PRELIMINARY DESIGN REPORT
For the
CHINO CREEK WELLFIELD WELLS I-19, I-20 AND I-21
Prepared for
CHINO BASIN DESALTER AUTHORITY 2151 South Haven Avenue, Suite 202 Ontario, California 91761
And
WESTERN MUNICIPAL WATER DISTRICT, (PROGRAM MANAGER) 14205 Meridian Parkway Riverside, California 92518
July 29, 2011
CONTENTS
REFERENCES USED…………………………………………………………..………………………..….1
INTRODUCTION……………………………………………………………………………...………..…..4 Figure 1: Project Location………………………………………………………..……..….. 5
GEOHYDROLOGIC SETTING…………………………………………………………………….………6 Figure 2: Geologic Setting………………………………………………………………….. 7
EXPECTED SUBSURFACE CONDITIONS……………………………………………………….………8 Figure 3a: Lithologic Cross-Section…………………………………………………..………9 Figure 3b: Lithologic Cross-Section Map View……………………………..………………..9
ANTICIPATED PRODUCTION AND POTENTIAL IMPACT OF PROPOSED WELLS……………10 Figure 4: Well Site Considerations…………………………………………….…...... 11
GROUND WATER QUALITY……………………………………………………………………………12 Table 1: Water Quality Summary of Existing CDA Wells…………………………...... 13 Figure 5: Ground Water Chemistry of Chino Creek Area………………………………….15
REGULATORY CONSIDERATIONS…………………………………………………………………….16 Table 2: Required Permits and Governing Agencies……………………………………...17
WELL SITE CONSIDERATIONS…………………………………………………………………...……18
PROPOSED WELL SITE: I-19………………………………………………………………...... 18 Figure 6a: Proposed Well Site I-19………………………………………………………….19
PROPOSED WELL SITE: I-20…………………………………………………….…………………..…..20 Figure 6b: Proposed Well Site I-20…………………………………….……………………21
PROPOSED WELL SITE: I-21…………………………………………………………….………………22 Figure 6c: Proposed Well Site I-21…………………………………………….…………....23
PRELIMINARY WELL DESIGN……………………………………………………………………....…24 Table 3: Details of Preliminary Well Design…………………………………………...... 24 Figure 7: Preliminary Well Design……………………………………………….………...25
DRILLING APPROACH…………………………………………………………………………………..26 Figure 8: Drilling Approach…………………………………………………….…………..27
GEOPHYSICAL LOGS……………………………………………………………………………………28 Table 4: Geophysical Logs…………………………………………………….…………..29
AQUIFER ZONE TESTING………………………………………………………………….……………30 Figure 9a: Aquifer Zone Selection………………………………………….………….…….31 Figure 9b: Aquifer Zone Construction……………………………………….……………....31
WELL CONSTRUCTION……...…………………………………………….……………………………32 Figure 10: Well Construction……………………………….……………………………….33
WELL DEVELOPMENT………………………………………………………………………………….34 Table 5: Well Development……………………………………………………………….34 Figure 11: Well Development……………………………………………………………….35
TEST PUMPING AND TITLE 22 WATER QUALITY ANALYSES……………………………………36 Table 6: Title 22 Analytes…………………………………………………………………37
ENGINEER’S ESTIMATES……………………………………………………………………………….38 Table 7: Engineer’s Estimates……………………………………………………………..39
APPENDIX A Summary of Existing CDA Wells in the Chino Creek Area
APPENDIX B Hydraulic Control Monitoring Well Water Level Graphs
APPENDIX C Anticipated Filter Pack Design
REFERENCES USED
American Water Works Association, December 2007, Water Wells. AWWA A100-06.
Black & Veatch, September 2008, Treatment Technologies Technical Memorandum, Metropolitan Dry-Year Yield Program Expansion Project, Prepared for the Chino Basin Watermaster.
California Department of Public Health (CDPH), November 2008, Maximum Contaminant Levels and Regulatory Dates for Drinking Water U.S. EPA versus California.
California Department of Water Resources (DWR), January 2006, California’s Groundwater: Upper Santa Ana Valley Groundwater Basin, Bulletin 118.
California Department of Water Resources (DWR), 1998, Water Well Standards, Bulletins 74-81 and 74-90
Carollo Engineers, December 2010, Chino Desalter Phase 3 Comprehensive Predesign Report, Prepared for The City of Ontario, Jurupa Community Service District and Western Municipal Water District.
Driscoll, F.G., 1986, Groundwater and Wells , Second Edition, St. Paul, Minnesota: Johnson Filtration Systems, Inc.
Fetter, C.W., 1994, Applied Hydrogeology , Fourth Edition, New York: McMillan.
Geoscience Support Service, Inc., January 2011, Letter: Chino Desalter Authority Well I-18 Recommended Casing, Screen and Filter Pack Design, Prepared for Western Municipal Water District.
Geoscience Support Service, Inc., September 2009, Preliminary Design Report for the Chino Creek Wellfield and Chino II Expansion Wellfield Chino Desalter Phase 3 Project, Prepared for Western Municipal Water District.
Geoscience Support Services, April 2005, Results of Drilling, Construction, Development and Testing of Chino I Expansion and Chino II Desalter Wells, Prepared for RPF Consulting and the Chino Basin Desalter Authority.
Kelly, W.E, & Mares, S. (editors). 1993. Applied Geophysics in Hydrogeological Engineering Practice in Developments in Water Science. p.262-264.
Kennedy/Jenks Consultants, 2008, Integrated Regional Water Management Plan 2008 Update. Prepared for Western Municipal Water District.
Keys, W. Scott, 1990. Techniques of Water-Resource Investigation of the United States Geological Survey: Chapter E2 Borehole Geophysics Applied to Ground-Water Investigations.
Metropolitan Water District of Southern California (MWD), September 2007, Groundwater Assessment Study, Report Number 1308.
Roscoe Moss Company, 1990, Handbook of Ground Water Development , New York: John Wiley & Sons
TetraTech, February 2011, TCE Plume Characterization and Monitoring Well Installation Report, Chino Airport Groundwater Assessment, San Bernardino County, California, Prepared for County of San Bernardino.
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2
United States Environmental Protection Agency, November 2009, Region IX Drinking Water Standards and Health Advisories Table.
United States Environmental Protection Agency, June 2001, Fact Sheet: Correcting Henry’s Law Constant for Soil Temperature.
United States Geological Survey, 1990, Techniques of Water-Resources Investigations of the United States Geological Survey , Chapter E2: Borehole Geophysics Applied to Ground-water Investigations by W.S. Keys.
United States Geological Survey, 1966, 7.5-minute topographic map: Corona North, California.
United States Geological Survey, 1966, 7.5-minute topographic map: Guasti, California.
United States Geological Survey, 1966, 7.5-minute topographic map: Prado Dam, California.
United States Geological Survey, 1966, 7.5-minute topographic map: Ontario, California.
United States Geological Survey, 2006, Geologic Map of the San Bernardino and Santa Ana 30’ x 60’ Quadrangles, California.
Wildermuth Synergies, LLC, 2009-2011, HydroDaVE Explorer: Compilation of Chino Basin Water Master data and information for public wells in the Chino Creek area.
Wildermuth Environmental, Inc., November 2009, Chino Basin Optimum Basin Management Plan, 2008 State of the Basin Report, Prepared for the Chino Basin Watermaster.
Wildermuth Environmental, Inc., 2007, Chino Basin Water Master Ground Water Model Documentation and Evaluation of the Peace II Project Description, Prepared for the Chino Basin Watermaster.
Wildermuth Environmental, Inc., April 15, 2006, Chino Basin Maximum Benefit Monitoring Program Annual Report, Prepared for Chino Basin Watermaster and Inland Empire Utilities Agency.
Wildermuth Environmental, Inc., September 2003, Optimum Basin Management Program Technical Memo Prepared for Chino Basin Watermaster.
Wildermuth Environmental, Inc., August 1999, Optimum Basin Management Program Draft Phase I Report, Prepared for Chino Basin Watermaster .
Yeats, R.S., Final Technical Report: The Chino Fault and its Relation to Slip on the Elsinore and Whittier Faults and Blind Thrusts in Puente Hills.
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INTRODUCTION Figure 1: Project Location
The Phase 3 Chino Desalter expansion project is being sponsored by Jurupa Community Services District, the City of Ontario and the Western Municipal Water District on behalf of the Chino Basin Desalter Authority. Western Municipal Water District (Western) acts as the Program Manager for the project. The objectives of which are to (1) provide additional capacity of 10 million gallons per day of product water; and (2) achieve hydraulic control of the Chino Basin ground water to minimize discharge of poor quality waters to the Santa Ana River in accordance with the Peace II Agreement.
To help achieve these objectives, six new wells were proposed as part of the Chino Creek Well Field (Carollo, 2010). Combined production of raw ground water from these six wells was projected to be between 5,000 and 7,700 acre-feet per year (Carollo, 2007). This translates to roughly 515 to 795 gallons per minute (gpm) of continuous pumping per well. Three of these wells have already begun construction and have been described in a previous design report (Geoscience, 2009).
In March 2011, Western authorized GSi/water to provide construction management services for three of the new Chino Creek Wells: I-19, I-20 and I-21 (Figure 1). The proposed sites for these wells are just north of Kimball Avenue along a ¾ -mi stretch between Euclid and Grove Avenues.
Our objective is three-fold with a scope of work that includes:
I. Provide preconstruction assistance: a. Extensive information review including an evaluation of data from existing wells (construction, production, water levels and water quality); b. Field reconnaissance of the proposed well sites and surrounding areas; c. Discuss potential issues with representatives from the Chino Basin Watermaster, City of Chino, Santa Ana Regional Water Quality Control Board, and the Sponsor Group for the Chino Desalter Authority; d. Prepare technical well specifications and final bidding documents; e. Prepare Preliminary Drinking Water Source Assessment and Protection documents; and f. Prepare a Preliminary Design Report (this report).
II. Provide assistance during bidding: a. Facilitate pre-bid meeting; b. Coordinate site logistics; c. Respond to questions from drilling contractors; d. Evaluate bids received and recommend contractor.
III. Provide oversight for drilling, construction, development and testing of I-19, I-20 and I- 21 (p. 26-37).
This report includes:
- Geohydrologic Setting and Expected Conditions (p. 6-9) - Production Estimates and Potential Impacts of Proposed Wells (p. 10-11) - Water Quality and Regulatory Considerations (p. 12-17) - Proposed Well Sites and Preliminary Well Design (p. 20-25) - Approach to Drilling, Constructing, Developing and Testing the Three Wells (p. 26-37) - Estimate of Drilling Costs (p. 38-39)
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Figure 1 PROJECT LOCATION Chino Basin Desalter Authority Ontario, California Merrill Ave. 06/13/11 1092.1/Task2/WellSpecifications/Figures/Fig1b_ProjectLocation.ai
Euclid Ave. Chino Airport 5
I-20 I-21
Kimball Ave. I-19 Kimball Ave. Hellman Ave. Hellman
Index Map Mill Creek Ave.
San Luis Obispo Kern Bickmore Ave.
