD KHEDASA SUBMINOR
ASPHALT ROAD
BLMW%8-:-22
ASPHALT ROAD
AN#1N
ASPHALT ROAD AN#2N
AN#4N
CART TRACK
ASPHALT ROAD AN#5N AN#8N AN#6N
ASPHALT ROAD AN#7N ASPHALT ROAD AN#9N
XMXE%2
ASPHALT ROAD
High Water Line OIL & NATURAL GAS CORPORATION LIMITED SCALE:- 1 : 10000 CAMBAY LEGEND:- MAP-6 SYMBOL DESCRIPTION SYMBOL DESCRIPTION
CH#1N TOPOGRAPHICAL MAP SHOWING CHAKLASHI FIELD DLBEã9
DLBEã3 XãOBEJBE
CANAL
CANAL
SH ASPHALT ROAD
SH
CANAL
DLã5
ASPHALT ROAD
ASPHALT ROAD
CANAL
CANAL CANAL
ASPHALT ROAD
CH#2N
CANAL CANAL
ASPHALT R DLã8
CANAL
CANAL
ASPHALT ROAD
CANAL
ASPHALT ROAD NADIAD BRANCH CANAL
ASPHALT ROAD
CANAL
CANAL
CANAL
CANAL
NH-228
ASPHALT ROAD DLã6
DLã7
CH#3N CK#3N -PROPOSED FLOW LINE (TENTATIVE) DLã4
WESTERN RAILWAY MAIN LINE CHAKLASHI WHI
ASPHALT ROAD
CANAL
XãVUTEã2
SH-150
SH-60 CANAL OIL & NATURAL GAS CORPORATION LIMITED SCALE:- 1 : 10000 LEGEND:- MAP-7 CAMBAY ASPHALT ROAD ASPHALT ROAD SYMBOL DESCRIPTIONASPHALT ROAD SYMBOL DESCRIPTION TOPOGRAPHICAL MAP SHOWING KATHANA FIELD
ASPHALT ROAD
CANAL
LUIO%27
ASPHALT ROAD
ASPHALT ROAD
WESTERN RAILWAY VASAD KATHANA SECTION CANAL
ASPHALT ROAD
CANAL LUIO%7
ASPHALT ROAD
LUIO%49
LUIO%48 LUIO%35 LUIO%39 ASPHALT ROAD LUIO%47 SFMJORVJTI"CMPDL LUIO%37 LUIO%31
ASPHALT ROAD
LUIO%32 LUIO%34 ASPHALT ROAD LUIO%3: ASPHALT ROAD ASPHALT ROAD LUIO%23 LUIO%41 LU%2O LUIO%45
KT#1N
ASPHALT ROAD LUIO%26
LUIO%3 LUIO%29 LU%3O LUIO%42
KT#2N LUIO%36
LUIO%24 LUIO%33
KT#1N -PROPOSED FLOW LINE (TENTATIVE) ASPHALT ROAD LU%4O (TENTATIVE)
KT#2N -PROPOSED FLOW LINE
KT#3N LUIO%44 LUIO%2:
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD LUIO%53 LUIO%46 LUIO%2
LUIO%6
LUIO%25 ASPHALT ROAD
LUIO%38 ASPHALT ROAD LUIO%28
ASPHALT ROAD LBUIBOB"N/M/ CANAL
ASPHALT ROAD LUIO%:
CANAL ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD ASPHALT ROAD
NALA
GZ034$æ"ICKN"ICU"R1NTO DHUVARAN
ASPHALT ROAD
WESTERN RAILWAY VASAD KATHANA SECTION LUIO%52
ASPHALT ROAD E0T
E0T SCALE:- 1 : 10000 ASPHALT ROAD DNCZã21 OIL & NATURAL GAS CORPORATION LIMITED
ASPHALT ROAD CAMBAY
ASPHALT ROAD ROAD ASPHALT ASPHALT TOPOGRAPHICALROAD ASPHALT MAP SHOWING MAHI HIGH FIELD DNCZã66 DNCZã45 DNCZã29B
DNCZã35
DNCZã77 DNCZã78
DNCZã26 Mahi High#2 (WHI)
NALA ASPHALT ROAD ASPHALT ROAD ASPHALT ROAD ASPHALT ROAD
DNCZã7: ASPHALT ROAD
DNCZã6: ASPHALT ROAD
ASPHALT ROAD E0T CART TRACK ASPHALT ROAD GZ032$æ"QKN"NKPG DNCZã46 (AKHOL EPS TO PADRA GGS)
DNCZã36
ASPHALT ROAD
ASPHALT ROAD CART TRACK
DNCZã29
DNCZã67
Mahi High#1
DNCZã79 ASPHALT ROAD
DNCZã4:
ASPHALT ROAD ASPHALT ROAD
DNCZã73 NARESHWAR TANK
ASPHALT ROAD DNCZã33
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
DNCZã72
SALWA TANK
T"B"M"U"""""Q"B"O" ASPHALT ROAD
DNCZã38B
DNCZã32
DNCZã43
T"B"M"U"""""Q"B"O"
DNCZã48
ONGC ROAD LEGEND:- MAP-8 DBNCBZ"N/M/""CMPDL")PJMFY*" SYMBOL DESCRIPTION SYMBOL DESCRIPTION MahiHigh#1N (WHI)
N/M/"DBNCBZ NI%2O MH#1N, N/M/"DBNCBZ T"B"M"U"""""Q"B"O"
ONGC ROAD T"B"M"U"""""Q"B"O"
ONGC ROAD
MAHI SAGAR RIVER SH-6 OIL & NATURAL GAS CORPORATION LIMITED SCALE:- 1 : 10000 LEGEND:- SW#1N CAMBAY MAP-9 SYMBOL DESCRIPTION SYMBOL DESCRIPTION TOPOGRAPHICAL MAP SHOWINGASPHALT ROAD SISWA FIELD SW#2N
SW#3N
CANAL
TJTX%6
SW#4N
TJTX%4
CANAL
SW#5N
ASPHALT ROAD
SW#6N PROPOSED WHI
SW#7N PROPOSED WHI
ASPHALT ROAD SW#9N ASPHALT ROAD
CANAL
ASPHALT ROAD
TJTX%5
ASPHALT ROAD
ASPHALT ROAD
TJTXB"N/M/ ASPHALT ROAD
ASPHALT ROAD
TJTX%7
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
GZ0:$æ"QKN"RKRG"NKPG CAMBAY GGS TO PADRA GGS
ASPHALT ROAD
ASPHALT ROAD
CANAL
ASPHALT ROAD ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
NALA
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD SW#8N
ASPHALT ROAD
ASPHALT ROAD
TJTX%:
ASPHALT ROAD
ASPHALT ROAD
ASPHALT ROAD
OAD DRAIN CAMBAYGZ0:$æ"QKN"RKRG"NKPG GGS TO PADRA GGS GZ0"8$æ"5"Pq0"TKN*KREN+PRODUCT PIPELI
ASPHALT ROAD ASPHALT ROAD
DRAIN CANAL
PD#3N XãQBESB%55 ASPHALT RO Hsffo"Wbmmz"ijhi"Sftjefou PD#1N
ASPHALT ROAD PD#4N TOPOGRAPHICAL MAP SHOWINGTdippm"Wjmmbhf;ãBnqbe PADRA FIELD GZ046))æ"Djcfdjwv"Rciwvjcp Serkhi GSPL Gas Pipeline
ASPHALT ROAD ASPHALT ROAD PD#2N QECTãQ%64
Ofx"E0T Q%27 ASPHALT ROAD
ASPHALT ROAD ASPHALT ROAD
Q%24 WAY HIGH EXPRESS PROPSOED
GZ034$æ"ICKN"ICU"R1N CHOKARI TO UNDERA
ASPHALT ROAD
ASPHALT ROAD
M A H I R I V E R ASPHALT ROAD PD#5N CANAL PD#7N PD#6N Q%31 ASPHALT ROAD
ASPHALT ROAD CANAL Q%44 ASPHALT ROAD
CANAL
ASPHALT ROAD Q%360B BCCFZ"Difnjdbmt"Qwu/"Mue/ Q%36
BNPMJ""Pshbojdt"qwu/"mue/ N/K/"Difnqibsn QBSBHPO""Pshbojdt
QSJNF""Pshbojd QEES FOWJSP""Jogsbtusvduvsf"mue/ Hvkkbs"Dsbujwf"Eftjho""Qwu/"Mue/ CANAL CFO[PM""Qfusp"mue/ Tijwb"Qibsn/"Difn/"qwu/"mue/ Q%:
ASPHALT ROAD
DRAIN
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SH64
GZ036))æ"CDIN"ICU"NKPG ASPHALT ROAD H/O/"Hftf""DifnjdbmtQSBTBE"Joufsobujpobm"q/"mue/)Dmptf* XãQBESBã25 PD#8N HBOFTI"Difnjdbmt Bwjtib"Difnjdbm"Dpnqboz [ZEFY""Joevtusjft TFBHBM"JOE/MUE/" SFMJORVJTI"CMPDL PD#9N LBOKBSB""Difnjdbm"mue/ Q%39 CBODP Fmojdp"Dpnqpoz ASPHALT ROAD Q%32 E/C/N/T/""Difnjd/ SFGPJM""Fbsui"qwu/"mue/ QEBIãQ%26 LBCBSB""Dpmpvst"qwu/"mue/ NFUSP""Difnjdbm"joe/"mue/ QEFãQ%67
CAMBAY GGS TO PADRA GGS ASPHALT ROAD GZ0:$æ"QKN"RKRG"NKPG ASPHALT ROAD
Q%73 ASPHALT ROAD XãQBESBã35 SPUPNPVME SH FOWJSP""Jogsbtusvduvsf"mue/ HVMCSBOETBO LFEJMB"Ifbmuidbsf"mue/ SH64
"Difnjdbmt"qwu/"mue/ POHD"SPBE
Serkhi GSPL Gas Pipeline Gas GSPL Serkhi GZ046))æ"Djcfdjwv"Rciwvjcp
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ASPHALT ROAD CAMBAY SYMBOL DESCRIPTION SYMBOL DESCRIPTION
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ASPHALT ROAD ALT ROAD OIL & NATURAL GAS CORPORATION LIMITED DLBEã3 SCALE:- 1 : 10000 LEGEND:- OEBE%2 CAMBAY MAP-12 SYMBOL DESCRIPTION SYMBOL DESCRIPTION PROPOSED WHI TOPOGRAPHICAL MAP SHOWING NADIAD FIELD OEBE%4 ND#6N ND#7N
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ND#2N EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4. DESCRIPTIO OF THE E VIRO ME T
4.1 Introduction
The different components of the Environment, namely Air, Noise, Water (Surface and Ground Water), Soil, Ecology and Socio Economy of the Study Area have been defined in this chapter. The whole of 9 ML/NELP Block Area 820.82sq.km is considered for study. 10 km radial distance from the center of the Oil Block, covering all the wells proposed in each block has been taken up as the Study Area for the Proposed Project. Both Primary and Secondary Information are used to assess the Baseline Condition. One season monitoring of various environmental parameters were carried out from October 2014 to December 2015.
Delineation of environmental baseline condition with respect to Air, Noise, Water (Surface and Ground Water), Soil, Ecology and Socio Economy, will further facilitate in Impact Identification and Assessment, which are described in the subsequent chapter.
4.2 Site Description and Its Environment Development Drilling of 108 wells, are proposed to be drilled in ML/NELP, total 9 blocks/fields of Cambay Asset in Anand, Kheda and Vadodara district. The Block mainly consists of Man made Environmental Setting i.e. Agricultural Field. The location of ML/NELP blocks is shown in Figure 4.1.
4 1
EIA Report for Development Drilling off 108 wellsw , laying of, 4” and8” dia. Oil and gas flow lines & establishmblishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injectionjection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 4.1 Block Location Map
4 2
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.3 Regional Setting
4.3.1 Topography & Geology
The CambayBasin is a major NW –SE trending rift graben extending from Gulf of Cambay in south to Barmer Basin of Rajasthan in North. The evolution of the Basin is broadly divided into two stages i.e, Late Jurassic to Early Cretaceous pre rift stage and Late Cretaceous tertiary syn rift post rift stage. The sedimentary fill ranges from Mesozoic to recent alluvium with a volcanic sequence equivalent of Deccan Traps in between. Based on structural styles, tectonics and structural morphology of Tertiary sedimentary fills, CambayBasin has been subdivided into five tectonic blocks. From North to South, they are
• Patan Sanchor Block • Ahmedabad Mehsana Block • Cambay –Tarapur Block • Jambusar Broach Block • Narmada Tapti Block
The two blocks i.e. Cambay –Tarapur & Jambusar Broach are separated by MahiSagar river and divided the Cambay Asset area into two parts. The Cambay basin is linear graben with general NNW SSE orientation, but in the Tarapur– Cambay and Jambusar Broach blocks the trend is in NS direction. The oil fields of Cambay Sub Asset are falling in the Cambay Tarapur and Broach blocks. Padra field is falling in Jambusar Broach tectonic block of the Cambay Basin, while rest of other fields viz. Akholjuni, Anklav, Kathana, Siswa, ChaklasiNadiad and Vadatal falls in the Cambay Tarapur block.
The basin came into existence during rifting along N S to NNW SSE trend in Late Jurassic to Early Cretaceous. The two dominant NW SSE and ENE WSW directions correlate well with the intra basinal horsts and grabens. Drilling of 108 No. of development wells in the producing oil fields of Cambay Asset by ONGC in coming up years 2014 2015 onwards. Details of proposed wells to be drilled in following ML/NELP Blocks is as below.The net oil gain from drilling of 108 wells may be 0.500 MMT. Drilling of these development wells which includes Horizontal / Hi Tech wells in addition to conventional wells will not only arrest the natural decline of field production but it is expected toaugment production.
4.3.2 Stratigraphy
Cambay –Tarapur & Jambusar Broach are separated by MahiSagar river and divided the Cambay Sub Asset area into two parts. The Cambay basin is linear graben with general NNW SSE orientation, but in the Tarapur–Cambay and Jambusar Broach blocks the trend is in NS direction. The oil fields of Cambay Sub Asset are falling in 4 3
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
the Cambay Tarapur and Broach blocks. Padra field is falling in Jambusar Broach tectonic block of the Cambay Basin, while rest of other fields viz. Akholjuni, Anklav, Kathana, Siswa, Chaklasi, Nadiad and Vadatal falls in the Cambay Tarapur block. The basin came into existence during rifting along N S to NNW SSE trend in Late Jurassic to Early Cretaceous. The two dominant NW SSE and ENE WSW directions correlate well with the intra basinal horsts and grabens.
Figure 4.2 Stratigraphy of Cambay Basin
Seismicity According to the Seismic zoning Map of India [IS 1893 (Part I):2002], the study region falls in Zone II of the seismic zoning map of India. Hence, the risk due to seismicity is very low, as the probability of an earthquake is also less. The Seismic Zoning Map is shown in Figure 4.3.
4 4
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Oil Block
Figure 4.3 Seismic Zonation Map of India
4.4 State of the Environment
The climate of this region is characterized by a hot summer and general dryness except in the southwest monsoon season. The year may be divided into four seasons. The cold season (December to February), hot season (March to middle of June), southwest monsoon (middle of June to September) and post monsoon season (October and November).
Table 4.1 the Climatological data of three districts for the period of (1971 2014). The project area has the period from December to February seems to be the coolest season for a particular calendar year. January is generally the coldest month with the mean daily maximum temperature at about 28.6°C and mean daily minimum at about 11.2°C. 4 5
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
March onwards, both day and night temperatures increases rapidly. March to May is usually the hottest period and May being the hottest month with a mean daily maximum temperature of about 40.6°C and mean daily minimum of about 25.3°C.
The distribution of rainfall in the region, which includes the study area, is uneven. Average mean rainfall in the region is 900.9 mm. About 93 percent of the annual rainfall in the region is received during the southwest monsoon months i.e. June to September. August is the rainiest month.
Table 4.1 Climatological Data of three districts (Gujarat) for the period 1971 2014
Mean Daily Rainfall No. of Relative Relative Temperature (mm) Month Rainy Humidity (%), Humidity (%), Monthly Max Min days (Morning) (Evening) Total
January 28.6 11.2 1.1 0.1 70 37 February 30.8 13 0.9 0.2 65 32 March 35.7 17.6 3 0.2 57 26 April 39.2 22 0.6 0.1 59 26 May 40.6 25.3 3.5 0.3 68 32 June 37.2 25.9 140.9 5 80 52 July 32.9 24.8 266.8 11.3 88 74 August 31.7 24.2 301.2 11.4 91 76 September 33.3 23.6 125.9 5.3 87 65 October 35.6 21.3 10.7 0.6 74 46 November 33.2 16.8 41 1.1 67 44 December 29.8 13.1 5.3 0.3 71 43 Total - - 900.9 35.9 73 - Average 34 19.9 - - 46 -
Zone Middle Gujarat
Climate Semiarid
Districts Covered Panchmahals Amod, Ankleshwar, Baroda and Anand, Balasior, Borsad, Kapadvanj, Kheda, Matar, Ahmedabad, Nadiad, Petlad and Thasara and taluks of Kheda.
4 6
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Rainfall(mm) 800 – 1000
Major Crops Rice, Wheat, Gram, Perlmillets, Sorghum, Maize, Kodra, Ragi, Pigeonpea, groundnut, Sesamum, Castor, Cotton, Sugarcane, Potato, Rapeseed & Mustard.
Soil Deep black, medium black to loamy sand
4.4.1 Land Use Pattern and Cropping Intensity Total reporting area in Gujarat was 188.1 lakh hectares in 2009 10. The net sown area (NSA) and gross cropped area (GCA) accounted for about 54.8 per cent and 59.2 per cent of reporting area, respectively. The districts namely Kheda, Amreli, Gandhinagar, Surat, Mehasana, Patan, Anand and Bhavnagar have more than 70 per cent of their area under cultivation. It is encouraging to note that the share of NSA has depicted an incresing trend since 1990 91, whereas it is disheartening to note that the share of area sown more than once has been falling since 2007 08. The forest area has hovered around 6 per cent of total reporting area. During the last two decades, net area sown has grown from 93 lakh hectares (1990 91) to 103 lakh hectares, (2009 10). Comparatively. The gross cropped area in the state has fluctuated a lot during last two decades. It has increased form 105.8 lakh hectares in 1990 91 to 121.1 lakh hectares in 2007 08, thereafter continuously declined to the level of 111.4 lakh hectates in 2009 10. Interestingly, the land put to non agricultural uses has not increased during last two decades. In fact, the share of non agricultural area has declined from 6.0 per cent inn 1990 91 to 5.4 per cent in 2009 10.
4.4.2 Weather and Climate As discussed earlier, broadly, Gujarat has a tropical climate viz., sub humid, arid and semi arid, are spread over different regions of the state. Out of total area of the state, 58.6 par cent fall under arid and semi arid climatic zone. The arid zone contributes 24.94 per cent, while the semi arid zone forms 33.66 per cent of the total area of the state. The analysis on rainfall pattern in Gujarat reveals reveals that the average annual rainfall over different parts of he state varies widely from 300 mm in the Wesatern half of Kutch for 2100 mm in the socuthern part of Valsad district and the Dangs. The average rainfall for the state during 1882 2011 was 798 mm compared to the all India averge of 1100 mm. About 95 per cent of the total annual rainfall is received during three months: July, August and September. Rainfall in the large parts of Gujarat is not only inadequate but also varies widely from year to year (Figure 3). The average of deviation of annual rainfall from long term normal is ( ) 15.43 per cent during a period of 1969 70 to 2010 11. The numer of rainy days in a season varies from one part of the state to another. The range is from minimum of 16 days in Kachhch to maximum of 48 days in Surat and the Dangs (GoG, 2012a). Generally, the number increase as one moves towards the eastern and the southern parts of the state.
4 7
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
As far as the pattern of temperature in the state is concerned, the day temperature in winter is around 28.330C and at night is 11.660C. Summers are extremely hot with the day time temperature deing 46.110C and the night temperature being 32.220C (WAPCOS, 2011).
4.4.3 Disaster and Calamity Management The state of Gujarat has been prone to disasters like eartquake, drought, flood, cyclones etc. These disasters have caused extensive damage to life and property and have adversely impacted economic development. In Gujarat, factors which contribute to the vulnerability to various disasters are: (i) having longest coastling of India leading to tropical cyclones and floods, (ii) a larger proportion of arid and semi arid area with higher frequency of drought occurrence, (iii) many regions of gujarat come under zone fivewhich is the most vulnerable zone for earthquake and (iv) very high rainfall in some parts of the state making it prone to floods. The state is thus vulnerble to many disasters largely because of its geographical location and geological factors. Keeping in view the level of vulnerability of the state to different kind of natural disasters, the Government of Gujarat has adopted a multi hazard holistic approach to disaster management with a focus on reducing risk and vulnerability through policy,legislation, capacity building, education and communication to mitigate the impact of Disaster and achieve better preparedness. Since the state falls in the high intensity Seismic zones III, IV & V, the state has set up an Institute of Sesmological Research (ISR) of international standard. With a view to impart training to Government officials at various levels, NGOs and communities on a continuous on going basis, the State Government also set up Gujarat Institute of Disaster management (GIDM) at Government. In the aftermath of the Gujarat State Disaster Management of 2001, the Gujarat government has enacted the Gujarat State Disaster Managment Act 2003 and in accordance with the provisions of this Act, the state Government has constituted the Gujarat State Disaster Managenment Authority (GSDMA). The GSDMA has already taken active measures for the construction of “District Emergency Operation Centers” (DEOCs) and to make it well equipped in the 26 Districts of Gujarat.
4.4.4 Micro Meteorology
Meteorological study exerts a critical influence on air quality as it is an important factor in governing the ambient air quality. The meteorological data recorded during the study period was used for identifying air quality sampling locations as well as input for air quality simulation models. Meteorological data was collected in winter season for the period of October 2014 to December 2014.
The wind rose diagram for the study area (ML/NELP Block) is shown in Fig. 4.4 to 4.7. The analysis of the average wind pattern shows predominant winds blowing mainly from Sowuth west and west. The average wind speed during this season ranged from 8.9 to 10.5 m/s w.r.t all the blocks mentioned in the study.
4 8
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 4.4 Windrose Diagram Ahmedabad (October2014 to December 2014) 4 9
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 4.5 Windrose Diagram Ahmedabad (October2014 to December2014) 4 10
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 4.6 Windrose Diagram Vadodara (October2014 to December2014)
4 11
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 4.7 Windrose Diagram Vadodara (October2014 to December2014) 4 12
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.4.5 Site Specific Meteorology Baseline meteorological data representing the winter season of 2014 15 (October 2014 – December 2014) has been collected from IMD Ahmedabad. The parameters for which data has been collected are: • Wind Speed • Wind direction • Temperature • Relative Humidity • Cloud Cover
Methodology for Collection of Meteorological Parameters
Hourly meteorological data (wind speed, wind direction, temperature, and relative humidity) were collected during winter season of 2014 15 (October 2014 – December 2014). Methodology for meteorological data collection is given in Table 4.2.
Table 4.2 Monitoring Methodology of Meteorological data
Sampling Range of Sensitivity/ Parameters Methodology equipment measurement Detection Limit
Cup Counter Wind Speed (0 to 65) in m/s 0.25 m/s Anemometer (0° to 357°) degree with Wind Direction Wind vane 1° respect to North direction IS 8829 1978 ( 40° to 60°) Temperature Thermometer in degree 0.1°C Celsius Relative Relative (0 to 99 %) 3% Humidity Humidity meter in percent Visual Cloud Cover Inspection by the observer
4 13
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Site Details of Drilling Location
108 Development wells has been proposed to be drilled from 2014 15 onwards in Cambay Asset in 9 Fields/Blocks. The details of these locations are listed in Table 4.3.
Table 4.3 Site Details of Proposed Drilling Locations (Tentative)
S. o. Fields/Blocks Well Lat Long ear by Village o.
1 Akholjuni 1 22°20'4.11"N 72°30'8.94"E Navagam Bara 2 2 22°22'2.09"N 72°30'9.84"E Navagam Bara 3 3 22°20'55.93"N 72°30'54.72"E Navagam Bara 4 4 22°20'51.89"N 72°32'1.86"E Navagam Bara 5 Kathana 1 22°18'27.85"N 72°48'54.22"E Diwel 6 2 22°18'14.79"N 72°49'3.62"E Diwel 7 3 22°18'6.09"N 72°48'52.24"E Diwel 8 Siswa 1 22°22'2.46"N 72°52'42.04"E Vadeli 9 2 22°21'55.06"N 72°52'56.67"E Vadeli 10 3 22°21'47.30"N 72°52'28.28"E Vadeli 11 4 22°21'23.52"N 72°52'25.16"E Vadeli 12 5 22°21'12.75"N 72°52'23.15"E Vadeli 13 6 22°20'57.17"N 72°52'30.68"E Vadeli 14 7 22°20'47.20"N 72°53'29.96"E Bhadrniya 15 8 22°18'18.32"N 72°54'10.07"E Vadeli 16 9 22°20'35.53"N 72°53'55.78"E Bhadrniya 17 Anklav 1 22°19'18.55"N 72°55'0.83"E Valvod 18 2 22°19'9.41"N 72°54'59.48"E Valvod 19 3 22°20'25.84"N 72°54'31.35"E Valvod 20 4 22°18'58.31"N 72°55'0.62"E Valvod 21 5 22°18'56.35"N 72°55'7.96"E Valvod 22 6 22°18'51.59"N 72°55'4.63"E Valvod 23 7 22°18'46.26"N 72°55'5.25"E Valvod 24 8 22°18'46.75"N 72°54'58.78"E Valvod 25 9 22°18'42.45"N 72°54'57.05"E Valvod 26 10 22°20'0.97"N 72°54'49.91"E Valvod 27 11 22°19'44.12"N 72°54'57.86"E Valvod 28 12 22°19'59.48"N 72°54'45.83"E Valvod 29 13 22°20'26.82"N 72°55'30.16"E Valvod 30 14 22°20'18.75"N 72°55'26.96"E Valvod 31 15 22°20'26.25"N 72°55'19.09"E Valvod 32 Chaklasi 1 22°43'27.53"N 72°52'45.42"E Nadiad 33 2 22°41'34.43"N 72°56'41.97"E Kanjoda 34 3 22°39'59.65"N 72°55'56.00"E Chakasi 35 Mahi High 1 22°18'0.93"N 72°36'28.46"E Khambhat 36 Padra 1 22°17'52.78"N 73° 5'24.40"E Ampad 37 2 22°17'33.83"N 73° 5'19.33"E Ampad 38 3 22°17'54.16"N 73° 6'8.52"E Ampad 39 4 22°17'50.19"N 73° 6'17.93"E Ampad 40 5 22°16'46.12"N 73° 5'51.73"E Rajpura 4 14
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
41 6 22°16'44.68"N 73° 6'4.89"E Rajpura 42 7 22°16'44.25"N 73° 5'45.20"E Rajpura 43 8 22°15'57.56"N 73° 4'58.56"E Ganpatpura 44 9 22°15'50.31"N 73° 5'8.64"E Ganpatpura 45 10 22°15'16.00"N 73° 4'8.39"E Tajpura 46 11 22°15'12.15"N 73° 4'6.87"E Tajpura 47 12 22°14'55.84"N 73° 4ʹ11.09ʺE Tajpura 48 13 22°12'44.56"N 73° 0'39.37"E Ranu 49 14 22°12'44.69"N 73° 0'27.31"E Ranu 50 15 22°13'18.25"N 73° 8'50.21"E Chapad 51 16 22°13'9.01"N 73° 8'49.05"E Chapad 52 17 22°14'11.24"N 73° 3'49.47"E Padra 53 18 22°14'3.14"N 73° 3'50.32"E Padra 54 adiad 1 22°39'39.52"N 72°54'44.87"E Uttarsanda 55 2 22°39'30.59"N 72°54'40.41"E Uttarsanda 56 3 22°39'39.90"N 72°54'31.14"E Uttarsanda 57 4 22°42'2.23"N 72°52'11.14"E Nadiad 58 5 22°41'41.08"N 72°52'48.69"E Nadiad 59 6 22°42'23.25"N 72°51'58.53"E Nadiad 60 7 22°42'19.37"N 72°52'38.99"E Nadiad 61 Vadatal 1 22°36'49.15"N 72°53'58.47"E Rajnagar 62 2 22°35'32.89"N 72°54'31.69"E Becharpur 63 3 22°35'18.15"N 72°54'38.20"E Becharpur 64 4 22°34'58.74"N 72°54'38.53"E Becharpur 65 5 22°34'37.23"N 72°54'42.82"E Bakrol part 66 6 22°35'56.71"N 72°54'15.72"E Bakrol part 67 7 22°35'10.22"N 72°54'7.69"E Bakrol part 68 8 22°34'29.63"N 72°54'24.41"E Bakrol part 69 9 22°40'9.98"N 72°51'54.97"E Piplag 70 10 22°39'43.32"N 72°52'2.50"E Piplag 71 11 22°39'24.72"N 72°51'48.93"E Piplag 72 12 22°39'10.20"N 72°52'3.42"E Gutal 73 13 22°38'47.60"N 72°51'54.13"E Gutal 74 14 22°38'28.21"N 72°51'58.78"E Gutal 75 15 22°37'58.11"N 72°51'45.65"E Keriavi 76 16 22°37'16.72"N 72°51'29.30"E Akhdol 77 17 22°39'11.81"N 72°52'4.60"E Gutal 78 18 22°39'39.90"N 72°52'3.65"E Piplag 79 19 22°39'45.67"N 72°51'38.71"E Piplag 80 20 22°39'3.53"N 72°51'34.45"E Piplag 81 21 22°38'25.77"N 72°51'36.39"E Keriavi 82 22 22°37'38.64"N 72°51'35.64"E Keriavi 83 23 22°37'4.37"N 72°51'37.11"E Bamroli 84 24 22°33'47.18"N 72°49'13.09"E Mahelav 85 25 22°33'15.98"N 72°49'35.49"E Bandhani 86 26 22°33'12.63"N 72°49'59.76"E Bandhani 87 27 22°32'51.03"N 72°50'9.28"E Bandhani 88 28 22°32'25.42"N 72°50'20.82"E Porda 89 29 22°32'3.85"N 72°50'26.26"E Porda 90 30 22°33'17.31"N 72°49'12.86"E Mahelav 91 31 22°32'43.41"N 72°49'32.22"E Mahelav
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
92 32 22°32'16.01"N 72°49'56.37"E Porda 93 33 22°38'13.16"N 72°52'45.24"E Gutal 94 34 22°38'9.54"N 72°52'56.78"E Gutal 95 35 22°37'31.79"N 72°52'42.36"E Narshanda
96 36 22°37'56.99"N 72°53'7.74"E Gutal 97 37 22°37'52.82"N 72°51'7.59"E Keriavi 98 38 22°36'26.86"N 72°53'53.15"E Rajnagar 99 39 22°36'27.16"N 72°53'39.53"E Rajnagar 100 40 22°36'54.15"N 72°54'20.19"E Kanjari 101 41 22°34'49.73"N 72°53'50.36"E Bakrol Part 102 42 22°34'27.35"N 72°49'25.01"E Mahelav 103 43 22°34'27.16"N 72°49'35.69"E Mahelav 104 44 22°34'43.98"N 72°48'49.41"E Mahelav 105 45 22°34'41.12"N 72°48'40.37"E Mahelav 106 46 22°34'29.72"N 72°50'40.99"E Ralvi 107 47 22°34'32.89"N 72°50'27.17"E Ralvi 108 48 22°34'55.89"N 72°49'52.63"E Padgol
4.5 Base Line Status Of Air Quality
The collection of baseline information for air environment includes identification of specific parameters expected to cause significant impacts and assessing their levels of existence in ambient air within the impact zone. 8 stations per locations were selected respectively in industrial, rural and mixed area for monitoring for Ambient Air Quality. The frequency of monitoring was 24 hrs twice in a week at each location and spread over 12 weeks.