San Bernardino Santa Barbara Ventura Los Angeles
Riverside Orange
San Imperial Diego Pine Ave. N 0 1,000 2,000 ft GEOHYDROLOGIC SETTING Figure 2: Geohydrologic Setting
The Chino Creek Well Field is in the southern part of the Chino Basin in Southern California (Figure 2). The Chino Basin is a fault-controlled alluvial basin, bounded in the southwest by the Chino Hills (Chino and Central Avenue Fault Zones), in the northwest by the San Antonio Fault Zone; in the north by the San Gabriel Mountains (Red Hill and Cucamonga Fault Zones); in the northeast by the Rialto-Colton Fault, in the east by the Jurupa Mountains, and in the south by La Sierra Hills.
The Chino Hills are composed of Tertiary sedimentary rocks of the Puente formation; the San Gabriel and Jurupa Mountains are made up of Paleozoic to Cretaceous granitic and metamorphic rocks. These rocks underlie the Chino Basin, the latter forming the crystalline bedrock. Depth to crystalline bedrock across the Basin varies widely from north to south and east to west, growing markedly shallower along the basin margins. Based on geologic cross-sections prepared for the Chino Basin Watermaster by Wildermuth Environmental (2007), depth to crystalline bedrock in the vicinity of the Chino Creek Well Field is estimated to be more than 850 feet below ground surface (bgs).
Over cycles of uplift and deposition through geologic time, sediments weathered from the uplands have filled the alluvial valley that makes up the Chino Basin. Several faults have been identified that cut through the alluvium and act, to varying degrees, as barriers to ground water flow. No fault is completely impermeable, but some are more restrictive than others. The Red Hill Fault is considered a barrier to ground water flow while the San Jose and Chino Faults are considered only partial barriers (CDWR, 2004). This is based on differences between ground water elevations on either side of the fault.
The geologic map prepared by the USGS indicates that alluvium in the vicinity of the Chino Creek Well Field, along the southern margin of the Chino Airport, is characterized as young fan deposits in the north and as very old fan deposits to the south (Morton and Miller, 2006). The latter are cut by very young channel deposits (Figure 2).
Ground water recharge to the Chino Basin includes infiltration of surface runoff along unlined channels; artificial recharge of storm waters, imported waters and recycled water at numerous spreading grounds; irrigation return flows; and underflow from adjacent basins. Ground water discharge from the Chino Basin is primarily through ground water production and upwelling in the vicinity of Prado Dam.
The principal water-bearing units include Holocene and Upper Pleistocene alluvium (DWR, 2006). The former consists of alluvial fan deposits, which are coarsest near canyon mouths and finer to the south with a maximum thickness of about 150 feet. The latter consists of interfingering alluvial and fluvial deposits with estimated thickness of 600 to 700 feet in the area of the Chino Creek Wells (Wildermuth, 2007). Sedimentary strata have been divided by Wildermuth Environmental into three aquifer systems – an upper (Layer 1); a middle (Layer 2), and a lower (Layer 3) (MWD, 2007). These are discussed in greater detail on p. 8-9
In the vicinity of the proposed wells, there are about a dozen production wells, including existing CDA wells and agricultural wells. Over roughly the past decade, the average static water level (SWL) in these wells has been about 540 feet above mean sea level (asl) or about 60 to 85 feet bgs (Appendix A). Near the proposed wells, observed fluctuations in SWL most likely reflect seasonal influences and interference from pumping in nearby wells or measurements that were collected before water levels had completely recovered from recent pumping. Generally, for existing CDA wells, production rates are higher to the east (> 1,000 gpm). These wells tap both the Upper and Middle aquifer systems (Layers 1 and 2). CDA wells to the west tap only the Middle aquifer system (Layer 2) and have lower average production rates that range from about 350 to 950 gpm. These estimates are based on initial production testing for CDA Wells in the area (Appendix A).
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Imperial Riverside Street Deposits Deposits San Freeway Diego San Bernardino Chino Airport Plio-Pleistocene Proposed Wells Location Certain County Boundary (I-19, I-20, & 1-21) Location Uncertain Sedimentary Rocks Sedimentary Rocks Metamorphic Rocks Location Concealed Legend Very Old Alluvial-Fan Quaternary Alluvium Location Approximate Cretaceous to Miocene Los Orange Pre-Tertiary Igneous and 7 Angeles Very Young Axial-Channel Kern Index Map Ventura Figure 2 1092.1/Task1/Figures/Fig2_GeologicSetting.ai
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Puente Hills Puente P Los Angeles County Angeles Los San Bernardino and Santa Ana 30’ x 60’ Quadrangles EXPECTED SUBSURFACE CONDITIONS Figure 3a: Lithologic Cross-Section Figure 3b: Lithologic Cross-Section Map View
Review of driller’s, geologic and geophysical logs from the area indicate that, in the vicinity of the Chino Creek Well field, water-bearing strata consist primarily of inter-bedded layers of clay, silt, sand, gravel and some cobbles in varying proportions (Figure 3). The logs show that sediments become generally finer to the west, with a larger proportion of silt and clay. There also appears to be a color change, with more red / red-brown sediments observed in the west transitioning to more green/grey-green sediments to the east. Although color descriptions are subject to qualitative judgment, color differences may indicate: (1) differences in mineralogy; (2) differences in redox conditions, where redder sediments typically indicate a more oxidizing environment; or (3) some combination thereof. If applicable, these explanations have important implications for water quality and production potential.
Some constituents, such as hexavalent chromium and uranium, are more mobile under oxidizing conditions. Conversely, other constituents persist more readily under reducing conditions. For example, oxidizing conditions are necessary to encourage the natural degradation of nitrate and organic contaminants. However, the persistence of nitrate in Chino Creek ground waters indicates that oxidizing conditions tend to prevail. Ground water quality is discussed in greater detail on p. 12-15.
There is a possibility that there is a minor fault located approximately between BH-5 and HCMP 1. Topographic evidence to support this interpretation includes contours that show the presence of a natural channel, which may indicate preferential weathering and erosion along the weakened sediments and gouge within the supposed fault zone. This channel appears to be extending northeastward by headward erosion, suggesting that, if present, the fault may trend northeast-southwest. However, other lines of evidence do not support this interpretation. Although lithologic layers do not correlate precisely, there does not appear to be significant offset on either side of the supposed fault. Likewise, SWL data from wells on either side of this feature suggest that, if faulting is present, it does not act as a significant barrier to ground water flow.
The dividing lines between the Upper (Layer 1) and Middle (Layer 2) aquifer system shown in Figure 3a are approximately located based on cross-sections prepared by Wildermuth Environmental (2007). In the area of the proposed wells, Layer 1 is estimated to extend from the static water level to about 210 feet below ground surface, below which Layer 2 extends to an approximate depth of 560 feet bgs with Layer 3 below (Wildermuth Environmental, 2007).
Layer 1 is characterized as unconfined to semi-confined while Layer 2 is characterized as semi- confined to confined (MWD, 2007). Lithologic logs show that the upper and lower systems are not separated by a laterally extensive clay layer, rather there appears to be some degree of hydraulic connectivity between them. Generally, the degree of connectivity appears to increase to the west. This interpretation is based on water level data from seven nested hydraulic control monitoring wells, which are located in the general vicinity of the Chino Creek Well Field (Appendix B). Water level data from these wells were used to compute differences in hydraulic head. The data suggest that, in areas with less hydraulic connectivity, the vertical component of ground water flow in the Chino Creek area tends to be downward.
Proposed Wells I-19, I-20 and I-21 are intended to penetrate only the Upper aquifer system. However, drilling is proposed to extend to 600 feet bgs in order to better characterize the aquifer systems in this area. During drilling, analysis of cuttings alone is unlikely to indicate when a deeper aquifer system has been reached. Aquifer zone testing and water quality analyses may give a better indication of the approximate division between Layers 1 and 2. Ultimately, the final recommended well design, including depth of penetration and screened intervals, will be based on an analysis of the data collected during drilling, geophysical logging and aquifer zone testing.
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West East 650 I-3 CAMW 14-I I-4 BH-5 HCMP-1 BH-7 BH-8 I-5 I-19 I-20 I-21 Ground Figure 3a N/A Surface 600 (0-60 ft) LITHOLOGIC CROSS-SECTION
Chino Basin Desalter Authority
Δ Δ Δ Δ Δ Δ Δ Ontario, California 550 06/13/11 1092.1/Task1/Figures/Fig3_LithologicLogs.ai SWL
500
450 Silt Sand (Layer 1) Upper Aquifer 400 Clay Gravel Estimated 350 Division between aquifer layers
(Wildermuth, 2007) 300 Δ Static Water Level (Estimated)
250 BH-5, BH-7, & BH-8 were Testholes Depth in feet above sea level Depth in feet 200 (Layer 2) Lower Aquifer
150 NOTE: Most Colors shown in well logs correspond to the Munsell color chart descriptions. Where color is absent, no color observations were recorded in the logs. 100
50 Estimated NOT TO HORIZONTAL SCALE Sea Level
NOTE: Plume Characterization Boreholes not shown on cross section (Figure 3a)
Figure 3b LITHOLOGIC CROSS-SECTION MAP VIEW Chino Basin Desalter Authority Ontario, California
06/13/11 1092.1/Task1/Figures/Fig3_LithologicLogs.ai
Hydraulic Control Monitoring Wells K3 HCMP1 I-4 BH-5 I-5 Plume Characterization Boreholes I-3 CAMW14 I-20 BH-7 K13 I-21 Chino Airport Monitoring Wells I-19 BH-8 Chino Desalter Testholes (Destroyed) 0 1,000 2,000 feet Chino Desalter Wells N Scale Proposed New Wells Modified from Google Earth, 2011 9
ANTICIPATED PRODUCTION AND POTENTIAL IMPACTS OF PROPOSED WELLS Figure 4: Well Site Considerations
Anticipated Production
Because the proposed wells are intended to tap primarily the Upper aquifer system, anticipated production rates from Chino Creek Wells I-19, I-20 and I-21 were estimated based on our interpretation of data from nearby wells that also tap the Upper aquifer system. We considered lithologic and geophysical logs, and production records. Based on this information (summarized below), we estimate that Wells I-19, I-20 and I-21 may achieve production rates between 300 to 800 gpm.
Three test holes were drilled in 1997 in the vicinity of Wells I-20 and I-21 by MWH. The test holes were not converted to production wells based on their interpretation of the lithologic and geophysical logs, which indicated that they would be unlikely to produce at the target rate of 300 gallons per minute (gpm).
Recently, Well I-18 was designed by Geoscience and constructed roughly ½-mile west of the proposed site for Well I-19. Based on their estimates from aquifer zone test data, Well I-18 may sustain pumping rates of about 420 gpm. Existing Well I-5 is located about ½-mile east of the proposed site for Well I-21. When it was constructed in 1997, it tested at over 1,000 gpm. Wells I-18 and I-5 are both screened in the Upper and Middle aquifer systems, however the screened intervals are proportioned differently for each. The screened interval in the Upper aquifer system makes up roughly 40% for Well I-18 and about 68% for Well I-5 (Appendix A). This is not meant to suggest that Well I-18 would have greater production if it had been designed with more screen in the Upper aquifer system. Rather, it helps to illustrate the differences in subsurface geology controlling permeability and production potential in the Chino Creek area.
Potential Impacts of Proposed Wells
Potential impacts associated with the proposed Chino Creek Wells I-19, I-20 and I-21 include (1) land subsidence, (2) interference with existing wells and (3) migration of the contaminant plumes and resultant water quality impacts.