Parameters monitored are PM10, PM2.5, SO2, NOX, Total Hydrocarbon, NMHC and Volatile Organic Compound (VOC), the equipment was placed at open space free from trees and vegetation which otherwise acts as a sink of pollutants resulting in lower levels in monitoring results. At locations close to highways, the equipment was placed at least 100 m away from such highways/roads to avoid influence of traffic exhaust emissions. The results of AAQ are given in Table 4.5 – Table 4.10. Monitoring methodology adopted and standards for AAQM is given in Table 4.4.
Table – 4.4 ational ambient Air Quality Standards
Sr. Pollutant Time Concentration in Ambient Air o. Weighted Industrial, Ecologically Methods of Measurement Average Residential, Sensitive Rural and Area Area ( otified by Central Government) (1) (2) (3) (4) (5) (6) 1 Sulphur Annual* 50 80 20 80 Improved West and Gaeke Dioxide (SO2), 24 hours** Ultraviolsat Fluorescence ug/m3 4 16
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
2 Nitrogen Annual* 40 0 30 80 Modified Jacob & Dioxide (NO2), 24 hours** Hochheiser (Na Arsenite) ug/m3 Chemiluminescence 3 Particulate Annual* 60 100 60 100 Gravimetric Matter (size 24 hours** TOEM less then Beta attenuation 10um) or PM10 ug/m3 4 Particulate Annual* 40 60 40 60 Gravimetric Matter (size 24 hours** TOEM less then Beta attenuation 2.5um) or PM2.5 ug/m3 5 Ozone (O3) 8 hours** 100 180 100 180 UV photometric ug/m3 1 hours** Chemilminescence Chemical Method 6 Lead (Pb) Annual* 0.05 1.0 0.05 1.0 AAS/ICP method after ug/m3 24 hours** sampling on EPM 2000 or equivalent filter paper ED XRF using Teflon filter 7 Carbon 8 hours** 02 04 02 04 non Dispersive Infra Red Monoxide 1 hours** (NDIR) spectroscopy (CO)mg/m3 8 Ammonia Annual* 100 400 100 400 Chemiluminescence 24 hours** Indophenol blue method 9 Benzene Annual* 05 05 Gas chromatography based (C6H6) ug/m3 continuous analyzer Adsorption and Desorption followed by GC analysis 10 Benzene Annual* 01 01 Solvent extraction followed (a)Pyrene by HPLC/GC analysis (BAP) Particulate phase only, ng/m3 11 Arsenic (As), Annual* 06 06 AAS/ICP method after ng/m3 Sampling on EPM 2000 or equivalent filter paper 12 Nickel (Ni), Annual* 20 20 AAS/ICP method after ng/m3 Sampling on EPM 2000 or equivalent filter paper
The sample collection was done 8 hrs per day for three days in each location and the average of the value w.r.t minimum to maximum was recorded. The similar study was conducted three times for each location in a frequeny of 15 days and the average was recorded for the study and reported.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.5 Ambient Air Quality Monitoring Stations (Locations)
Sr. Stations Code Locations Direction No. 1. AAQMS1 Mahelav Within Vadatal Field 2. AAQMS2 Piplag Within Nadiad Field 3. AAQMS3 Bakrol Within Vadatal 4. AAQMS4 Bandhani Near vadatal & Nadiad Fields 5. AAQMS5 Gutal Near Vadatal Field 6. AAQMS6 Akhdol Near Nadiad Field 7. AAQMS7 Uttarsanda Within Nadiad Field 8. AAQMS8 Valvod Near Anklav & Kathana Field 9 AAQMS9 Kathana Kathana field
Table 4.6 Average, Cumulative Percentile, Maxima & Minima Particulate Matter (PM10)(Winter Season)
24 Hrs. Avg. Unit : µg/m3 Sr. Station Code Site ame Max. Min. Avg. Percentile o. 98% 1. AAQMS1 Mahelav 93 30 65 93 2. AAQMS2 Piplag 99 66 85 99 3. AAQMS3 Bakrol 86 34 52 84 4. AAQMS4 Bandhani 106 65 86 102 5. AAQMS5 Gutal 79 32 44 72 6. AAQMS6 Akhdol 84 29 39 81 7. AAQMS7 Uttarsanda 95 54 74 93 8. AAQMS8 Valvod 78 32 56 78 9 AAQMS9 Kathana 117 59 82 108
Table 4.7 Average, Cumulative Percentile, Maxima & Minima Particulate Matter (PM2.5)(Winter Season)
24 Hrs. Avg. Unit : µg/m3 Sr. Station Code Site ame Max. Min. Avg. Percentile o. 98% 1. AAQMS1 Mahelav 44 15 29 43 2. AAQMS2 Piplag 38 17 19 37 3. AAQMS3 Bakrol 32 15 18 31 4. AAQMS4 Bandhani 46 22 26 46 5. AAQMS5 Gutal 41 19 21 40 6. AAQMS6 Akhdol 35 18 20 33 7. AAQMS7 Uttarsanda 42 21 27 39 8. AAQMS8 Valvod 33 12 18 31 9 AAQMS9 Kathana 41 20 22 40
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
3 Table 4.8 Ambient Air Quality Status of SO2 (Winter Season Unit: µg/m )
24 Hrs. Avg. Unit : µg/m3 Sr. Station Code Locations Max. Min. Avg. Percentile o. 98% 1. AAQMS1 Mahelav 30 6 10 30 2. AAQMS2 Piplag 18 6 7 16 3. AAQMS3 Bakrol 46 6 19 40 4. AAQMS4 Bandhani 87 6 22 76 5. AAQMS5 Gutal 84 6 19 70 6. AAQMS6 Akhdol 51 6 13 47 7. AAQMS7 Uttarsanda 81 6 26 76 8. AAQMS8 Valvod 66 6 18 65 9 AAQMS9 kathana 13 8 9 13
Table 4.9 Ambient Air Quality Status of Ox (Winter Season)
24 Hrs. Avg. Unit : µg/m3 Sr. Station Code Locations Max. Min. Avg. Percentile o. 98% 1. AAQMS1 Mahelav 26 6 1 25 2. AAQMS2 Piplag 27 3 14 31 3. AAQMS3 Bakrol 58 3 25 51 4. AAQMS4 Bandhani 48 3 20 46 5. AAQMS5 Gutal 43 3 23 32 6. AAQMS6 Akhdol 49 5 19 43 7. AAQMS7 Uttarsanda 58 6 26 55 8. AAQMS8 Valvod 49 3 19 45 9 AAQMS9 Kathana 27 10 12 24
Table 4.10 Levels of Volatile Organic Pollutants
Sr. Station Locations CO Banzene THC MHC MHC 03 o. Code Mg/m3 MQ/m3 ppm ppm ppm ljg/m3* 1. AAQMS1 Mahelav 0.09 ND 0.09 0.05 0.05 3.71 2. AAQMS2 Piplag 0.05 ND ND 0.04 0.03 ND 3. AAQMS3 Bakrol 0.09 ND 0.01 0.06 0.05 5.10 4. AAQMS4 Bandhani 0.00 ND 0.00 0.09 ND ND 5. AAQMS5 Gutal 0.03 0.13 0.08 0.05 0.03 ND 6. AAQMS6 Akhdol 0.08 1.1 ND ND ND ND 7. AAQMS7 Uttarsanda 0.05 0.13 0.10 0.06 0.05 2.44 8. AAQMS8 Valvod ND ND ND ND ND ND 9 AAQMS9 Kathana ND ND 0.1 ND 0.01 ND NAAQM 4 5 (2009)
THC=Total Hydrocarbon; MHC= Methane Hydrocarbon; NMHC=Non methane 3 Hydrocarbon * 8 hours ozone (03) NAAQS = 100 ljg/m
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Observation and Inferencess:
From the results trabulated and it is observed that the 24 hrourly average value of air pollutntants SO2, NOx were well below the permissible level as per CPCB since the area were mostly agricultural fields and rural residential places. The levels of PM10 and PM2.5 were slightly higher due to the agricultural activities and local vehicular emmisionss. But yet they are well within the limits. Methane, VOC and NMHC were also observed and found in insignificant quantities. No were Mercurcy was detected within the detectable limit of the sensors.
4.6 Water Environment
4.6.1 Surface Water Sources
The major river in the study area Mahi river which flows in Vadodara and Anand districts. The Mahi river rises in Madhya Pradesh from the western Vindhya Range is Minda Village situated in Dhar district Madhaya Pradesh. After flowing through MP and Rajasthan,.the river enters Gujarat and flows into Arabian sea by a wide estuary past Khambhat after about a 360 mile (580 km) course. It is one of three west flowing rivers in India, along with Tapti River and the Narmada River. Two major dams build on the river Mahi are Mahi Dam near Banswara area in Rajasthan and Kadana dam in Panchmahals District in Gujarat to provide drinking water, irrigation, hydropower and flood protection. Surface water samples were collected from the river Mahi and various ponds present in the study area. Hese ponds include Dabhasa Pond &Sejakuwa Pond in Vadodara district; Kanbha Pond, Kankapura Pond, Valvod Pond, Nepa Pond And Relej Pond, Nawagam Pond, Navi Akhol Pond & Juni Akhol Pond in Anand district
4.6.2 Water Requirement Water consumption in the region can be divided into three categories i.e. irrigation, domestic and industrial. Besides irrigation, water of Mahi River in the area is being utilized in industrial sectors, domestic and other purposes. The ponds form the major source of drinking water and irrigation.
4.6.3 Water Analysis Methodology
The methodology used for the analysis of water samples taken from the project area is given in Table 4.11.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.11 Analysis Methodology of Ground Water and Surface Water
S. Parameters Methodology Minimum o Detection Limit 1. pH APHA, Edition 21 (4500 H+ B), pH meter 0.01 2. Turbidity APHA Edition 21 (2130 B), Nephelophotometric 0.1 NTU 3. TDS APHA Edition 21 (2540 C) Gravimetric 4 mg/l 4. COD APHA Edition 21 (5220 B), Titrametic open 4 mg/l reflux 5. BOD 3 days IS 3025 part 44, 1993 Iodometric 1 mg/l 5 days APHA edition 21 (5210 B) Iodometric 6. Chlorides APHA Edition 21 (4500 Cr B) Titrametic 5 mg/l 7. Sulphates APHA Edition 21 (4500 SO2 4 E) Turbidimetric 0.1 mg/l 8. Total Hardness APHA Edition 21 (2340 C) Titrametric (EDTA 10 mg/l Method) 9. Total Alkalinity APHA Edition 21 (2320 B) Titrametric 10 mg/l 10. Fluoride APHA Edition 21 (4500 F D) Colorimetric 0.005 mg/l 11. Calcium APHA Edition 21 (3500 Ca B) Titrametric 1 mg/l (EDTA Method) 12. Magnesium APHA Edition 21 (3500 Mg B), by difference 2 mg/l 13. Cadmium (as Cd) APHA Edition 21 (3500 Cd), 3111 B, AAS 0.001 mg/l Method 14. Chromium (as Cr) APHA Edition 21 (3500 Cr B) Colorimetric 0.001 mg/l 15. Copper (as Cu) APHA Edition 21 (3500 Cu B), (3111B), AAS 0.02 mg/l Method, Colorimetric 16. Iron (as Fe) APHA Edition 21 (3500 Fe B) Colorimetric 0.01 mg/l 17. Lead (as Pb) APHA Edition 21 (3500 Pb A), AAS Method 0.02 mg/l 18. Manganese (as Mn) APHA Edition 21 (3500 Mn B) (3111 B), AAS 0.007mg/l Method/ Colorimetric 19. Nickel (as Ni) APHA Edition 21 (3500 Ni), AAS Method 0.02 mg/l 20. Zinc (as Zn) APHA Edition 21 (3500 Zn B) (3111 B), AAS 0.002 mg/l Method/ Colorimetric 21. Total Coliform APHA Edition 21 (9221 B), Multiple Tube 2 MPN/100ml Fermentation 22. Oil & Greese API rp45 5.3.21.2 mg/l 23. Phenol SM5530 D mg/l 24. Sulphide SM4500 S2F Mg/l
4.6.4 Baseline Water Quality Sampling Lactations for ground and surface (River and Pond) water are based on the vicinity of the upcoming location and existing locations of the development wells. Ground water samples were collected from the tubewell and handpump. Surface water samples were
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
collected from upstream and down streem of the nearest reiver and the ponds falling in the 10 KM radius of the well locations. Physico chemical parameters have been determined to ascertain the baseline status of the existing groundwater and surface water resources. Locations are listed in Tables 4.12 and Table 4.13. The Ground water quality was assessed by collecting samples from tube wells/ wells water at different locations. The ground water and surface water samples were analysed for physico chemical parameters to arrive at the baseline environmental status of water quality. The characteristics of groundwater are presented in Tables 4.14 and Table 4.15. Table 4.12 Detail of Ground Water Samples
S. o. Sample Source of collection Field Date of Sample ame Collection 1. GW 1 DABHASA VILLAGE PADRA 17/03/2015 2. GW 2 TAJPURA VILLAGE PADRA 17/03/2015 3. GW 3 SEJAKUWA VILLAGE PADRA 17/03/2015
4. GW 4 KATHA A GGS KATHA A 18/03/2015
5. GW 5 SISWA VILLAGE SISWA 18/03/2015
6. GW 6 VALVOD VILLAGE A KLAV 18/03/2015
7. GW 7 DEHWA VILLAGE KATHA A 18/03/2015
8. GW 8 MAHI HIGH AREA (CAMBAY) MAHI HIGH 16/03/2015 9. GW 9 KHAMBHAT TOW MAHI HIGH 16/03/2015 10 GW 10 METPUR VILLAGE MAHI HIGH 16/03/2015 11. GW 11 AVAGAM VILLAGE AKHOLJU I 16/03/2015 12. GW 12 AVI AKHOL VILLAGE AKHOLJU I 16/03/2015
Table 4.13 Detail of Surface Water Samples
S. o. Sample Source of collection Field Date of Sample ame Collection 1. SW 1 DABHASA PO D PADRA 17/03/2015 2. SW 2 MAHI RIVER PADRA 17/03/2015 3. SW 3 SEJAKUWA PO D PADRA 17/03/2015 4. SW 4 KA BHA PO D KATHA A 18/03/2015 5. SW 5 DEHWA /KA KAPURA PO D KATHA A 18/03/2015
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6. SW 6 VALVOD PO D A KLAV 18/03/2015 7. SW 7 EJA (KHAMBHAT) PO D MAHI HIGH 16/03/2015 8. SW 8 RALEJ PO D MAHI HIGH 16/03/2015 9. SW 9 JU I AKHOL PO D AKHOLJU I 16/03/2015 10. SW 10 AVAGAM PO D AKHOLJU I 16/03/2015 11. SW 11 AVI AKHOL PO D AKHOLJU I 16/03/2015
GROU D WATER RESULTS Table 4.14 a Analysis of water Samples from different locations
Sr. PARAMETER U IT LOCATIO S o. TEST METHODS GW 1 GW 2 GW 3 GW 4 GW 5 GW 6 01 pH at 25⁰C SM 4500 H+ B 7.10 7.50 7.36 7.94 7.39 7.52 02 Turbidity NTU SM 2130 B 0.20 0.30 0.26 0.20 0.56 0.21 03 Total Dissolved mg/L API RP 45 5.3.33.1 3523.67 1215.67 1629.74 1295.4 1328.9 2320.41 Solids 1 7 +2 04 Calcium as Ca mg/L SM 3500 Ca B 44.00 44.00 32.00 12.00 24.00 32.00 05 Chloride as Cl mg/L SM 4500 Cl B 1668.50 248.50 319.50 142.00 177.50 142.00 06 Copper as Cu mg/L SM 3111 B 0.006 0.014 0.021 0.014 0.014 0.014 07 Fluoride as F mg/L SM 4500 F D 0.05 Nil Nil Nil Nil Nil 08 Total Iron mg/L SM 3500 Fe B 1.29 1.91 0.90 2.57 2.89 1.81 09 Magnesium as mg/L SM 3500 Mg E 55.89 114.21 53.46 19.44 26.73 31.59 Mg+2 10 Oil & Grease mg/L API RP 45 5.3.21.2 0.78 Nil 0.29 Nil 0.009 Nil 11 Phenols mg/L SM 5530 D 0.039 Nil Nil 0.25 Nil Nil 2 12 Sulphate as SO4 mg/L SM 4500 SO4 F 5.05 5.11 9.04 3.62 3.75 3.78 13 sulphide mg/L SM 4500 S2 F Nil Nil Nil Nil Nil Nil 14 Total Alkalinity mg/L SM 2320 B 490.00 540.00 680.00 640.00 630.00 1260.00 as CaCO3 15 Total Hardness as mg/L SM 2340 C 340.00 580.00 300.00 110.00 170.00 210.00 CaC03 16 Zinc as Zn mg/L SM 3111 B 0.022 0.021 0.01 0.037 0.02 0.023 17 Chromium as Cd mg/L SM 3111 B * * * * * * 18 Lead as Pb mg/L SM 3111 B Nil 0.73 0.31 0.096 Nil Nil 19 Nickel as Ni mg/L SM 3111 B Nil Nil Nil Nil 0.37 0.019 20 Total Chromium mg/L SM 3111 B 0.449 0.20 0.02 Nil 0.17 Nil as Cr 21 COD mg/L SM 5220 B 368.58 370.02 355.97 367.92 466.00 348.09 22 BOD mg/L (Calculated) 210.61 211.44 203.41 210.24 266.29 198.90
Table 4.14 b Analysis of water Samples from different locations
Sr. PARAMETER U IT LOCATIO S o. TEST GW 7 GW 8 GW 9 GW GW GW 12 METHODS 10 11 01 pH at 25 C SM 4500 H+ B 7.57 6.44 7.60 8.40 8.14 8.09 4 23
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
02 Turbidity NTU SM 2130 B 0.18 0.21 1.20 0.31 1.20 1.64 03 Total Dissolved mg/L API RP 45 1909.6 34692. 4405.2 2218. 548.8 644.42 Solids 5.3.33.1 2 89 9 67 5 +2 04 Calcium as Ca mg/L SM 3500 Ca B 16.00 576.00 96.00 52.00 40.00 64.00 05 Chloride as Cl mg/L SM 4500 Cl B 14200 21584. 2414.5 1065. 88.75 124.25 50 0 00 06 Copper as Cu mg/L SM 3111 B 0.006 0.107 0.026 0.022 0.02 0.018 07 Fluoride as F mg/L SM 4500 F D Nil Nil Nil Nil Nil Nil 08 Total Iron mg/L SM 3500 Fe B 4043 2.67 3.45 5.69 4.36 4.13 09 Magnesium as mg/L SM 3500 Mg E 29.16 1970.7 179.84 70.47 19.44 29.16 Mg+2 3 10 Oil & Grease mg/L API RP 45 Nil Nil 0.604 Nil Nil Nil 5.3.21.2 11 Phenols mg/L SM 5530 D Nil 0.09 0.065 0.23 Nil Nil 2 12 Sulphate as SO4 mg/L SM 4500 SO4 F 4.91 122.75 43.72 20.56 3.88 2.77 13 sulphide mg/L SM 4500 S2 F Nil Nil Nil Nil Nil Nil 14 Total Alkalinity mg/L SM 2320 B 1010.0 470.00 320.00 300.0 250.0 310.00 as CaCO3 0 0 0 15 Total Hardness mg/L SM 2340 C 160.00 9550.0 980.00 420.0 180.0 280.00 as CaC03 0 0 0 16 Zinc as Zn mg/L SM 3111 B 0.017 0.137 0.033 0.02 0.015 0.013 17 Chromium as mg/L SM 3111 B * * * * * * Cd 18 Lead as Pb mg/L SM 3111 B Nil Nil Nil Nil Nil Nil 19 Nickel as Ni mg/L SM 3111 B 0.004 Nil Nil Nil Nil Nil 20 Total Chromium mg/L SM 3111 B 0.204 1.34 0.166 0.126 0.258 0219 as Cr 21 COD mg/L SM 5220 B 346.52 1988.9 560.82 401.9 318.5 380.53 4 3 8 22 BOD mg/L (Calculated) 198.00 1136.5 320.46 229.6 218.0 217.44 3 7 4
Discussion: The physico chemical characteristics of groundwater w.r.t the 9 ML/NELP Blocks indicate pH in the range of 6.44 8.40; temperature during study period is in the range of 30O 39OC. The inorganic parameters viz., Alkalinity was in the range of 250 1260 mg/l; Total Hardness 110 980 mg/l; Chlorides 88 21000 mg/l; Sulphates 2.77 122.75 mg/l).
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
SURFACE WATER RESULTS
Table 4.15 a Analysis of Surface water Samples from different location Sr. PARAMETER U IT LOCATIO S o. TEST SW 1 SW 2 SW 3 SW 4 SW 5 METHODS 01 pH at 25 C SM 4500 H+ B 8.29 8.91 8.87 8.63 8.72 02 Turbidity NTU SM 2130 B 23.00 21.00 110.00 26.10 177.00 03 Total Dissolved mg/L API RP 45 1625.1 884.44 1834.2 363.64 847.11 Solids 5.3.33.1 7 6 +2 04 Calcium as Ca mg/L SM 3500 Ca B 104.00 24.00 44.00 16.00 12.00 05 Chloride as Cl mg/L SM 4500 Cl B 781.00 355.00 461.50 71.00 124.25 06 Copper as Cu mg/L SM 3111 B 0.01 0.007 0.015 0.008 0.017 07 Fluoride as F mg/L SM 4500 F D Nil 0.07 0.08 0.03 Nil 08 Total Iron mg/L SM 3500 Fe B 3.46 2.89 2.55 0.98 2.82 09 Magnesium as mg/L SM 3500 Mg E 65.61 26.73 34.03 24.30 9.72 Mg+2 10 Oil & Grease mg/L API RP 45 3.66 1.12 2.19 0.86 1.83 5.3.21.2 11 Phenols mg/L SM 5530 D 0.039 Nil Nil Nil Nil 2 12 Sulphate as mg/L SM 4500 SO4 F 11.07 14.81 13.35 3.74 3.28 SO4 13 sulphide mg/L SM 4500 S2 F 0.82 0.63 1.02 0.63 0.83 14 Total Alkalinity mg/L SM 2320 B 280.00 205.00 740.00 180.00 430.00 as CaCO3 15 Total Hardness mg/L SM 2340 C 530.00 170.00 250.00 140.00 70.00 as CaC03 16 Zinc as Zn mg/L SM 3111 B Nil Nil 0.003 Nil 0.004 17 Chromium as mg/L SM 3111 B * * * * * Cd 18 Lead as Pb mg/L SM 3111 B 0.433 0.488 Nil Nil 0.443 19 Nickel as Ni mg/L SM 3111 B 0.01 Nil 0.001 Nil Nil 20 Total mg/L SM 3111 B Nil 0.135 0.178 0.049 Nil Chromium as Cr 21 COD mg/L SM 5220 B 745.30 3824.0 967.50 337.46 352.56 0 22 BOD mg/L (Calculated) 425.88 2185.1 552.85 192.83 201.46 4 23 Total Coli form MPN/10 APHA 9221 B 94 920 110 13 240 0 ml 24 E. Coli MPN/10 APHA 9221 F 84 <1.8 14 <1.8 17 0 ml
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.15 b Analysis of Surface water Samples from different location Sr. PARAMETER U IT LOCATIO S o. TEST SW 6 SW 7 SW 8 SW 9 SW 10 SW 11 METHODS 01 pH at 25⁰C SM 4500 H+ B 8.73 8.82 8.03 7.59 8.44 7.21 02 Turbidity NTU SM 2130 B 186.00 34.20 11.30 17.40 11.50 24.00 03 Total Dissolved mg/L API RP 45 491.47 714.64 399.03 2317.6 351.40 454.56 Solids 5.3.33.1 2 +2 04 Calcium as Ca mg/L SM 3500 Ca B 16.00 24.00 16.00 44.00 20.00 28.00 05 Chloride as Cl mg/L SM 4500 Cl B 106.50 213.00 106.50 1207.0 71.00 53.25 0 06 Copper as Cu mg/L SM 3111 B 0.01 0.027 0.028 0.02 0.008 0.016 07 Fluoride as F mg/L SM 4500 F D Nil Nil Nil Nil Nil Nil 08 Total Iron mg/L SM 3500 Fe B 3.30 3.52 1.65 3.19 4.99 2.25 09 Magnesium as mg/L SM 3500 Mg E 17.01 29.16 17.01 109.35 17.01 24.30 Mg+2 10 Oil & Grease mg/L API RP 45 6.58 0.95 1.42 1.004 0.59 3.91 5.3.21.2 11 Phenols mg/L SM 5530 D 0.054 0.02 Nil Nil 0.12 Nil 2 12 Sulphate as mg/L SM 4500 SO4 F 3.76 7.08 4.00 31.41 5.80 4.26 SO4 13 sulphide mg/L SM 4500 S2 F 0.82 0.63 Nil Nil 0.63 0.83 14 Total Alkalinity mg/L SM 2320 B 210.00 250.00 140.00 230.00 160.00 230.00 as CaCO3 15 Total Hardness mg/L SM 2340 C 110.00 180.00 110.00 560.00 120.00 170.00 as CaC03 16 Zinc as Zn mg/L SM 3111 B Nil 0.007 0.014 0.012 0.003 0.009 17 Chromium as mg/L SM 3111 B * * * * * * Cd 18 Lead as Pb mg/L SM 3111 B Nil 0.367 0.822 0.108 0.212 1.64 19 Nickel as Ni mg/L SM 3111 B 0.017 0.002 0.024 0.002 Nil Nil 20 Total mg/L SM 3111 B 0.091 0.006 0.007 0.110 Nil 0.037 Chromium as Cr 21 COD mg/L SM 5220 B 344.81 362.67 350.98 2273.9 325.11 320.78 0 22 BOD mg/L (Calculated) 197.03 207.24 200.56 1299.3 185.77 183.30 7 23 Total Coli form MPN/1 APHA 9221 B 14 130 920 2.0 1600 1600 00 ml 24 E. Coli MPN/1 APHA 9221 F 4.0 11 25 <1.8 26 14 00 ml
Table 4.16: Standard Limits for Drinking Water (IS 10500:1991)
STANDRA LIMITS PARAMETAR UNIT Desirable Permissible Alkalinity mg/L 200 600 Aluminium (as Al) mg/L 0.03 0.2 4 26
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Arsenic (as As) mg/L 0.01 NR Boron (as B) mg/L 1.0 5.0 Cadmium (as Cd) mg/L 0.01 NR Calcium (as Ca) mg/L 75 200 Chloride (as Cl) mg/L 250 1000 Chromium Hexavalent (as Cr+b) mg/L 0.05 NR Colour mg/L 5 25 Copper (as Cu) mg/L 0.05 1.5 Cyanide (as CN) mg/L 0.05 NR Fecal Coliform MPN/100ml Absent NR Fluoride (as F) mg/L 1.0 1.5 Hardness (as CaC03) mg/L 300 600 Iron (as Fe) mg/L 0.3 1.0 Lead (as Pb) mg/L 0.05 NR Magnesium (as Mg) mg/L 30 100 Manganese (as Mn) mg/L 0.1 0.3 Mercury (as Hg) mg/L 0.001 NR Nitrate (as N03) mg/L 45 NR Oil & Grease mg/L 0.01 0.03 PH 6.5 8.5 NR Phenolic Compounds (as mg/L 0.001 0.002 C6HOH Selenium (as Se) mg/L 0.01 NR Sulphate (as S04) mg/L 200 400 Total Coliform MPN/100ml 10.0 NR Total Dissolved Solid mg/L 500 2000 Total Residua Chlorine mg/L 0.2 Turbidity NTU 5 10 Zinc (as Zn) mg/L 5 15 ND Not Detectable NR No Relaxation
Discussion:
The physico chemical characteristics of surfacewater indicate pH in the range of 7.2 8.9; temperature 29.0 36.0OC. The inorganic parameters viz., Alkalinity was in the range of 180 740 mg/l; Total Hardness 70 560 mg/l; Chlorides 71 1207 mg/l; Sulphates 3.28 31.41 mg/l; Microbiological parameter Ecoli and Total coliforms was also present in almost all surface water samples in all blocks.
4.7 Land Environment
4.7.1 Soils The term soil refers to the loose material composed of weathered rocks, other minerals and also partly decayed organic matter that covers large parts of the earth’s surface. Soil is an essential component of the terrestrial ecosystem. Soil also acts as a medium of transport of various dissolved materials to be the underlying ground water. Hence, the impact of the proposed project on soil needs to be understood to properly plan the mitigating measures wherever required. The effects of pollution particularly acidity may have detrimental consequences for crops through disruption of hydrogen ion balance within cells, through enhanced loss of important 4 27
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
nutrients or by other means. However, acidity can be neutralized on leaf surfaces through natural dilution or through buffering effects of the plant tissues and physiological processes which tend to resist changes in Hydrogen ion concentration. The study is intended to specify the agricultural potentials of the soil and the possible impact on soil quality due to the emission from proposed power plant.
4.7.2 Soil Patterns in India On the basis of the physical, topographical, physiological and geological structure, Indian soil has been divided into following different categories: • Red soil • Laterite soil • Red and yellow soil • Shallow soil • Medium and deep black • Black soil • Coastal alluvium • Alluvial soil • Grey brown soils • Desert soil • Terai soil • Erown hill soil • Sub mountain soil
4.7.3 Baseline Status In the around the project area, the soil varies considerably in composition and constitution. Due to the mixed nature of granite and trap rock formations, the soils vary in fertility also. The common types of soils observed are shallow sandy soils, fertile soils, alluvial soils, black, grey and brown soils. The general soil map of the Gujarat is shown in Fig.4.8. The soil samples are collected from 25 cm depth. The details of eight locations selected for collection of soil samples are presented in Table 4.17. Soil samples were analyzed for physic chemical characterization.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Fig.4.8: Soil Map of Gujarat
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.7.4 Physico chemical Characteristics Physical characteristics of soils in the study area are assessed from samples collected at different villages and through laboratory analysis for specific parameters, viz. Texture, bulk density, water holding capacity and porosity. As presented in Table 4.18 the particle size distribution data corresponding to various soil samples have been used to classify predominant soil texture through standard texture triangle as shown in Fig. 4.9. It is apparent from the Fig. 4.9 that the soils are Clay loam and Loam in texture. Bulk density and porosity is found in the range of 1.28 1.55 gm/cm3 and 4.52 66.31% respectively (Table 4.18). Water holding capacity (WHC) is observed in the range of 10.41 70.27% Soil porosity is an indicative parameter for plant root penetration apart from water holding capacity.
Fig. 4.9: Standard texture triangle It is apparent from Table 4.19 that pH of the soil are in the range of 7.90 8.66 and electrical conductivity ranging between 0.1 1.2 mS/cm. The moderate electrical conductivities could be attributed to excess application fertilizers and insufficient drainage in the fields. Chemical analysis results of soil saturation extracts show that the calcium and magnesium are in the ranges of 0.72 3.12 meq/l and 0.62 2.12 meq/l respectively.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Cation exchange capacity (CEC) is a consequence of positive electrical charges on clay and humous particles in soils and is balanced by adsorption of positively charged loam it is this property that largely determines the storage capacity of nutrient in soil in the region are having moderate CEC indicating moderate to high production potential (Table 4.20) as evident from the more exchangeable sodium percentage. CEC is observed in range of 13.6 72.75 meq/100 gm. Among the exchangeable cations Ca2+, Mg2+are in the range of 5.36 21.34 meq/100 gm and 1.9013.26 meq/100 gm respectively. Na+ & k+ are found in the range of 2.44 4.56 meq/100 gm & 0.26 3.79 meq/100 gm respectively. Exchangeable sodium percentage is observed in the range of 6.34 29.98%.
The organic matter in the soils is found in the range 3.24 6.46 %. Phosphorous as P2O5 and Potassium as k2O is observed to vary between 0.31 1.74 kg/ha and 1.21 26.8 kg/ha respectively (Table 4.21).
Table 4.17 Sampling Locations for Soil Quality Monitoring
Sr. No. Locations 1. Mahelav 2. Piplag 3. Bakrol 4. Bandhani 5. Gutal 6. Akhdol 7. Uttarsanda 8. Valvod 9. Vadeli 10. Ganpatpura
Table 4.18 Particle size Distribution and Physical Properties
Sr. Sampling Particle Size Textural Bulk Porosity W.H.C. o. location Coarse Fine Silt Clay Class Density sand sand (%) (%) (gm/cm3) (%) (%) (%) (%) 1. Mahelav 3 20 42 34 Clay 1.38 38.33 28.64 Loam 2. Piplag 11 44 28 15 Sandy 1.53 66.31 70.27 loam 3. Bakrol 2 60 37 23 Loam 1.32 44.42 51.22 4. Bandhani 3 38 27 31 Clay loam 1.42 55.81 41.48 5. Gutal 4 51 29 15 Sandy 1.28 56.72 48.86 loam 6. Akhdol 2 45 29 24 Loam 1.40 13.62 10.41 7. Uttarsanda 3 46 34 17 Loam 1.55 4.52 2.602 8. Valvod 9 31 23 37 Clay 1.44 43.44 26.42 Loam 9. Vadeli 3 46 29 23 Loam 1.44 13.57 10.39 10. Ganpatpura 3 44 31 17 Loam 1.51 13.68 11.03
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.19 Chemical Properties of soil Water (1:1) Extract
Sr. Sampling pH EC (mS/cm) Ca2+ Mg++ a+ K+ o. location (meq/l) 1. Mahelav 8.17 0.360 0.72 0.90 1.28 0.08 2. Piplag 7.90 1.200 3.12 2.12 2.88 0.02 3. Bakrol 7.85 0.150 0.82 0.66 1.32 0.05 4. Bandhani 8.08 0.310 0.76 0.62 0.81 0.02 5. Gutal 8.55 0.100 1.56 1.78 2.53 0.07 6. Akhdol 8.21 0.340 0.76 1.48 0.12 0.01 7. Uttarsanda 8.24 0.330 0.78 0.96 0.60 0.22 8. Valvod 8.42 0.400 0.76 0.98 1.21 0.03 9. Vadeli 8.38 0.375 0.76 0.99 0.15 0.03 10. Ganpatpura 7.95 0.360 0.82 0.61 1.21 0.02
Table 4.20 Cation Exchange Capacity of Soil in Study Area
Sr. Sampling Ca2+ Mg2+ a+ K+ CEC ESP o. location (meq/100 gm) (%) 1. Mahelav 19.76 10.08 3.045 0.135 48.0 6.34 2. Piplag 5.36 4.98 4.078 1.342 13.6 29.98 3. Bakrol 21.34 13.26 2.82 0.260 37.0 7.62 4. Bandhani 11.14 4.34 2.44 0.250 27.0 9.037 5. Gutal 10.72 2.38 4.56 3.790 21.3 21.400 6. Akhdol 14.72 3.52 3.09 0.40 37.87 8.15 7. Uttarsanda 11.9 1.90 2.61 0.49 72.75 20.47 8. Valvod 19.54 2.80 4.02 0.26 25.25 15.92 9. Vadeli 15.00 3.60 2.99 0.40 35.65 8.50 10. Ganpatpura 12.24 3.42 2.65 0.265 37.0 8.21 CEC : Cation Exchange Capacity ESP : Exchangeable Sodium Percent
Table 4.21 Fertility Status of Soils in Study Area
Sr. Sampling location Organic matter P2O5 K2O o. (%) Kg/ha. 1. Mahelav 5.13 0.412 9.759 2. Piplag 4.55 0.612 2.430 3. Bakrol 3.24 0.787 6.090 4. Bandhani 6.10 0.550 2.430 5. Gutal 6.46 1.740 8.530 6. Akhdol 4.42 0.870 1.210 7. Uttarsanda 4.06 0.360 26.80 8. Valvod 3.88 0.310 3.65 9. Vadeli 4.41 0.880 1.211 10. Ganpatpura 4.50 0.600 2.440
Level in poor soil <0.5 <23 <133 Level in Medium Soil 0.5 0.75 23 57 133 1337 Level in fertile soil >0.75 >57.0 >337.0 4 32
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.8 oise Environment
The noise problem is said to exist when the sound level in the air causes interference in human activities such as disturbance in sleep, work and speech communication leading to annoyance. Perception of noise by individuals varies depending on number of factors such as natural sensitivity/hearing ability, level of exposure, time of the day, socio cultural activities etc. at the time of exposure to sound. The impact of noise at community level can have different effects varying from aesthetic impairment such as annoyance, frequent hypertension to as high as loss of hearing. The health impact of noise on individual depends on several factors, viz. physical dose (intensity of sound pressure level and duration of exposure), frequency spectrum, intermittency etc. as well as human factors like sex, age, health condition, occupational exposure etc.
Assessment of noise impacts and the significance of any impact as a result of development are dependent upon the number of factors such as the ambient or background noise levels in the vicinity of the site, the type of development and its operating characteristics. Therefore noise monitoring was carried out to identify and quantify so far as reasonably possible the ambient condition to predict the increase in noise levels and causes of variability of noise levels as a result of the proposed development.
4.8.1 Reconnaissance The ML/NELP Block area of Cambay basin under the Anand, Kheda and Vadodara districts of Gujarat. Cultivation is the main agricultural activity in this block. There are exploratory and development well exists in these block. The objective of noise monitoring survey around the proposed blocks is to identify the existing noise sources so as to measure background noise levels and to suggest mitigation measures to alleviate adverse impact of noise. The study has been executed in the following steps: Reconnaissance Survey Identification of noise sources and measurement of noise levels Measurement of noise levels in residential, commercial, industrial and silence zone
4.8.2 Methodology for oise Monitoring
Noise standards (Table 4.22) have been designated for different types of landuse, i.e. residential, commercial, industrial and silence zones, as per ‘The Noise Pollution (Regulation and Control) Rules, 2000, Notified by the Ministry of Environment and Forests, New Delhi on February 14, 2000’. Different standards have been stipulated during day time (6 am to 10 pm) and night time (10 pm to 6 am). The noise rating method as Leq i.e. equivalent sound pressure level has been adopted for the measurement of noise level in various selected sampling locations of this region. It is the energy mean of the noise level over a specified period and is expressed in terms of decibels.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
1 T L = 10 log 10 LP ( t ) / 10 dtdB ( A) eq ∫ T 0 The noise scale A weighted network in dB(A) was used for monitoring of noise level. Leq in dB(A) denotes the frequency weighting in the measurement of noise and corresponds to frequency response characteristics of human ear. The average of Leq at each location is calculated using energy average formula
n 1 Lpi / 10 Energy ..average = 10 log ∑ 10 n i =1 At some locations total noise due to multiple sources at observer’s location was calculated as follows
n = Lpi / 10 Lp TOTAL 10 log ∑ 10 i = 1 Day night sound level (Ldn) for 24 hours equivalent sound level can be calculated as follows:
16 8 1 ( Leq ) i / 10 ( Leq ) j +10 / 10 Ldn = 10 log ∑10 + ∑ 10 24 i=1 j =1 Where, Ldn : Day night sound level ‘i’ :Denotes the sum over the 16 hours during the daytime ‘j’ :Denotes the sum over the 8 hours during the night time th Leq (i) : Equivalent noise level for ‘i’ hours th Leq (j) : Equivalent noise level for ‘j’ hours
otes:
1. Day time shall mean from 6.00 a.m. to 10.00 p.m. 2. Night time shall mean from 10.00 p.m. to 6.00 a.m. 3. Silence zone is defined as an area comprising not less than 100 meters around Hospitals, Educational Institutions and courts. The silence zones are zones which are declared as such by the competent authority. 4. Mixed categories of areas may be declared as one of the four abovementioned categories by the Component Authority. * dB (A) Leq denotes the time weighted average of the level of sound in decibels on scale A which is related to human hearing "A", in dB (A) Leq, denotes the frequency weighting in the measurement of noise and corresponds to frequency response characteristics of human ear. 4 34
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.22 oise standards
* AreaCode Category of Area/Zone Limits in dB (A) Leq (A) Industrial Area 75 70 (B) Commercial Area 65 55 (C) Residential Area 55 45 (D) Silence Zone 50 40 (A) Industrial Area 75 70
Leq: It is energy mean of the noise level over a specified period
4.8.3 Background oise Levels The residential, commercial, industrial areas and silence zones in the study area have been identified in the vicinity of the location of Development wells. Some of the locations were identified which were away from the major roads and major noise sources so as to measure ambient noise levels. Equivalent noise levels (Leq) for a period of about 60 minutes were measured at each monitoring location during day time and night time. The noise survey was conducted at fifty six locations listed in Table 4.23. All measurements were carried out when the ambient conditions were unlikely to adversely affect the results. Table 4.23 oise level survey in Cambay
S.No Field Tentative village Noise level reading (Location & Timing) where drilling is proposed Panchayat office Market/industry area Day (7AM) Night (7PM) Day (7AM) Night (7PM) 1 PADRA Khanderipura 40 40 46 42
2 Dhar/niyapura 40 40 42 42
3 KATHANA Kanchoda 40 40 40 40
4 Jhakriyapura 40 41 40 43
5 ANKLAV Valvod 40 40 43 44
6 pipli 40 40 40 41
7 AKHOLJUNI Navagam 40 41 40 40
8 Navi Akhol 40 41 40 44
9 SISWA Vadeli 40 40 41 40
10 Siswa 40 40 42 41
11 CHAKLASI Kanjoda 41 40 49 43
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
12 Chaklasi 41 40 48 42
13 VADTAL 41 40 46 42 Narsanda 14 Porda 40 41 43 46
15 NADIAD MARIDA 41 40 44 41
16 BILODRA 41 40 45 41
17 MAHI HIGH SHAKARPUR 40 41 43 43
18 VASNA 40 42 41 42
It is observed from the noise level monitored in the proposed project area, the noise was within the limits The Noise Pollution (Regulation and Control) Rules, 2000, Notified by the Ministry of Environment and Forests, New Delhi on February 14, 2000.
Impact on terrestrial fauna due to noise
• Project infrastructure and well development may disturb agriculture land near site. • Drilling activity may increase deposition of dust and dust settling on the vegetation may alter or limit plants' abilities to photosynthesize and/or reproduce
Mitigation Measures • Acoustic enclosure shall be provided to D.G. set to reduce the noise intensity during the drilling operation so that the avifauna is not disturbed due to the noise generated during drilling. • ONGC will develop and implement a spill management plan. • Use existing facilities (e.g. Access Roads) to the extent possible to minimize the amount of new disturbance. • Avoid use of unnecessary lighting at night to avoid attracting avifauna.
4.9 Biological Environment
4.9.1 Introduction
Study of biological environment is one of the most important components for Environmental Impact Assessment, in view of the need for conservation of environmental quality and biodiversity. Ecological systems show complex inter relationships between biotic and abiotic components including dependence, competition and mutualism. Biotic components comprise of both plant and animal communities which interact not only within and between themselves but also with the abiotic components viz. Physical and chemical components of the environment.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Generally, biological communities are good indicators of climatic and edaphic factors. Studies on biological aspects of ecosystems are important in Environmental Impact Assessment for safety of natural flora and fauna. Information on the impact of environmental stress on the community structure serves as an inexpensive and efficient early warning system to check the damage to a particular ecosystem. The biological environment includes mainly terrestrial ecosystem and aquatic ecosystem.
Biological communities are dependent on environmental conditions and location of its resources. They show various responses and sensitivities to anthropogenic activities. The changes in biotic community are studied by the pattern in the distribution, abundance and diversity. These changes over a span of time can be quantified and related to the existing environmental conditions. The sensitivity of plants and animal species to changes occurring in their ecosystem can therefore be used for monitoring the biological environment for environmental impact assessment.
Natural flora and fauna are important of the environment. They are organized into natural communities and are sensitive to outside influences. Integrating ecological thinking into the planning process is an urgent need in the context of deterioration of natural environments, which is unwanted but direct consequence of development. Biological communities, being dependent on the condition and resources of its location may change if there is change in the environment. Hence changes in the status of flora and fauna are an elementary requirement of Environmental Impact Assessment studies. Information on flora and fauna were collected within the study area and other secondary data source and district offices. Relevant details on aquatic life within the study area were collected from related government offices.
Data Source of the Study Area Total geographical area of the 9ML/NELP block covered in four districts is 820.82 sq. km, out which of there is no area covered by forest including reserved forest, protected forest and unclassified forest. The assessment of wild life fauna was carried out by field observation, enquiring with local people and on the basis of secondary data collected from different government offices like District Forest office, Fishery Department, Agriculture Department etc. The results w.r.t each block was presented as follows. Also the following booksand articles serveras important source for identifying various species.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
(i) Botanical Survey of India (1983). Flora and Vegetation of India An Outline. Botanical Survey of India, Howrah. (ii) Champion, H.G. (1936). A preliminary survey of the forest types of India and Burma. Indian Forest Record ( ew Series) (iii) Pillai, V.N.K. (1982). Status of wildlife conservation in states and union territories. In: Saharia, V.B. (Ed.), Wildlife in India. Natraj Publishers, Dehra Dun. (iv) Salm, R.V. (1981). Coastal resources in Sri Lanka, India and Pakistan: description etc. 4.9.2. Biological characteristics (j)
Standard procedures were adopted for phytoplankton and zooplankton counts involving preservation. Analysis of phytoplankton was done by lacked drop (micro transect) method and counting was done as follows: No. Of phytoplankton/ml = (C × A1) / (A2 × S ×V) C : No, of organism counted A1 : Area of cover strip, mm2 A2 : Area of one strip, mm2 S : No. Of strips counted and V : Volume of sample under the cover strip, ml
Analysis of zooplankton is done by Sedwick Rafter (SR) cell. The sedwick Rafter cell is 50 mm long, 20 mm wide and 1 mm deep. Total area is 1000 mm2 and the total volume is 1 ml. Counting of zooplankton was done as follows:
Number of Zooplankton n =Number C X ml/ V Where, C : Volume of concentrate in ml V : Volume of sample filtered in ml The results of phytoplankton and zooplankton counts are expressed as no./100 ml and no./m3 respectively.
The nature and population of biological species in water are dependent on its physic chemical characteristics, i.e. pH, conductivity, alkalinity, BOD, salinity and nutrient levels. Thus, the type and population of plankton species may serve as indicators of the physic chemical quality and the trophic levels of water body. Plankton community structure of a water body can be assessed through following parameters:
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.9.3. Species Composition
The type of a group of organisms the tropic conditions of aquatic environment. Similarly many organisms have been known to be favoured by certain physic chemical conditions, such as silicates for diatoms. Presence of desmids and diatoms indicate good water conditions. Dominance of diatoms, protozoa, ciliates, Chlorophyceae and Cyanophyceae indicate moderately tropic conditions. Presence of Euglenophyceae indicates highly eutrophic conditions. Planktonic rotifers are usually more abundant in fresh water then in estuarine water. It is believed that when crustaceans such as Copepod, Cirripedia, Ostracoda etc. and insects outnumber other groups, the water body is considered to be enriched by organic matter thus, it is evident that presence of typical organisms also helps in classifying a water body into different tropic levels based on its physic chemical characteristics.
4.9.4. Species Diversity
Diversity of plankton is determined by physic chemical characteristics or the tropic level of the water body. In oligotrophic water, the diversity of plankton is high, while in mesotrophic and eutrophic conditions (increased pollution) the diversity of plankton decreases. The Shannon Weaver Index (d), a measure of diversity of plankton, takes into account the total as well as individual species counts in a water sample.
D = ∑ (ni/n) log2 (ni/n) Where, d = Shannon Weaver Diversity Index ni = number of individual of each individual species in a sample n = total number of individual and of all species in a sample An index value of 3 and above is generally considered to be a non polluted water body. Values between 1 and 3 and less than 1 are believed to be mild polluted and highly polluted respectively. Lower fluctuating index values at selected points might be attributed to point and non point sources of pollution, turbidity, tides, flow etc. A widely accepted ecological concept enunciated that the communities with larger numbers of species (i.e. with high diversity) will have a high stability and thus can resist adverse environmental factors, providing a greater structural complexity of the food wed. In order to evaluate baseline biological characteristic of surface water and groundwater in the study area the data also generated. Water samples were preserved and enumerated for phytoplankton and zooplankton. Shannon weaver index was also estimated.
Table 4.24 Formulae for analyzing Phytosociological Characteristic of Vegetation Density = Number of individuals species A Area Sampled Relative Density = Density of species A × 100 Total density of all species Dominance = Total cover of basal area of species Area sampled 4 39
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Relative dominance = Dominance of species A × 100 Total dominance of all species Frequency = Number of plots in which species A occurs Total number of plots sampled Relative Frequency = Frequency value for species A × 100 Total frequency values of all species Abundance/Quadrate = Total number of Species A occur in all quadrates Total number of quadrate in which species A occur Importance Value index = R. Density + R. Dominance + R. Frequency 3 Simpsons’s Diversity = ∑ n= ni (ni 1) Index i= 1n (n 1) ni is the number of individuals of the lth species in the sample n is the number of individuals in the sample
Simpson Diversity index of the plants in the total study area, which is based on the total number of individuals of different species and the total number of all species, is presented in Table 4.25. The study area has good biodiversity of trees (0.040) shrubs (0.048) and herbs (0.029). Biodiversity of trees is comparative!y good at various places where the area is suitable for their growth. Study area shows the different density of flora as per the climatic condition and suitable. The details of density per shown in Table 4.26. Table 4.25 Simpson Diversity Index in Project Area
Sr. o. Flora SDI Trees 0.040 2 Shrub 0.048 3 herb 0.029
Table 4.26 Density of Different Plant Species in Project Area
Sr. o. Flora SDI Trees 156 2 Shrub 425 3 herb 26250
4.9.5 Methodology The primary objective of survey was to describe the floristic and faunal communities within the study area. The sampling plots for floral inventory were selected randomly in the suitable habitats within the 2km radius from the project well locations. The methodology adopted for faunal survey involve; faunal habitat assessment, random intensive survey, opportunistic observations, diurnal bird observation, active search for reptiles, active search for scats and foot prints and review of previous studies. The aim was to set baselines in order to monitor and identify trends after the commencement of mining activity. Emphasis has been placed on presence of rare, endemic, migratory and threatened species, if any present in the study area. Desktop literature review was conducted to identify the representative spectrum of threatened species, population and ecological communities as 4 40
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
listed by IUCN, ZSI, BSI and in Indian wild Life Protection act, 1972. The status of individual species was assessed using the revised IUCN category system.
4.9.6 Bio Diversity of Vadodara District
There are 1537 villages and 866 village panchayat, 5 nagar – palika in Vadodara district. Part of the district is in forested region, dominated by tribal population. The Mahi river forms northern boundary in the western part of the district. The soil of the area is black in a large part of the district and it is saline near sea. A part of the jambughoda wildlife sanctuary is in the district. Chhotaudepur forest is knwon for production of non timber forest prpduce. Chhotaudepur is a proposed new district. Tree counting was done in 77 villages, covering a total of 32,683 ha of non forest area. A total of 633,011 trees were counted in these villages. Tree cover is moderate, although Vadodara city is a green city in the state. The tree cover has consistently improved in the district during the last decade. Nilgiri, Neem, Deshi baval, Gando baval, Mango and goras amli are the main tree species. Other, Bamboo and Mahuda. Mahuda population in the district is about 1.23. In this district, tree richness is high as each of two dozen species have tree population over one lakh. Population of Eucalyptus has increased in substantial area due to preference of the farmers in agro forestry. Number of semal trees declined at cost of other species. Gando baval is dominant species along streams, rivers and in the areas near sea coast. In this district, about 62.3 % trees grow on farm lands, 7.5 % in forest department’s plantation and the rest in human habitation, institutional compounds and misellaneous areas. On an averge, tree population increased at annual rate of about 5.2 lakh trees. Forest and tree cover in the district is above state’s average but is is below the national average. Eucalyptus, Su baval, Teak, Bamboo and Neem are important agro forestry species in the district. Table 4.27: TOF in Vadodara district Year Tree population in Tree density Trees/hs lakh 2003 82.96 12.21 2008 97.25 14.31 2013 135.66 19.87
Table 4.28: TOP ten tree species in Vadodara district ame of Species o. of % Trees 1. Nilgiri – Eucalyptus sp 18.63 13.73 % 2. Neem – Azadirachta indica 12.52 9.23 % 3. Deshi baval Acacia nilotica 10.05 7.40 % 4. Gando baval – prosopis chilensis 8.43 6.21 % 5. Mango – Mangifera indica 6.73 4.96 % 4 41
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6. Goras amli – Pithecellobium dulce 5.30 3.91 % 7. Samdi – prosopis cineraria 4.21 3.10 % 8. Teak – Tectona grandis 4.17 3.07 % 9. Subaval – Leucaena leucocephala 3.51 2.59 % 10. Khair – Acacia catechu 3.49 2.57 % 11. Others 58.63 43.22 % Total 135.66 100.00 %
Tree population in the district Total trees in rural area 12,780,770 Total trees in urban area 784,890 Total trees in non forest area 13,565,660 Trend Tree population has increased consistently – about 31 % increase in a decade
Forest and tree cover in sq. Km. Forest cover (2011) 52 km2 Tree cover (2013) 661 km2 Tree+forest cover 1,019 km2 forest and tree cover in the district is 13.50 % of the geographical aea of the district
Cultivated Plant in the Study Area in Vadodara District
Major Crops Major crops in the study area are Rice (Oryza sativa L.) and Wheat (Triticum aestivum)
Minor crops The minor crops of this region are Bajra (Pennisetum typhoides), Jowar (Sorghum bicolar) and Divel (Ricinus communis)
4.9.7 Floral Diversity in the Study Area in Vadodara District
Trees The dominant trees in the study area were Eucalyptus sp, Azadirachta indica (Limbado), Acacia nilotica, prosopis chilensis, Mangifera indica and Pithecellobium dulce which are generally planted as the road side plantation or along the agriculture fields for shades. The list of tree species is enlisted in the Table 4.26. 50 species of trees belong to 24 families are enumerated from the study area. 4 42
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.29: Trees in the Study Area in Vadodara District S. No. Family & Scientific name Vernacular name
1 Family:Anacardiaceae 1/1 Mangifera indica L. Kari 2 Family:Annonaceae 2/1 Annona squamosa L. Saitafal 2/2 Polylathia longifolia (Conn.) Thw. Asopalav 3 Family: Apocynaceae 3/1 Plumeria rubra L. Champo 4 Family:Arecaceae 4/1 Cocos Nucifera L. Narial 5 Family:Bombacaceae 5/1 Bombax ceiba L. Shimalo 6 Family:Caesalpiniaceae 6/1 Delonix regia (Boj.) Raf. Gaulmor 6/2 Delonix elata (L.) Gamble. Sandsro 6/3 Cassia fistula L. Garmalo 6/4 Cassia siamea Lam. Kasid 6/5 Peltophorum pterocarpum (DC.) Backer ex Heyne Sonmukhi 6/6 Tamarindus indicum L. Amali 7 Family:Caricaceae 7/1 Carica papaya L. Papaya 8 Family:Casuarinaceae 8/1 Casuarina equisetifolia L. Sharu 8/2 Family:Combretaceae 8/3 Anogeissus latifolia ( Roxb) Dhavdo 8/4 Terminalia catappa L. Badam 9 Family:Ehretiaceae 9/1 Cordia dichotoma Forst Gunda 10 Family:Euphorbiaceae 10/1 Emblica officinalis Gaertn. Ambla 11 Family:Malvaceae 11/1 Thespesia populnea (L.) Sol.ex Corr. Paras piplo 12 Family:Meliaceae
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. No. Family & Scientific name Vernacular name
12/1 Azadirachta indica A.Juss Limbado 12/2 Melia azadirachta L. Bakanlimdo 13 Family: Mimosaceae 13/1 Acacia auriculiformis L. Austrianbaval 13/2 Acacia chundra (Roxb.ex Rottl.) Willd. Khair 13/3 Acacia leucophloea (Roxb) Willd. Hermobaval 13/4 Acacia nilotica (L.) Del.subsp.indica (Bth.) Brenan Baval 13/5 Acacia Senegal (L.) Willd. Goradiobaval 13/6 Albizia lebbeck (L.) Bth. Siris 13/7 Albizia procera (Roxb.) Bth. Kalo siris 13/8 Leucaena leucocephala (Lam.) De Pardesi Baval 13/9 Pithecellobium dulce (Roxb.) Bth. Gorasmli 13/10 Prosopis cineraria (L.) Druce Khyigdo 14 Family:Moraceae 14/1 Ficus benghalensis L. Vad 14/2 Ficus hispida L. Dhedhumaro 14/3 Ficus racemosa L. Umaro 14/4 Ficus religiosa L. Piplo 15 Family:Moringaceae 15/1 Moringa oleifera Lam Sargavo 16 Family:Myrtaceae 16/1 Eucalyptussp. Nilgari 16/2 Syzygium cumini (L.) Skeels. Jambu 17 Family:Papilionaceae 17/1 Butea monosperma (Lam.) Taub. Khakaro 17/2 Bauhinia purpurea L. Kanchner 17/3 Dalbergia latifolia Roxb. Sisam 18 Family:Poaceae 18/1 Dendrocalamus strictus (Roxb) Bans 19 Family:Salvadoraceae 19/1 Salvadora persica L. Piludo 19/2 Salvadora oleoides Decne Piludi 20 Family:Sapotaceae
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. No. Family & Scientific name Vernacular name
20/1 Manilkara hexandra (Roxb.) Dub. Rayan 20/2 Manilkara zapota (L.) Chikoo 21 Family:Simaroubaceae 21/1 Ailanthus excelsa Roxb. Aurdso 22 Family:Rhamnaceae 22/1 Zizyphus glabrata Heyne ex Roth. Bor 23 Family:Rutaceae 23/1 Limonia acidissima L. 24 Family:Verbenaceae 24/1 Tectona grandis L.f. Sag
Shrubs Shrubs observed during the present survey are given in the Table 4.30. 28 shrub species belong to 17 families are enumerated from the study area. The dominant shrub community in this area was represented by, Calotropis procera, C. gigantea (Akado), Ipomoea fistulosa ( asarmo), Lawsonia inermis (Mendhi), and Lantana camara (Ganthai).
Table 4.30: Shrubs Species Observed in the Study Area in Vadodara District
S. No Family & Scientific name Vernacular name
1 Family :Apocynaceae 1/1 Nerium indicum Lalkaren 1/2 Thevetia peruviana Merr. Pili karan 2 Family: Asclepiadaceae 2/1 Calotropis gigantea (L.) R. Br Akado 2/2 Calotropis procera (Ait.) R.Br Akado 3 Family: Bignoniaceae 3/1 Tecoma stans (L.) H.B.& K. Peilafol 4 Family: Caesalpiniaceae 4/1 Cassia auriculata L 5 Family:Capparaceae 5/1 Capparis decidua( forsk.)Edgew 6 Family:Compositae 6/1 Xanthium strumarium L. Gokhru 7 Family: Convolvulaceae
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. No Family & Scientific name Vernacular name
7/1 Ipomoea fistulosa Mart.ex Choisy Nasarmo 8 Family:Euphorbiaceae 8/1 Euphorbia neriifolia L. Thor 8/2 Jatropha curcas L. Ratanjot 8/3 Ricinus communis L. Devalo 9 Family:Lythraceae 9/1 Lawsonia inermis L. Mendhi 10 Family:Malvaceae 10/1 Abelomoschus manihot (L.) Medic. Jagali bhindi 10/2 Abutilon indicum (L.) Sw. Khapat 10/3 Gossypium herbaceum Kapas 11 Family:Musaceae 11/1 Musa paradisiaca L. Kela 12 Family:Mimosaceae 12/1 Prosopis juliflora DC Gando baval 12/2 Acacia bjacquemontii Bth. Rato baval 12/3 Mimosav hamata Willd Kai baval 13 Family:Nyctaginaceae 13/1 Bougainvillea spectabilis Willd. Bougainvel 14 Family:Papilionaceae 14/1 Sesbania sesban (L.) Merr. Shevari 15 Family:Rhamnaceae 15/1 Zizyphus nummularia (Burm.f.) W. &. Chanibor 16 Family:Solanaceae 16/1 Datura metel L Daturo 16/2 Solanum incanum L Ubhi ringan 16/3 Solanum indicum 17 Family:Verbenaceae 17/1 Clerodendrum inerme (L.) Gaertn. Madhi 17/2 Lantana camara L.var.aculcata (L.)Mold. Ganthai
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Herbs As the study area is dominated by the waterlogged grass lands and paddy fields, the area is with remarkably rich herbaceous ground cover. The herbs observed in the sampling plots, during the survey period in the study area have been enlisted in the Table 4.31. 82 species of herbs belongs to 34 families were documented from the sampling plots laid in different habitats.
Table 4.31: Herbaceous Species in the Study Area in Vadodara District S. NO. Family & Scientific name Vernacular name
1 Family: Acanthaceae 1/1 Barleria sp. 1/2 Hygrophila ainguriculata (Schum.) Kanatashelio,Akaro 2 Family: Alismataceae 2/1 Limnophyton obtusifolium L 3 Family Amaranthaceae 3/1 Achyranthes aspera L. Anghedi, Anghedo 3/2 Aerva javanica (Burm.f.)Juss. Bur,Gorakhganjo 3/3 Celosia argentea L 4 Family : Aponogetonaceae 4/1 Aponogeton natans L. 5 Family :Araceae 5/1 Colocasia esculenta (L) 5/2 Pistia stratiotes Jalasankhala 6 Family: Asclepiadaceae 6/1 Leptadenia pyrotechnica i(forsk.) Khip, Ranser 7 Family :Asteraceae 7/1 Blumea eriantha DC. Kalhar 7/2 Blumea mollis D. Don Merr 7/3 Echinops echinatus Roxb Shulio 7/4 Eclipta prostrata (L.) Bhangro 7/5 Lacunae procumbens (Roxb) .Moti Bhonpatri 7/6 Parthenium hysterophorus L 7/7 Tridax procumbens L Pardesi Bhangro 7/8 Vernonia cinerea Less Sadedi 8 Family: Boraginaceae 8/1 Trichodesma indicum 9 Family : Caesalpiniaceae
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. NO. Family & Scientific name Vernacular name
9/1 Cassia tora L Kuvandio 10 Family: Ceratophyllaceae 10/1 Ceratophyllum demersum L. 11 Family: Convolvulaceae 11/1 Cressa cretica L 12 Family: Commelinaceae 12/1 Commelina benghalensis L 12/2 C.forskalaei Vahl., Enum 13 Family: Cyperaceae 13/1 Cyperus difformis L. 13/2 Cyperus rotundus L. 13/3 Cyperus sp. 13/4 Fimbristylis dichotoma Vahl. 13/5 Fimbristylis sp. 14 Family: Euphorbiaceae 14/1 Chrozophora rottleri (Geis.) Juss. 14/2 Euphorbia hirta L. 15 Family: Gentianaceae 15/1 Nymphoides indicum (Roxb.) Kumudini 15/2 N. parvifolium (Griseb.) 16 Family: Hydrocharitaceae 16/1 Hydrilla verticillata (L.f.) Royle 16/2 Vallisneria spiralis L. 16/3 Ottelia alismodies L. 17 Family: Lamiaceae 17/1 Leucas aspera. 17/2 Ocimum sanctum L. Tulsi 17/3 O. canum Sims Ramtulsi 17/4 O .basilicum L. Damro 18 Family: Lemnaceae 18/1 Lemna gibba L. 19 Family: Liliaceae 19/1 Aloe barbadensis Mill. Kunvarpato
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. NO. Family & Scientific name Vernacular name
19/2 Urginea indica (Roxb.) Jungli Dungli 20 Family: Malvaceae 20/1 Abutilon indicum L. Khapat,Dabaliar 20/2 Sida alba L.. Bala 21 Family: Martyniaceae 21/1 Martynia annua L. 22 Family: Menispermaceae 22/1 Cocculus hirstus L Vevdi 23 Family: Nyctaginaceae 23/1 Boerhavia diffusa L. Satodi 23/2 Boerhavia chinensis Druce 24 Family: Nymphaeaceae 24/1 Nymphaea pubescens Wild Kamal 24/2 Nelumbo nucifera Gaertn. Motu kamal 25 Family: Papilionaceae 25/1 Alysicarpus scariosus rottl.ex.Spr. 25/2 Cajanus cajan (L) Tuvar 25/3 Crotalaria burhia Bach. – Ham. Kharshan 25/4 Crotalaria medicaginea Lam. Ranmethi 25/5 Rhynchosia minima (L.) DC. 25/6 Indigofera oblongifolia Forks. 25/7 Tephrosia sps. 25/8 Medicago sativa L. Rajko 26 Family: Poaceae 26/1 Aleuropus lagopoides (L) 26/2 Aristida sp. 26/3 Cynodon barberi Rang. 26/4 Cynodon dactylon (L.) 26/5 Oryza sativa L. 26/6 Phragmites kara (Retz.) 26/7 Triticum aestivum L. Ghau 26/8 Sorghum bicolor (L.) Jowar 26/9 Zea mays Makai
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. NO. Family & Scientific name Vernacular name
27 Family: Piperaceae 27/1 Peperomia pellucidaL. 28 Family: Polygonaceae 28/1 Polygonum glabrumwilld 29 Family: Scrophulariaceae 29/1 Bacopa monnieri (L.) Jalnaveri 30 Family: Solanaceae 30/1 Solanum indicum L. Ringni 30/2 Solanum nigrum L. Piludi 30/3 Solanum surattense Brum. Bhoringni 30/4 Solanum trilobatum L. 30/5 Physalis minima L. Popti 31 Family: Trapaceae 31/1 Trapa natans L var. bispinosa Shinghoda 32 Family: Tiliaceae 32/1 Corchorus depressus Stocks 32/2 Triumfeta rotundifolia Lam. 33 Family: Typhaceae 33/1 Typha angustata Bory & Chaub Ramban,Ghabajariu 34 Family: Zygophyllaceae 34/1 Fagonia cretica L. Dhramau 34/2 Tribulus terrestris L. Mithu Gokhru
Climbers and Twiners Climbers/ twiners in the study area dominated by, Ipomoea pes tigridis (Wagpadi), Ipomea pes caprae (Dariani vel), Ipomea aquatica (Nali ni Bhaji), Coccinia grandis (Ghiloda), Luffa cylindrica (Galku), and Abrus precatorius (Chanothai). The major climbers and twiners observed in the study area in the sampling plots are given in the Table 4.32. 25 species of climbers/ twiners belongs to 9 families are recorded from the area.