Chino Creek Wells I-19, I-20 and I-21 are to be located just south of the Chino Airport in the vicinity of several existing CDA wells, airport monitoring wells, hydraulic control monitoring wells and agricultural wells (not shown). It is preferred that the new wells be screened primarily in the Upper aquifer system. The reason for this is two-fold: (1) to maximize hydraulic control to help minimize the amount of poor quality ground water that would otherwise discharge to the Santa Ana River and (2) to minimize the potential for land subsidence and ground surface fissuring caused by over-withdrawal from the lower aquifer system(s). Land subsidence has primarily been observed in a zone northwest of the proposed well sites (Figure 4).
The nearest known active wells include two agricultural wells (not shown), located at least 400 feet from any of the proposed well sites. At the estimated production rate of 300 to 800 gpm, mutual combined interference of up to about 7.5 feet may be anticipated with the nearest known production wells. This is based on aquifer test data from Well I-5, which is screened in both Layers 1 and 2. GSi/water will coordinate with the Chino Desalter Authority and Chino Basin Watermaster to monitor water levels in nearby accessible wells during test pumping in order to monitor for and assess potential interference effects.
Two volatile organic compound (VOC) plumes are located in the vicinity of the proposed wells: the Chino Airport and the Ontario International Airport (OIA) plumes (Figure 4). The primary contaminant of concern in these plumes is trichloroethylene (TCE). Well I-19 will be approximately 650 feet east of the easternmost mapped extent of the Chino Airport plume. It is possible that contaminated materials may be encountered at this site during drilling. Necessary precautions will be taken, including the use of appropriate Personal Protective Equipment, including nitrile gloves. It will be the responsibility of the Drilling Contractor to treat and/or dispose of any contaminated water and soil in accordance with applicable regulations. Well I- 21 will be located approximately ½ mile west of the southernmost mapped extent of the OIA VOC plume. Although it is not anticipated that contaminated materials will be encountered at this site, it may become a concern in the future. Over time, pumping from Wells I-19, I-20 and I-21 may induce plume migration towards these wells, which may necessitate building on-site treatment facilities at some point in the future. 10
Legend
VOC Plumes^
Primary Source of Subsidence*
Zone of Subsidence* (1992-2001) [as indicated by InSar; southern extent uncertain]
CDA Wells
Ontario Airport Proposed Wells
Chino Airport Monitoring Wells Hydraulic Control Monitoring Wells
^ From Tom Dodson & Associates, Inland Empire Utilities Agency Peace II SEIR, Chapter 3 - Project Description, page 50
* From Wildermuth Environmental, Inc Optimum Basin Management Program Prepared for Chino Basin Watermaster, September 2003, page 13
OntarioOntario AirportAirport PlumePlume
Chino Airport
Chino Airport Plume N
Figure 4
WELL SITE CONSIDERATIONS 0 1 2 miles Chino Basin Desalter Authority Ontario, California Scale 06/13/11 1092.1/Task1/PreliminaryDesignReport/Figures/Figure_4_WellSiteConsiderations.ai Modified from Google Earth, 2011 11 GROUND WATER QUALITY Table 1: Water Quality Summary of Existing CDA Wells
Ground water quality data from existing wells near the Chino Creek Well field shows a range of values (Table 1). Salinity generally increases from west to east. Nitrate has been detected in all CDA wells in the Chino Creek area, but is much higher in wells to the east. Two wells to the west (I-2 and I-3) show elevated concentrations of Trichloroethylene (TCE) and Trichloropropane (TCP). Other organic contaminants have also been detected in these wells. Similarly, chromium has also been detected in all CDA wells in this area, but with no apparent pattern in geographic distribution. Radionuclides have also been detected in the Chino Creek ground waters, with higher gross alpha concentrations to the east.
Salinity
Ground waters with less than 1,000 mg/L total dissolved solids (TDS) are characterized as fresh. Wells I-1, I-2, I-3 and I-4 merit this designation, however wells to the east (I-5 and I-8) would be characterized as brackish. The California Department of Public Health (CDPH) has set a Secondary Recommended Maximum Contaminant Limit (MCL) of 500 mg/L for TDS, with a Maximum of 1,000 mg/L, and a Short-term Maximum limit of 1,500 mg/L. Based on this information, it is anticipated that new Wells I-19, I-20 and I-21 will conform to the CDPH Recommended and Maximum limits for TDS with concentrations likely between 300 to 1,000 mg/L.
Nitrate
Nitrate is most likely associated with historic agriculture, ranching and sewage/septic disposal operations in the area. The CDPH has set a primary MCL of 10 mg/L for nitrate as nitrogen (NO3-N). Well I-4, I-5 and I-8 all show average nitrate levels that exceed this standard. Based on this information, it is anticipated that the new Wells I-19, I-20 and I-21 will also exceed this standard, with NO3-N concentrations likely ranging from about 10 to 60 mg/L.
Volatile Organic Compounds (VOCs)
Five VOCs have been detected in existing CDA wells: trichloroethylene (TCE); trichloropropane (TCP); 1,1-Dichloroethylene (1,1-DCE); cis-1,2-Dichloroethylene (cis-1,2-DCE) and chloroform. These are most likely associated with the Chino Airport VOC plume. Only two of these, TCE and TCP, show average concentrations above the California MCL for drinking water in any of the existing CDA Wells. The CDPH has set a primary MCL of 5 μg/L for TCE. Only CDA Well I-3 shows average concentrations that exceed the limit at this time. The CDPH has also established a Notification Level of 0.005 μg/L for TCP. Two existing CDA wells (I-2 and I-3) show average TCP concentrations above this threshold. Based on this information, it is anticipated that new Well I-19 may have slightly elevated levels of TCE and TCP, but given the possibility of plume migration toward pumping wells, virtually all wells in this area may potentially be at risk for VOC contamination at some point in the future.
Both TCE and TCP are considered dense non-aqueous phase liquids with densities that are roughly 40% to 50% greater than water. They therefore have a tendency to “sink” to the bottom of an aquifer layer. Between CDA Well I-3 and proposed Well I-19, three exploratory boreholes were completed as part of plume characterization (TetraTech, 2011; see Figure 3b, p. 9). They are from west to east: a nested monitoring well (CAMW-14) with screened intervals at shallow (55 to 75 feet bgs) and intermediate (130 to 140 feet bgs) depths; a direct push borehole (K13); and a cone penetration test (K3 to 120-ft depth), which was located approximately 150 feet northeast of site I-19 (TetraTech, 2011). Results from drilling, water quality sampling and testing at CAMW-14 show TCE and TCP were first encountered at a depth of about 130 feet bgs, with concentrations rapidly dropping off with depth. No VOCs were detected in either the direct push or cone penetration tests (K3 or K13). However, it is still possible contamination could be present at greater depths at or near these locations.
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Table 1. Water Quality Summary of Existing CDA Wells*
West East Well I‐1 I‐2 I‐3 I‐4 I‐5 I‐8 MCL
pH 8.1 8.2 8.3 7.8 7.1 7.2 ‐
TDS 254 239 311 443 1256 1292 500a (mg/L)
NO ‐N (mg/L) 4.5 3.1 5.4 19.7 55.8 62.9 10 3
TCE (μg/L) ND 3.9 30.8 ND ND ND 5
TCP (μg/L) ND 0.256 1.780 ND ND ND 0.005b
1,1‐DCE (μg/L) ND ND 0.64 ND ND ND 6
Cis‐1,2‐DCE ND 0.53 1.1 ND ND ND 6 (μg/L)
Chloroform ND 0.6 1.5 ND 1.1 0.64 80 (μg/L)
Chromium 5.3 14.3 3.8 5.3 11.3 12.6 50 (μg/L)
Cr‐III ‐ ‐ ‐ ‐ 29.5 31.0 ‐ (μg/L)
Cr‐VI 5.6 5.3 4.2 5.0 2.5 2.3 0.02c (μg/L)
Gross alpha 2.0 0.4 0.9 1.4 13.2 16.6 15 (pCi/L)
Uranium ‐ ‐ ‐ ‐ 13.7 16.7 20 (pCi/L)
Silica 20.4 19.8 20.5 22.4 33.8 34.0 ‐ (mg/L)
Chloride 22.4 18.1 32.7 62.8 174.4 181 ‐ (mg/L)
* Values shown were averaged from available water quality data for detected concentrations spanning roughly ten years. Numbers in red show that the average concentration exceeds the applicable regulatory limit.
a Secondary MCL: 500 mg/L recommended, 1,000 mg/L maximum, 1,500 mg/L short term maximum.
b Notification Level – a health-based advisory level with no formal MCL.
c EPA Public Health Goal – a concentration limit that poses no significant health risk if consumed over a lifetime; no formal MCL has been developed.
13
GROUND WATER QUALITY Continued Figure 5: Ground Water Chemistry of Chino Creek Area
Volatile Organic Compounds (VOCs) – Continued
Although not currently detected in any CDA wells in the area, other potential contaminants of concern associated with the Chino Airport plume identified as part of a recent plume characterization study include: acetone, benzene, bromomethane, 2–butanone, carbon tetrachloride, chlorobenzene, chloroethane, chloromethane, 1,2–dichlorobenzene, 1,3–dichlorobenzene, 1,4–dichlorobenzene, 1,1– dichloroethane, 1,2–dichloroethane, trans–1,2–DCE, ethylbenzene, PCE, toluene, 1,1,2–TCA, TCE, 1,2,3–TCP, Freon–11, 1,2,4–trimethylbenzene, o–xylene, and m,p–xylenes (TetraTech, 2011). In the preceding list, water quality results for the italicized constituents do not appear in the available data for the wells examined.
Chromium
Chromium can originate from both natural and anthropogenic sources. The CDPH has set a MCL of 50 μg/L for total chromium. Based on available data, existing CDA wells in the Chino Creek area show average total chromium concentrations that fall well below this value. Chromium is generally present in ground water in one of two redox states: chromate (Cr-VI) and chromite (Cr-III). The CDPH has recently revised its initial Public Health Goal of 0.06 μg/L to 0.02 μg/L for Cr-VI and is moving forward with establishing a formal MCL for this constituent. Chino Creek ground waters exceed this threshold by about two orders of magnitude. Based on this information, it is anticipated that new Wells I- 19, I-20 and I-21 will be in compliance with the MCL for total chromium, but may exceed the Cr-VI limit, with expected concentrations ranging from 5 to 15 μg/L for total chromium and from 2 to 6 μg/L for Cr-VI.
Radionuclides
Uranium and other radionuclides are most likely associated with a naturally occurring source, weathered from igneous and/or metamorphic rocks. The CDPH has set a primary MCL of 15 and 20 pCi/L for gross alpha and uranium respectively. Only one well in the Chino Creek area (I-8) shows average water quality that exceeds the threshold for gross alpha, with elevated uranium that has occasionally exceeded the MCL. Based on this information, it is not anticipated that new Wells I-19, I-20 and I-21 will exceed the MCLs for these constituents.
Silica and Chloride
Silica and chloride are both naturally occurring constituents that may affect the operating efficiency of the reverse osmosis plant at the Chino Desalter I. Wells to the west appear to have slightly higher silica levels and nearly three times the chloride concentration compared to wells to the east. Based on this information, it is anticipated that new Wells I-19, I-20 and I-21 may have silica concentrations between 20 to 35 mg/L and chloride concentrations between 30 and 180 mg/L, with I-21 likely tending toward the higher part of these ranges.
Chemistry
Ground water chemistry is characterized as sodium-bicarbonate type in the west (I-1, I-2 and I-3) and calcium bicarbonate type to the east (I-4, I-5 and I-8). This suggests that the Chino Creek ground waters are recharged from slightly different source areas (Figure 5).