Table 4.32 Climbers and Twiners Observed in the Study Area in Vadodara District
S. No Family & Scientific name Vernacular name
1 Family: Asclepiadaceae 1/1 Pentatropis spiralis (Forsk.) Decne Shingroti 1/2 Oxystelma secamone L. Karst. Deuts.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
S. No Family & Scientific name Vernacular name
2 Family: Convolvulaceae 2/1 Ipomea cairica (L.) 2/2 Ipomoea obscura L. 2/3 Ipomea pulchella Roth 2/4 Ipomea aquatica Forsk. Nadanivel 2/5 Ipomoea pes caprae Dariani vel/Maryad vel 2/6 Ipomoea pes tigrides L 3 Family: Caesalpiniaceae 3/1 Caesalpinia cristaL. Kachka 4 Family: Cucurbitaceae 4/1 Coccinia grandis Ghiloda 4/2 Luffa cylindrica (L.) M.J.Roem Galku 4/3 L. acutangula (L) Jungli turia 4/4 Diplocyclos palmatus (L.) C.jeffrey Shivelangi 4/5 Corallocarpus epigeus (Arn.) 4/6 T richosanthes cucumerina L. 5 Family: Cuscutaceae 5/1 Cuscuta reflexa Roxb. Amarvel 6 Family: Euphorbiaceae 6/1 Dalechampia scandensL, 7 Family: Liliaceae 7/1 Asparagus racemosus Wild var, javanicus Satavari 7/2 Gloriosa superba L 8 Family: Menispermaceae 8/1 Cocculus hirsutus (L.) Diels Vevdi 8/2 Tinospora cordifolia (Willd.) Miers Galo 9 Family: Papilionaceae 9/1 Mucuna prurita Hk.f. Kavach, Koyli 9/2 Abrus precatorius L. Chanothi 9/3 Clitoria ternatea L. Gokaran 9/4 Clitoria biflora Dalz.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Faunal Biodiversity in the Study Area in Vadodara District Birds, reptiles, amphibians, and butterfly species observed in the study area are given below
Birds The most commonly spotted water bird species of this area were;,Cattle Egret, Intermediate Egret, Little Egret, Indian Cormorant, Black winged Stilt, Red wattled Lapwing, Red naped Ibis, Black headed Ibis, White breasted Water hen. Systematic account of the birds in the study area with the status of occurrence is given in the Table 4.33.
Table4.33: Birds Species Observed in the Study Area in Vadodara District
Old Common name New Common Name Scientific Name R S
I ORDER: APODIFORMES Family: Apodidae (swifts) Common Swift Common Swift Apus apus R House swift Little Swift Apus affinis R II ORDER: FALCONIFORMES Family: Accipitridae (vulture, Sparrow hawk, Eagle, Harrier, Kite and Vulture) Shikra Shikra Accipiter badius R Black winged Kite Black winged Kite Elanus caeruleus R Pied Harrier Pied Harrier Circus melanoleucos R III. ORDER: : CICONIIFORMES Family: Family: Anhingidae Anhinga melanogaster Darter or Snake Birds Oriental Darter R A.rufa Family: Ardeidae (heron, Egret, Bittern) Grey Heron Grey Heron Ardea cinerea RW Giant Heron Goliath Heron Ardea goliath r?V Pond Heron Indian Pond Heron Ardeola grayii R Cattle Egret Cattle Egret Bubulcus ibis R Mesophoyx intermedia Median or Smaller Egret Intermediate Egret R Egretta intermedia Little Egret Little Egret Egretta garzetta R Casmerodius albus Large Egret Great Egret Rw Ardea alba Family: Charadriidae (Plover, Stilt, Oystercatcher, Lapwing, Avocet ) Black winged Stilt Black winged Stilt Himantopus himantopus R Red wattled Lapwing Red wattled Lapwing Vanellus indicus R 4 52
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Old Common name New Common Name Scientific Name R S
Family: Ciconiidae (Open bill, stork, Adjutant) Painted Stork Painted Stork Mycteria leucocephala R Family: Phalacrocoracidae ( Cormorant) Large Cormorant Great Cormorant Phalacrocorax carbo RW Indian Shag Indian Cormorant Phalacrocorax fuscicollis R Little Cormorant Little Cormorant Phalacrocorax niger R Family: Podicipedidae (Grebe) Little Grebe Little Grebe Tachybaptus ruficollis R Family: Pteroclidae (Sandgrouse) Chestnut bellied Pterocles exustus Indian Sandgrouse R sandgrouse Family: Threskiornithidae (Spoonbill and Ibis) Spoonbill Eurasian Spoonbill Platalea leucorodia RW Black Ibis Red naped Ibis Pseudibis papillosa R Threskiornis White Ibis Black headed Ibis R melanocephalus IV ORDER: COLUMBIFORMES Family: Columbidae (Pigeon, Dove) Blue Rock Pigeon Rock Pigeon Columba livia R Ring Dove Eurasian Collared Dove Streptopelia decaocto R Rufous Turtle Dove Oriental Turtle Dove Streptopelia orientalis R V : ORDER: CORACIFORMES Family: Dacelonidae (King fishers) White breasted Kingfisher White throated Kingfisher Halcyon smyrnensis R Family: Cerylidae Pied Kingfisher Pied Kingfisher Ceryle rudis R Family: Coraciidae (Roller) BlueJay or Roller Indian Roller Coracias benghalensis R Family: Meropidae (Bee Eater) Chestnut headed Bee eater Chestnut headed Bee eater Merops leschenaulti R VI. ORDER: CUCULIFORMES Family: Centropodidae (Cocucal) Crow Pheasant or Coucal Greater Coucal Centropus sinensis R
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Old Common name New Common Name Scientific Name R S
Family: Cuculidae (cuckoo, Koel) Koel Asian Koel Eudynamys scolopacea R Indian Drongo Cuckoo Drongo Cuckoo Surniculus lugubris R VII. ORDER: GALLIFORMES Family: Phasianidae (Peafowl , Partridge, Quail, francolin, spur fowl, jungle fowl, Monal, ) Common Peafowl Indian Peafowl Pavo cristatus R Grey Partridge Grey Francolin Francolinus pondicerianus R VIII. ORDER: GRUIFORMES Family: Rallidae ( Waterhen, coot, crake water cock, Moorhen, Rail,) White breasted Water hen White breasted Water hen Amaurornis phoenicurus R Purple Moorhen Purple Swamphen Porphyrio porphyrio R IX. ORDER: PASSERIFORMES Family: Paridae (Tit ) Grey Tit Great Tit Parus major R Family: Cisticolidae ( Warbler or Prinia) Jungle Wern Warbler Jungle Prinia Prinia sylvatica R Family: Corvidae Coracina macei Large Cuckoo shrike Large Cuckoo shrike R Coracina novaehollandiae Raven Common Raven Corvus corax R House Crow House Crow Corvus splendens R Dicrurus macrocercus Black drongo King Crow Black Drongo R Dicrurus adsimilis Tree Pie Rufous Treepie Dendrocitta vagabunda R Greater Racket tailed Dicrurus paradiseus Racket tailed Drongo Drongo Family: Laniidae (shrike) Rufous backed Shrike Long tailed Shrike Lanius schach R Grey Shrike Northern Shrike Lanius excubitor R Family: Muscicapidae ( Short wing, Chat, Robin, Shama Indian Robin Indian Robin Saxicoloides fulicata R Pied Bushchat Pied Bushchat Saxicola caprata R Family: Nectariniidae ( Sun Birds, Flower pecker, Spider hunter )
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Old Common name New Common Name Scientific Name R S
Purple Sunbird Purple Sunbird Nectarinia asiatica R Small Sunbird Crimson backed Sunbird Nectarinia minima R Family: Passeridae ( Avadavat,Pipit, Wagtail, Munia, Snowfinch, sparrow, weaver ,Accentor) House Sparrow House Sparrow Passer domesticus R Grey Tit Great Tit Parus major R Dendronanthus indicus Forest Wagtail Forest Wagtail R Motacilla indica Family: Pycnonotidae (Bulbul, ) Red whiskered Bulbul Red whiskered Bulbul Pycnonotus jocosus R Red vented Bulbul Red vented Bulbul Pycnonotus cafer R Family: Sturnidae (Myna, Starling) Bank Myna Bank Myna Acridotheres ginginianus R Indian Myna Common Myna Acridotheres tristis R Family: Sylviidae ( Warbler, Browning, Fulvetta ,Babbler, Laughing thrash, Tailor birds, Common Babbler Common Babbler Turdoides caudatus R Jungle Babbler Jungle Babbler Turdoides striatus R Tailorbird Common Tailorbird Orthotomus sutorius R X. ORDER: PSITTACIFORMES Family: Psittacidae (Parrot and Parakeet) Rose ringed Parakeet Rose ringed Parakeet Psittacula krameri R XI ORDER: STRIGIFORMES Family: Strigidae (Owl and Owlet) Spotted Owlet Spotted Owlet Athene brama R XII Order: Upupiformes Family: Upupidae Hoopoe Eurasian Hoopoe Upupa epops RW
Butterflies in the Study Area in Vadodara District
Bustterflies observed in the study area are given in Table 4.34.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 4.34: Butterflies Observed in the Study Area in Vadodara District S. No Scientific name & family Common name
1 Family Papilionidae 1/1 Papilio polytes Linnaeus Common Mormon 1/2 Papilio demoleus Linnaeus Lime butterfly 2 Family Pieridae 2/1 Eurema hecabe Linnaeus Common Grass yellow 2/2 Catopsilia pomona Fabricius Common Emigrant 2/3 Catopsilia pyranthe Linnaeus Mottled Emigrant 2/4 Delias eucharis Drury Common Jezebel 2/5 Cerpora nerissa Fabricius Common Gull 2/6 Ixias mariane Cramer White orange tip 2/7 Ixias pyrene Linnaeus Yellow orange tip 2/8 Colotis danae Fabricus Crimson tip 3 Family: Nymphalidae 3/1 Melanitis leda Linnaeus Common evening Brown 3/2 Junonia lemonias Linnaeus Lemon pancy 3/3 Junonia almanac Linnaeus Peacock pancy 3/4 Junonia orithya Linnaeus Blue pancy 3/5 Junonia hierta Fabricius Yellow pancy 3/6 Danaus chrysippus Linnaeus Plain Tiger 3/7 Danaus genutia Cramer Stripped Tiger 3/8 Hypolimanas misippus Linnaeus Danaid egg fly 3/9 Mycalesis perseus Fabricius Common bush brown
Herpatofauna Reptile Observed in the Study area in Vadodara District are given in Table 4.35.
Table 4.35: Reptile Observed in the Study Area in Vadodara District S. No Common Name Scientific name
1 Common garden lizard Calotes versicolor (Daudin) 2 Common rat snake Ptyas mucosus (Linn.) 3 Common Indian monitor Varanus bengalensis ( Daudin) 4 Brahminy skink Eutropis carinata (Schneider) 5 House Gecko Hemidactylus flaviviridis (Ruppell) 6 Common Indian Cat Snake Boiga trigonata ( Schneider)
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
7 Spotted Indian House Gecko Hemidactylus brookii (Gray) 8 Fan Throated Lizard Sitana ponticeriana ( Cuvier) 9 Indian Cobra Naja naja (Linn.) 10 Russell’s Viper Daboia russelii ( Shaw and Nodder) 11 Common Indian Krait Bungarus caeruleus ( Schneider)
Mammals The wild mammals observed other than domesticated ones from study area is documented in the Table 4.36.
Table 4.36: Mammals Observed in Study Area in Vadodara District S. No Common Name Scientific name
1 Indian field mouse Mus booduga (Gray) 2 Common Mongoose Herpestes edwardsi (Geoffroy) 3 Hare Lepus sp. 4 Five striped Palm squirrel Funambulus pennanii ( Wroughton) 5 Nilgai Boselaphus tragocamelus (Pallas)
4.10 Socio economic Environment The study of socio economic component of environment is incorporating various facets viz. Demographic structure, availability of basic amenities such as housing, education, health and medical services, occupation, water supply, communication and power supply, prevailing diseases in the region. The study of these parameters helps in identifying, predicting and evaluating the likely impacts due to project activity in that region.
4.10.1 Baseline Status The survey has been carried out with the help of a pre designed set of questionnaires. Adult male and female representing various communities were interviewed on judgmental or purposive basis data on following parameters has been collected for the study region. • Demographic structure • Infrastructure resource base • Economic attributes • Health status • Aesthetic attributes • Socio economic status • Awareness and opinion of the people about the project
The data is generated using secondary sources viz. Census Records, District Statistical Abstract, Official Document and primary Sources.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.10.2 Demographic Structure The highlights of demographic structure of the study area in which information on population, employment, household, literacy, community structure, and the summarized information is presented in below in Table 4.37. The demographic details have been abstracted from primary Census Abstract 2011 of Gujarat.
Table 4.37 Highlights of demographic structure of the study area SL. DETAILS NO. VADODARA 1 AREA(KM2) 7546 2 RURAL POPULATION 2099855 3 RURAL POPULATION MALE 1077943 4 RURAL POPULATION FEMALE 2021912 5 URBAN POPULATION 2065771 6 MALE POPULATION 2153736 7 FEMALE POPULATION 2011890 8 TOTAL POPULATIAON 4165626 9 POPULATIAON DENSITY (/KM2) 552 10 SEX RATIO(PER 1000) 934 11 LITERATES 2893080 12 LITERACY RATE 78.92 13 MALE LITERACY RATE 85.39 14 FEMALE LITERACY RATE 72.03 15 LITERACY RATE RURAL MALE 77.14 16 LITERACY RATE RURAL 58.07 FEMALE
4.10.3 Socio economic Survey Socio economic survey was conducted with the help of predesigned tool to measure the socio economic status of the people in the study area. The salient socio economic features observed under the study are: • Most of the rural people in study area use Wood, Cooking Gas & charcoal as the main source of fuel for cooking purpose. • Villages, have better communication and transportation facilities. Road conditions are good. There is bus facility available in the interior villages. • Medical facilities available in the area are is good. Lack of drainage and control of mosquitoes nuisance, have resulted in higher prevalence of dengue and malaria in the area, especially during rainy season. • Electricity facility is available in villages is good.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4.10.4 Population Distribution The statistics regarding the human population and the number of households in the study area given in Table 4.38, indicates that there are 540 villages in the study area. This information is used from the Census of India, 2001. Table 4.38: Villages, Households and Population in Study Area
Study Area within Vadodara District (AKLV 3, GGS Padra, GGS Dabka, GGS Jambusar) S. o. Taluka Village Distance Households Population
1 Vadodara Anagadh 0 10 kms 2,560 13,531 2 Vadodara Dhanora 0 10 kms 675 3,573 3 Vadodara Kotna 0 10 kms 379 2,051 4 Vadodara Koyli 0 10 kms 1,911 9,580 5 Vadodara Sherkhi 0 10 kms 1,627 8,425 6 Vadodara Sindhrot 0 10 kms 1,262 6,174 7 Vadodara Hinglot 0 10 kms 182 988 8 Vadodara Ampad 0 10 kms 251 1,328 9 Vadodara Gorva 0 10 kms 372 1,669 10 Vadodara Ankodiya 0 10 kms 708 3,567 11 Vadodara Mahapura 0 10 kms 242 1,335 12 Vadodara Sevasi 0 10 kms 1,224 6,107 13 Vadodara Bhayli 0 10 kms 1,553 7,096 14 Vadodara Raypura 0 10 kms 870 4,594 15 Vadodara Gokalpura 0 10 kms 176 904 16 Vadodara Samiyala 0 10 kms 1,286 6,073 17 Vadodara Bil 0 10 kms 966 4,471 18 Vadodara Chapad 0 10 kms 496 2,280 19 Vadodara Navapura 0 10 kms 67 315 20 Vadodara Dhaniyavi 0 10 kms 425 2,320 21 Vadodara Alamgir 0 10 kms 146 763 22 Vadodara Khalipur 0 10 kms 200 937 23 Vadodara Varnama 0 10 kms 899 4,177 24 Vadodara Sundarpura 0 10 kms 245 1,121 25 Vadodara Karali 0 10 kms 172 937 26 Vadodara Itola 0 10 kms 861 3,826 27 Vadodara Vadsala 0 10 kms 709 3,115 28 Vadodara Untiya (Kajapur) 0 10 kms 79 312 29 Vadodara Mastupur Gamdi 0 10 kms 92 384 30 Vadodara Por 0 10 kms 1,111 5,237 31 Vadodara Raman Gamdi 0 10 kms 117 517 32 Vadodara Untiya (Medhad) 0 10 kms 134 705 33 Vadodara Fajalpur (Ankhi) 0 10 kms 98 520 Petro Chemical Complex INA 34 Vadodara (INA) 0 10 kms 1,731 7,338 35 Vadodara Karachiya (CT) 0 10 kms 1,589 7,736 4 59
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Study Area within Vadodara District (AKLV 3, GGS Padra, GGS Dabka, GGS Jambusar) S. o. Taluka Village Distance Households Population 36 Vadodara GSFC Complex INA (INA) 0 10 kms 725 3,037 37 Vadodara Bajwa (CT) 0 10 kms 1,724 9,192 Jawaharnagar (Gujarat Refinery) 38 Vadodara (CT) 0 10 kms 1,111 4,667 39 Vadodara Vadodara (M Corp+OG) 0 10 kms 303,130 1,411,228 40 Vadodara Tarsali (CT) 0 10 kms 5,887 26,706 41 Vadodara Nandesari (CT) 0 10 kms 1,553 7,270 42 Vadodara Nandesari INA (INA) 0 10 kms 645 2,814 43 Padra Luna 0 10 kms 414 2,245 44 Padra Umaraya 0 10 kms 660 3,481 45 Padra Ekalbara 0 10 kms 767 3,885 46 Padra Mujpur 0 10 kms 1,702 8,542 47 Padra Majatan 0 10 kms 571 2,741 48 Padra Somjipura 0 10 kms 456 2,478 49 Padra Mahuvad 0 10 kms 910 4,326 50 Padra Dabhasa 0 10 kms 1,403 7,240 51 Padra Sokhdakhurd 0 10 kms 419 1,976 52 Padra Patod 0 10 kms 470 2,337 53 Padra Darapura 0 10 kms 633 2,964 54 Padra Ghayaj 0 10 kms 494 2,431 55 Padra Latipura 0 10 kms 563 2,793 56 Padra Ranu 0 10 kms 997 5,069 57 Padra Bhoj 0 10 kms 1,244 6,466 58 Padra Vadu 0 10 kms 1,562 8,506 59 Padra Sandha 0 10 kms 433 2,166 60 Padra Chitral 0 10 kms 342 1,733 61 Padra Gavasad 0 10 kms 713 3,448 62 Padra Lola 0 10 kms 260 1,443 63 Padra Muval 0 10 kms 818 3,946 64 Padra Karnakuva 0 10 kms 244 1,153 65 Padra Vadadla 0 10 kms 188 842 66 Padra Pipli 0 10 kms 355 2,019 67 Padra Sejakuva 0 10 kms 472 2,306 68 Padra Goriyad 0 10 kms 388 1,859 69 Padra Chansad 0 10 kms 547 2,601 70 Padra Amla 0 10 kms 425 2,015 71 Padra Sadhi 0 10 kms 756 3,661 72 Padra Anti 0 10 kms 626 4,135 73 Padra Jalalpur 0 10 kms 399 1,956 74 Padra Mobha 0 10 kms 991 4,896 75 Padra Kalyankui 0 10 kms 123 568 76 Padra Ambada 0 10 kms 245 1,099 4 60
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Study Area within Vadodara District (AKLV 3, GGS Padra, GGS Dabka, GGS Jambusar) S. o. Taluka Village Distance Households Population 77 Padra Saras Vani 0 10 kms 512 2,391 78 Padra Shihor 0 10 kms 143 786 79 Padra Thikariya Mubarak 0 10 kms 70 352 80 Padra Virpur 0 10 kms 75 336 81 Padra Medhad 0 10 kms 131 637 82 Padra Husepur 0 10 kms 136 667 83 Padra Bhadari 0 10 kms 190 1,089 84 Padra Gayapura 0 10 kms 125 589 85 Padra Kanda 0 10 kms 169 742 86 Padra Shahera 0 10 kms 159 730 87 Padra Thikariya Math 0 10 kms 80 380 88 Padra Sadad 0 10 kms 134 660 89 Padra Kothwada 0 10 kms 138 695 90 Padra Padra (M+OG) 0 10 kms 7,315 39,205 91 Padra Narsipura 0 10 kms 476 2,631 92 Padra Vishrampura 0 10 kms 510 2,623 93 Padra Brahmanvasi 0 10 kms 395 1,978 94 Padra Masar 0 10 kms 716 3,429 95 Padra Gametha 0 10 kms 483 2,399 96 Padra Kural 0 10 kms 567 2,620 97 Padra Kanzat 0 10 kms 910 4,538 98 Padra Abhol 0 10 kms 448 2,141 99 Padra Pindapa 0 10 kms 282 1,473 100 Padra Bhadara 0 10 kms 112 624 101 Padra Shanpur 0 10 kms 277 1,253 102 Padra Sampla 0 10 kms 286 1,473 103 Padra Danoli 0 10 kms 202 978 104 Padra Bhanpur 0 10 kms 143 721 105 Padra Vanchhara 0 10 kms 300 1,409 106 Padra Kotna 0 10 kms 261 1,123 107 Padra Jaspur 0 10 kms 1,299 7,035 108 Padra Rajupura 0 10 kms 252 1,125 109 Padra Dabka 0 10 kms 1,470 7,691 110 Padra Pavda 0 10 kms 394 1,940 111 Padra Chokari 0 10 kms 1,561 7,880 112 Padra Tithor 0 10 kms 960 4,495 113 Padra Dudhwada 0 10 kms 400 1,804 114 Padra Karkhadi 0 10 kms 983 4,484 115 Karjan Virjai 0 10 kms 362 1,734 116 Karjan Sambhoi 0 10 kms 230 1,225 117 Karjan Surwada 0 10 kms 264 1,264
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Study Area within Vadodara District (AKLV 3, GGS Padra, GGS Dabka, GGS Jambusar) S. o. Taluka Village Distance Households Population 118 Karjan Manpur 0 10 kms 219 964 119 Karjan Pingalwada 0 10 kms 278 1,276 120 Karjan Harsunda 0 10 kms 78 374 Total 3,86,275 18,22,209
According to the Provisional Census Data 2011, Vadodara district had a population of 41,57,568 of which male and female were 21,50,229 and 20,07,339 respectively. There was change of 14.16 percent in the population compared to population as per 2001. In the previous census of India 2001, Bharuch District recorded increase of 19.87 percent to its population compared to 1991.
Details of crop, Irrigation facilities, occupation and village status Crop: Tobacco, vegetables, wheat, flowers, Divela (Arneda), cotton, fur. Irrigation facilities: Mahi River, Narmada canal, tube wells, Rain water and ponds Occupation: Most of villagers are farmers, some are working in nearby industries like pharmaceuticals, and chemical industries. Vadoadara has a waste disposal/effluent disposal channels for industrial waste disposal. Village status: Every village has at least a primary school, angnwadi, nanadgahr, post office, and public health center in bigger villages. Padra has a very big vegetable market. Every village is connected by road and have adequate transport facilities. CSR fund is provided for the creation of educational facilities. Availability of drinking water is a not problem for the local people. There are sufficient drinking water facilities in the study area. The rivers Mahi, Dhadhar, Vishwamitri, pass through the study area. Mahi, being the life line of the people, suffices the need for water. Various central and state run schemes are implemented within the study area for social welfare. Swarnajayanti Gram Swarojgar Yojana (SGSY) and Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) are the schemes implemented for employment. Women led Self Help Groups (SHGs) also function efficiently in many areas providing employment to rural women. Indira Awas Yojana (IAY) and Sardar Awas Yojana (SAY) are the schemes for housing. Hygiene and sanitation are maintained under Nirmal Bharat Abhiyaan – Gujarat, Total Sanitation Campaign under District Rural Development Agency (DRDA) and Gokul Gram Yojana (GGY). Anganwadis function under the Integrated Child Development Services Scheme (ICDS) in all the villages of the study area to provide Montessori training and education to children of the age group of 3 6 years. Community Health Worker (CHWs) and Multi Purpose Health Workers (MPHW) regularly
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
visit the village schools and anganwadis and keep a check on the health status of the children.
Awareness and opinion of the people about the project Public Consultations were carried out by the EIA team during the Study period at various places of the block. During consultation, it was observed that people had concerns with respect to their existing socio economic conditions like saline ground water, poor condition of the village roads etc. With respect to the proposed project, the public had positive perception; also people in the region expect job opportunities in educational, transportation and sanitation facility from project authority and had welcomed the project.
4.10.4 Resettlement and Rehabilitation As the proposed land area in which the developmental wells are to be drilled is within 3 District, the proposed project does not attract National Resettlement & Rehabilitation policy (NRRP), 2007. However, the proposed drilling sites and approach road, which mainly falls over agricultural land area, will be taken in lease by ONGC. The consultation towards crop will be fixed by District Administration once in three years in consultation with Agricultural Department and land holders. If, the drilled well is found to be viable for production, then the land will be permanently acquired by ONGC and the compensation will by fixed by District administration.
4.10.5 Corporate Social Responsibility (CSR) ONGC is actively engaged in CSR Activities in the surrounding area of the existing activity/installation. The same will be continued for the proposed project also. The details of the CSR Activities provided in the following Table: 2010 11 2011 12 2012 13 2013 14
50,000 13,10,000 1,90.000 1, 28, 652. 20
CSR Year Wise Details is as under:
CSR Activities during 2010 11: District Vadodara
S. Beneficiary Purpose Amount o. 1. Primary School, Taadna Muwaada, Computer, sports item, 50,000 District Vadodara Water cooler etc.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
CSR Activities during 2011 12: District Vadodara
S. Beneficiary Purpose Amount o. recommended 1. To construct Dabhasa Gram Panchayat, Padra community hall 2,50,000
2 RCC roads and Sejakuwa Gram Panchayat, Padra 3,70,000 street light 3 Ranu Gram Panchayat, Padra RCC road 2,85,000 4 Toilets, Drinking water facility, Sangama Gram Panchayat, Padra 1,50,000 compound wall etc
5 Toilet, tube well and Gokulpura Gram Panchayat, pump set and 55,000 Vadodara compound wall for cremation ground 6 Motor pump for Drinking water tank, drainage line, RCC Anmpad Gram Panchayat, Vadodara 2,00,000 road, repairing of Anganbaadi building, toilet Total 13,10,000
CSR Activities during 2012 13: District Vadodara
S. Beneficiary Purpose Amount o. recommended 1. Sim Committee, Gram Sejakuwa, Repairing of 1,80,000/ Padra Community hall. This SIM committee helped in acquiring land for PDEK. 2 Sarvoday Uttar Buniyaadi Vidyalaya, Toilets (plan and 1,00,000/ Mahuwad estimate is attached) Total 1,90,000/
CSR Activities during 2013 14: District Vadodara
S. Beneficiary Purpose Amount o. recommended 1. Tajpura Gram Panchayat, Padra construction of 1,28,652.20 Room for RO system
2 Total 1,28,652.20
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
5. A TICIPATED E VIRO ME TAL IMPACTS & MITIGATIO MEASURES
5.1 Environmental Impacts Associated with Drilling
The major element involved in the process of environmental impact assessment is identification as it leads to other elements such as quantification and evaluation of impacts. Although, in general, a number of impacts can be identified while describing the project, all the impacts may not be considered significant. Hence, it is necessary to identify the critical impacts that are likely to cause significant impact on various components of environment due to proposed drilling
A number of techniques are available for identification of impacts. In the present case for the activities proposed to be carried, adaptation of “Network Method” which involves understanding of “cause condition –effect” relationship between as activity and environmental parameters for identification of impacts has been found to be most appealing tool. Table 5.1 shows the criteria adopted for classifying the impacts into five broad categories. Likely impacts from Drilling have been identified in Table 5.2.
Table 5.1: Impact Significance Criteria
Impact Significance Criteria Major Adverse When the impact is of: • High intensity • High spread (regional) or moderate spread • High or moderate duration When the impact is of • Moderate intensity • High or moderate or low spread • High or moderate or low duration
Minor Adverse When the impact is of • Moderate or low intensity • low spread • High or moderate or low duration
Insignificant Adverse When the impact is of • low intensity • low spread • low duration
Moderate When the impact are positive
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Table 5.2: Identification of Likely Impacts from Drilling – Impacts/Risks Interaction Environmental Sensitivities
Physical Biological Socio economic Impacts/ Risks Activities Soil & & Soil Sediments Water Resource & Quality Air Quality Flora Fauna Reserve Forest/ Protect Ed Forests Living Condition Local Economy Existing Oil & Gas Traffic hazards Onsite Risks (Occupati onal exposure) Culture/ Archael ogical places Tourism/ leisure Land Use (Mudflats/ Agricultur e) Drilling Site Preparation Physical √ √ √ √ presence including land acquisition/l ease Site √ √ √ Clearance Site √ √ √ Preparation
Equipment √ √ √ Transportat ion Campsite √ √ √ √ √ Drilling Operations Atmospheri √ √ c emissions oise & √ √ √ √ Vibrations Waste √ √ √ generation Storage of √ √ √ flammables Well kick √ √
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
The detailed list of activities and actions described earlier in this report has been taken into consideration for generation of cause condition effect network (i.e. chain of events). This type of method is advantageous in recognizing the series of impacts that would be triggered by the proposed activities. Thus, this method has provided a “roadmap” type of approach to the identification of second and third order effects.
The idea was to account for the project activity and identify the types of impact, which would initially occur. The next was to select each impact and identify the secondary and tertiary impacts, which induced as a result. This process was repeated until all possible impacts were identified. The greatest advantage of this type of approach was that it allowed identifying the impacts by selecting the tracing out the events as they are expected to occur. While identifying the impact network for drilling operations in the study area all significant activities such as land acquisition, road/site clearance, drill site preparation, diesel generation sets, waste pits well development and work over operations have been accounted for.
The availability of energy resource (oil/gas) the end product has been considered for the purpose of economic benefits.
The identified impacts for various components of environment viz. Air, noise, water, land and socio economic are presented in figs. 5A to 5E respectively. The comprehensive environmental impact network for proposed drilling in typical case is presented in Fig. 5F. It is to be noted that in these illustration the lines are to be read as, “has an effect on”. Several scientific techniques and socio economic environment. Mathematical air environment models are the best tools to quantitatively describe the cause and effect relationships between sources of pollution and different components of environment. In case, it is not possible to identify and validate a model for a particular situation, predictions could be arrived based on extrapolations.
5.2. Air Environment
For the purpose of impact predictions on air environment emission sources can be classified into point and area sources. There are no areas sources considered for the purpose of predictions. The point sources identified are diesel generator sets at drill sites. These will be in operation 24 hours a day. Emissions from the generators will consist of mainly CO2, NOX, SO2 and suspended particles. The concentration of SO2 in the emitted gas will depend on the fuel source. Since diesel contains low values of sulphur, using diesel as fuel will lend to low SO2 emissions. Emissions are expected during temporary well flaring in the event gas is discovered. Impact Significance of Air Quality during drilling has been given in Table 5.3.
The meteorological data has been used for predictions for impacts of NOX on air environment; an inter active model that estimates short term concentrations for a number of arbitrarily located receptor points at or above ground level due to the point sources was used.
The incremental GLC as a result of DG set operation are within the permissible limits as per the CPCB. Regular monitoring for pollution levels indicate GLC levels to be within permissible limits.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Table 5.3: Impact significance of Air Quality during Drilling
Activity Impact Context Duration intensity Significance
local Medium Regional Short Medium Long Low Moderate High Insignifica nt Minor moderate major Drilling Deterioration of of Air quality Develo √ √ √ √ pment wells
5.2.1 Assessment of Air Quality Impacts
The detail of likely emissions (particulate and gaseous) from the above mentioned sources for drilling is given in Table 5.4.
Table 5.4: Emission during drilling of Development wells
Sr. Parameters Unit Operation of rig DG power Test flaring No. engines (including generation pump requirement) 1 Capacity 1000 HP/932.5KVA 670 HP/625 Test flaring# KVA 2 Number of Nos 2 1 1(Occasional) Stack 3 Fuel type* HSD HSD Gas Consumption** 3 4 m3/day 0.5 2 n3/day 125 M3/hr 4 Stack Height M 10 9 10 5 Stack Diameter M 0.305 0.254 0.0762(Flare diameter 0.3048 m) 6 Temperature 0C 325 325 208 7 Velocity m/s 22.4 21.6 8 PM10 Mg/Nm3 75 75 g/s 0.0622 0.0417 9 SO2 Mg/Nm3 50 50 g/s 0.0395 0.0265 10 NOX Mg/Nm3 2340 2340 95 g/s 1.9064 1.2778 0.03040 11 CO Mg/Nm3 890 890 550 g/s 0.7250 0.486 0.197
*Good quality HSD is being used for drilling activity having Total Sulphur Content 0.009% against prescribed limit 0.25%.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
* Consider per day HSD consumption
**Consumption is shown during Drilling hours
#the test flaring will be temporary in nature and will be for about 24 to 48 hours period depending upon the gas Encountered in the well. It is expected that about 3000 m3/day of gas will be test flared with an hourly average quantity of 125 m3/hour.
5.2.2 Decommissioning of Project
The impacts on air environment during decommissioning of project will be particularly in form of dust due to dismantling operations drilling rigs and equipment at unviable wells. Although the impacts on air environment will be short term but will require to be mitigated to minimize dust emissions. Proper air emissions control measures will be implemented during the decommissioning phase. Dust suppression system to be used on the decommissioning site and dirt track. Impacts on air quality due to above project activity are discussed below.
5.2.3 Impact from Air Emission
Considering emissions as described in the incremental values of SPM, SO2, NOx, and CO have been worked out using USEPA Industrial Source Complex Short Term model with meteorological data recorded at site from January to December 2007. The modeling has been done for different scenarios as given:
Scenario 1: During drilling of a well [from Power engines at rig generators and DG sets];
Scenario 2: During well testing and venting of hydrocarbons [for 24 to 48 hours and DG sets)
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Scenario 1
Output of Model Suspended Particulate Matter
Pollutant SPM Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 1.77 g/m3 Distance and direction of max. GLC 237.2 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 1.772 ( 225.00, 75.00) GC 2 1.67 ( 300.00, 150.00) GC 3 1.632 ( 150.00, 225.00) GC 4 1.616 ( 225.00, 150.00) GC 5 1.607 ( 300.00, 75.00) GC 6 1.572 ( 225.00, 300.00) GC 7 1.502 ( 300.00, 75.00) GC 8 1.492 ( 300.00, 225.00) GC 9 1.487 ( 225.00, 75.00) GC 10 1.469 ( 225.00, 225.00) GC Isopleths
Drawn at interval 0.3 g/m3 Minimum concentration 0.4 g/m3
Predominant direction of dispersal SW quadrants
5-6 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Output of Model Sulphur dioxide
Pollutant SO2 Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 1.125 g/m3 Distance and direction of max. GLC 237.2 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 1.125 ( 225.00, 75.00) GC 2 1.06 ( 300.00, 150.00) GC 3 1.036 ( 150.00, 225.00) GC 4 1.026 ( 225.00, 150.00) GC 5 1.02 ( 300.00, 75.00) GC 6 0.999 ( 225.00, 300.00) GC 7 0.954 ( 300.00, 75.00) GC 8 0.948 ( 300.00, 225.00) GC 9 0.0944 ( 225.00, 75.00) GC 10 0.933 ( 225.00, 225.00) GC Isopleths
Drawn at interval 0.20 g/m3 Minimum concentration 0.25 g/m3
Predominant direction of dispersal SW quadrants 5-7 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Output of Model Oxides of itrogen
Pollutant Ox Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 1.125 g/m3 Distance and direction of max. GLC 237.2 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 54.307 ( 225.00, 75.00) GC 2 51.187 ( 300.00, 150.00) GC 3 50.015 ( 150.00, 225.00) GC 4 49.522 ( 225.00, 150.00) GC 5 49.251 ( 300.00, 75.00) GC 6 48.175 ( 225.00, 300.00) GC 7 46.037 ( 300.00, 75.00) GC 8 45.729 ( 300.00, 225.00) GC 9 45.575 ( 225.00, 75.00) GC 10 45.025 ( 225.00, 225.00) GC Isopleths
Drawn at interval 12.0 g/m3 Minimum concentration 10.0 g/m3
Predominant direction of dispersal SW quadrant 5-8 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Output of Model Carbon Monoxide
Pollutant CO Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 33.186 g/m3 Distance and direction of max. GLC 237.2 m to the South west 8 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 33.186 ( 225.00, 75.00) GC 2 32.384 ( 225.00, 300.00) GC 3 31.192 ( 150.00, 75.00) GC 4 29.561 ( 225.00, 75.00) GC 5 29.5 ( 150.00, 75.00) GC 6 29.375 ( 300.00, 225.00) GC 7 28.995 ( 225.00, 225.00) GC 8 28.826 ( 225.00, 225.00) GC 9 28.683 ( 300.00, 150.00) GC 10 28.465 ( 150.00, 300.00) GC Isopleths
Drawn at interval 6.0 g/m3 Minimum concentration 8.0 g/m3
Predominant direction of dispersal SW quadrants 5-9 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Scenario 2
Output of Model Suspended Particulate Matter
Pollutant SPM Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 1.527 g/m3 Distance and direction of max. GLC 375 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 1.527 ( 225.00, 300.00) GC 2 1.356 ( 150.00, 225.00) GC 3 1.293 ( 225.00, 300.00) GC 4 1.262 ( 150.00, 300.00) GC 5 1.176 ( 225.00, 225.00) GC 6 1.171 ( 300.00, 300.00) GC 7 1.074 ( 150.00, 300.00) GC 8 1.057 ( 225.00, 225.00) GC 9 1.013 ( 150.00, 225.00) GC 10 0.986 ( 300.00, 300.00) GC Isopleths
Drawn at interval 0.3 g/m3 Minimum concentration 0.2 g/m3
Predominant Direction of dispersion SW Dispersal 5-10 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Pollutant SO2 Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 0.97 g/m3 Distance and direction of max. GLC 375 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 0.97 ( 225.00, 300.00) GC 2 0.861 ( 150.00, 225.00) GC 3 0.821 ( 225.00, 300.00) GC 4 0.802 ( 150.00, 300.00) GC 5 0.747 ( 225.00, 225.00) GC 6 0.744 ( 300.00, 300.00) GC 7 0.682 ( 150.00, 300.00) GC 8 0.672 ( 225.00, 225.00) GC 9 0.644 ( 150.00, 225.00) GC 10 0.626 ( 300.00, 300.00) GC Isopleths
Drawn at interval 0.2 g/m3
Minimum concentration 0.1 g/m3
Predominant Direction of Wind SW Quadrants
5-11 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Output of Model Oxides of itrogen
Pollutant OX Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 46.97 g/m3 Distance and direction of max. GLC 375 m to the South west 24 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 46.968 ( 225.00, 300.00) GC 2 41.711 ( 150.00, 225.00) GC 3 39.79 ( 225.00, 300.00) GC 4 38.688 ( 150.00, 300.00) GC 5 36.502 ( 225.00, 225.00) GC 6 36.207 ( 300.00, 300.00) GC 7 32.945 ( 150.00, 300.00) GC 8 32.578 ( 225.00, 225.00) GC 9 31.138 ( 150.00, 225.00) GC 10 30.382 ( 300.00, 300.00) GC Isopleths
Drawn at interval 10.0 g/m3 Minimum concentration 5.0 g/m3
Predominant direction of dispersal SW quadrants
5-12 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Output of Model Carbon Monoxides
Pollutant CO Model ISCST3 Grid Size 75m x 75m Maximum GLC predicted 33.29 g/m3 Distance and direction of max. GLC 375 m to the South west 8 hourly average GLC (first 10 highest) S.N Concentration X , Y Type 1 46.968 ( 225.00, 300.00) GC 2 41.711 ( 150.00, 225.00) GC 3 39.79 ( 150.00, 300.00) GC 4 38.688 ( 225.00, 225.00) GC 5 36.502 ( 300.00, 300.00) GC 6 36.207 ( 225.00, 300.00) GC 7 32.945 ( 225.00, 375.00) GC 8 32.578 ( 150.00, 225.00) GC 9 31.138 ( 150.00, 300.00) GC 10 30.382 ( 150.00, 225.00) GC Isopleths
Drawn at interval 5.0 g/m3 Minimum concentration 6.0 g/m3
Predominant direction of dispersal SW quadrants
5-13 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Inference: Scenario 1 & 2
The baseline ambient air quality has been added to the maximum incremental concentration to get resultant air quality parameters during different stages of drilling activities
3 Resultant SPM, SO2, Ox, & CO in Ambient Air ( g/m )
S. o Parameters Maximum Baseline Resultant AAQ Incremental AAQ 98 Max. GLC Standard(CPCB) Concentration Percentile
Scenario 1
1 SPM 1.77 108.66 110.43 500 (24hrs)
2 SO2 1.125 23.20 24.32 120 (24hrs)
3 NOx 54.3 14.91 69.21 120 (24hrs)
4 CO (8hrs) 1.125 1755 1756.12 5000
Scenario 2
1 SPM 1.527 108.66 500 (24hrs) 110.187
2 SO2 0.97 23.20 120 (24hrs) 24.17
3 NOx 46.96 14.91 120 (24hrs) 61.87
4 CO (8hrs) 33.29 1755 1788.29 5000
The above air quality data reveals that even after considering incremental concentration in to baseline air quality from various operations, Ground Level Concentration (GLC) does not exceeds limits as prescribed by National Ambient Air Quality Standards (AAQS) It may be concluded that impact of proposed activities will be insignificant.
5.2.4 Mitigation Measures
Measures proposed to control air emissions during drilling of oil and gas wells include:
• Minimization of emissions from drilling machineries, generators and optimize fuel efficiency; • Minimization of flaring and emissions from any production tests as far as possible; and
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
• Optimization flare burner characteristics to ensure maximum during of hydrocarbons produced during production test of wells (only in case required). • Generators to conform to the emission norms notified under the Environment (Protecting) Act, 1986; • Cold venting of gases will never be resorted • All tests flaring will be done by elevated flaring (stack) system (if required so).
5.3 oise Environment
For hemispherical sound wave propagation through homogenous loss free medium, one can estimate noise levels at various location due to different sources using model based on first principle.
Lp2=LP1 20 Log (r2 /r1) – Ae1, 2...... (1)
Where Lp2 and LP1 are sound levels at points located distance r1 and r2 from the source Ae1, 2 is the excess attenuation due to environmental conditions.
Combined effect of all the sources can be determined at various locations by logarithmic addition. It has been observed that generally all the noise in a rig installation are scattered in an area of about 100 m × 100 m. As the proposed drilling operations are carried out at 0.5 to 1.0 km away from the human habitation, the first approximation one can assume that for general population in the village, every drilling site is a “point” source of noise.
The average equivalent sound level of such a point source can be estimated by measurements of noise levels at approximately 50 meters in different directions from a hypothetical source by applying equation:
Lp = lw – 20 log r Ae 8...... (2)
Where, Lw is sound power level of the source, Lp is sound pressure level at distance r and Ae is the environmental attenuation factor. The noise level at different location can be calculated using equation (2) for averaged noise source. The asymmetry of the source gets masked in this model due to working approximation, but it is allowable for distant receptors (>1 km).
When a mechanical rig is in operation at its maximum efficiency, the drilling platform (derrick) can be assumed as the location of the hypothetical source of noise at the drill site where maximum noise levels are recorded (102dBA). Further the noise levels recorded in various direction at distance 50 m can be used for estimation of magnitude of the average noise equivalent source. Noise level due to such a source works out to be 44 dBA at a distance of 1 km. As environmental attenuation, particularly due to less by absorption and crops/grass/shrubs cannot be neglected the levels will work out to be less by 7 to 10 dBA depending on the nature of vegetation, relative humidity and frequency of the noise. Therefore average noise levels at about 1 km from the drilling rigs would be around 37 44 dBA. The overall background noise levels would increase by 3 4 dBA and 2 3 dBA during day night time respectively dus to drilling operation. Deployment of electrical rigs would minimize the noise levels and impact can be minimized.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Day night sound level, Ldn is often used to describe community noise exposure which includes 10 dBA night time penalties. As per WHO recommendations there is no identified risk in damage of hearing due to noise levels less than 75 dBA (Leq 8 hrs). Most of the international damage risk criteria for hearing loss permit Leq (12 hrs) up to 87 dBA. Further, WHO recommendations for community noise annoyance, permits day time outdoor noise levels of 55 dBA Leq, and night time outdoor noise level of 45 dBA Leq to meet steep criteria i.e. Leq (24 hrs) = 52.2 dBA and Ldn = 55 DBA.
The damage risk criteria for hearing, as enforced by OSHA (Occupational Safety & Health Administration) to reduce hearing loss, stipulate that noise level up to 90 dBA are acceptable for eight hours exposure per day. At places except the drilling platform, continuous attendance of workers is not required. Hence, the noise levels only at the drilling platform are of concern for occupational consideration.
5.4. Land Environment
During the drilling operation, two major sources of solid wastes are envisaged: (i) drill cuttings, separated on a shaker (vibrating screen) which is a part of solids handling system attached to rig and (ii) rejected drilling mud with sand and silt separation in desander and desilter:
Drill cuttings from the wells are allowed to collect in the sump below the shale shaker and removed periodically whereas mud is recovered and sent to recycling tanks. Around 5 to 10 T/day of drill cutting are expected to generate depending on type of formation and drill performed. Drill cuttings are washed before leaving shaker for recovery of attached mud. Though some mud particles are likely to be associated with drill cuttings, the overall nature of solids will
It is anticipated that approximately 121 m3 of drill cuttings will be generated over a period of 40 45 days for from each well. It is planned to wash the drill cuttings and dispose it into lined waste pit and covered by native soil.
Mud portion, which is recovered in shale shaker, passes though desander and desilter where sand & silt are removed by centrifugal action. The sand silt generated at this unit is contaminates with mud particle and is allowed to flow to waste pit by washing it down. These solids contain mainly bentonite, barite and small portion of organics along with heavy metals. These solids accumulate at the bottom of waste pit and possess the characteristics of natural earth materials. Quantity of rejected fine sand, silt and mud is expected to be 200 250 kg/day will be generated.
In order to predict the environmental impacts due to drilling mud reject pits, simulating field conditions carried out laboratory studies. The studies included investigation of leaching potential of possible hazardous constituents from these sources. Table 5.5 outlines the impact significance of waste generation.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Table 5.5: Impact Significance of Waste Generation during Development Drilling
Activity Context Duration intensity Significance
Local Medium Regional Short Medium Long Low Moderate High Insignifica nt Minor moderate major Drilling of Develop √ √ √ √ ment wells
Subsurface soils were collected from collected from the KG PG Basin and experiments for investigation of leaching potential of drilling mud and wastewater were carried out in laboratory. Since pH an alkalinity can directly affect the solubility of many parameters, especially the metals, the comparison of the two gave some indications of the mobility of the metals. Generally, solubility of metal decreases with increase in pH and alkalinity.
On application of the drilling mud and wastewater to soils, this was found to be true as soils were alkaline in nature. The transportation of ions revealed that Na, Cl and metals would tend to be slightly elevated in subsurface soils close to the mud pits or emergency wastewater impoundments; however, most parameters will not migrate any significant distance away from the disposal/temporary storage facilities. Na, Cl was the only ions to show definite vertical migration through subsurface soils, specific conductance was used as the characteristic of zones with elevated ions.
The studies further revealed that drilling improves water holding capacity and cation exchange capacity of soils. Thus, drilling mud could actually benefit vegetative production. This could be attributed to the fact that the drilling mud is, by design, impermeable suspensions of clays which form an even more impermeable contact surface between the mud and native soils.
As a result of these characteristics, the potential for leaching of constituents from mud pits is practically negligible. In mud pits migration of constituent will be dominated by surface runoff rather than by percolation of precipitation downward through the relatively impermeable drilling mud clays. Thus, neither the drill cuttings nor the barites used would cause any toxicity to the land environment. The aforesaid scenario of negligible pollution is a direct consequence of implementation and continual monitoring of the environmental parameters.
Further, barite was analyzed for Cd and Hg. The results always showed the absence of these heavy metals. The various lot of barite used by ONGC has never indicated the presence of heavy metals.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
5.5 Water Environment
It is estimated that approximately 700 m3 of drilling fluid will be formulated during the course of one development well to be drilled. Drilling fluid or mud is basically a mixture of water, clay, polymers and weighting material with all individual components being environmentally friendly. This mud will be reused as much as possible. The mud circulation is a closed loop with the return mud going back to the mud tanks. At the end of drilling operations, the residual (unusable) mud is discharged in to the waste pit. The impact significance on water environment is shown in Table 5.6
Table 5.6: Impact Significance of Waste Resource Quality during Development Drilling
Activity Impact Context Duration intensity Significance
local Medium Regional Short Medium Long Low Moderate High Insignifica nt Minor moderate major Drilling of Deterioratio Developm n of Air √ √ √ √ ent wells quality
In order to estimate the effects of surface water runoff/overflow of waste from the storage pits on aquatic ecosystems, short term bioassay studies were carried out by several institutes such as NEERI in the past. These studies revealed that effects of toxic substances on fish food organisms are vital factors in determining whether fish can flourish or survive in polluted water, as in many cases the lower organisms upon which fish depend are even more susceptible to a poison than are the fish themselves. In order to predict the impacts, bioassay tests were conducted on algae (Scenedesmus), Zooplankton (Daphnia and Cypris) and fish (Lebistesreticulatus) on laboratory scale.
Pure culture of the organisms was used for the test and were exposed separately at various dilutions of the waste. The result indicated that the waste was not toxic to algae. The growth of algae was stimulated in 30% within a period of 5 days. Among other organisms tested, the fish and Daphnia were the most resistant and susceptible to the waste. At 100% waste only 20% fish died in 48 hours.
Life cycle test with the juveniles (less than 24 hrs) of Daphnia was conducted through two generations at two nutrient fortified concentrations (50% & 80%) of waste in laboratory (31° 32°C) for 12 days. Only one juvenile was added at each concentration and control on zero day. Daphnia got matured and released 6 offspring (neonates) asexually at each toxicant level and control in fifth day. The parent Daphnia at 80% waste died on fifth day. However, in second generation 12% more and 33%less neonates were recorded at 50% and 80% waste respectively on twelve day. It was thus concluded that the waste at 50% dilution did not impair the growth of Daphnia.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Algal bioassay of mixed algal species showed that green and blue green algal species are much more resistant to drilling pit waste and water soluble fractions of crude oil, while diatoms and desmids are highly susceptible to these wastes. When exposed to these wastes phytoplankton community is dominated by green and blue green algae only. These studies indicate that the phytoplankton community structure would change if surface run off of waste fluids present in waste pits mixes with surface water. Since, lined pits will be used for solar evaporation of the unusable mud, the chances of run off or leaching is very low.
5.6. Biological Environment
Prediction of impact on Biological environment due to any development drilling activity is practically difficult because:
• Living subjects has a natural, variation in numbers; changes in number cannot always be directly attributed to changes in the environment • Most of the impacts on the living system or ecosystem take long time period cannot become fully visible externally.
5.6.1. Terrestrial Environment
The forests are getting vanished and the growing industrialization will affect the plant life due to industrial pollution load and influx of population. Therefore to minimize the adverse effect; it is proposed that the adequate management of these be taken up in a systematic manner. The natural vegetation in the study area is not considerable. It will be affected due to increased pollution load; however, it will improve due to follow up of Environmental Management plan (EMP). There are no rare and endangered plant and animal species in the study area and hence no changes are anticipated.
5.6.2 Aquatic Environment
There are no rare and endangered aquatic species and hence no change will occur. The characteristics of the water bodies may not change appreciably. In general, due to operation of drilling, adverse impacts are anticipated in biological environment. Aquatic environment is likely to be affected more adversely than the terrestrial environment without EMP. However, with the proper follow up EMP there will be significant improvement in biological environment covering terrestrial and aquatic ecosystems.
5.6.3. Socio economic Environment
Critically analysing the existing status of socio economic profile vis a vis its scenario with proposed project, the impacts of the project would be of varying nature. The predicted impacts are as follows:
• The proposed activities would generate indirect employment in the region; labour force will be required in site preparation and drilling activities, supply of raw material, auxiliary and ancillary works which will improve the economic status of the local unemployed persons.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
• The commissioning of project would lead to improvement in transport facilities as loose or soft surface rural roads and trails will be upgraded to facilitate movement of the drilling rig and supply vehicles
5.7. Environmental Impact Evaluation
5.7.1. Ecology
Agricultural and fishing activities form the source of livelihood for residents living in proximity to the identified drilling areas of the Block. Paddy fields cover most of the area. The impacts on ecology of this area will be marginal because the land is mostly agricultural area and not falling in forest area.
5.7.2. Environmental Pollution
As the EMP recommends appropriate treatment and disposal of water, there will be negligible adverse impact on aquatic environment. The air quality of area under reference will not be altered. However, control measures are proposed in environment management plan to mitigate any adverse impact. It has been proposed to plant select trees for trapping toxic hydrocarbons. Further restoration of drill sites is ensured, consistent with prior use pattern on all well sites as per the statutory norms. Noise levels due to transportation would not rise. The noise levels are likely to increase (5 10) dB (a) near the drill site posing occupational health problems but the nearby population will not get affected.
5.7.3. Aesthetics
The proposed well sites will be restored to their former land use on abandonment such that no impacts to local aesthetics will occur. For any wells eventually put into production there would be minor facilities placed at wellhead. The other aesthetic parameters will show marginal effects.
5.7.4. Socio economics
The impact on community health due to the proposed drilling activities is negligible but the social status will improve due to increase in employment opportunities. There will be positive impact on sanitation, transportation, communication and community health in the region. There will be occupational hazards due to proposed activities but these hazards will reduce through implementation of precautionary measures suggested in EMP.
5.8. Environmental Impact Statement
The impact statement focuses on the study area within block boundary. of the proposed drilling sites the five basic environmental components of concern are:
• Air Environment • Noise Environment • Water Environment • Land Environment • Socio economic Environment
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
For each of the above components of environment, the impacts are identified through cause condition network predicted through appropriate mathematical models and evaluated through environmental evaluation system.
5.8.1 Air Environment
The impacts on air emissions arising out of proposed activity are mainly due to construction activity, temporary flaring during well testing and emissions from DG sets. These will have no adverse impact and it is anticipated that this will to only marginal increase in PM 10, PM 2.5, NOx, etc. The impact of these parameters will be negligible from the proposed activity since the terrain is plain and sufficient amount of atmospheric mixing is available in that region. The impact network for Air Environment is given in Fig. 5A.
5.8.2. oise Environment
The impact of noise generated by the drilling on the general population is expected to be insignificant. Table 21 show the expected noise levels due to drilling. On the basis of expected noise levels calculated through standard attenuation model, it is observed that the noise levels in the region would be within the standard limits (IS: 4954). The increase will only be marginal in comparison to the existing noise levels.
The estimated background noise levels in the villages near the drilling site varied between 40 and 60 dB (A) and in commercial places and highways it varied from 55 to 60 dB (A). It is estimated that the general noise levels near the drill site will vary from 45 to 80 dB (A). The impact of the noise on general population is therefore expected to be insignificant. The impact network for Noise Environment is given in Fig. 11
Table 5.7 oise Exposure levels to Typical Drilling Rigs
Elect. Rig (dBA) Occupational Exposure Leq (12 hrs) (on the derrick) 71 Leq (12 hrs) (within the premises) 60 Human Settlement Exposure Leq (24 hrs) (villages 1 km away) 37 Ldn (village 1 km away) 39
5.8.3. Land Environment
The proposed drilling activity will lead to temporary and minor soil erosion and loss of agricultural land. Impact on land environment, due to site preparation is minor. There shall be loss of vegetation or change in land use from agriculture/scrub land/open vegetation/plantation to industrial land use. During site preparation the topsoil will be removed from the project site and the approach road, which contains most of the nutrients and organisms that give soil productivity. This will in turn result in minor changes of topsoil structure. Soil quality may be affected by setting up of rig and associated machinery and will continue till the site is restored to its original 5-21
EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset condition. Contamination of soil can result from the project activities if certain operations like storage of chemicals, crude and fuels cement and mud preparation, spent oil and lubricants are not managed efficiently
Mitigation measures
• Necessary efforts will be made during selection of drill site to minimize disruption of current land use to the extent possible; • On completion of works (in phases), all temporary structures, surplus materials and wastes will be completely removed; • Temporary new approach roads can be constructed and existing roads may be improved, if required, for smooth and hassle free movement of personnel as well as materials and machineries;
5.8.4. Water Environment
No significant impacts on water quality are envisaged due to discharges of wastewater if properly treated as the baseline status show dissolved solids, total hardness, chloride, sulphate, sodium, potassium and nutrients. Groundwater quality around the drilling sites shows alkaline nature with a pH range of 7.22 to 7.51. The chloride values are below the stipulated standards. Phosphate and nitrate concentration of groundwater are well within the prescribed limits. The impact network for Water environment is given in Fig. 5 C.
5.8.5. Biological Environment
Vegetation in the vicinity of the drilling sites will not get affected by proposed drilling because of marginal change in ambient air quality. Re establishment of crops by natural means is expected to adequately mitigate the impact due to emissions of pollutants.
5.8.6. Socio economic Environment
The proposed development drilling of 108 wells of different fields covered under Cambay Gujarat would create certain impacts with beneficial as well as adverse effects on the socio economic environment. The prediction of qualitative Impacts on Socio economic Environment is described in table 23 (Source: ONGC/NEERI/ Published data /report from various departments of Gujarat Govt.) while the expected change in the subjective and the average quality of life after the implementation of EMP measures presented in Table 24 & 25 respectively. The impact network for socio economic Environment is given in Fig. 5.7.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Table 5.8: prediction of Qualitative Impacts on socio Economic Environment
Parameter Local Regional Direct Indirect Reversible Irreversible Employment + • + + + • Income + • • + + • Transport + + + + • + Education • • • • • • Medical • • • • • • Facilities Communication + + + • • + Sanitation • • • Housing • • • • • • Health • • • Recreation • • • • • • Agriculture • • • Cost of living + + + • • + Business + + + • • + Per Capita + + + • • + Income pollution • • •
+: Positive Impact : Negative Impact •: Insignificant
In order to mitigate the adverse impacts on social economic aspects, due to the project, it is necessary to formulate certain EMP measures for the smooth functioning and commissioning of the project. The suggested measures are given below:
• Preference shall be given for employment of the local people during construction phase which will secure the economic life of the unemployed population on temporary basis
• Communication with the local community will be institutionalized & done on need basis by the project authorities to provide as opportunity for mutual discussion.
• Create various awareness campaigns in the community, specially related to basic health, hygiene and sanitation.
• Protection of persons against dust emissions during construction and transportation activities.
• Welfare measures will be decided and planned according to the priority and need of the community
• It will be ensured that the houses near to drill sites do not affected.
• Environmental Awareness programs will be organized to bring forth the environmental management measures being undertaken & the beneficial aspect of the proposed project for improving their quality of life.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Table 5.9: Expected change in Subjective quality of life Vadatal Field area
Sr. o. Villages QoL (s) QoL (s) After Implementation of EMP and Welfare Measure 1. Mitral 0.45 0.48 2. Bakrol 0.46 0.47 3. Vadatal 0.46 0.48 Average 0.46 0.48 QoL(s) = Subjective Quality of Life
Table 5.10: Expected CHA GE I Average Quality of Life
Sr. o. Villages QoL (s) QoL (s) After Implementation of EMP and Welfare Measure
1. Gutel 0.47 0.48 2. 0.46 0.49 3. Vadatal 0.47 0.5 Average 0.47 0.49
QoL(s) = Average Quality of Life
It is necessary to identify the extent of these impacts for further planning of control measures leading to mitigation of the adverse impacts due to proposed project on parameters of human interest socio economic have been assessed in term of:
5.9. Positive Impacts
The positive impacts identified from proposed project are described below:
Increase in job opportunities during the construction as well as operational phase for the qualified and skilled as well as unqualified and unskilled people in the study area that may have distinctive impact on the socio economic development of the region.
Fulfilment of the gas demand in the industrial sector of the region which will ultimately improve the economy of the region.
The construction of gas wells will be accompanied by the development of roads and other Infrastructure which can help to develop local area.
Quality of life will improve by proposed project through development of infrastructure resource such as development of roads, water supply, electricity etc.
The civil amenities like medical facilities, market, education, sports and cultural activities are likely to improve in the study area.
The gas exploited by drilling can be used as a domestic fuel which may help to boost local economy.
With the enhancement of infrastructure facilities, better employment opportunities the overall quality of life of the people will be upgraded Increase in the availability of fuel in the area
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Many auxiliary and ancillary industries may develop due to the proposed project activity.
5.10. egative Impacts
Occupational hazards in terms of injuries of accidents may occur during movement of rig & drilling of the wells.
Vehicle and drilling equipment can create noise pollution construction phase for short period.
Due to influx of population and pollution that may arise out of the proposed project activity, undesirable problem on the social, economic and health status of the people may rise in the region
During construction phase of project there could be added unavoidable pollution in the region if proper abatement measures are not adopted
Change in the occupational patterns within the study area, as employment will be provided only on short term basis.