14
Figure 5 GROUND WATER CHEMISTRY OF THE CHINO CREEK AREA Chino Basin Desalter Authority Ontario, California
06/09/2011 Fig5_GroundWaterChemistry.ai water
- Ca
2+
+ Mg + Cl 2- 4 2+ SO
- 3
Na
2+ + SO + K + HCO 4 2- Mg 2-
+ 3
CO
- Ca2+ Cl CATIONS ANIONS EXPLANATION I-1 I-2 I-3 I-4 I-5 I-8
15 REGULATORY CONSIDERATIONS Table 2: Required Permits and Governing Agencies
A number of regulatory agencies oversee compliance with existing laws and regulations pertaining to the work involved with drilling, constructing and testing new ground water production wells (Table 2). As part of construction management oversight, GSi/water will confirm that all necessary permits are in place before work commences.
The Drilling Contractor would be responsible for securing a well drilling permit for each well from the San Bernardino County Department of Environmental Health Services Division (DEHS). In addition, the Drilling Contractor would be responsible for obtaining clearance for each site from Underground Services Alert. GSi/water water will request copies of all Dig Alert certificates prior to commencing drilling. GSi/water will stake the well site and provide inspection services during emplacement of the conductor casing and seal (minimum depth 50 feet) and during any site visit by the County Department of Environmental Health Services Division.
GSi/water will provide the Drilling Contractor with a copy of NPDES Permit No. R8-2009-0003. The Drilling Contractor would be responsible for containing and removing all drill cuttings, fluids and wastewaters associated with well drilling, construction and testing until water quality testing confirms whether wastewaters meet NPDES permit requirements and may be discharged off-site. Additionally, if waters are to be discharged off-site, the storm drain access points for Well I-19 and I-21 may require that the Drilling Contractor first obtain an encroachment permit from the City of Chino and/or California Department of Transportation and, if necessary provide traffic control measures. Collection and analysis of water quality samples for NPDES compliance would be the responsibility of the Drilling Contractor. If wastewaters exceed the water quality limits set forth in the NPDES permit, the Drilling Contractor would be responsible for providing storage, treatment and disposal for wastewaters during all drilling and testing operations.
In order to secure access to fresh water for drilling and construction operations, the Drilling Contractor will need to coordinate with the City of Chino to obtain a hydrant meter permit. This permit requires a $2,000 deposit, $50 registration fee and certified backflow prevention device to be supplied by the Drilling Contractor. GSi/water will request a copy of backflow prevention device certificate prior to commencing drilling activities. The Drilling Contractor would be responsible for providing hosing, pipeline and any other necessary appurtenances to obtain water from City of Chino hydrants.
The City of Chino has a noise ordinance, which will require the installation of sound barriers around noise-generating equipment at the proposed well sites. Additional noise abatement practices may be required, including but not limited to those listed in Table 2. The Drilling Contractor shall be responsible for conducting work in the manner most effective to minimize noise generation while being consistent with the timely and economic execution of the contract. Noise levels at the property boundary shall not exceed 65 decibels.
Equipment used in the execution of the work must be permitted with the South Coast Air Quality Management Board and/or the California EPA Air Resources Board to insure that emission standards are met.
After the wells have been constructed, tested and approved, the Drilling Contractor is required to submit a Water Well Driller’s Report to the California Department of Water Resources. This report shall include the well location and name; descriptions of formations encountered; depth and diameter of well casing and seals; depth of perforated intervals; production rate and specific capacity.
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Table 2. Required Permits and Governing Agencies Name of Permit / Report Regulatory Agency Responsible Party Required Compliance Actions - To be filed at least 10 days prior to drilling. Environmental Health Services – - Meet with County inspector prior to drilling and as required to verify seals (Minimum 50-ft depth Well Drilling Permit Drilling Contractor County of San Bernardino bgs). - Notify Underground Services Alert at least 48 hours in advance of drilling. CDA - Permit holder NPDES Permit Santa Ana Regional CDA or Representative - File quarterly reports with SARWQCB. No. R8-2009-0003 Water Quality Control Board Drilling Contractor - Water Quality Sampling and Analysis at specified locations and frequency. - One-day notice required: $2,000 deposit, $50 registration fee. Hydrant Meter Permit City of Chino Drilling Contractor - Provide certified backflow prevention device. - Equip internal combustion engines with mufflers; - Shield noise-producing equipment by erecting 24-ft high sound barriers that completely surround each work site; - Locate equipment in positions which will direct the greatest noise emissions away from nearby Notification City of Chino Drilling Contractor areas of human occupancy; - Wrap mast with insulated sound blankets; - Conduct operations to effectively minimize noise generation; - Nose levels not to exceed 65 decibels. City of Chino Encroachment Permit / Right- California Department of Transportation Drilling Contractor - May be required to access some storm drain inlets (see p. 18-23). of-Entry Permit Leaseholders on Chino Airport Property South Coast Temporary Source Permit Drilling Contractor - Equipment must be permitted. Air Quality Management District California Water Well Driller's Report Drilling Contractor - To be submitted within 30 days after well completion. Department of Water Resources Chino Airport / Notification Drilling Contractor - To comply with flagging of tall structures and lighting requirements FAA Flight Standards Office WELL SITE CONSIDERATIONS
Each new water supply well must be located in compliance with separation distance requirements set by the CDPH and the San Bernardino County DEHS. These are equivalent to those set forth in the State Water Well Standards (California Department of Water Resources, 1998). At a minimum, this includes positioning well(s) at least:
- 150 feet from a cesspool or seepage pit - 100 feet from an animal or fowl enclosure - 100 feet from a sewer manhole - 50 feet from sewer lines and laterals
In addition to health and safety concerns, there are additional site considerations pertaining to well drilling operations such as easy access for heavy machinery and sufficient space to allow the work to proceed. Well drilling operations typically require a minimum of 10,000 square feet for the drilling rig and associated equipment. Overhead clearance and the presence of underground utilities / infrastructure are also important considerations. Chino Creek Wells I-19, I-20 and I-21 are proposed to be located at the southern margin of the Chino Airport in San Bernardino County. The proposed sites are clear from the paths of the major runways. To comply with Federal Aviation Administration regulations, lighting, drilling rig mast(s) and sound walls must be positioned and appropriately marked to allow visibility to air traffic.
PROPSED WELL SITE: I-19 Figure 6a: Proposed Well Site: I-19
Proposed Chino Creek Well I-19 is to be located at approximately 7572 Kimball Avenue in the City of Chino. The proposed well site is roughly 0.5 miles east of Euclid Avenue and 100 feet north of Kimball, just south of an existing storm control berm (Figure 6a). Access to the site is along paved perimeter roads within the Chino Airport property, which is enclosed by chain-link fence. The proposed site includes a field and part of a gravel parking lot adjacent to the fire station. If necessary, the Drilling Contractor should coordinate with the Chino Airport for the removal of fencing segments. The Drilling Contractor would be responsible for any necessary grading of the site and for the modification of the existing fence line and installation of a locking gate, if necessary.
Fresh water would most likely be accessible from a fire hydrant located approximately 300 feet southeast of the proposed well site, provided that a permit has first been secured from the City of Chino as described on p. 16-17.
Provided that NPDES permit requirements are met, there are two suitable discharge points: (1) a bar ditch in the Cal Trans right-of-way located approximately ½-mi west of the proposed site and (2) an unlined channel located approximately ½-mi east of the proposed site. This channel flows beneath Kimball Avenue and discharges into a series of retention ponds maintained by the Lewis Operating Company (LOC). If water quality exceeds NPDES permit limits, the Drilling Contractor would be responsible for disposing of wastewaters by vacuum truck to an appropriate recycling/treatment facility or for providing on-site treatment prior to discharging.
Potential overhead obstructions include powerlines. Potential underground utilities include a gas line and electrical line(s). However the proposed well site has been selected to avoid these utilities. The pipeline trends roughly northwest-southeast, approximately 40 feet south of the proposed site. The electrical lines would extend from the northernmost and southernmost utility poles. Clearance with Underground Service Alert will be critical at this site.
The proposed location complies with separation distance requirements set forth in the California Department of Water Resources Water Well Standards, as outlined above.
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Figure 6a PROPOSED WELL SITE I-19 Chino Basin Desalter Authority Ontario, California
06/09/11 1092.1/Task1/PreliminaryDesignReport/Figures/Fig6a_WellSiteLayout.ai water Fire Station
Airport Property Perimeter Road Existing Agric. Well Storm Control Berm
92 ft. 85 ft. 19
160 ft.
140 ft.
140 ft.
25 ft. Clearance for future development Kimball Ave.
GSi/water Proposed Well Location Fire Hydrant Assumed Underground Pipeline IEUA Sewer Manhole Modified from Google Underground Sewer Main (Approximate) Powerline Poles 0 75 150 ft Earth Image provided by N R.W. Beck Fence Short Fence PROPSED WELL SITE: I-20 Figure 6b: Proposed Well Site: I-20
Proposed Chino Creek Well I-20 is to be located at approximately 7906 Kimball Avenue, roughly 1 mile east of Euclid Avenue and 75 feet north of Kimball Avenue.
Access to the site is along a paved perimeter road, dirt road and through an agricultural field within the Chino Airport property, which is enclosed by chain-link fence (Figure 6b). The proposed site is on a former agricultural plot that slopes gently to the east and southeast. The Drilling Contractor would be responsible for coordinating with the Chino Airport for the removal of any nuisance vegetation, to facilitate access to the site and for any necessary grading of the site. This shall include the modification of the existing fence line and installation of a locking gate at a location to be determined.
Fresh water would most likely be accessible from a hydrant located approximately 150 feet south of the proposed well site, provided that a permit has first been secured from the City of Chino as described on p. 16-17.
For this site, the nearest candidate discharge point is located approximately 90 feet to the southeast into an unlined channel that flows beneath Kimball Avenue the LOC retention ponds. These ponds are flood control structures that also provide habitat for a threatened species of burrowing owl. However, because the habitats are located above the freeboard and outside of the 100-year flood zone, discharge waters should not interfere with any wildlife activities (Jason Miller, verbal communication). Based on conversations with Engineering Project Manager for the Lewis Operating Company, these facilities are in the process of being turned over to the City of Chino, which is anticipated to occur by September 2011.
Provided that NPDES permit requirements are met, these ponds would be a suitable discharge point. However, the Drilling Contractor may be required to provide erosion control measures to discharge into the unlined channel. If ground water quality exceeds the NPDES permit limit, the Drilling Contractor would be responsible for disposing of wastewaters by vacuum truck to an appropriate recycling/treatment facility or providing on-site treatment prior to disposal.
There are no overhead obstructions and no underground utilities / infrastructure are anticipated at the proposed site. Nevertheless, the Drilling Contractor would be responsible for obtaining clearance from the Underground Services Alert.
The proposed location complies with separation distance requirements set forth in the California Department of Water Resources Water Well Standards, as outlined on page 18.
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Figure 6b PROPOSED WELL SITE I-20 Chino Basin Desalter Authority Ontario, California
06/09/11 1092.1/Task1/PreliminaryDesignReport/Figures/Fig6b_WellSiteLayout .ai water
Airport Property
Existing Farm
100 ft. x 150 f t. 21
GATE
Kimball Ave. Mill Creek Ave. Mill Creek
Fence GSi/water Proposed Well Location Powerline Poles Modified from Google 0 150 300 ft Earth Image provided by Underground Sewer Main Fire Hydrant (Approximate) N R.W. Beck IEUA Sewer Manhole PROPSED WELL SITE: I-21 Figure 6c: Proposed Well Site: I-21
Proposed Chino Creek Well I-21 is to be located at approximately 8088 Kimball Avenue, roughly 1 mile west of Hellman Avenue and 80 feet north of Kimball Avenue.
Access to the site is along a paved perimeter road and a dirt road within the Chino Airport property, which is enclosed by chain-link fence. Alternatively, the site may be accessed from Grove Avenue, a dirt road extending north from Kimball Avenue and running adjacent to an existing palm tree nursery. The proposed site is currently occupied by 3 to 4 dozen large planter boxes containing palm trees. It is anticipated that these will be removed by the current occupant following property acquisition.
Fresh water would most likely be accessible from a hydrant located approximately 500 feet west of the proposed well site, provided that a permit has first been secured from the City of Chino as described on p. 16-17.
Provided all NPDES permit requirements are met, there are two suitable discharge points: (1) the nearest is located approximately 300 feet to the southeast, into a storm drain inlet located in the City of Chino right-of-way. The storm drain leads to the LOC retention ponds. Prior to discharging to the inlet, the Drilling Contractor would need to obtain an encroachment permit from the City of Chino, and if necessary provide traffic control measures. (2) An alternate discharge option would be to run discharge line to the unlined channel located roughly 800 feet west of the proposed site, which also flows into the LOC retention basins. However, the Drilling Contractor may be required to provide erosion control measures to discharge into the unlined channel.
There are no overhead obstructions and no underground utilities / infrastructure are anticipated at the proposed site. Nevertheless, the Drilling Contractor would be responsible for obtaining clearance from the Underground Services Alert.
The proposed location is located approximately 375 feet south of a septic intake. Based on information from the occupant, the leach field is presumed to extend to the west an estimated 200 to 300 feet. Defining the exact location and extent of the leach field would require hiring a septic contractor to perform a camera survey and dig up the existing lines. To mitigate against the possibility that this site is within the stipulated separation distance requirements, modifications to the proposed well design and/or location may be necessary. Detailed drawings showing the proposed well site and estimated extent of existing facilities have been submitted to CDPH and DEHS for review and approval.
22
Figure 6c PROPOSED WELL SITE I-21 Chino Basin Desalter Authority
Ontario, California X
06/09/11 ProposedWellSite_I21.ai water Estimated direction of septic leach field drainage
200-ft leach field buffer
300-ft leach field buffer 23
Existing CBWM 100 ft. x 150 ft. monitoring well
Gate
50 ft. clearance for future development Kimball Ave.
Manhole drain Approximate Location GSi/water Proposed Well Location X of Septic Intake Storm drain Underground Sewer Main Fence 0 100 200 ft N (Approximate) IEUA Sewer Manhole Powerline Poles PRELIMINARY WELL DESIGN Table 3: Details of Preliminary Well Design Figure 7: Preliminary Well Design
Preliminary well design is summarized in Table 3 (Figure 7). Actual depth of penetration may vary depending on information from lithologic samples, geophysical logs and aquifer zone testing. Placement of the screen intervals will be based on a detailed analysis of the aquifer zone testing data water quality analyses, geophysical logs and formation samples. The well screen perforation size and gravel pack design will be based on detailed sieve analyses of formation samples collected during the drilling (See Appendix C).
Table 3. Details of Preliminary Well Design
Pilot Borehole 17.5-in diameter to 600 feet deep Reamed Borehole 30-in diameter to 125 feet deep 26-in diameter to 370 feet deep Conductor Casing 52-ft length (+2 – 50 feet bgs) Cemented in placea 36-in O.D. x 0.375-in thickness (3/8-in) ASTM A53 Grade B mild steel or ASTM A139 Grade B mild steel Well Casing 16-in I.D. x 0.3125-in thickness (5/16-in) Type 304L Stainless Steel, Factory assembled in not less than 40-ft lengths Welded Cover and Bottom Plate Cap
Blank Casing 112-ft length (+3 – 70 feet bgs; 230 – 250 feet bgs; 330 – 350 feet bgs)
Blank Casing w/ Sounding Port 20-ft length (70 – 90 feet bgs); 16-in I.D. x 0.3125-in thickness (5/16-in) 3 x 3 x 24-in Sounding Port from 78 to 80 feet bgs
Blank Casing w/ Camera Port 20-ft length (90 – 110 feet bgs); 16-in I.D. x 0.375-in thickness (3/8-in) 4 x 4 x 96-in Camera Port from 92 to 100 feet bgs (factory-welded stiffener rings)
Louvered Casing 100-ft length (110 – 230 feet bgs; 250 – 330-feet bgs) ~0.080-in aperture Centralizers Three every 60 feet, beginning from the bottom of the casing Type 304L Stainless Steel ¼ -in thick x 2 ½- in wide Approximate 36-in length Sounding/Camera Tubes (x 2) Schedule 40 Type 304L Stainless Steel
Sounding Tube 2-in diameter; 80-ft length (+3 –78 feet bgs)
Camera Tube 4-in diameter; 94-ft length (+3 – 92 feet bgs) Gravel Feed Tubes (x2) 3-in diameter Schedule 40 Type 304L Stainless Steel 122-ft length (+3 – 120 feet bgs) x 2 Filter/Gravel Pack 265 feet (105 – 370 feet bgs) (Actual particle size for the filter pack will be determined by analysis of cuttings and geophysical logs. See Appendix C) Fine Sand Layer 5 feet (100 – 105 feet bgs) Bentonite Grout Seal 20 feet (230 – 250 feet bgs) Annular Sanitary Seala 100 feet (0 – 100 feet bgs) a 10.3-Sack Cement Sand Grout (ASTM TYPE II C 150-95) Portland Cement
24
Side View CHINO CREEK WELL I-19, I-20, & I-21 Threaded Pipe Cap 1/4 - inch Thick Plate Welded Cover Vent tube Well Pad Air Vent
GL 100-ft Sanitary Seal: 10.3 Sack (ASTM Type II C150-95 Portland cement) 2 - inch
0-ft to 100-ft Sounding Tube 36 inches 3 - inch Gravel Feed Tube x 2 24 inches 25 48-inch borehole 24 inches 36-inch I.D. Conductor Casing (+2 - 50-ft) 4-inch Cement Seal 3/8-inch (0.375-inch) Wall thickness Camera Tube 50 50-ft ASTM A53 Grade B mild steel or 36 - inch ASTM A 139 Grade B mild steel Conductor Casing Conductor Casing 4-inch I.D. Camera port tube (+3 - 92-ft) 16 x 0.3125 inch Camera port connection (92 - 100 ft) 75 diameter Well Casing Inner Cement Seal 16-inch ID x 0.3125 (5/16) Type 304L Stainless Steel 90-ft Blank Casing (+3 - 110 ft, 230 - 250 ft, 330 - 350 ft) 100 100-ft Camera Port to Extend from 90 - 98 ft 105-ft 3-inch I.D. Gravel Feed Tube x 2 (+3 - 120-ft) Top View 110-ft Mild Steel 120-ft 3-inch Gravel Feed Tube 125 125-ft 30-inch borehole ream
5-ft Fine Sand Layer (100-ft to 105-ft bgs) 48-inch borehole
36-inch Conductor Casing 150 4-inch Camera Tube 2-inch I.D. Sounding Tube (+3 - 80 ft) Type 304L Stainless Steel 2-inch Sounding Tube Sounding Tube Connection (78 - 80 ft) 175 Air Vent 16-inch Well Casing
Outer Cement Seal 26-inch borehole ream Inner Cement Seal 200
3-inch Gravel Feed Tube 225 230-ft Bentonite Seal
Depth in feet bgs. Depth in feet (230 - 250 ft) 250 250-ft Centralizers
16-inch ID x 0.3125 (5/16) 275 Type 304L Stainless Steel 1. For conductor casing, space 3 guides Ful Flo Louvered 0.080 slot 14 holes/ circle; (110 - 230 ft, 250 - 330 ft) equidistant around circumference 2 1/2-inch x 2. For well casing, space 3 guides equidistant 300 821 ft around circumference Filter/Gravel Pack 1/4-inch(T.D. Flat Pilot) Bar (105 - 230 ft, 250 ft - 370 ft) 3. Casing guides shall be spaced pursuant to 325 the basic specification 330-ft "R" 16-inch Well Casing Placement of first centralizers (347 - 350 ft); ± 3 -feet 4. Guides shall be shop fabricated 12-inch 3 Centralizers every 60 ft 350 350-ft 5. Install first set of guides 5' 0" above bottom Bottom Plate Cap (350-ft bgs) 26-inch borehole of casing 370-ft 6. "R" = Radius of bore minus 1/2" 375
17 1/2-inch pilot borehole (to 600 ft) Figure 7 600 600-ft PRELIMINARY WELL DESIGN Chino Basin Desalter Authority NOT TO HORIZONTAL SCALE Ontario, California
05/19/11 1092.1/Task2/WellSpecifications/Figures/Fig4_CasingGuideDetail.ai DRILLING APPROACH Figure 8. Drilling Approach
Procedures for the drilling of the three wells will begin with the setup of the drill rig (Figure 8) and all necessary equipment into the well site for I-20, including sound attenuation walls, fluid containment tanks, sample collection box and any other necessary equipment. A 48-inch borehole will be drilled to a depth of 50 feet bgs and a 36-in mild steel conductor casing will be installed in the borehole. A sanitary cement seal will be placed in the annular space between the borehole and conductor casing via pressure grouting.
A 17½-in pilot hole will then be drilled using the flooded reverse circulation drilling method to a depth of 600 feet bgs. GSi/water will collect cutting samples at 5-ft intervals; water quality of the formation and drilling fluids including pH, electrical conductivity, and temperature; and record any observations with regard to changes in drilling conditions (i.e. drilling rate, “rig chatter” and local weather). From these data GSi/water may interpret changes in fluid chemistry with depth, which may indicate an increase or decrease in formation water or of possible VOC contamination. The Contractor will perform directional deviation survey alignment tests every 100 feet. The purpose for performing a directional deviation survey is to insure vertical plumbness of the pilot hole.
When total depth has been confirmed, GSi/water will recommend a company to run a suite of geophysical logs in the borehole (p. 28-29). The Geophysical logs will help GSi/water identify zones of greater potential for water within the borehole.
Following completion of the Geophysical logs, GSi/water may select up to three zones for aquifer zone testing based on the formation samples collected and the geophysical logs. Aquifer zone testing is done to estimate ground water yield and water quality within each of the boreholes and would be done as described on p. 30-31.
If well construction is justified at site I-20, to minimize down time while waiting for full Title 22 analysis results from each zone, the pilot hole will be filled with pea gravel to 5 feet below the ground surface and a bentonite cap will be placed on top of the pea gravel to provide a temporary seal. The drill rig will then move to the second pilot hole location, I-19. If well construction is not justified, the borehole will be abandoned and destroyed in accordance with the County of San Bernardino requirements before remobilizing the drill rig and support equipment to the next well site.