5.11 Mitigation Measures
• It is recommended that all equipment is operated within specified design parameters during construction and operational phases • This can be achieved by minimizing the duration of testing through careful planning and using high combustion efficiency, smokeless flare/burners • It is recommended that while deploying major noise generating equipment such as diesel generators etc., • It will be checked that all mufflers are in good working order and that the manufacturers have taken the normal measures for minimizing the noise levels • Noise barriers/shields in the form of well berm will be provide around the units wherever possible • Use of ear muffs/plugs and other protective devices will be provided to the workforce prone areas • Wherever generator noise occurs in proximity to human settlements, sound deadening barriers will be provided • The effluents (wastewater) generated during drilling operations are recommended to be collected in lined waste pits to avoid groundwater contamination • The additional manpower requirement for drilling for drilling activities will increase employment opportunities for the local population, thus improving their social status
5.12 Project Post monitoring Program
Monitoring is one of the most important components of a management system. The Continuous monitoring needs to be carried out for regulatory requirements, environmental effects and performance of EMP implementation. Development drilling is for short duration 3 4 months. During drilling waste water quality, air quality monitoring and monitoring will be carried out.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
5.12.1 Occupational Health Surveillance Program:
ONGC onshore operations are comes under Mine Act (Ministry of Labour) and as per Mines Act every person employed in mine should go under PME (Periodical Mine should go under PME (Periodical Medical Examination) by approved medical doctor / Hospital at fixed interval i.e. Up to 45 yrs. – Once in a 05 Yrs. 46 to 55 Yrs. – 03 yrs. & > 55 yrs. – 01 yr. As per plan 10% employees are being medically examined every year and record is being kept for future reference and track.
There are ONGC Panel hospitals / Laboratories / Doctors with necessary medical facilities for PME like X Rays, ECG, Sonography, PFT, Audiometery, Eye / ENT Surgeon / Blood/ urine test etc.
ONGC Rajahmundry Asset has its own dispensaries and empanelled hospitals for employees and their family members for day to medical problems. Ambulance is available 24 hrs.
All the work canters have first Aid Box, Stretcher and 24 Hrs. Emergency vehicles. The main occupational health hazards may be nose at drilling rigs, and necessary guidelines are available sites.
Free medical camps (medical check ups / eye check up) are also organized by ONGC in Villages around the operational area, and accordingly patients are treated and free medicines are given. If required free operations are also bone by ONGC.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.1: Impact network for Air Environment
An Illustrative case of Typical Development Drilling
Activity Drilling
Release of Air Pollutants
Primary impacts Change in Air Quality Deposition of Particulates on Impact on Visibility Soil, Water and Vegetation
Secondary Impact on Human Impact on Flora & Impact on Soil Impact on Impacts Health Fauna Quality Aesthetics
Impact Agricultural Tertiary Production Impacts Impact on Economic Output Impact on Socio-Cultural Environment
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.2: Impact etwork for oise Environment
An Illustrative case of Typical Development Drilling
Drilling Activity
Release of Air Pollutants Primary Impacts Change in Ambient Noise Level
Secondary Health Risks Impact on Work Output Migration of Impacts (Quantity and Quality) Population
Tertiary Impacts Impact on Economic Output Impact on Socio-Cultural Environment
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.3: Impact etwork for Water Environment
An Illustrative case of Typical Development Drilling
Activity Drilling
Change in Surface Abstraction of Release of Primary Morphology Water Wastewater impacts Impact on Run off/Seepage
Impact on Hydraulics of Impact on Water Environmental Health Water course Quality and Aesthetic Risk
Secondary Impact on Impacts Impact on Cost of Water Impact on Agricultural Aquatic Life Treatment Amenity Production
Tertiary Impacts Impact on Socio-Cultural Impact on Economic Output Environment
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.4 : Impact etwork for Land Environment
An Illustrative case of Typical Development Drilling
Drilling Activity
Abstraction of Water Disturbance of Soil Disposal of Wastewater and Sludge’s on Land Change in Groundwater Change in Structure Primary Regime: Soil Moisture/water of Soil: Addition/Removal of impacts LCYCL/flow Pattern/Salt Water Texture/Permeability Substances or Heat Intrusion /Soil Aeration To/From the Soil
Secondary Impact on Soil Biota Impact on Mora and Fauna Impact on Landscape Impacts
Impact on Agricultural Production Impact on Livestock
Tertiary Impacts Impact on Economic Output Impact on Socio-Cultural Environment
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.5 : Impact etwork for Socio economic Environment
An Illustrative case of Typical Development Drilling
Activity Drilling
Deployment of Consumption of Product Output Work Force Materials/Chemicals and Primary Energy impacts
Change in Demand for Change in Change in Environmental Employment Infrastructural Resource Economy Trade Pollution Pattern Facilities Rasa and Commerce
Secondary Change in Change in Land Impact on Environmental Impacts Impact on Income use Pattern Landscape Amenity/ Health and Distribution Recreation Aesthetics
Tertiary Impacts Change in Economic Base and Cultural Values
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos. of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
Fig. 5.6 : Comprehensive Impact etwork
An Illustrative case of Typical Development Drilling
Land Road Site Site Diesel Waste Pit Well Work over
Acquisition Clearance Preparation Generators Development Operations
Drilling
Air Pollution Noise Pollution Water Pollution Land Pollution
Air Quality Increase in Increase in Increase Surface Ground Estuarine Aquatic Natural Leach ate Soil Increase Effect on I loath Economic Increased Impairment Temp and Particulate in Noise Water Water Water Biota Vegetation Effects Quality in Fisheries and Effects Demerits Employment Odour Matter Levels Pollution Pollution Impairme Salinity Salt Planning Facilities nt
IMPACT ON AIR NOISE IMPACT ON WATER IMPACT ON LAND IMPACT ON SOCIO ECONOMIC
ENVIRONMENT
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6. E VIRO ME T MA AGEME T PLA
6.1 General
The EIA for the proposed development drilling programme has identified a number of impacts that are likely to arise during the site preparation, well testing and demobilization. The EIA has examined biophysical and socio-economic effects of the proposed activity from site clearance and preparation of the site and testing through to abandonment, demobilization and restoration. On assessment of environmental impact it is observed that the real benefits of proposed activity can result only if the risks of pollution are minimized. This can be accomplished through implementation of adequate preventive and control measures through rigorous monitoring.
The probable activity/ scenarios pertaining to the development drilling activity that can cause adverse impacts have been identified through this study. This EIA study has also examined the extent to which these impacts would be mitigated through the adoption of industry standard practice, guidelines and by following statutory requirements. The Environmental Management Plan (EMP) describes both standard operating procedures and site specific measures which are to be implemented for mitigating the potential impacts associated with the development drilling activity.
The EMP provides a delivery mechanism to address potential adverse impacts like providing instructions to the contractors/operators and also to introduce good standards operating procedures which should be adopted for the complete project work. The EMP was prepared as a standalone document covering each stage of the development drilling activity.
For each stage of the activity, the EMP lists all the requirements to ensure effective mitigation of every potential biophysical and socio-economic impact identified in the EIA. For each activity or operation which could give rise to an adverse impact, the following information’s are presented:
• A comprehensive listing of the mitigation measures.
• The parameters that are to be monitored to ensure effective implementation of the action.
• The timing for implementation of the actions to ensure that the objectives of mitigation are fully met.
The EMP comprises a series of components covering direct mitigation - environmental monitoring, an outline waste management plan and restoration plan.
ONGC is committed to the adoption of these measures and will carry out continuous inspection to ensure their implementation and effectiveness by its contractors and operators.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
The present development drilling programme has been designed to avoid or minimize impacts to the environment. Yet the probability of residual degradation always remains, which may have moderate or significant impacts on the environment. The mitigation measures prescribed in this EIA will either reduce the impact to an acceptable level or adequately offset it.
All the Drilling Rigs deployed for development drilling operations are duly accredited as per ISO 14001:2004 standards and the effectiveness of the EMP envisaged is duly audited periodically internally as well as by external certification bodies.
Based on the impacts identified, a conceptual Environmental Management Plan (EMP) is recommended as below:
6.2 Drilling Fluids & Drill Cuttings Impact and Management
The present practices drilling a hydrocarbon involves the use of drilling fluid (or) Mud which requires different chemicals, water (or)Synthetic oil and additives to improve flow properties. The preparation and use of drilling mud may cause adverse impacts when it accidentally spills over vegetation and water body outside the drill site. Any adverse impacts due to drilling fluid will be minimum if, only water based mud (WBM) is used as drilling fluid in the proposed development drilling to maintain hydrostatic pressure control in the well and to lubricate the drill bit. The following regulations are also stipulates the criteria for Drilling Mud and the same could be adopted for preparing the EMPs.
Regulations
G.S.R.546 (E) Notification dated 30-08-2005 of MoEFCC states that , The chemical additives used in the drilling fluids (WBM) will be biodegradable (mainly organic constituents) and will have toxicity of 96 hr LC50 value > 30,000 mg/l as per mysid toxicity of test conducted on locally available sensitive sea species. The chemicals used (mainly organic constituents) should be biodegradable.
Also states that Hexavalent chromium compound should not be used in DF. Alternative chemical in place of chrome lignosulfonate should be used in DF. In case, chrome compound is used, the DF/ DC should not be disposed offshore.
Such conditions may be adhered strictly and the Water Base Mud prepared shall be recycled to a maximum extent there by reducing the consumption of raw material like water and other chemicals.
Drill Cuttings:
G.S.R.546 (E) also stipulates the following with respect drill cutting originating from onshore drilling activity:
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
• Drill Cuttings (DC) originating from on-shore drilling will be separated from Water Base Mud (WBM) and the same will be properly washed. The separated drill cuttings, wash water and unusable drilling fluids (DF) may be disposed off in a well-designed lined pit with impervious liner. The disposal pit will be provided with a leachate collection system. • Design aspects of the impervious waste disposal pit; capping of disposal pit will be informed by the oil industry to State Pollution Control Board (SPCB) at the time of obtaining consent. • In case of any problem due to geological formation for drilling, low toxicity OBM having aromatic content < 1% will be used. If the operators intend to use such OBM to mitigate specific hole problem/ SBM it will be intimated to Ministry of Environment and Forests/State Pollution Control Board. • The waste pit after it is filled up shall be covered with impervious liner, over which, a thick layer of native soil with proper top slope is to be provided. • Drilling wastewater including DC wash water will be collected in the disposal pit evaporated or treated and will comply with the notified standards for on-shore disposal.
Accordingly drill cuttings shall be handled properly to avoid any spillage and adverse impacts due to it on the surrounding environment. Moreover the land acquired for preparation of drill site has to be restored after completion of drilling operation leaving no waste material at site if the well is found to be dry. During restoration all the drill cuttings will be buried as per the standard land filling methodology of CPCB.
6.3 Air Environment
The proposed development drilling activity show his impact on due to the emission from heavy machineries used at the drill site and also an account of movement of vehicles. The following methodologies shall be adopted for effective management and minimization of impact on air due to the proposed activity:
All equipment associated with drilling activity has be operated within specified design parameters during construction, drilling and operational phases. The approach road to site shall be made pucca and frequent water spraying may be carried out to reduce the dispersion of dust into the surrounding .Well planned duration of testing operation of the will minimize impacts of emissions on account of gas flaring ( in successful hydrocarbon producing well ) . By adopting regular- scheduled maintenance of DG sets and by using HSD with very low sulphur content the impact of increase in GLC could be reduced.
It may be noted that drilling activities are temporary and last for few months only per each site /well and hence do not cause any significant impact on the air environment if the mentioned precautions were strictly adhered.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6.4 oise Environment
The noise environment shall be affected due to the diesel generators and high capacity engines of Draw-works and mud pumps etc. To minimize the impact the following methodologies shall be adopted.
While deploying major noise generating equipment such as diesel generators etc… it should be checked that all mufflers are in good working order and that the manufacturers have taken the necessary measures for minimizing the noise levels. Noise barriers/shields in the form of acoustic enclosures shall be provided around the units generating high noise. Ear muffs/plugs and other Personal Protective devices shall be made available to the workforce in noise prone areas. Enclosures around noise sources may be provided depending on the size of the unit. Preventive and predictive maintenance of engines, machineries, generators and vehicles should be done periodically to reduce the impact on surrounding noise levels. Except core drilling activity the other associated noise generation process like vehicular movement, utility operations and welding- brazing jobs shall be to be restricted to daytime only to the extent possible, which will reduce the disturbances to surrounding noise at night time consistently. Also Personnel Protective Equipments (PPE) like ear plugs/muffs should to be given to all the workers at site and it shall be ensured that the same are used by every employee of the drill site during their shift. This will ensure the impact of occupational hazard to the people working in the project.
6.5 Land Environment
The soils in the Cauvery delta districts of Tamilnadu is filled with thick shale-clay and posses moderate infiltration rates amenable to groundwater pollution. Considering this fact and moderate ground water quality, every precaution would be taken to avoid spillages of chemicals on soils to avoid any deterioration of groundwater quality and danger to soil microbial populations which are sensitive to hydrocarbon.
The non-degradable solid wastes generated is drill site during operation have to be collected in secured container and the same shall be disposed in designated disposal sites like TSDF authorized by Tamilnadu State Pollution Control Board. The earth cuttings (approx. 150 – 200 MT per well) generated at drill site will be mostly inorganic in nature and can be used either for land filling or road making. Hence these drill cuttings would be collected and transported to the identified sites to land environment of the site. If this is uneconomical separate drying pits may be made at a corner of drill site. All precautionary efforts will be made during selection of drill site to minimize disruption to existing land use pattern to the extent possible.
On completion of works (in phases), all temporary structures, surplus materials and wastes are to be completely removed till 1m below the surface. A temporary new approach road could be constructed or the existing roads can be improved depending upon the scenario keeping the impact of minimization of land utilization. Optimization of land requirement through proper site lay out design will be basic criteria at the design phase. Finally if the well is found to be dry proper restoration methodologies should be adopted to bring back the site to near original condition.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6.6 Water Environment
The water environment would get affected if any kind chemical or oil spill and waste water generated accidentally mix with water body or ground water. To minimize the impact the following methodologies shall be adopted.
Wastewater generated during drilling operations would be recycled. Wastewater characteristics would be of varied nature and likely to contain soil particulate matter along with organics. The waste water generated shall be collected in waste pit lined with impervious HDPE sheet and left for solar evaporation as per G.S.R.546 (E) Notification dated 30-08-2005 of MoEFCC.
Garland drains shall be made around the drill site to collect all the storm water falling inside the drill site and also accidental spill of effluent are not allowed to mix with the water/ land outside the site.
The possibility of treating the waste water generated using mobile ETP shall be the evaluated and scheme comprising of treating the raw effluent with chemicals such as Alum and Lime to facilitate desired coagulation and flocculation. Adequate settling time has to be ensured for the removal of the separated solid material. The treated waste water shall be reused during drilling operations there by raw water consumption will reduced.
The mobile ETP shall be a single trailer mounted fully mobile facility designed in such a way that dismantling, transportation from one location to another and commissioning time should not exceed ten days. The plant shall not occupy area more than 6m x 9m for its installation. The plant should be designed to process the drill site effluent, so as to deliver minimum 30 m3/day of treated water having the desired characteristics of treated effluent as per the standards. The plant has a storage tank of 10 m3 capacity for initial storage of treated water prior to its discharge/ delivery. The plant has the arrangement and capacity to draw raw effluent 150 ft. away from waste pit. The ETP should possess one discharge pump of adequate capacity to pump treated water to water storage tank/mud tanks for mud preparation which are approximately 150 ft away from the plant.
6.7 Biological Environment
In order to avoid any adverse impacts on the biological environment the discharge of the gaseous, liquid and solid waste into the atmosphere should be minimized. Destruction of natural habitat of animals will be very insignificant. Nesting, mating and other wildlife behavioral patterns will not be disrupted or destroyed as the activity of temporary in nature. The removal of native vegetation would create profound effects upon the natural environment and animal life temporarily which has to be minimized proper planning and execution. Rich and diverse vegetation in the study area will be maintained by adapting proper protection measures. Special attention may be given on publication of zoological articles, guides, books and monographs indicating importance of local and regional plant and animal life to acquire knowledge about the biological environment and its sensitivity. Local individuals and authorities are important resources and shall not be overlooked w.r.t conservation of bio-diversity.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
• Water runoff, erosion and siltation shall be minimized or completely shut, because these may have chronic impacts to the biodiversity of the area. • Special care will be taken to protect localized animals and endangered species if any.
The concept of sustainable development will be kept main ideology in all activities related to the proposed development drilling activity. This conception of sustainable development in all aspects of development drilling provides a conceivable way by which negative developmental impacts can be curtailed.
6.8 Socio economic Environment
In order to mitigate the adverse impacts on social and economic aspects, due to the project, it is necessary to formulate certain EMP measures for the smooth functioning and commissioning of the project. The suggested measures are given below:
Preference shall be given for employment of the local people during construction phase which will secure the economical life of the unemployed population on temporary basis. Communication with the local community has to be institutionalized and carried out on regular basis by the project authorities to provide an opportunity for mutual discussion. Community awareness programs related to basic health, hygiene and sanitation shall be conducted under CSR scheme to enhance the knowledge of the local people about healthy life style and habits. Vocational training programmes, if required, may be organized for the local people that may develop their capacity and skills and shall be helpful for them in getting more employment opportunities. Necessary measure like water spraying shall be adopted for protection of persons against dust emissions during construction and transportation activities. Welfare activities such as organizing free medical check-up camps and extending multi- specialty medical facilities to local population would be undertake under CSR scheme of the corporate. Welfare measures may be decided and planned according to the priority and need of the community during development phase. Environmental Awareness programmes will be organized to the local briefing the various environmental protection measures adopted by ONGC for sustainable development of the country and also the beneficial aspects of the proposed project for improving their quality of life.
6.9 Social Management Plan (ECSR)
Though much has been expected from ONGC by the local public with respect the facilities and comforts to modify their life styles, ONGC could afford only a portion under Enterprise Corporate Social Responsibility plan with the proposed development drilling project which could extend for a time period of 5 years. The annual plan is as below:
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 6.1 Social Management Plan (ESR)
S. Social eed Unit rate o. of Units Total Cost o (I R) per year per annum Facilities for better quality drinking water storage and distribution 1. Installation of R.O Treatment 400000 4 16,00,000 Plant ( 1000 litter /day) 2. Building storage tanks 400000 3 12,00,000 3. Establishment of distribution 300000 3 9,00,000 system Medical facilities 1 Free health Check up Camps 500000 4 20,00,000 2. Up gradation of Primary health 300000 1 3,00,000 centers Educational Facilities 1 Maintenance and improvement of 200000 5 10,00,000 Panchayat School building and facilities Infrastructure Facilities 1. Improvement of existing roads 100000 3 3,00,000 2. Construction of new roads 400000 2 8,00,000 3. Community hall for panchayats 400000 1 4,00,000 Total per annum 85,00,000
6.10 Waste Management Plan
The waste management plan (WMP) covers disposal of all wastes with further reference to offsite disposal of those wastes, which cannot be dealt with onsite. The objectives of the WMP are: • To provide the necessary guidance for the reduction and management of wastes generated on drilling site. • To comply with all current Indian environmental regulations. • To meet industry standards on waste management and control. • To prevent occurrence of any environmental degradation within the locality due to waste handling.
6.10.1 Disposal Options
The following disposal options will be available on site. However, it will be necessary to evaluate the suitability of various waste specific technologies for the site and select an option that will cause minimum environmental impact on the surrounding:
Landfill: Non-hazardous inert drill cuttings and waste residual mud shall be disposed of in the waste pit lined impervious HDPE sheet and left for solar evaporation. After drying the
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
left over cuttings shall be buried as per standard Landfill guidelines (Waste mud and drill cuttings disposal plan).
Offsite Disposal: Domestic and other degradable wastes which cannot be handled at the drilling site will be removed to a designated offsite and suitably disposed for reuse/recycling /municipal disposal. Hydrocarbon Gas Flaring: Only gas produced during well testing will be flared via a conventional burner system during initial testing. No flaring of oil will be done at drill-site. Sewage Disposal: A sewage disposal system will be established in the campsite during the drilling operation. Being a temporary activity the sewage will be diverted to septic tank combined with soak pit. The treated liquid waste will be used, wherever possible for agriculture purposes.
6.10.2 Waste Reduction, Reuse & Recycle
Waste reduction effort will concentrate on reuse, recycling, minimization of packaging material, reduction in size of waste material and finally reduction of time spent on location via optimization of drilling efforts.
Plastic containers, especially those used for stock up fluid and cementing chemicals, are prime targets of the local villagers for use as water containers. As some of these may contain substances, which can be harmful to humans, care will be taken to ensure that they are not removed from the drilling site intact. In general, after emptying chemical containers, which did not contain any substances, container will be punctured and eventually compacted and sent for disposal to authorized agency.
Used medical wastes, inclusive of but not limited to bandage material, syringes etc., will be collected in a special collection drum to minimize manual handling. Contents of the drum will be labeled as biomedical waste and shipped offsite for disposal through authorized agency.
Waste oil and lubricants generated in the drilling process will be sent to authorize recyclers. All spent lead acid batteries will be sent for recycling by authorized contractors.
All waste storage area within the site will have proper bunds to prevent any escape of contaminated runoff. It shall be ensured that any runoff from such temporary storage area will channelized into the waste-water pit, adequately treated and discharged in compliance with the regulatory requirements.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6.11 Environment Protection and Reclamation Plan
• Construction activities will be coordinated in consultation with landowners to reduce interference with agricultural activities. • Top soil will be stripped to a depth where color change takes place or to plough depth and will be stored on the site. The depth of stripping will be on the basis of site specific soil survey. • If required for rig stabilization the well site will be temporarily padded with granular fill. • The drill site would be provided with sufficient sanitary facilities. • Combustible wastes generated would be burnt in a controlled manner or disposed through approved agency. • Hazardous materials such as petroleum, spirit, diesel lubrication oil and paint materials required at the site during construction activities would be stored as per safety norms. To ensure that the local inhabitants are not exposed to the hazards of site construction activity the drill site would be secured with manned entry posts. • It would be ensured that both gasoline and diesel powered construction vehicles are properly maintained. The vehicle maintenance area would be so located that the contamination of surface/soil/water by accidental spillage of oil/diesel will not take place and dumping of waste oil will be strictly prohibited. • All irrigation canals and ditches encountered by the proposed well site access and well site will be maintained in a fully functional state. • No Construction material debris will be left on site.
6.12 Plans for Well Site Operation and or Abandonment
• The site will be fenced in the event the well is successful. The well site will be reduced to approximately 30 m x 30 m for the production phase and all non-essential areas will be fully restored and reclaimed to near original condition. • If the well becomes operational the site will be monitored and kept in a weed free state. Weed control will be achieved through either mechanical control or strategic and responsible application of an appropriate herbicide. • In the event the well is unsuccessful the well bore will be cement plugged as per OISD guidelines. • Any contaminated soils (e.g. by accidental spills of fuel, lubricants, hydraulic fluids, saline produced water) will be treated on site if necessary or shall be removed from the site to an appropriate landfill for further bioremediation. • On abandonment newly constructed access will be fully reclaimed unless specifically requested by the landowner. • Any irrigation ditches diverted to accommodate a well site will be realigned to their pre-well site configuration in consultation with the landowner.
In conclusion, it is imperative that ONGC as a premier oil producer of the nation voluntarily accepts the responsibility of ensuring the protection of the environment around its operational areas so as to ensure the sustainable development of the area. Further, ONGC shall adopt the following monitoring program and accordingly use best available technology to reduce the impact on environment due to oil exploitation activities.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
6.13 Environmental Monitoring Program
Monitoring is one of the most important components of a management system. Continuous monitoring needs to be carried out for regulatory permit requirements, environmental effects and performance of EMP implementation. Monitoring indicators have been developed for each of the activity considering the mitigation measures proposed. Indicators have been developed for ascertaining the performance of the EMP implementation through Environmental Indicators (EI’s) which focus not only on quantifying or indexing activity- environment interactions that may potentially impact the environment but at the same time also help in comparing different components of environmental quality against previously established baseline values. Monitoring results would be to be documented, analyzed and reported internally to Drilling Supervisor and HSE Coordinator.
Monitoring requirements, Monitoring parameters, Period and Frequency of monitoring have been presented in the Table 6.1.
The table also categorizes each indicator presented according to the project phase in which they have to be monitored under the following categories:
• Disturbance to Local Environment • Disturbance to Local Communities • Global Environmental Problems • Resource Consumption • Waste Generation • Benefits to the Local Population Each indicator has been tagged with an EI number (Refer Table 6.2) in order to establish the linkage between the suggested mitigation measures and the proposed monitoring framework.
Table 6.2 Environmental Monitoring framework
Ei. Environmental Monitoring Location Period & o. Indicator (Ei) Parameter Frequency A : Design And Planning A.1 Proximity of vulnerable Distance between the N. A. Once in project environmental habitat drill site and vulnerable lifecycle environmental habitat A.2 Proximity of nearest Distance between the Site Once in project habitation drill site and nearest lifecycle habitation A.3 Location and Size of Number of land owners Site Once in project Land Leased affected Total area lifecycle leased for all the drill sites (Ha) A.4 Present Crop Cycle Crop period Site Once in project (in months) lifecycle A.5 Land use Land use Type Site Area Once in project lifecycle A.6 Approach Roads Distance Leased Area Once in project
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
NH/SH/ODR/MDR lifecycle from project site Condition of road. A.7 Lease period Number of rainy days Leased During site within the lease period Area planning A.8 Terrestrial Number of matured Leased During Habitat/Vegetation trees to be felled Area identification of Cover Distance of leased area. site areas A.9 Emissions during Height of flare stack Site During flaring Location of flare stack Production with respect to testing campsite and habitations A.10 Compliance of Air % of machinery and Site always standards equipment meeting source emission standards A.11 Compliance of Noise % of machinery and Site Once in project standards equipment meeting lifecycle source emission standards A.12 Hazardous / Toxic List of Hazardous/ Site Once in project Drilling Chemicals Toxic Drilling lifecycle Chemicals to be used in Drilling Project A.13 Chemical and fuel Area of chemical and Site Once in project storage fuel storage Area made lifecycle impervious around such storages Height of chemical and fuel storage A.14 Terrestrial Habitat / Species Diversity Leased During Vegetation Cover Index Area identification of borrow areas B : APPROACH ROAD & SITE DEVELOPME T B.1 Topsoil Area occupied for Site Weekly during topsoil storage/ Area site preparation planned for topsoil storage Height of topsoil stockpile B.2 Fugitive emission of Visual observation of Site & Daily during site dust during site dust in air by haziness approach preparation preparation roads B.3 Air emissions from SPM, NOx, SOx, CO, Exhausts Twice in project vehicles and HC) based on emission lifecycle or Daily machineries factors Visual Contractor observation of Selection, Case- emissions (black to-case - if signifying more considerable
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
pollution) % of emissions vehicles possessing observed during valid PUCC operations Certificates B.4 Night time operations Hours of operation Site & Daily during site of vehicles & during night time approach preparation machinery road B.5 Noise emissions from Noise pressure level in Site & Daily during site vehicles and dB(A) near noise approach preparation machineries sources (5m) road B.6 Subsoil Compaction Visual observation of Adjacent to Daily during site compacted area / Site & preparation trampled vegetation / approach crops roads B.7 Fugitive emission of Visual observation of Transport Daily during site dust during material dust in air by haziness route preparation transport B.8 Servicing schedule for Percentage of vehicles Site & Monthly during vehicles not complying with the approach site preparation servicing schedule road B.9 Supervision of Number of vehicles Site Daily during site movement of heavy reported with preparation vehicles within site movement outside platform area and access road
B.10 Fugitive emission of Visual observation of Near Daily during the dust during material dust in air by haziness stockpiles entire project life- handling and storage and storages cycle B.11 Spilled Chemicals/Oil Area of Spill / Quantity At storage As and when Spilled / Severity of point within spills occur Spill / Characterization site of Spilled Substances for Contaminants (Heavy Metals, Toxics, etc.) Storage & Disposal Details (Qty, Method) B.12 Soil Fertility Fertility parameters Site & Once before site like pH, NPK ratio, adjacent preparation Total Carbon, etc. areas B.13 Quality of water Visual observation and Nearby Daily during site Analysis of Parameters river, canal, and road works as per CPCB Use-class pond etc. Monthly during site and road works
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
B.14 Ambient Air Quality Visual observation At Monthly during Odour/smell (NOx) Surrounding site and Measurement of SPM, receptor road works RPM, SOx, NOx, CO, points using HVS
B.15 Ambient noise quality Hearing / perception At Monthly site and Measurement of Noise surrounding road works Pressure Level in receptor dB(A) points
B.16 Condition of Natural Visual observation of N.A N.A Habitats (forests etc.) signs of visible pollution / degradation B.17 Consultation with Number of Inhabitants Twice in project villagers consultations with of nearest lifecycle Once in villagers regarding settlement project lifecycle selection of alternate foot track access to agricultural fields Number of consultations with villagers regarding site restoration B.18 Local labor force Number of temporary Nearby Once in project land losers (or their settlements lifecycle family members) employed in project activities.
C : DRILLI G & TESTI G ACTIVITY C.1 Gaseous pollutant Pollutant DG Stack Quarterly during emissions from DG Set concentrations in drilling & testing gaseous emissions and For the entire maintenance project life- parameters (air, fuel cycle period filters & air-fuel ratio) of DG sets influencing air emissions Visual observation of exhaust smoke characteristics Emission rates of PM, NOx, SOx, CO, HC based on emission factors
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
C.2 Noise emission from Noise pressure level in Near noise Regularly (day & DG Sets dB(A) sources (5m) night)
C.3 Noise emission from Noise pressure level in Near noise Regularly (day & rig dB(A) Number of sources (5m) night) Case-to- cases of workers not Site case basis using PPE C.4 Ground water usage Daily withdrawal rate Site Daily C.5 Noise emission during Noise pressure level in Near noise Regularly (day & mud preparation dB(A) sources (5m) night)
C.6 Waste from Spillage Mass generated in kg At storage Daily during containment Storage & disposal point within entire life-cycle details (qty, method) site of project C.7 Noise emissions from Noise pressure level in Near Case-to-case : vehicles dB(A) vehicles only if high noise is noticed C8 Spilled Chemicals/Oil Area of Spill / Quantity Site As and when Spilled / Severity of spills occur Spill / Characterization of Spilled Substances for Contaminants (Heavy Metals, Toxics, etc.) Storage & Disposal Details (Qty, Method) C9 Fugitive emission of Visual observation of Near Daily during the cement dust during cement dust in air by stockpiles entire project life- handling and storage haziness and storages cycle C.10 Runoff from temporary Supervision of Site Fortnightly storage areas functioning of conduits during drilling / drains channelising phase runoff into the waste pit C.11 Engineering control at Supervision of waste Final Fortnightly the disposal site disposal at the on-site Disposal during drilling final disposal site Site phase C.12 Runoff from final Supervision of Final Fortnightly disposal site functioning of garland Disposal during drilling drains Site phase C.13 Waste Oil and Volume of waste At storage Daily during Lubricants generated in it Storage point within entire life-cycle & disposal details (qty, site of project method) C.14 Spent batteries Numbers, size Storage At storage Monthly during & disposal details (qty, point within entire life-cycle method) Authorisation site of project of waste recyclers of spent batteries
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
C.15 Metallic, packing, Mass generated in kg At storage Daily during scrap waste Storage & disposal point within entire life-cycle details (qty, method) site of project C.16 Emissions from Flaring Total CO, Non- Flare Stack Twice during Methane well testing Hydrocarbons, NOx emission estimates based on emission factors C.17 Domestic Solid Waste Mass of waste At storage Daily during generated in kg Storage point within entire life-cycle & disposal details (qty, site of project method and frequency) C.18 Sewage (Black, grey Volume estimate Basic At discharge Monthly during water) quantity & pollutant parameters point the project quality (pH, solids, COD) life-cycle All parameters as per Consent to Operate
C.19 Waste water quantity & Volume estimate Basic At discharge Monthly during quality (Process water) pollutant parameters point the project life- (pH, solids, COD) cycle
All parameters as per Consent to Operate
C.20 Air emissions from PM, NOx, SOx, HC) Exhausts Twice in project vehicles based on emission lifecycle factors Visual Daily observation of Contractor emissions % of election, Case-to- vehicles possessing case if valid PUCC considerable Certificates emissions observed during operations C21 Fugitive emission of Visual observation of Near Daily during the dust during material dust in air by haziness transport entire project life- transport routes cycle C.22 Servicing schedule for Percentage of vehicles Site & Monthly during vehicles not complying with the approach drilling phase
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
servicing schedule road
C.23 Evacuation Procedures Arrangements for safe Nearby Once during shelters, evacuation villages / drilling phase routes and vehicles camp site workers C1 Ambient Air Quality Visual observation At Regularly Odour/smell surrounding Measurement of PM10, receptor SOx, NOx, CO, and points HC C2 Ambient noise quality Hearing / perception At Regularly Measurement of Noise surrounding Pressure Level in receptor dB(A) points
C3 Groundwater Quality Analysis of Parameters Nearby Regularly as per IS10500 wells C4 Quality of water Visual observation Nearby Regularly Analysis of Parameters Nalla, canal, as per CPCB Use-class
D : DECOMMISSIO I G / CLOSURE D.1 Noise pressure level in Near noise sources Site & Daily during dB(A) (5m) Approach decommissioning road D.2 Decommissioning Mass generated in kg At storage Daily during entire waste Storage & disposal point life-cycle of details (qty, method) within site project D.3 Spilled Chemicals/Oil Area of Spill / Quantity Site As and when spills Spilled / Severity of occur Spill / Characterization of Spilled Substances for Contaminants (Heavy Metals, Toxics, etc.) Storage & Disposal Details (Qty, Method) D.4 Air emissions from SPM, NOx, SOx, CO, Exhausts Once in project vehicles HC) based on emission lifecycle Daily factors Visual Contractor observation of Selection, Case- emissions (black to-case-if signifying more considerable pollution) emissions % of vehicles observed during possessing valid PUCC operations Certificates
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
D.5 Fugitive emission of Visual observation of Near Daily during the dust during transport of dust in air by haziness stockpiles entire project life- drilling facilities and cycle storages D.6 Fugitive emission of Visual observation of Near Daily during the dust during excavation dust in air by haziness stockpiles entire project life- of raised platform and cycle storages D.7 Site restoration Visual observation of : Site monthly during Clearing of restoration decommissioning waste levelling of site Relaying of top soil Regeneration of top soil
D1 Ambient noise quality Hearing / perception At Quarterly after Measurement of Noise surrounding decommissioning Pressure Level in receptor till 10 years dB(A) points D2 Quality of water Visual observation Nearby Quarterly after Analysis of Parameters river, canal decommissioning as per CPCB Use-class and ponds. till 10 years
D3 Ambient Air Quality Visual observation At Daily during Odour/smell (NOx) surrounding decommissioning Measurement of SPM, receptor Monthly after RPM, SOx, NOx, CO, points decommissioning using HVS till 10 years
D4 Soil Fertility Fertility parameters Site & Once after site like pH, NPK ratio, adjacent restoration Total Carbon, etc. areas
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
7. ADDITIO AL STUDIES
7.1 I TRODUCTIO ONGC has proposed 108 Developmental Drilling Locations in nine ML/NELP Blocks/fields of Cambay sub Asset, spread over Vadodara, Anand & Kheda Districts in Gujarat. The total Block Area is 820.82 km2. This chapter elucidates the Risk Assessment (RA), Disaster Management Plan (DMP) and Emergency Response Plan (ERP) for the proposed project.
7.2 RISK ASSESSME T Hydrocarbon Operations are generally hazardous in nature by virtue of intrinsic chemical properties of hydrocarbons or their temperature or pressure of operation or a combination of them. Fire, Explosion, Hazardous Release or a combination of these are the hazard associated with Hydrocarbon Operations. These have resulted in the development of more comprehensive, systematic and sophisticated methods of Safety Engineering such as Identification and Analysis of Hazards and Risk Assessment to improve upon the Integrity, Reliability and Safety of Hydrocarbon Operations.
The RA studies are based on Quantitative Risk assessment Analysis (QRA).Normally a three ‘levels’ risk assessment approach is adopted for the industrial activities. The risk assessment levels are generally consistent with the practices encountered through various assignments for medium and large chemical complexes. The brief outline of the three tier approach is given below:
A. Level 1 – Risk Screening The Top-Down Review of Worst- Case Potential Hazards/Risks, present in identifying Drilling Sites or location within Blocks is identified and listed, various screening factors considered include:
• Inventory of Hazardous Materials; • Hazardous Materials Properties; • Storage Conditions (e.g. Temperature and pressure); • Location Sensitivity (Distance to Residential Areas / Populace). • The Data/Information is obtained from Site. The results provide a relative indication of the extent of hazards and Potential for Risk Exposure.
B. Level 2 – Major Risk Survey (Semi Quantitative) The survey approach combines the Site Inspection with established Risk Assessment Techniques applied both Qualitative as well Quantitative Mode. The primary objective is to identify and select Major Risks at a specific Location in the Drilling Site considering possible soft spots / weak links during Operation / Maintenance. Aspects covered in the Risk usually include:
• Process Hazards;
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
• Process Safety Management Systems; • Fire Protection and Emergency Response Equipments and Programs; • Security Vulnerability; • Impact of Hazards Consequences (Equipment Damage, Injury, Fatalities etc..); • Qualitative Risk Identification of Scenarios Involving Hazardous Materials.
Risk Reduction Measures Selection of critical scenarios and their potential of damage provide means of prioritizing Mitigate Measures and allocate the resources to the areas with Highest Risks.
C. Level 3 – Quantitative Risk Assessment (Deterministic)
This is the stage of Assessment of Risks, associated with all Credible Hazards (scenarios) with potential to cause an undesirable outcome such as Human Injury, Fatality or Destruction of Property. The four basic elements include:
• Hazards Identification utilizing formal approach (Level 2, HAZOP etc.); • Frequency Analysis: Based on past Safety Data’s (incidents / accidents), identifying likely pathway of failures and quantifying the toxic / inflammable material release; • Hazards Analysis to quantify the consequences of various hazards scenarios (Fire and Explosion[due to uncontrolled release of NG/Crude], Toxic Vapour Release [due to release of H2S] etc.). Establish minimum value for damage (e.g. IDLH, Over Pressure, Radiation Flux) to assess the Impact on Environment. • Risk Quantification: Quantitative techniques are used considering effect / impact due to weather data, population data, and frequency of occurrences and likely hood of Ignition / Toxic release. Data are analyzed considering likely Damage (in terms of Injury / Fatality, Property Damage) each scenario is likely to cause. QRA provides a means to determine the relative significance of each of a number of undesired Events, allowing Analyst and the Team to focus their Risk Reduction Efforts, which will be most beneficial. Risk Screening Approach Some of the common hazards associated with the regular drilling operations are: • Fires and Explosions o Non-Process Hydrocarbon Leak (Diesel, lubricating Oil, etc.); o Non-Process Fire; o Control system failure including electrical failure in control room. • Impact and Collisions o Accidental Falling of Object from Crown Block. • Loss of Station Keeping / Loss of Stability o Structural Failure; o Equipment Failure. • External Hazards
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
o Failure due to Extreme Weather, Strong Winds, Earthquake and Sabotage etc.
These have resulted in the development of more comprehensive, systematic and sophisticated methods of Safety Engineering such as, Hazard Analysis and Risk Assessment to improve upon the Integrity, Reliability and Safety of Hydrocarbon Operations. The primary emphasis in Safety Engineering is to reduce Risk to Human Life and Environment. The broad tools attempt to minimize the chances of Accidents Occurring. Yet, there always exists, no matter how remote, that Small Probability of a Major Accident occurring. If the accident involves hydrocarbon in sufficient large quantities, the consequences may be serious to the project, to surrounding area and the population therein.
Drilling Rig floor is the centre stage of all the drilling operations and it is most Susceptible to accidents. Safety precaution with utmost care is required to be taken during drilling as per the Prevailing Regulations (Mines Act, Mines Rules, and Oil Mines Regulation) and Practices so that accidents can be avoided. Due to advancement in technology, number of equipments has been developed over a period to cater the need of smooth operation on Rig Floor. Various standards are required to be referred to cover the variety of equipments used for safe operation in drilling and it is desirable to use a properly prepared manual for occupational safety while working or drilling using a non land Rig. It may, however, be noted that Well Testing and Production Testing of hydrocarbons also require proper Analysis of Hazards involved in production testing operations and preparation of an appropriate Emergency Response Plan.
7.2.1 Identification of Hazards in Drilling and Production Testing Operations Various hazards associated with onshore hydrocarbon drilling and testing operations are briefly described in following sub-sections.
7.2.1.1 Minor Oil Spill Testing at Well Site: Drill Stem Testing leading to an Oil Spillage from Lines, Valves, Separator and Tank failure. During the well testing operation, there exists a possibility of Hydrocarbon (gases / oil) getting released due to some unavoidable incidents. Once the flow of Oil / Gas from well is stopped, then on-site access for clean-up is possible.
7.2.1.2 Major Oil Spill Significant hydrocarbon inventories will not be maintained at the rig. A major spill can, therefore, only arise as a result of an uncontrolled flow from a well i.e. Blowout. Provided that ignition does not take place and the well head is not obstructed the well can be shut in at the wellhead.
7.2.1.3 Blowout Blowout means uncontrolled violent escape of hydrocarbon fluids from a well. Blowout followed by ignition which prevents access to the wellhead is a major hazard. Contributors to blowout are: Primary • Failure to keep the hole full; • Mud weight too low; • Swabbing during trips; • Lost circulation; and • Failure of differential fill-up equipment.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Secondary
• Failure to detect and control a kick as quickly as possible; • Mechanical failure of BOP; • Failure to test BOP equipment properly; • Damage to or failure of wellhead equipment; • Failure of casing; and • Failure of formation or bond of cementing around casing. If the hydrostatic head exerted by the column of drilling fluid is allowed to drop below the formation pressure then formation fluids will enter the wellbore (this is known as a kick) and a potential blowout situation has developed. Fast and efficient action by operating personnel in recognizing the above situations and taking precautionary measure can avert a blowout.
Hydrogen Sulphide (H2S)
Hydrogen sulphide gas (H2S) is extremely toxic, even very low concentrations can be lethal, depending upon the duration of exposure. Without any warning, H2S may render victims unconscious and death can follow shortly afterwards.
The Occupational Safety and Health Act (OSHA Regulations) set a 10 ppm ceiling for an eight hourly continuous exposure (TWA limit), a 15 ppm concentration for Short Term Exposure Limit for 15minutes (STEL) and a Peak Exposure of 50 ppm for 10 minutes.
7.2.2 Proposed Development Drilling in 9ML/ ELP Onshore Block
108 Developmental Drilling Locations in nine ML Blocks/fields of Cambay Asset, spread over Vadodara, Anand & Kheda Districts in Gujrat. The total Block Area is 820.82 km2. The Geographical coordinates of the block are presented in Table 2.1 to Table 2.18.
The fuel for the drilling rigs, DG sets, other machineries and vehicles will be Diesel (HSD with low sulphur < 0.05%). Daily fuel requirement for diesel sets will be 6 KLD. The HSD storage will be limited to 30 KL. The exhaust stacks of the DG sets are likely to vent the emissions. The Bulk Hazardous Chemical Storage Facility at Drilling Site (Tentative) is given in Table 7.1.
Table 7.1 Bulk Hazardous Chemical Storage facility at Drilling Site (tentative) Compound Stored Quantity HSD (low Sulphur) 30 Kilo litter
7.2.3 QRA Approach Identification of hazards and likely scenarios (based on Level-1 and Level-2 activities) calls for detailed analysis of each scenario for Potential of Damage, Impact Area (may vary with Weather Conditions / Wind Direction) and Safety System in
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
place. Subsequently each incident is classified according to Relative Risk Classifications provided in Table below:
Table 7.2 Risk Classification
Stage Description High A failure which could reasonably be expected to occur within the (>1/100) expected life time of the plant. Examples of high failure likelihood are process leaks or single instrument or valve failures or a human error which could result in releases of hazardous materials. Moderate A failure or sequence of failures which has a low probability of (1/100 to occurrence within the expected lifetime of the plant. 1/1000) Examples of moderate likelihood are dual instrument or valve failures, combination of instrument failures and human errors, or single failures of small process lines or fittings. Low A failure or series of failures which have a very low probability (<1/1000) of occurrence within the expected lifetime of plant. Examples of ‘low’ likelihood are multiple instruments or valve failures or multiple human errors, or single spontaneous failures of tanks Minor Impact limited to the local area of the event with potent for Incidents ‘knock – on- events’ Serious One that could cause: Incident Any serious injury or fatality on/off site; Property damage of $ 1 million offsite or $ 5 million onsite. Extensive One that is five or more times worse than a serious incident. Incident
7.2.3.1 Damage due to Explosion
The explosion of oil or gas (either as a deflagration or detonation) results in a reaction front moving outwards from the ignition source preceded by a shock wave or pressure front. After the combustible material is consumed the reaction front terminates but the pressure wave continues its outward movement. [In oil exploration the likely chances of explosion (due to blow out and consequential release of NG/Crude) are very less] Blast damage is based on the determination of the peak overpressure resulting from the pressure wave impacting on the object or structure. Damage estimates based on overpressure are given in Table 7.3 below:
Table 7.3 Damage due to Overpressure Sl. Overpressure Damage o (bar) 1. 0.04 Loud Noise / sonic boom glass failure 2. 0.15 Typical pressure for glass failure 3. 0.5 – 1 Large and small windows usually shattered
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
4. 0.7 Minor damage to house structure 5. 1 Partial demolition of houses, made uninhabitable. 6. 2.3 Lower limit of serious structure damage 7. 5 – 7 Nearly complete destruction of houses 8. 9 Loaded train box wagons completely demolished 9. 10 Probable total destruction of houses 10. 200 Limits of crater lip
7.2.3.2 Thermal Incidents / Fire in Storage Area The diesel storage on the drilling site is limited to 30 KL. Any fire in the tank area if not controlled in time (less chances/ unlikely) may soon spread in the rig site. During blow out some Natural Gas coming out with some oil can also catch fire. However its thermal radiation impact (1st degree burn) will be limited (as the fuels are stored in remote place). Minor spill can occur as various scenarios and may also catch fire. If fire is not controlled these can lead to domino effect as major scenarios. During the drilling crude oil production will be nil or very limited; some well water may come out which can be treated and disposed off or pushed back in the nonproducing well. The likely impact due to major scenario considered as given below in Table 7.4.
Table 7.4: Possible Major Scenarios
S. Scenario Impact Zone Remarks o. 1. HSD Tank failure, spillage & ~ 8.5 From edge of pool Fire (~ 5 m Pool fire)
The impact due to the above scenarios will be within the block. It may have some impact on the nearby vegetation but will not have any impact on local population.
H2S and Its Effects
Important characteristics of H2S gas are given as below:
• H2S is a toxic colourless gas heavier than air. • It has an odour of rotten eggs but see ‘point 6’ below. • In concentrations greater than 100 ppm, it will cause loss of senses in 3 to 15 minutes and death within 48 hours. • In concentrations greater than 600 ppm death occurs in less than 2 minutes. • The safe concentration for a normal working period without protection is 10 ppm. • In concentration greater than 10 ppm, the Olfactory Nervessense to smell the gas is lost, the need for detectors is apparent.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
• It attacks the body through the respiratory organs. • It dissolves in the blood and attacks through the nervous system. • It is very irritating for the eyes as it forms sulphurous acid together with water. • The Occupational Safety and Health Act (OSHA) sets a 10 ppm ceiling for an 8 (eight) hour continuous exposure (TWA limit), a limit of 15 ppm for short term exposure limit for 15 minutes (STEL) and a peak exposure concentration of 50 ppm for 10 minutes. • The best protection is breathing apparatus, with mask covering the whole face and a bottle containing breathing air. • It burns with a blue flame to sulphur dioxide which is almost as dangerous as H2S. • It forms an explosive mixture with air at concentrations from 4% to 46%. • Short exposure of high tensile steel to as little as 1 ppm in aqueous solution can cause failures. • Concentrations greater than 15 ppm can cause failure to steel harder than Rockwell C-22. High stress levels and corrosive environments accelerate failures. • When pH is above 9 and solubility is relatively high, it is readily soluble in mud and especially in oil mud’s. • The compressibility factor (Z) is higher than that for natural gas and H2S will thus expand at rather lower pressures; or further up in the bore hole than natural gas. • A 35% hydrogen peroxide solution will neutralize H2S gas in the mud or 20 gallons of H2O2 per 100 barrels of mud. • It occurs together with natural gas in all oil provinces of the world. • In characteristic H2S gas areas concentration above 42% in natural gas have been reported. • Coughing, eye burning and pain, throat irritation, and sleepiness are observed from exposure to low concentrations of H2S. • Exposure to high concentrations of H2S produces systems such as panting, pallor, cramps, paralysis of the pupil and loss of speech. This is generally followed by immediate loss of consciousness. Death may occur quickly from respiratory and cardiac paralysis. The effect of H2S concentration on Living Being/Human Being & Animal is given in Table 7.5.
Table 7.5: H2S Effects on Living Being/Human Being & Animal
H2S Effect on Living Being/Human Being & Animal Concentration <10 ppm Safe for normal Working Period, without protection. >10 ppm Effect on Olfactory Nerves, resulting Sense to Smell is Lost. >100 ppm Loss of sense within 3 to 15 Minutes Death within 48 Hours >600 ppm Death within Less Than 2 Minutes (Immediate)
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
7.2.4 Mitigation Measures
7.2.4.1 Control Measures for Major Hazards
Out of different hazards described in sections 6.2, occurrence of (a) Blowout and (b)
Emission of Sour Gas (H2S) are the two major hazards and (c) HSD spillage/ fire is a minor one which is very unlikely to occur. The first two possible incidents can have built in alarm and preventive measures (as more likely to occur if system fails). The third incident has remote chances and more likely due to some domino effect caused
by other incident. Occurrence of H2S along with oil and gas, if detected in any new well, is the major hazard during production testing of each well. Control measures for
occurrence of blowout and Emission or Leakage of H2S gas are discussed in following sub-sections.
Blowout
The precautionary and control measures used for blowout prevention are discussed below:
A. Precaution against Blowout
(i) The following control equipments for Drilling Mud System shall be installed and kept in use during Drilling Operations to prevent the Blowout:
• A Tank Level Indicator registering increase or reduction in the Drilling Mud Volume and shall include a visual and audio –warning device near the Driller Stand. • A device to accurately measure the volume of Mud required to keep the well filled at all times. • A Gas Detector or Explosimeter at the Primary Shale Shaker and connected to audible or visual alarm near the Driller Stand. • A device to ensure filling of well with Mud when the string is being pulled out. • A control device near driller stand to stop the Mud Pump when well kicks.
(ii) BOP Drill shall be carried out as per OMR & OISD. (iii) BOP Control Unit shall be kept available near the well which can be used to close the well fully/partially in case of emergency to control the well. (iv) When runningin or pullingout tubing, Full Opening Safety Valve (FOSV) shall be kept readily available at rig floor.
B. Precaution after Blowout
On appearance of any sign indicating the Blowout of well, all persons, other than those whose presence is deemed necessary for Controlling Blowout, shall be withdrawn from the Well.
During the whole time while any work of Controlling a Blowout is in progress, the following precautions shall be taken:
(i) A competent person shall be present on the spot throughout.
(ii) An area within the 500 meters of the well on the down wind direction shall be demarcated as
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Danger Zone. • All Electrical Installations shall be de-energized. • Approved Safety Lamps or torches shall only be used within the Danger Zone. • No Naked Light or Vehicular Traffic shall be permitted within the Danger Zone. (iii)A competent person shall ascertain the condition of ventilation and presence of gases with an approved instrument as far as Safety of persons is concerned. (iv) There shall be available at or near the place, two approved type of self containing Breathing Apparatus or any other Breathing Apparatus of approved type for use in emergency. (v) Adequate Firefighting Equipment shall be kept readily available for immediate use.
Control Measures for H2S Leakage/Emission during Drilling
The following control measures for H2S will become necessary if presence of H2S is detected at any new well.
A. H2S Detection System Presence A four channels H2S gas detection system should be provided. Sensors should be positioned at optimum points for detection, actual locations being decided on site but likely to be: • Just above Riser/Flow Nipple • Shale shaker The detection system should be connected to an Audio Visual (Siren and Lights) Alarm system. This system should be set to be activated at a concentration of 15 ppm H2S. The Mud Logging will have a completely independent Detection System which is connected to an alarm in the cabin. This system will be adjusted to sound an Alarm at a concentration level of 10 ppm H2S as suggested in the Drilling and Production Safety Code for Onshore Operations issued by The Institute of Petroleum.
A stock of H2S scavenger will be kept at drilling site for emergency use.
B. Small Levels of H2S
Small levels of H2S (less than 10 ppm) will not activate the well site alarms. Such levels do not create an immediate safety hazard but could be a first indication of high levels of H2S to follow.
H2S will cause a sudden drop of mud pH. The Mud Engineer/Mud Services will therefore organize and supervise continuous pH checks while drilling. Checks should be as frequent as possible and always made following a formation change. Following control measures will be taken in case of small level of detection:
• Add H2S scavenger to mud. • Check H2S levels at regular intervals for possible increase. • Inform all personnel of the rig about the presence of H2S and current wind direction. • Commence operations in pairs. • Render sub base and cellar out-of-bounds without further checking levels in this
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
area.
C. High Levels of H2S
Higher levels of H2S (greater than 10 ppm) do not necessarily cause an immediate safety hazard. However some risk does exist and, therefore, any levels greater than 10 ppm should be treated in the same manner. Occurrence of 10 ppm or more H2S concentration will sound an alarm in the mud logging unit.
If higher levels of H2S (greater than 10 ppm) are found, following steps will be taken:
• Driller to Shut Down Rotary, pick up Kelly, close BOP and Shut Down Pump. • One pre-assigned roughneck will go to doghouse and put on breathing apparatus. All other Rig Personnel will evacuate the rig and move in Up-Wind direction to Designated Muster Point.
• Driller and roughneck will return to the rig floor and commence circulating H2S scavenger slowly and reciprocating pipe.
• The level of H2S will be checked in all work areas. H2S Scavenger will be added to the Mud and circulated. If H2S levels drop, drilling will be continued with scavenger in the mud. Approximately 30 % of hydrogen peroxide (H2O2) solution will neutralize H2S gas in the mud at 20 gallon of H2O2 per 100 barrels of mud.
Fire Fighting Facility
Fixed Fire Fighting System as per Oil Industry Safety Directorate (OISD) Standard 189 should be in place.
Fire Water System
• One water tank/pit of minimum capacity of 40m3should be located at the Drilling Rig Site. • For production testing, one additional tank of 40m3should be provided. • One diesel engine driven trailer fire pump of capacity 1800 lpm should be placed at the approach area of drilling site. • One fire water distribution single line with minimum 4 “ size pipe/casing should be installed at drilling site with a minimum distance of 15 m from the well.
First Aid Fire Fighting Equipments at Drilling Rig
Portable Fire Extinguisher will be installed as per IS: 2190 on the Drilling Rig. The minimum quantities of fire extinguishers at various locations should be provides as per the following (Table 7.6).
Table 7.6 Fire Extinguishers Distribution
Sl. Type of Area Portable Fire Extinguishers o. 1. Drilling Rig floor 2 nos. 10 kg DCP type Extinguisher
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
2. Main Engine Area 1 no. 10 kg DCP type Extinguisher for each engine 3. Electrical motor/pumps 1 no. 10 kg DCP type Extinguisher for water circulation for mud pump 4. Mud Gunning Pump 1 no.10 kg DCP type Extinguisher
5. Electrical Control Room 1 no. 6.8 kg CO2 type Extinguisher for each unit 6. Mud mixing tank area 1 no. 10 kg DCP type Extinguisher 7. Diesel Storage Area 1 no. 50 lit mechanical foam 1 no. 50 kg DCP type Extinguisher 2 nos. 10 kg DCP type Extinguisher 2 nos. sand bucket or ½ sand drum with spade 8. Lube Storage Area 1 no. 10 kg DCP type Extinguisher 1 no. sand bucket 9. Air Compressor area 1 no. 10 kg DCP type Extinguisher 10. Fire Pump Area 1 no. 10 kg DCP type Extinguisher 11. Near Dilling In-charge One fire extinguisher/shed with 3 nos. 10 kg DCP Office type extinguisher and 2 sand buckets 12. Fire bell near Bunk House 1 no. 10 kg DCP type Extinguisher
7.2.5 Occupational Health
Occupational hazards associated with onshore drilling include exposure to hazardous substances, noise, vibrations, heavy manual handling activity at the site etc. At Drill Site qualified doctor is available 24 hrs on the Drilling Rig for the Immediate Treatment and First Aid. For serious injuries and diseases patient is evacuated by the Emergency Vehicles exclusively meant for Emergencies to the Nearest Medical Center. Health Hazard Control is done by adopting following measures:
• Prioritize the health hazards based on their risk potential. • Identify specific work groups affected by each hazard. • Determine the controls required to manage these identified hazards. The cost of each identified control versus benefits of its implementation may be evaluated. • Develop an action plan identifying work to be done. The health and hygiene of the personnel working at the Drilling Rig for long period will be monitored through periodic health checks of the persons. All employees undergo a periodic medical examination. The record of the health check-up will be maintained centrally off site in confidential file by the medical section. The medical officer at base recommends appropriate treatment for the persons found to be having any Health Problems requiring attention. During the proposed Drilling Operations, inspections of cleanliness are carried out. First aid boxes are provided at different strategic locations on the drilling rig. The
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
medical officer on board shall regularly inspect the First Aid Boxes and ensures that their contents are in order. Majority of the employees on the drilling rig are trained in First Aid. Regular Drills and Lectures on First Aid are carried out at the Rig. Occupational Health Surveillance Program is summarized in Table 7.7. Table 7.7 Occupational Health hazards and mitigating measures Cause of health hazard Risk Mitigation Measures Noise (Generators, Cranes, Hearing loss Use of PPEs in high noise Rig, Movement of Vehicles, area and written Standards etc) Operating Handling of heavy equipment Back problem Procedures(SOP)to be and material (Manual followed. handling of material) Procedures to be followed Handling of chemicals Eye problems and as per Material Safety (Chemical stores, Chemical chemical ingestion, Data Sheet(MSDS) of all dosing areas, Chemical labs, Dermal effect of hazardous chemicals for etc) chemicals safe handling.
7.2.6 Frequency of Occurrence of Accident Scenario Frequency of Occurrence of incident is important in risk analysis. Standards Operating Procedures (SOP), Proper Maintenance and Safety Precaution reduce the Frequency of occurrence of such Incident. The data sources referred for failure frequency is E&P Forum (Oil Industry International Exploration & Production Forum) frequency data base from TNO and Failure Frequency Data from the Rajmond Report (COVO study). The frequency occurrences for various scenarios are given below in Table 7.8.
Table 7.8: Frequency occurrence for various accidents scenarios Sl. Scenarios Frequency of o. Occurrence 1. Catastrophic failure of largest 1/1,000,000 per tank per year nozzle connection in HSD tank Probability of Ignition • Immediate Ignition 65/1000 • Delayed Ignition 65/1000 • No Ignition 87/100 2. Catastrophic failure of Tank 67/1,00,00,000 per tank per year Safety precaution, proper maintenance of equipments and risk mitigation measures adopted in storage and handling of inflammable materials will reduce the probability of occurrence of hazardous incident.
Precautionary Sensors Installation: • Hydrocarbon vapour Concentration Detector should be installed at some critical. Lower Flammability Limits (LFL) for some gaseous hydrocarbons are as under Compound LFL (% in air) Methane 5.0 Ethane 3.0
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Propane 2.1 Butane 1.6
• Smoke sensors and thermal detectors are to be installed at Strategic Locations on the Rig. These Sensors with caution and alert the rig crew in case of any abnormality present in the site to take immediate remedial action.
7.3 DISASTER MA AGEME T PLA For meeting the emergencies caused by major accidents, planning response strategies are termed as Disaster Management Plans (DMPs). DMPs cannot be considered in isolation or act as a substitute for maintaining good safety standards at a project site. The best way to protect against major accidents occurrence is by maintaining very high levels of safety standards. The Offsite & Onsite Disaster Management Plan (DMP) and Emergency Response Plan (ERP) are available for existing facilities in the proposed ML/NELP Blocks, which are also extended to proposed activities. The scope of the DMP On-site Emergency Preparedness Plan is to evaluate the various types of emergencies that can occur at Oil Installations (Drilling and Production activities) and to formulate emergency plans, procedures that can be implemented by ONGC in house. In case the contingency exceed in dimension beyond ONGC’s capability, the off-site Emergency plan shall be activated concurrently with the help of District administration. In Anand, Kheda, Vadodara Districts, following oil installations are established. • Group Gathering Station – Anand, Padra. • Early Production System – Akholjuni, Chaklasi. As per the need drilling rigs and work over rigs are deployed for operational purpose near by the installation mentioned above.
7.3.1 Statutory Requirements 1. Oil Mines Regulation, 1984 of Mines Act 1952 Contingency plan for Fire shall be prepared for any oil installation – OMR 72. 2. Environment Protection act and the rules: In exercise of the provisions under the Environment Protection Act 1986, the ‘Manufacture, Storage and Import of Hazardous Chemicals Rules’ came into force in November 1989. Under these rules, ‘Preparation of On-site Emergency Plan’ is covered in Rule No.13 and ‘Preparation of Off-site Emergency Plan’ in Rule No.14,
7.3.2 ature of Emergencies
In ONGC, have three tiers of Emergency Preparedness at Work centers: 1. A unit specific emergency (ERP): A unit specific emergency response plan is a plan prepared by every unit considering the emergency scenarios envisaged in the risk
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
register. In case of emergency respective installation activates emergency response plan (ERP) and the emergency is mitigated with the facilities available within the installation. The ERP is activated by the Installation Manager. 2. On site emergency (On site DMP): The On-site Disaster Management plan is activated in case the emergency requires mobilization of resources from the other units / Asset. This plan is activated by the Chief Emergency Coordinator (CEC). Asset Manager of Cambay Asset is the CEC at Asset level and will exercise control through the Asset Emergency Control Room (ECR). 3. Off site emergency (off site DMP): The off-site disaster management plan will be put into action in the following situations
i) In case of an Onsite emergency spreads beyond the boundary of installation and causes damage to the life or property outside the boundary. ii) In case an emergency originated from outside the premises of the installation/Drilling Rig/Work over Rig which is likely to effect the operations of installation. The off-site emergency requires mobilization of resources beyond ONGC capabilities such as TNFS and other government agencies.
7.3.3 Onsite Emergency Organization
The Asset Manager, Cambay Asset is head of the On-site emergency organization and is designated as the Chief Emergency Coordinator (CEC) at Asset level. He will exercise control through the Asset Emergency Control Room (ECR). The CEC is assisted by an expert team drawn from various disciplines.
The Chief emergency coordinator will assume control through the Assistant Emergency Coordinator (AEC). The emergency coordinator (CEC) may appoint Surface Manager / Head Drilling Services / Head Well Services as Assistant Emergency Coordinator (AEC).
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.1 Onsite Emergency Organization 7.3.3.1 Functions & Responsibilities of Various Coordinators The specified functions and responsibilities of the different coordinators are elaborated. These are the emergency functions and therefore the normal time functions become void. All the coordinators will assume their emergency roles immediately without any time lag. Chief Emergency Coordinator (CEC): Sub Asset Manager will be the Chief Emergency Coordinator for all the Emergency Management activities at the Emergency Control Centre located at Base office Cambay Sub Asset.