Once the drill rig and all necessary equipment are set up at I-19, the same procedure will be used that was followed for the pilot hole drilling at I-20. After the water samples for Title 22 have been collected and all aquifer zone testing has been completed in I-19, if well construction is justified, it will be backfilled with pea gravel to the top of the conductor casing and the drill rig will move to site I-21. Otherwise it will be abandoned as described above. Once the drill rig and all necessary equipment is set up at I-21, the same procedure will be used that was followed for the pilot hole drilling at I-19 and I-20.
While waiting for Title 22 results from I-21, the drill rig will be mobilized back to I-20 for reaming operations by reverse circulation. Reaming would be followed by well construction and development by air-lifting and swabbing as described on p. 34-35. After completion of development by dual-swabbing and airlifting at I-20, if justified, the drill rig will mobilize to I-19, where it will follow the same reaming and development operations done in Well I-20. When initial development is complete in I-19, if justified, the drill rig will mobilize to I-21 and follow the same procedures used in I-19 and I-20.
Once the drill rig has mobilized from I-20 to I-19, a pump rig will be mobilized into I-20 for development pumping and production testing. After the conclusion of test pumping of I-20 and initial development at I-19, the pumping rig will be mobilized to I-19 for pumping development and production testing. After the conclusion of test pumping at I-19 and initial development at I-21, the pumping rig will be mobilized to I-21 for pumping development and production testing. Development pumping and production testing are described in detail on p. 34-37.
26
Figure 8 DRILLING APPROACH Chino Basin Desalter Authority Ontario, California
06/09/11 1092.1/Task1/PreliminaryDesignReport/Figures/Fig8_DrillingApproach.ai water
Flooded Reverse Circulation Drill Rig 17 1/2-inch Drill Bit
Consultant Collecting Formation Samples 28-inch Reamer Drill Bit
27 GEOPHYSICAL LOGS Table 4: Geophysical Logs
Geophysical logs are used to obtain information on the character of formations and on the presence and chemical characteristics of ground water. They provide continuous records that can be interpreted to provide an understanding of the physical properties of the formation material and of the contained fluids (Keys, 1990).
The Electric Log, or E-log, usually consists of natural gamma, spontaneous potential, short and long normal resistivity, single point resistance measurements, and Laterolog 3. The E-log is usually done immediately following the pilot hole drilling, before aquifer zone testing, reaming and construction. These logs help determine lithology, clay content, and potentially, water bearing zones.
The Temperature Log is usually done in conjunction with the E-log, and is sometimes done at the same time. The purpose of the temperature log is to measure the changes in temperature throughout the borehole. However, since most temperature logs are done immediately following pilot hole drilling operations, before the borehole has been cleaned out by continuous circulation of fluids, there may not have been enough time to allow the fluids to settle to provide results that accurately reflect formation temperatures.
The purpose of the caliper survey is to measure the borehole diameter. Borehole erosion (voids) and the presence of swelling clays can also be interpreted from the caliper log. It is used to estimate the volume of filter pack required for well construction.
The Gyroscopic (Deviation) survey measures borehole attitude and inclination and can be done either after reaming has occurred or after the well has been constructed. In some instances, it may be wise to do a gyroscopic survey at both times. Results from the Gyroscopic survey show how straight and plumb a borehole is. A borehole that is plumb is one whose center does not deviate from an imaginary vertical line that runs from the ground surface to the center of the Earth. Alignment of the borehole is important because it determines whether or not a properly sized pump can be installed to a desired depth. A pump installed in a misaligned well may have a shorter lifespan and require more frequent maintenance than one installed in a properly aligned well. The gyroscopic deviation survey should be run twice in the completed well. If results from either indicate that the well deviates more than 6 inches per 100 feet, it is recommended that the Drilling Contractor perform a plumbness and alignment caging test.
A spinner survey measures the direction and rate of vertical flow in the borehole. It can be run during test pumping and under idle conditions. In non-pumping wells, a spinner survey can locate confining zones and calculate ground water flow velocity between zones.
A sonic porosity log can measure the porosity of the formation via sound waves. Sound waves have a longer travel time in more porous formations and shorter travel times in less porous formations.
An acoustic Variable Density Log (VDL) measures the quality of the cement bond with the casing in cased boreholes.
A Dual-Cam video survey is run after well construction, development and production testing have been completed. It is used to view casing condition including openness of perforations, degree of encrustation, and presence of sediments. For a newly constructed well, perforations should be clear with no clogging or encrustation. In this case, it is used to verify that the well has been adequately cleaned of sediment accumulation and to confirm that no damage has been done to the well casing.
28
Table 4: Geophysical Logs
E-logs Description Measures natural radioactivity of the formations encountered; Elements contributing to formation radioactivity are thorium, uranium, and potassium; Used in conjunction with Natural Gamma Log other logs to determine formation lithology.
Measures the natural electric potential that develops between the formation and the borehole fluids; Can be used to determine bed thickness, geologic correlation and for Spontaneous Potential delineation of permeable rocks; Also used to distinguish between clay and sand, based on
the differences in salinity in borehole fluid and formation fluid.
Measures resistivity; The short-normal curve indicates the resistivity of the zone close to the borehole; the long-normal curve indicates the resistivity farther away from the Short & Long Normal borehole, beyond the influence of the drilling fluid. Typical spacing for potential Resistivity electrodes is 16-inches for short-normal resistivity and 64-inches for long normal
resistivity.
Measures the electrical resistance within the borehole of all rocks between electrodes; Lithologies with high resistance include sand, sand and gravel, and sandstone; Clay and Single Point Resistance shale have the lowest resistance; Increasing salinity will cause a decrease in resistance.
Can be used for water level detection and cement detection, location of loss of circulation zone, and for measuring formation temperature, once it has reached environmental Temperature equilibrium.
Measures resistivity in uncased holes that are filled with mud with additional current Laterolog 3 electrodes.
Additional Borehole Logs Description Measures borehole diameter; Can establish borehole erosion and presence of swelling clays; can measure diameter reduction due to mud-cake deposition; Volume of cement Caliper Log and/or volume of gravel pack can be calculated from caliper log.
Measures borehole attitude and inclination. Gyroscopic Deviation
Uses a pump “dummy” to measure the horizontal deviation of a well bore from plumb; Plumbness and Alignment Recommended if results from gyroscope exceed AWWA standards. Caging Test
Measures the direction and rate of vertical flow in the borehole; Can be collected under Spinner (Flowmeter) non-pumping (static) or pumping (dynamic) conditions.
Measures the porosity of the formation via sound waves. Sonic Porosity Log
Measures the quality of the cement bond with the casing in cased boreholes. Acoustic Variable Density Log
Records visual image of casing from two orientations: down-hole view and 360° lateral view; Can be used to identify casing conditions including openness of perforations, degree of encrustation, and presence of sediments. In a new well it is used to confirm that the Dual-Cam Video Survey well has been adequately cleaned of sediment accumulation and that the casing has not been damaged.
29
AQUIFER ZONE TESTING Figure 9a: Aquifer Zone Selection Figure 9b: Aquifer Zone Construction
Aquifer zone tests are designed to isolate specific aquifer zones and to test for depth-specific production and water quality. It is done after drilling the pilot borehole and prior to constructing the well. Based on the analysis of formation samples collected during drilling and geophysical logs, three intervals are expected to be selected for aquifer zone testing. Figure 9a illustrates a hypothetical example of the zone selection process, whereby zones appearing to have the greatest production potential were selected for testing.
Zone testing begins with the construction of the first zone, which will be the lowermost selected zone. Backfill material consisting of 3/8-in diameter pea gravel is placed in the borehole to a depth of 10 feet below the selected zone. A 10-ft bentonite seal is placed on top of the backfill material to isolate any aquifers occurring below each zone selected for testing. Each isolated zone will span a 50-ft interval.
An 8-in diameter by 20-ft long perforated drill pipe will be used to test production. The perforated drill pipe will be attached to the bottom of a 6-in threaded drill pipe and lowered into the pilot hole. The 20-ft length perforated pipe is to be placed opposite the zone selected for testing, 15 feet from the bottom of the isolated zone. The annular space between the 8-in perforated pipe and the borehole will be backfilled using 3/8-in diameter pea gravel to 15 feet above the top of the perforated tool. A 10-ft bentonite seal will then placed on top of the filter pack material and allowed to hydrate for at least 1 hour to insure that the seal is firmly set would not break.
Following zone construction, the isolated zone will be developed by airlifting until water produced is clean enough such that a submersible pump could be used without sand and silt clogging the bowl assembly and seizing the motor. The time required for airlifting is dependent on the type(s) of formation encountered during the drilling.
After airlifting, a submersible pump will be placed inside the 6-in I.D. drill pipe (Figure 9b). The zone will be pumped initially at low production to further develop the zone and pull more formation water with a lesser risk of breaking the seal, until the discharge is significantly cleared from drilling fluid, formation mud and clay. The zone will be pumped for a minimum of one hour, although much more time may be needed, to acquire a representative formation sample for water quality analysis.
A calibrated flow meter, totalizer, and a gate valve are to be installed on the discharge line for accurate measurement and to control flow rate. Water levels will be measured with an electric sounder and pressure transducer to determine drawdown and specific capacity of the zone. Near the completion of pumping, GSi/water will collect water samples for Full Title 22 analysis and submitted to a certified laboratory. Turnaround time for Full Title 22 results, including radiological data is about four weeks.
Following completion of testing in the first zone, the tools will be removed and each successive zone will be constructed, developed and tested in the manner described above.
30
Geophysical Lithology Logs Zone #3 Construction GL Gamma RSN Single Spontaneous RLN Point Potential Resistance to ground surface 50 80-ft
Bentonite Seal 100 Zone 3 90-ft
150 Submersible Pump
200 100-ft 6-in diameter drill pipe
250 110-ft 8-in diameter perforated tool 300
Depth in feet bgs. 120-ft 350
400 Zone 130-ft 2 450 3/8-in diameter pea gravel 140-ft 500 Bentonite Seal
550 Zone 150-ft 1 3/8-in diameter 600 pea gravel
to 600-ft bgs NOT TO HORIZONTAL SCALE NOT TO HORIZONTAL SCALE
Figure 9a Figure 9b AQUIFER ZONE SELECTION AQUIFER ZONE CONSTRUCTION Chino Basin Desalter Authority Chino Basin Desalter Authority Ontario, California Ontario, California
06/09/10 Fig9_AquiferZoneSelection.ai water 06/09/10 Fig3_AquiferZoneSelection.ai water 31 WELL CONSTRUCTION Figure 10: Well Construction
This section provides a general overview of the anticipated well construction details, which are subject to revision based on information gathered during drilling, geophysical logging and aquifer zone testing. The 17.5-in diameter pilot hole will be reamed to a final diameter of 30-in from 50-ft to 125-ft depth and 26-in from 125-ft to 370-ft (includes 20-ft “rat hole”). Once the final reaming pass reaches the completion depth, the drilling fluid shall be thinned prior to running a caliper log. After the Caliper Log has been completed to the satisfaction of GSi/water, a tremie pipe shall be set in each borehole to a depth of not more than 30 feet above the bottom of the reamed borehole. Construction must be continuous, from installation of the casing to installation of the cement seal. Construction would begin with the installation of blank and louvered casing, a sounding tube, a camera tube, and two gravel feed tubes in the borehole. Gravel/Filter pack will be used to fill the annular space between the borehole wall and the casing, with a bentonite seal between screen intervals to isolate the Upper and Middle aquifer systems (see Figure 7, p. 25).
Casing sections will be joined by lap (fillet) welding around the circumference of the two connecting ends. Connections shall be by bell-and-spigot or factory-installed welding collars with at least three alignment holes. All welding shall be done by a qualified welder. A root pass shall be made at the fillet joining the casing sections. After slags have been removed, one or two filler passes shall be made. If bell-and-spigot connections are made, extreme care should be taken to insure proper alignment of the joints so that no “dog legs” result. Appropriate sized washers may be required. If welding collars are used, alignment holes shall be completely welded shut to insure a watertight seal. Centralizers shall be welded to the casing to center the casing in the borehole. They shall be placed at 60-ft intervals with a clearance of approximately 0.5 inches from the borehole wall. Centralizers attached to blank sections shall measure approximately 36 inches in length. Those attached to the well screen should be of an appropriate length such that they are not welded directly to the louvers, but to the blank portions of the louvered screens. The casing shall be suspended in tension from the surface by means of a landing clamp. The bottom of the casing shall be at a sufficient distance above the bottom of the reamed hole so that none of the casing will be supported from the bottom.
One 2-in diameter sounding tube and one 4-in diameter camera tube shall be attached to the outer surface of the well casing at 20-foot intervals. The sounding tube will allow for the installation of a pressure transducer to measure water levels in real time and shall be welded to the sounding tube connection port built into the well casing at 78-ft depth. The camera tube shall be welded to the camera tube connection port built into the well casing at 92-ft depth. Its purpose is to facilitate access for logging tools without first having to remove the pump. Two gravel feed tubes shall also be provided and shall extend 20-feet below the base of the inner cement seal and 3-feet above the existing grade. All tubes shall be provided with a standard cap.
After the well casing and screen are centered in the borehole, the drilling fluid will be thinned with clean water prior to installation of the filter/gravel pack, which shall be emplaced by tremie pipe and water circulation into the annular space between the borehole wall and the casing. To minimize potential bridging, the tremie pipe will be maintained a maximum of 60 feet above the top of the gravel pack. Liquid chlorine (sodium hypochlorite) will be added with the filter/gravel pack material. After the completion of the placement of the first filter/gravel pack interval, preliminary development should commence. Beginning at the bottom of the perforated interval, the swab is vigorously raised and lowered the length of the available drill mast. Drill pipes are removed to insure that swabbing occurs throughout the perforated interval. This helps break down bridges, fill voids, and flush the drilling fluids and debris from the gravel and formation. One or two passes through each perforated interval shall be done. The depth to the top of the gravel pack shall be measured to ascertain if any settling of the gravel pack has occurred. If needed, additional gravel will be added, after which the bentonite seal will be placed uniformly on top of the filter/gravel pack material, followed by the upper gravel pack interval with initial swabbing development.
A fine sand layer will be place atop the upper filter pack interval. This is to prevent the cement for the sanitary seal from disturbing the upper part of the filter/gravel pack material. Then, the remaining annular space shall be filled with 10.3-Sack Cement-Sand Grout. The placing of the cement shall be done in such a manner that the casing is entirely sealed against infiltration of water. The sanitary cement seal shall be left undisturbed for a period of not less than 24 hours before further work is engaged.
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Figure 10 WELL CONSTRUCTION Chino Basin Desalter Authority Ontario, California
06/09/11 Fig10_WellConstruction.ai water 33 Installation of Sounding Tube Installation of Well Casing
Installation of Gravel Pack via Tremie Pipe Installation of Cement Seal WELL DEVELOPMENT Table 5: Well Development Figure 11: Well Development
Well development is an integral phase of well construction. Well Development has two objectives. The first is to repair any damage done to the formation by drilling operations so that the natural hydraulic properties are restored. The second is to alter the basic physical characteristics of the aquifer near the borehole so that water will flow more freely to the well (Driscoll, 1986). It is critical that all new wells be developed long enough to produce consistently clean water and until the highest specific capacities are achieved. Well development will be completed in each well via two parts: first, by airlifting and dual-swabbing, and secondly, by pumping and surging.
Development by Airlifting and Dual-Swabbing (~60 hours)
After the seal has cured, initial development shall be by airlifting. An “open-ended” pipe is lowered to near the bottom of the well. An air compressor will provide air to an airline inside the drill pipe to lift the water and clean the remaining drilling fluids and sediment from the bottom of the well.
Following initial airlifting, a dual-swab tool will be added to the bottom of the drill pipe. The swab tool will be placed at different levels adjacent to the screened intervals to agitate the gravel pack material, remove all drilling mud, and to develop all water producing zones. The process will be repeated until most sand, silt, and mud has been washed and removed from the filter pack envelope. Development shall continue until all sand, silt and mud have been washed from the filter/gravel pack envelope.
Development by Pumping and Surging (~60 hours)
The effectiveness of initial development by airlifting and swabbing is a primary factor in the time required to complete development by pumping and surging. A vertical turbine pump is used to pump at different rates. The initial pumping rate shall be restricted and, as the water clears, it shall be increased gradually until the maximum rate is reached. The pump will be installed at a deeper depth than the final pump depth to be able to stress the aquifer enough to complete development.
At appropriate time intervals, typically every ½-hr, the pump shall be stopped and the water in the pump column shall be allowed to surge back through the pump bowls and through the well screen. The Drilling Contractor shall record drawdown and production rates and maintain a record of changes in specific capacity. Specific capacity is the ratio of production rate to drawdown in gpm/ft, which will increase as the amount of sand and sediment produced through pumping diminishes and production rates increase. Development shall continue until specific capacity ceases to increase and sand content is less than 5 parts per million (ppm).
Table 5. Well Development
Type Hours Airlifting & ~60hrs Dual Swabbing Pumping & ~60 hrs Surging Total ~120 hrs
34
Figure 11 WELL DEVELOPMENT Chino Basin Desalter Authority Riverside, California
06/13/11 Fig11_WellDevelopment.ai water
Development by Development by Airlifting & Swabbing (Beginning) Airlifting & Swabbing (End)
Development by Pumping & Surging
35 TEST PUMPING AND TITLE 22 WATER QUALITY ANALYSES Table 6: Title 22 Analytes
A pumping test is the most useful way of determining hydraulic properties of a well and aquifer system. Production testing for each well shall include an 8-hour step-drawdown pumping-test, a 24-hour constant rate pumping-test, and a recovery test. Before production testing commences, a minimum of 24 hours will be required following development pumping for water level recovery.
A step-drawdown pumping test is done by incrementally increasing the discharge rate and measuring the drawdown at each discharge increment. Water levels are typically monitored for a duration of two hours at each increment to see if they are able to stabilize. For each well, there will be four steps, each consisting of two hours in duration. GSi/water will monitor water levels in nearby accessible well to assess interference effects.
From the results of the step-drawdown test, GSi/water will recommend a production rate for the constant rate test. During the constant rate test, GSi/water will monitor changes in water level in the pumping well and any nearby accessible wells over the entire duration of the test.
Data from the constant rate test can be used to estimate transmissivity (T), the rate at which water flows through a vertical strip of aquifer one-foot wide and extending through the saturated thickness of the aquifer under a hydraulic gradient of one. Transmissivity values typically range from less than 100 to several hundred thousand gallons per day per foot-width of an aquifer (gpd/ft). Based on testing data from CDA Well I-5, we anticipate that the transmissivity of the Upper aquifer system may range from about 75,000 to 105,000 gpd/ft.
Near the conclusion of the constant rate pumping test, GSi/water will collect water samples for Full Title 22 analyses and submit them to a state certified laboratory (Table 5).
After the pump has been shut off, water levels will begin to rise or recover to static conditions. This is known as the recovery period. During recovery, GSi/water will measure changes in the depth to water over time until water levels reach 90% of original static water level.
36