• Establish a control centre and will be In-charge of the entire on-site emergency operation. • Passing on information to relevant persons and agencies and also warning and advising people who are likely to be affected. • Convene an emergency meeting of all coordinators to discuss issues such as Rescue operations, Evacuation, Mobilizing the foods and also plans to augment the manpower.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
• Get feedback from all coordinators on the latest developments, other information and requirements at frequent intervals to decide on the future course of action. • Arrange to operate Mutual Aid Scheme through I/C HSE. In case of Major Fire / Explosion he has to get mobilized force and appliance from State / Municipal Fire Service. • In case On-site emergency is escalating and speeding to an off-site emergency, the matter to be informed to the District Collector to enable them trigger off-site emergency plan activities to combat emergency. Assistant Emergency Coordinator (AEC): In case of an emergency in production operations, the I?C Surface Team will assume the responsibilities of AEC. He will work under the orders of CEC. The responsibilities are:
• Assessment of the gravity of the situation and to declare the state of emergency • Establishment of Site Control Room (SCR) • Mobilization of resources • Control of logistic support • Control of rescue operations • Supervision of Medical attention to injured • Oversees all situation reports • Organizes all Post emergency operations On-Scene Coordinator (OSC): The senior most person or the Installation Manager will assume the role of OSC, unless otherwise directed. In case of abandoning the installation in distress, the In-charge of the nearest Installation will take over the role of OSC. CEC may also appoint a person from base to take over the task of OSC at Site Control Room. On-scene coordinator is the key person in emergency situation. After receiving the message, shall reach the spot immediately.
• He will take control of Fire Fighting operation / damage control measures till the arrival of Incharge Fire. • In coordination with Incharge Fire, arrange to take all steps to control emergency situation. • Closely monitor the emergency situation and change action plan as per need. • In case of Major / Serious Emergency arrange to blow all clear siren when the emergency situation is under control. Key Personnel: Key personnel for respective services, depending upon the nature of the emergency shall arrive at the site to take charge of their respective positions such as Logistics Coordinator, Safety (HSE) Coordinator, Fire Coordinator, Finance Coordinator, Medical Coordinator, Communication Coordinator etc. 7.3.3.2 Emergency Control Room (ECR) at Base office An emergency control room (ECR) will be set up at base office in radio room under the control of Chief Emergency coordinator (CEC). Management decisions and plans will be conveyed from ECR to emergency site by AEC. From Site Control Room (SCR) all developments at emergency site will be communicated to ECR at base.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
7.3.3.3 Responding to an Emergency The procedures for combating emergency situations viz. Blowout at a rig, release of toxic gases in an uncontrolled manner, fire or explosion are defined as emergency procedures. There are written laid out action sequences to be followed while fighting an emergency. 1. A person who detects say a fire, an explosion or a leak of hazardous gas should shout “Fire, Fire, Fire” Help, Emergency as applicable” and communicate the event to the people all around and to Shift I/C by using fire alarm / bell. 2. Should attempt to control or contain the emergency with the available resource if possible. 3. The emergency actions are put into action immediately by the Shift In-charge / Tool Pusher / Rig Manager, who then assumes the role of On Scene Coordinator (OSC). He then accesses the nature of emergency and informs AEC regarding requirement of crisis management team if any to mitigate the emergency. 4. The “Crisis Management Team” arrives at the scene and joins hands with the site crew, other supporting team to further combat the crisis under the guidance of the OSC and AEC. 5. A buddy team is created from the available manpower and kept as standby to the main team. Assembly point At every drill site/Installation, assembly point is identified as Safe Assembling point during an emergency. People working in the field and who do not have any direct role in Emergency Situation will quickly assemble here and wait for any instructions from the OSC or AEC.
Emergency procedures in the event of blowout A blow out situation is a consequence of uncontrolled flow of oil / gas and there is every likelihood of fire being triggered off. To tackle such an emergency situation the flow of action can be divided into following two steps. Step - I : Action on the spot - On-site. Step - II : Action of Asset in co-ordination with Basin. The various functions with regard to these steps have been elaborated in the form of action flow sequences and kick control procedures. With a view to avoid overlapping of functions, the various actions required to be taken during a blowout have been identified and the personnel responsible for taking actions have been specified. The position of blowout well being different in different cases the exact action plan of work to control the blowout spill / blowout fire and for capping of the well would be finalized by competent authorities of the Asset / Basin / Headquarters.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Functions of On-Scene Coordinator (OSC) Take charge of the situation at the rig and follow the standing instruction given below
• Evacuate all personnel to safe site. • Switch off engines and generators. • Remove and secure all well records. • Avoid and extinguish all naked flames / sparks. • Pull out all inflammable materials i.e. HSD, Petrol, Gas Cylinders, Chemicals etc. from well premises. • Pull out all possible equipments to safe distance. • Start spraying water on well mouth to keep it cool. • Cordon off the area and do not allow entry of any unauthorized person. Allow only the persons directly involved in operations to go near blowout well and maintain record of such persons. • Intimate Emergency Control Room (ECR) at base for deployment of additional manpower, materials, logistics / transport arrangements and technical support if any. • Keep in touch with ECR through Site Control Room (SCR) for update, feedback and instructions from base. • Assign responsibilities to the concerned persons to control the situation. • Evacuate all equipments and materials to safe location if required. Make record of following information for forwarding to Emergency Control Room (ECR) at base:
• Well condition. • Position of drill string / Tubing string in the well. • Last tubing and annulus pressure recorded. • Number, Name and Designation of persons at site, measures initiated to meet the situation, details of injury / casualty, if any.
Emergency procedure for Control of Kick A kick during drilling or work over operations is an event preceding a blowout. A blowout situation is never sudden and almost always follows after several indications or pointers. A kick is sudden outflow or upsurge of the drilling mud or work over fluid due to unexpected encountering of a gas zone or high pressure fluids, which throws out the fluids upwards out of the well bore. The kick of the out flowing fluid needs immediate remedial attention lest it assumes a more dangerous form of blowout. The remedial action by the crew and the kick control procedures are elaborated below.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Duty guidelines for Rig operational crew All operations will be carried out under the control and guidance of the Shift In- charge / Tool Pusher, who then functions as the OSC. When a kick is detected, the Shift In-charge will give a signal and all members of the crew will take up their respective positions. The signals will be in the form of short sirens in a continuous manner from the driller’s console.
Stand on brake and control as necessary. Supervise all activities to control the situation. SHIFT IN- Ensure functioning of BOP and choke manifold lines. CHARGE Ensure help is provided to Chemist in order to maintain mud (SIC) parameters as directed by authorities. Ensure safe removal of records, men and materials to safe and secure place. Be available at control panel of BOP to operate as per direction of RM / SIC / AE(D) / AEE(D) and the guidelines issued to close BOP, install Kelly cock etc. Keep watch on pressure on discharge line, stand pipe and annulus pressure and increase in mud volume in the pit / tanks. Help Chemist in preparation of mud and maintaining mud ASSISTANT parameters as required. SIC Ensure operation of degassing unit, if any. Also keep watch for rise in mud level in the suction tank. Work on choke line / kill line of BOP. - Keep watch on the float in the mud pit for loss or gain of mud and inform SIC the status and request SIC to alert site personnel of impending danger. TOP MEN Both of them will work on choke-line and valves. They will help the SIC in fitting NRV / Kelly etc. and will be RIG MEN available at derrick floor. RIG ENGINEER To be near the engine waiting for directives from SIC. (M) FITTER To be available near the pump and will give pump connection as and when advised by SIC / Chemist. RIG To be available near BOP panel board and will attend ENGINEER electrical work if any needed for charging the accumulators. (E) To liaison with SIC and calculate kill mud weight as per available data and take necessary steps to prepare mud as per CHEMIST requirement. It must be ensured however, it should be checked at the time of kick control and SIC should be informed of condition. GEOLOGIST To keep contact with the SIC and keep him abreast of possible
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
reservoir condition and convey the data recorded at Mud Logging Unit. To see that no unauthorized person enter the site. He should SECURITY remain at the drill site and not allow the villagers to assemble GUARD near the gate. He should ensure that there is no open fire nearby. To assemble near the bunk house or storehouse within full view of SIC so that any of them is summoned by SIC at the OTHERS time of need. They should also ensure that there is no open fire at the site and nearby area.
After above mentioned steps are completed, all lines, valves, closed position of BOP are to be inspected by shift In-charge and certified.
Well Kick Shut in procedure for On Land and Jack up Rigs
A well kick shut in procedure for On-land and Jack up rigs as listed below is adopted from OISD STD 174
i) Shut in procedure while drilling 1. Stop rotary 2. Pick up Kelly to clear tool joint above rotary table. 3. Stop mud pump, check for self-flow. If yes, proceed further to close the well by any of the following methods for shut in the well as shown in Table 7.9.
Table 7.9 Shut in Procedure while Drilling
Sl. Soft Shut – in Hard Shut – in o. 1. Open hydraulic control valve Close Blow out Preventer. (HCR valve) / manual valve on (Preferably Annular Preventer) choke line. 2. Close Blowout Preventer. Open HCR/Manual valve on choke line when choke is in fully closed position. 3. Gradually close adjustable Allow pressure to stabilize and /remotely operated choke, record SIDPP, SICP and Pit Gain. monitoring casing pressure. 4. Allow the pressure to stabilize ------and record SIDPP, SICP and Pit gain.
SIDPP – Shut In Drill Pipe Pressure SICP – Shut In Casing Pressure FOSV - Full Opening Safety Valve
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
ii) Shut in procedure while tripping 1. Position tool joint above rotary table and set pipe on slips. 2. Install Full Opening Safety Valve(FOSV) in open position on the drill pipe and close it. Following methods are recommended for shut-in the well as shown in Table 7.10.
Table 7.10 Shut in Procedure while Tripping
Sl. Soft Shut – in Hard Shut – in o. 1. Open hydraulic control valve (HCR valve)/ Close Blow out Preventer. manual valve on choke line. (Preferably Annular Preventer) 2. Close Blowout Preventer. (Preferably Make up Kelly and open Annular Preventer) FOSV. 3. Gradually close adjustable/ remotely Open HCR/Manual valve on operated choke, monitoring casing pressure. choke line when choke is in fully closed position. 4. Make up Kelly and open FOSV Allow pressure to stabilize and record SIDPP, SICP and Pit Gain. 5. Allow the pressure to stabilize and record ------SIDPP, SICP and Pit gain. 1. Shut in procedure when string is out of hole 2. Close blind/shear ram. 3. Close adjustable/remotely operated choke and open HCR valve. 4. Record shut in pressure.
7.3.4 OFFSITE EMERGE CY PLA The OFF-SITE Emergency Plan for Padra GGS, Kathana GGS and Akholjuni EPS of ONGC, Cambay Sub Asset is a compilation of various emergency scenarios. It also includes the probable impact on ‘off the site’ due to emergency and the action plan to combat / mitigate the consequences of a disaster situation. Quantity of Crude oil (Hazardous substance) which is being handled by EPS is much less than the threshold quantity specified in manufacture storage and import of hazardous chemicals Rules, 1989.
The risk analysis study was conducted by Institute of Engineering and Ocean Technology (IEOT), ONGC, Panvel, to assess the potentiality of impact due to various mishaps at the installations. The case study of GGS is as below:
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Table 7.11 Flammable Hazard Distances: GGS
Sl. Facility Radiation level o 4.5 KW/m2 12.5 KW/m2 37.5 KW/m2 . S M L S M L S M L 1 Storage Tank 11 35m 35m 9m 18m 18 4m 9m 9m m m 2 Separator No.1 - 46m 93m - 42m 77 - 38 67 m m m 3 Separator No.2 24 45m 54m 19m 27m 34 - - 10 m m m
7.3.4.1 Assessment of Hazard leading to Off Site Emergency
GGS and EPS of ONGC are vital installations of Cambay Sub Asset. The crude oil produced from these installations is transported to Gujarat Refinery through trunk lines and tankers. The equipments at the installation mainly consist of separators, storage tanks and oil dispatch pumps. Crude oil is always stored in bulk. Fire is the most common hazard in a Crude Oil and Natural Gas processing operations and there are also possibilities of explosion and toxic gas dispersion which can arise due to the severe operating and storage conditions. Any incident of the above nature is likely to cause extensive damage to the plant property and personnel.
Disaster situation arising out of the hazards encountered in the above mentioned installations is normally not expected to affect beyond 200m. An estimated maximum area within 1.0 - 1.5 Km radius can be considered for declaration as emergency or danger zone.
Outside the premises of the these installations, environmental hazards are likely to occur due to the leakage / bursting of either trunk pipeline or flow lines from wells and flaring of natural gas.
Hazard in Flow Lines: A pipeline connecting one installation to another installation is termed as a trunk line while a pipeline connecting hydrocarbon well to the installation is called as a flow line.
The trunk line of 65.5 km length, 10” dia. carries Crude oil from EPS Akholjuni to GGS Kathana to Padra GGS to Laxmipura. The trunk pipeline and almost all the well flow lines pass through the paddy/Wheat/Tobacco fields. The trunk and flow lines are sub-surface pipelines and are laid 1.2 m below the ground level. Due care has been taken during laying of trunk and flow lines. As far as possible laying of pipeline is avoided in populated area. The main risk in transportation of oil / gas through pipeline is leakage of oil / gas which may result in fire if source of ignition is present. Once, detected, the emergency procedure will be activated and remedial action will be
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
taken to control the leak, spread of fire etc. Moreover, no major evacuation is required as pipelines are passing through non populated areas.
Hazard in Transportation of Condensate by Tankers: The crude oil is transported through road tankers from various isolated installations within the Asset to GGS Kathana and GGS Padra & Akholjuni EPS. There is a chance of oil spill due to overturning or collision of tankers. In this case, a small quantity of crude oil is likely to be spilled. When an emergency arises the nearby police station may be contacted to cordon off the affected area and all sources of ignition are removed to safe distance to avoid fire. Nearby public is instructed not to light any source of ignition. Efforts should be made to stop the flow of oil into nearby water bodies to avoid water contamination.
Disaster due to Man made causes (Terrorist attack)
Other than above technical and operational hazards ONGC units also poses disasters due to man-made causes such as Terrorist attack, Bomb threats. The action plan for these scenarios is as below:
i) IED Attack
Primary rule
If a suspected device is encountered, it should not be handled and the area should be secured. Improvised explosive devices are very unstable. They are extremely sensitive to shock, friction, impact, and heat, and may detonate without warning. Even the smallest devices can cause serious injury or death.
Secondary rule
Always assume that there is more than one device present, whether any other bomb or a device has been located.
Package-type IEDs: Institute security procedures in receipt and dispatch section and instruct employees on how to recognize suspicious packages.
Luggage-type IEDs: Train security personnel and employees regarding unattended packages of any type. Never pick up or open any suspicious package or piece of luggage. If an IED is discovered, call the police and do not touch the device.
Vehicle-borne IEDs: Perform a vulnerability/threat assessment for the facility with special attention to this type of explosive delivery mechanism. Consider the use of enhanced security away from your key buildings (such as a vehicle checkpoint) or the use of bullards or barriers to block vehicular access to building entrances.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
ii) Chemical Attacks
A chemical emergency occurs when a hazardous chemical has been released and has the possibility of harming people’s health. Potentially lethal, chemical agents are difficult to deliver in deadly amounts. If released outdoors, the agents often dissipate rapidly. As such, the most lethal area for a chemical release is inside a confined space, such as a building, public place, or subway system.
Industrial chemicals, while not as lethal, can be just as effective if released in sufficient quantities. Chlorine, ammonia, benzene, and other toxic chemicals are routinely transported through densely populated areas in rail tankers or truck tankers and could be the target of a terrorist attack.
Chemical terrorist attacks will most likely be overt because the effects of most chemical agents are immediate and obvious. Your response will have to be thought out and practiced in advance to be effective.
Evacuation
Some types of chemical emergencies will require evacuation from the immediate area. If you are up-wind and in the open, evacuate up-wind and away from the incident. Cover your mouth and nose with a damp cloth. If you have been exposed, you will have to be decontaminated by first responders.
Shelter in Place
If you are already in down-wind and/or in a multistory building, you may be instructed to shelter in place or to make that decision on your own. Most likely you will only need to shelter for a few hours. The procedure includes:
• Go inside as quickly as possible shut and lock all windows and doors; turn off all HVAC equipment and any fans. • If you have multiple floors, go as high as practical, three to five floors. (Most chemical agents are heavier than air.) • If you have duct tape, tape over door and window • cracks, vents, electrical outlets, and any opening to the outside. • Wait for instructions from first responders before leaving.
iii) Biological Attacks
A bio-terrorist attack could happen in any workplace, yet most company personnel know little about potential bio-toxins or bio-pathogens or how to recognize these agents and respond in the event of an attack.
There are several ways a bio-terrorist event may manifest itself. The biological event may result from a covert attack. A covert attack may be unleashed by the receipt of an object, such as a package or piece of mail, accompanied by a warning or threat. For example, release of a biological agent could occur through delivery of a package
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
contaminated with anthrax spores or another pathogen. Biological agent release also could occur via the ventilation system (HVAC) in a building, where dispersal could take place within a matter of minutes. Because the covert release is not witnessed, the effects of such an event can be widespread and difficult to isolate or recognize.
While terror is intended to produce casualties, disruption, and fear, the use of biological agents is particularly injurious. Biological attacks are delayed events. The sudden appearance of generalized symptoms in victims who present themselves to medical providers may initially disguise the true source of exposure. Only when a trickle of patients turns into a flood or mysterious pathogens quickly make their presence felt does the magnitude of the event reveal itself.
The goal of the medical care community (i.e., hospitals, physicians, and other health care providers) is to recognize and diagnose the disease (which frequently may be unfamiliar to most clinicians) and to provide treatment. The goal of public health authorities is to detect and control the outbreak of the illness. Public health officials will focus on identifying and treating exposed persons and preventing the spread of disease.
In response to a covert release, it is important for ONGC health officials to recognize the signs and symptoms of an emerging disease among employees. If an overt release is recognized, take immediate action to isolate the exposed employees and/or area of agent dispersion and to remove others from the area of release. Notify local public health authorities immediately and follow their directions. Decontamination may also be warranted in response to an overt release.
iv) Radiological Attacks
A radiological weapon or “dirty bomb” is a crude device that combines a conventional explosive with highly radioactive material. When detonated, the blast vaporizes the radioactive material and propels it across a wide area.
The main danger from a dirty bomb is the initial blast, which could cause serious injury or property damage. The radioactive materials will likely not be concentrated enough to cause immediate serious illness, except to those very close to the blast site or those who inhale smoke and dust. Dirty bombs are designed to cause tremendous psychological damage by exploiting the public’s fear of radiation. These are not weapons of mass destruction, but weapons of mass disruption aimed at wreaking economic havoc by making target areas uninhabitable for extended periods.
There are three basic ways to reduce your exposure:
1. Reduce the time near the source of radiation,
2. Increase the distance from the source of radiation,
3. Increase the shielding between person and the source of radiation. Shielding is anything that puts distance and mass between person and the radiation source.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Evacuation
If a person is outside, evacuate up-wind from the blast site cover the nose and mouth with a wet cloth to reduce the risk of inhaling radioactive smoke or dust. Once out of the immediate area, seek shelter and wait for instructions from first responders. If individual has been exposed to dust or smoke, follow the decontamination procedure.
Shelter in Place
If a person is close to the blast and inside a building, stay inside if the building is intact. Move to the basement and turn off all HVAC equipment and fans bringing in outside air it is not necessary to seal doors and windows, but it may be helpful. Wait for instructions from first responders.
Action Plan Reporting of an Off Site Emergency
The off-site disaster management plan will be put into action in the following situations: a) In case of an Onsite emergency spreads beyond the boundary of installation and causes damage to the life or property outside the boundary. b) In case an emergency originated from outside the premises of the installation/Drilling Rig/Work over Rig which is likely to effect the operations of installation. The off-site emergency requires mobilization of resources beyond ONGC capabilities such as GSFC and other government agencies. In case of an off-site emergency, the On-site Chief emergency coordinator (Sub Asset Manager, Cambay Sub Asset) will report the matter to the District Collector of the specific district who is Chairman of District emergency committee. Further, the Chairman will mobilize other members of District Emergency committee as per the organization Chart for an Off-site emergency management (figure-6.). Communication to Corporate Disaster Management Group (CDMG) The Chief Emergency coordinator shall immediately inform CMD, Director (HR),- CCEC, Director-concerned and Director-I/C HSE on the situation and his assessment for intervention of Corporate Disaster Management Group (CDMG).
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.2 Flowchart for Offsite Emergency Management
Functions and responsibilities of emergency Committee When a call is received from On-site Emergency coordinator regarding emergency / disasters, District Collector of district, who is also chairman of the District Emergency committee, will initiate the district level action plan to combat the emergency. Responsibilities of Chairman of District Emergency Committee a) Take overall responsibility for combating the off-site emergency.
b) Declare an area of 500 m or up to 1.5 Kms as felt appropriate around the site as a “Hazardous Zone”.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
c) Inform the District Police, Fire Personnel to combat the emergency. Arrange if necessary, for warning and evacuating the public from the villages by the Superintendent of Police.
d) Inform the team of Doctors headed by District Health & Medical Officer; also help and support from nearby hospitals may be called for.
e) Inform the Regional Transport Officer to arrange for transportation of victims and evacuation of people trapped within the hazardous zone.
f) Inform the GEB Executive Engineer to give uninterrupted power supply or de- energize power supply, as required.
g) Inform the Revenue Divisional Officer (RDO) and District supply officer to provide safe shelter, food and other life-sustaining requirements for the evacuees.
Responsibilities and duties of members of Service group
In the implementation of the Off-site emergency plan a service group will assist the Collector of respective district. This group consists of the following members from the district area & has responsibilities as indicated.
District Collector Press and Public Relations Superintendent of Police Warning & Advice to the public security measures, Rescue & Evacuation District Revenue Officer Coordinates Transport, Civil Supplies, Health, Medical and other services. Revenue Divisional Officer Rallying post Regional Transport Officer Provide transport Sr. Regional Manager, Catering to the evacuees and others involved in the GCSC relief measures Deputy Director Health To take care of Public Health & Preventive medicines District Medical Officer Treatment of affected persons Divisional Fire Officer Help in firefighting operations & rescue. District Environmental Advice for protection of environment and reduction Engineer in environmental losses
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Joint Director, Animal Taking care of cattle in the affected area. Husbandry Joint Director, Agriculture Taking care of standing crops Executive Engineer, GEB Ensuring uninterrupted powers supplies or de- energizes power supply as required.
Mock Drill for Onsite and Off Site Emergency Management
ONGC may conduct Mock Drill to check the efficacy of Onsite and Off-site Emergency plan for review and updating in association with Government officials.
Once in every year this plan will be practiced on field mock exercise involving dramatized scenarios to test the communication system, action plan and response of all Key agencies within ONGC and Government officials. Such on field mock exercise will be selected from high risk areas and near real approach of actual fire fighting / evacuation operations will be undertaken. An emergency will be alerted through different types of Siren Sound Code example fire, explosion, toxic release etc. Siren codes as per OISD STD-116 reproduced here in Format-I will be followed. During mock drill exercise observers would be appointed in key areas to take note (as per format-II) of individual responsibilities, response time and lapses. Every mock exercise will be followed by “post – mock-drill meeting” to discuss the findings of observers and shortcomings. The lessons learnt from such exercises will be summarized in the form of a report to improve upon the overall preparedness and will also be used as inputs for updating the plan to the extent necessary.
If in any case the exercise cannot be carried out due to operational reasons the same shall be done as the table top exercise to test the communication system, action plan and response of all Key agencies within ONGC and Government officials.
Review of the Plan
The off-site emergency plan will be reviewed by ONGC and District Emergency Committee as per requirement and updated accordingly.
Contingency Plans
The Contingency Plan for Earthquake, Tsunami, Flood, Fire, Bomb Threat, Pipe Line/Flow Line Leakage (Oil Spill) and Blowout is shown in Figure 7.3 to7.9.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.3Earthquake Contingency Plan
7-30 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.4 Tsunami Contingency Plan
7-31 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.5 Flood Contingency Plan
7-32 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.6 Bomb Contingency Plan
7-33 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.7 Fire Contingency Plan
7-34 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.8 Leakage/Oil spill Contingency Plan
7-35 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Continued
7-36 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Figure 7.9 Blowout Contingency Plan
7-37 EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
8. PROJECT BE EFITS
8.1 PROJECT BE EFITS
Oil & Natural Gas Corporation Limited (ONGC), a premier Govt. of India Undertaking and the major National Oil Company, is a vertically integrated company producing crude oil, natural gas and value added products like LPG, NGL, Petrol, HSD etc. Operations of ONGC extend over both onshore as well as offshore within India and outside India. ONGC has proposed 108 Developmental Drilling Locations in nine ML Blocks/fields of Cambay sub Asset, spread over Vadodara, Anand & Kheda Districts in Gujrat. The total Block Area is 820.82 km2. Will lead to the following benefits: The Project will enhance domestic hydrocarbon production of the Indian Subcontinent, the hydrocarbon gain is expected to be 788 MT/day and 1.2 MMSCMD (combined capacity of successful development wells in the proposed 9ML/NELP Block),which will in-turn contribute to Nations economy by enhancing energy security and reducing foreign exchange outgo. • Employment under this project: - 1. ONGC Employment – 80-100 man days for 30 - 40, officers and staff. 2. Contractual Employment – 80-100 man days for 30 - 40, persons, obligation of the contractor. 3. The Project will result in the indirect employment opportunities to the skilled / Unskilled local people through number of contractual jobs which are required during site preparation, drilling and restoration activities of the ONGC, which provide ample opportunities only to the local for such jobs as per the policy there by increasing the business opportunities for local Entrepreneurs. 4. The mentioned project will be beneficial to the area around which the drilling . site are planned to be established by way of creation and improvement of infrastructure facilities like creation of new roads, drainage facilities etc… which will be used by the villagers in future. • ONGC being a responsible corporate provide financial assistance to the people and communities under their Corporate Social Responsibility (CSR) schemes. The following are the focus area under CSR scheme of ONGC Cambay Asset:
Education Infrastructural support Social Health Care Arts & Crafts- promotion Conservation- Environment, Ecological Initiatives for physically & mentally Challenged. Promoting sports The CSR funds are allotted only to operational area only also the fund allotted under ECSR will be completely utilized for the benefit of same people.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
9. A ALYSIS OF ALTER ATIVES
The development drilling activity is site specific and generally the well is spudded in the pre- determined coordinates as the centre of the cellar pit. However the alternate site is chosen in case the well undergoes complication. In some of the case the wells are drilled from the same site as cluster wells where the availability of land becomes critical.
The several techniques for drilling to reach the target depth
Directional drilling
Air Drilling
Foam drilling
9.1 DIRECTIO AL DRILLI G
Directional drilling is defined as the science of direction a wellbore along a pre- determined trajectory to intersect a designated subsurface target.
9.1.1 Applications of Directional Drilling
Multiple wells from offshore structures :The most common application of directional drilling techniques is in offshore drilling. Many oil and gas deposits are situated well beyond the reach of land based rigs. Drilling a large number of vertical wells from individual platforms is both impractical and uneconomical. The obvious approach for a large oilfield is to install a fixed platform on the seabed, from which many directional boreholes can be drilled. The bottom hole locations of these wells are carefully spaced for optimum recovery.
Fig 9.1 Multiple wells from offshore structures
In conventional development wells cannot be drilled until the platform has been constructed and installed. This can mean a delay of several years before production begins. Such delay can be considerably reduced by pre-drilling some of the wells through a subsea-template while the platform is being constructed. These wells are directionally drilled from s semi-submersible rig and tied back to the platform once it has been installed.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Relief wells: Directional techniques are used to drill wells in order to kill blowouts. Relief wells are deviated to pass as close as possible to the uncontrolled well. Heavy mud is pumped into the reservoir to overcome the pressure and bring the wild well under control.
Fig 9. Relief wells
Controlling vertical wells: Directional techniques are used to straighten crooked holes when deviation occurs in a well which is supposed to be vertical various techniques can be used to bring the well to vertical. This was one of the earliest applications of directional drilling.
Fig 9.3 Controlling the vertical wells
Side tracking : Side-tracking out of an existing well bore is another application of Directional drilling .This is done to bypass an obstruction(fish) in the original well bore to explore the extent of a producing zone in a certain sector of a field or sidetrack a dry hole to a more promising target. Wells are also side-tracked to access more reservoir by drilling a horizontal hole section from the existing wellbore.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Fig 9.4 Sidetracking
Inaccessible Locations: Directional wells are often drilled because the surface location directly above the reservoir is inaccessible either because of natural or manmade obstacles.
Fig 9.5 Inaccessible locations
Fault Drilling: Directional wells are also drilled to avoid drilling a vertical well through a steeply inclined fault plane which could slip and shear the casing.
Fig 9. Fault drilling
Salt dome drilling: Directional programs are used to overcome the problems of drilling near salt domes. Instead of drilling through the salt the well is drilled at one side of the dome and is then deviated around and underneath the overhanging cap.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Fig 9.7 Salt Dome Drilling
Shore line Drilling: In the case where a reservoir lies in the offshore but quite close to the land the most economical way to exploit the reservoir may be to drill directional wells from a land rig on the coast.
Fig 9.8 Shoreline drilling
9.2 Air Drilling
These technologies are developed to offset the formation damage created by drilling with mud. In Air drilling the drilling fluid is air and compressed air is used to lift up the cuttings. However air has the possibility of making an explosive mixture with the hydrocarbon encountered during drilling and hence sufficient precautions should be taken during air drilling.
9.3 Foam Drilling Foam drilling uses foam as a drilling fluid .In this technique foam lifts up cuttings and this prevents loss circulation where the formation pressures are sub hydrostatic.
9.4 Horizontal Drilling Another technique called horizontal drilling is used. To drill reservoir which are not accessible through conventional drilling methods horizontal drilling is classified into the following types.
Long Radius 2˚-6˚/100ft 3000-1000ft radii Medium Radius 8˚-25˚/100ft 700-225ft radii Intermediate Radius 25˚-100˚ /100ft 225-60ft radii Short Radius 150˚-350˚/100 ft 40˚-20ft radii.
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 o. of WHI, 03 os. of Water injection Facilities and 03 nos. of ETP’s in operational areas of O GC Cambay Asset
Fig 9.9 Horizontal Drilling Techniques
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EIA Report for Development Drilling of 108 wells, laying of, 4” and8” dia. Oil and gas flow lines & establishment of 03 nos.of EPS, 01 No. of WHI, 03 Nos. of Water injection Facilities and 03 nos. of ETP’s in operational areas of ONGC Cambay Asset
10. SUMMARY A D CO CLUSIO
10.1 SUMMARY A D CO CLUSIO
Oil & Natural Gas Corporation Limited (ONGC), a premier Govt. of India Undertaking and the major National Oil Company, is a vertically integrated company producing crude oil, natural gas and value added products like LPG, NGL, Petrol, HSD etc. Operations of ONGC extend over both onshore as well as offshore within India and outside India. ONGC has proposed 108 Developmental Drilling Locations in nine ML Blocks/fields of Cambay sub Asset, spread over Vadodara, Anand & Kheda Districts in Gujarat. The total Block Area is 820.82 km2 is delineated with respect to air, noise, water, biological and socio-economic environment. The different project activities in the construction and operation phase are identified and evaluated on the basis of primary and secondary data collection through field investigations, environment monitoring and from secondary sources viz. maps, reports, scientific literatures etc. A summary of the identified impacts are given in the following paragraphs.
During the construction/site preparation phase, different construction activities (land clearance, Site levelling, Earth work, Site grading etc.), movement of vehicles (for transportation of construction materials and rig accessories), operation of generators and discharge of wastewater will have some impact on air, water, soil, flora, fauna and surrounding communities. On the other hand during operational phase, operation of generators, gas compressors etc… flaring (while production testing), discharge of wastewater and movement of vehicles (Augment and monitor day to day activities) will also propose some agreeable affect on air, noise, soil, ecology and social environment of the project area.
With respect to occupational health, impacts are anticipated on the health of the employees who are employed on the rig during operation phase of the well drilling production testing and connecting to nearby collection facility. Personnel working near the noise generating machines, DG sets, flare and hazardous waste storage area are more susceptible to health hazards.
However, all these impacts can be managed with the proposed mitigation measures proposed in Chapter 6 and Chapter 7. Overall; this project will bring economic benefits, increase energy security of the country and generate employment opportunities.
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