Table 6. Title 22 Analytes 1,1,1,2-Tetrachloroethane 4,6-Dinitro-o-cresol Bromide Diethylbenzene Iodide Octylphenol polyethoxylate Sulfate (SO4) 1,1,1-Trichloroethane (1,1,1-TCA) 4-Bromophenyl Phenyl Ether Bromobenzene Diethylhexylphthalate (DEHP) Iodinated contrast media Odor Threshold @ 60 C Sulfide 1,1,2,2-Tetrachloroethane 4-Chloro-3-Methylphenol Bromochloroacetic Acid (BCAA) Diethylphthalate Iron (Fe) Oxamyl (Vydate) Terbacil 1,1,2-Trichloroethane (1,1,2-TCA) 4-Chlorophenyl phenyl Ether Bromochloromethane Diisopropyl Ether (DIPE) Isophorone o-Xylene Terbufos 1,1-Dichloroethane (1,1-DCA) 4-Chlorotoluene Bromodichloroacetic Acid (BDCAA) Dimethoate (CYGON) Isopropyl alcohol Parachlorometa cresol Terbufos Sulfone 1,1-Dichloroethylene (1,1-DCE) 4-Nitrophenol Bromodichloromethane Dimethyl phthalate Isopropylbenzene (Cumene) PCB-1016 (as decachlorobiphenyl (DCB)) tert-Amyl Methyl Ether (TAME) 1,1-Dichloropropane Acenaphthene Bromoform di-n-Butylphthalate Kerosine PCB-1221 (as DCB) tert-Butyl Alcohol (TBA) 1,1-Dichloropropene Acenaphthylene Bromomethane (Methyl Bromide) di-n-Octylphthalate Langelier Index at 60 C PCB-1232 (as DCB) tert-Butyl Formate (TBF) 1,2,3-Trichlorobenzene Acetaldehyde Butachlor Dinoseb (DNBP) Langelier Index at Source Temp. PCB-1242 (as DCB) tert-Butylbenzene 1,2,3-Trichloropropane Acetaminophen Cadmium (Cd) Diquat Lead (Pb) PCB-1248 (as DCB) Tetrachloroethylene (PCE) 1,2,3-Trimethylbenzene Acetochlor Caffeine Diuron Lindane (gamma-BHC) PCB-1254 (as DCB) Thallium 1,2,4-Trichlorobenzene Acetochlor Ethane Sulfonic Acid (ESA) Calcium (Ca) Endosulfan I Lipitor PCB-1260 (as DCB) Thiobencarb (BOLERO) 1,2,4-Trimethylbenzene Acetochlor Oxanilic Acid (OA) Carbamazepine Endosulfan II Lithium Pentachloroethane Toluene 1,2-Dichlorobenzene (o-DCB) Acetone Carbaryl (Sevin) Endosulfan Sulfate m,p-Xylene Pentachlorophenol (PCP) Total 1,3-Dichloropropene 1,2-Dichloroethane (1,2-DCA) Acrylonitrile (Acritet) Carbofuran (FURADAN) Endothall Magnesium (Mg) Perchlorate Total Anions 1,2-Dichloropropane Aggressiveness Index Carbon Dioxide Endrin Manganese (Mn) pH, Laboratory Total Filterable Residue @ 180 C (TDS)
1,2-Diphenylhydrazine Alachlor (ALANEX) also UCMR 2 Monitoring-TM 525.2 Carbon Disulfide Endrin Aldehyde MBAS (Foaming Agents) Phenanthrene Total Organic Carbon (TOC) 1,3-Dichloropropane Alachlor Ethane Sulfonic Acid (ESA) Carbon Tetrachloride Estrone Mercury (Hg) Phenol (Carbolic Acid) Total Trihalomethanes (TTHMs) 1,3-Dichloropropene, Total Alachlor Oxanilic Acid (OA) Carbonate (as CO3) Ethinyl estradiol Methadone Phosphate (as PO4) Total Xylenes (m,p, & o) 1,3-Dinitrobenzene Aldicarb (TEMIK) Chlorate Ethyl Benzene Methomyl Phosphate, Ortho (as PO4) Toxaphene 1,3,5-Trichlorobenzene Aldicarb Sulfone Chlordane Ethylene Dibromide (EDB) Methoxychlor Picloram trans-1,2-Dichloroethylene (t-1,2-DCE) 1,3,5-Trimethylbenzene Aldicarb Sulfoxide Chloride Ethylenediamine tetra-acetic acid (EDTA) Methyl Ethyl Ketone (MEK, Butanone) p-Isopropyltoluene Tribromoacetic Acid (TBAA) 1,3-Dichlorobenzene (m-DCB) Aldrin Chlorine Dioxide Ethyl-tert-Butyl Ether (ETBE) Methyl Isobutyl Ketone (MIBK) Polybrominated diphenyl ethers Trichloroacetic Acid (TCAA) 1,4-Dichlorobenzene (p-DCB) Alkalinity, (Total) (as CaCO3 equivalents) Chlorite Field pH Methyl tert-Butyl Ether (MTBE) Polychlorinated Biphenyls, Total, as DCB Trichloroethylene (TCE) 1,4-Dichlorobutane alpha-BHC Chloroethane Field Turbidity Metolachlor Potassium (K) Trichlorofluoromethane (FREON 11) 1,4-Dioxane Aluminum (Al) Chloroform (Trichloromethane) Fluoranthene Metolachlor Ethane Sulfonic Acid (ESA) Prometryn (CAPAROL) Trichlorotrifluoroethane (FREON 113) 17-B estradiol Ammonia Chloromethane (Methyl Chloride) Fluorene Metolachlor Oxanilic Acid (OA) Propachlor Triclosan 1-Naphthol Amoxicillin Chlorothalonil (DACONIL, BRAVO) Fluoride (F) (Natural-Source) Metribuzin Propane Tritium 2,2',4,4',5,5'-Hexabromobiphenyl Anthracene Chromium (Total Cr) Fluoride (Treatment Related-Distribution) Molinate (ORDRAM) p-Xylene Tritium Counting Error 2,2',4,4',5,5'-Hexabromodiphenyl Ether Antimony Chromium, hexavalent (CrVI) Foaming Agents (MBAS) Molybdenum Pyrene Tritium MDA95 2,2',4,4',5-Pentabromodiphenyl Ether Arsenic Chrysene Fonofos Monobromoacetic Acid (MBAA) RA-226 for CWS or Total RA for NTNC by 903.0 Turbidity, Laboratory 2,2',4,4',6-Pentabromodiphenyl Ether Asbestos Ciprofloxacin gamma-BHC Monochloroacetic Acid (MCAA) RA-226 or Total RA by 903.0 C.E. Uranium 2,2',4,4'-Tetrabromodiphenyl Ether Atrazine (AATREX) cis-1,2-Dichloroethylene (c-1,2-DCE) Gemfibrozil Monochlorobenzene (Chlorobenzene) RA-226 or Total RA by 903.0 MDA95 Uranium 2,2-Dichloropropane Azithromycin Cobalt Glyoxal Morphine Radium 226 Uranium Counting Error 2,3,7,8-TCDD (Dioxin) Barium (Ba) Color, Apparent (Unfiltered) Glyphosate m-Xylene Radium 226 Counting Error Uranium MDA95 2,4,5-TP (SILVEX) Bentazon (BASAGRAN) Combined Ra 226 + Ra 228 Gross Alpha Naphthalene Radium 226 MDA95 Vanadium 2,4,6-Trichlorophenol Benzene Combined Ra 226 + Ra 228 Counting Error Gross Alpha Counting Error n-Butylbenzene Radium 228 Vinyl Acetate 2,4,6-Trinitrotoluene (TNT) Benzidine Combined Ra 226 + Ra 228 MDA95 Gross Alpha MDA95 Nickel Radium 228 Counting Error Vinyl Chloride (VC) 2,4-D Benzo (a) Anthracene Copper (Cu) Gross Beta Nitrate (as NO3) Radium 228 MDA95 Zinc (Zn) 2,4-Dichlorophenol Benzo (b) Fluoranthene Cyanide Gross Beta Counting Error Nitrate + Nitrite as Nitrogen (N) Radon 222 2,4-Dimethylphenol Benzo (ghi) Perylene Dalapon Gross Beta MDA95 Nitrite as Nitrogen (N) Radon 222 Counting Error 2,4-Dinitrophenol Benzo (k) Fluoranthene DCPA (total di & mono acid degradates) Gross Beta, Calculated Dose Equivalent Nitrobenzene RDX (Hexahydro-1,3,5-trinitro-1,3,5-triazine) 2,4-Dinitrotoluene Benzo(a)pyrene delta-BHC Haloacetic Acids (five) (HAA5) N-Nitrosodiethylamine (NDEA) Salicylic acid 2,6-Dinitrotoluene Benzyl Butyl Phthalate Di(2-ethylhexyl) Adipate Hardness, (Total) as CACO3 N-Nitrosodimethylamine (NDMA) sec-Butylbenzene 2-Chloroethylvinyl Ether Beryllium Diazinon Heptachlor N-Nitrosodi-n-butylamine (NDBA) Selenium (Se) 2-Chloronaphthalene beta-BHC Dibenzo (a,h) anthracene Heptachlor Epoxide N-Nitrosodi-n-Propylamine Silica 2-Chlorophenol Bicarbonate (as HCO3) Dibromoacetic Acid (DBAA) Hexachlorobenzene N-Nitrosodi-n-propylamine (NDPA) Silver (Ag) 2-Chlorotoluene bis (2-Chloroethoxy) methane Dibromochloroacetic Acid (CDBAA) Hexachlorobutadiene N-Nitrosodiphenylamine Simazine (PRINCEP) 2-Methyl-4,6-Dinitrophenol bis (2-Chloroethyl) Ether Dibromochloromethane Hexachlorocyclopentadiene N-Nitrosomethylethylamine (NMEA) Sodium (Na) 2-Methylphenol bis (2-Chloroisopropyl) Ether Dibromochloropropane (DBCP) Hexachloroethane N-Nitrosopiperidine (NPIP) Sodium Absorption Ratio 2-Nitrophenol bis-1,1-Dimethylethylperoxide Dibromomethane Hexanol N-Nitrosopyrrolidine (NPYR) Source Temperature 3,3-Dichlorobenzidine bis-1,1-Dimethylperoxide Dicamba (BANVEL) Hydrazine n-Octacosane Specific Conductance (E.C.) 3-Hydroxycarbofuran Bisphenol A Dichloroacetic Acid (DCAA) Hydrogen Sulfide Nonylphenol Strontium – 90 4,4’-DDD Boron Dichlorodifluoromethane (Freon 12) Hydroxide (as OH) Nonylphenol polyethoxylate Strontium – 90 Counting Error 4,4’-DDE Bromacil (HYVAR) Dichloromethane (Methylene Chloride) Ibuprofen n-Propylbenzene Strontium – 90 MDA95 4,4’-DDT Bromate Dieldrin Indeno (1,2,3-cd) Pyrene Octylphenol Styrene
ENGINEER’S ESTIMATES Table 7: Engineer’s Estimates for Three Wells
Engineer’s estimates for the drilling, construction, development and testing of three Chino Creek production wells are shown in Table 7. The costs shown are based on (1) winning bids for similar projects recently completed in Southern California and (2) conversations with and preliminary estimates provided by the three major drilling companies in Southern California: Bakersfield Well and Pump, Best Drilling and Pump, and Layne-Christensen.
The total cost for the three wells, excluding well abandonment costs, comes to $1,633,650. This includes items 1-33 as detailed in Table 7 and excludes abandonment cost(s). Note that item number 4 in Table 7 does not include the cost of more advanced treatment options, if needed, such as filtration through granular activated carbon (GAC) media. The costs shown are approximate and are anticipated to change if too much time should elapse between the date of this report and the initiation of the bidding process.
38
Table 7. Engineer's Estimates for Three Wells Item Description Qty Unit Unit Price Total Item Price 1 Mobilization, demobilization, site clean up and restoration 6 site $ 34,000 $ 204,000 2 Provide Noise Control Measures (3 sites for three months) 3 site $ 48,000 $ 144,000 3 Testing and disposal of drill cuttings from pilot and conductor boreholes 3 site $ 11,000 $ 33,000 4 NPDES compliance including waste water treatment and water quality sampling 3 site $ 4,500 $ 13,500 5 Drill 48 inch diamter borehole to 50 feet, furnish and install 36 inch by 3/8 inch mild steel conductor casing with seal emplaced by pressure grouting 150 ft $ 500 $ 75,000 6 Drill minimum diameter 17.5 inch diameter pilot hole to 600 feet 1800 ft $ 60 $ 108,000 7 Provide geophysical borehole logging 3 sets $ 4,700 $ 14,100 8 Install seals, gravel envelope and tools for isolated aquifer zone testing (up to 3 per well) 9 zone $ 7,700 $ 69,300 9 Airlift and pump isolated zones (est. 20 hours per zone) 180 hrs $ 200 $ 36,000 10 Zone test Title 22 Water Quality Analyses (1 sample / zone) 9 each $ 3,500 $ 31,500 11 Ream pilot borehole to 30 inch diameter to 125 feet 375 ft $ 60 $ 22,500 12 Ream pilot borehole to 26 inch diameter to 350 feet 1050 ft $ 55 $ 57,750 13 Provide caliper survey of reamed borehole 3 each $ 1,700 $ 5,100 14 Furnish and install 16-inch ID x 0.3125-inch 304L stainless steel blank casing (92 ft/well) 276 ft $ 400 $ 110,400 15 Furnish and install 16-inch ID x 0.3125-inch304L stainless steel louvered casing (200 ft/well) 600 ft $ 500 $ 300,000 16 Furnish and install 16-inch ID x 0.3125-inch 304L stainless steel casing with 3-in x 3-in x 2-ft sounding tube connection port (20 ft/well) 60 ft $ 450 $ 27,000 17 Furnish and install 16-inch ID x 0.375-inch 304L stainless steel casing with 4-in x 4-in x 8-ft camera port attachment (20 ft/well) 60 ft $ 475 $ 28,500 18 Furnish and install 16-inch ID x 0.3125-inch 304L stainless steel casing with end cap (20 ft/well) 60 ft $ 450 $ 27,000 19 Furnish and install 2-inch (schedule 40) 304L stainless steel sounding tubes (80 ft/well) 240 ft $ 36 $ 8,640 20 Furnish and install 4-inch diameter 304L stainless steel camera tube (94 ft/well) 282 ft $ 45 $ 12,690 21 Furnish and install two 3-inch diamter mild steel gravel feed tube (2/well, 122 feet each) 732 ft $ 10 $ 7,320 22 Furnish and install filter pack and 5-ft fine sand layer (3 wells, each 370 ft) 1110 ft $ 40 $ 44,400 23 Furnish and install inner bentonite grout seal (20-ft/well) 60 ft $ 35 $ 2,100 24 Furnish and install anular cement seal (3 wells, 100 ft) 300 ft $ 56 $ 16,800 25 Develop and clean wells by airlifting and dual-swabbing (est. 60 hr/well) 180 hrs $ 350 $ 63,000 26 Furnish, install and remove development/test pump 3 each $ 18,000 $ 54,000 27 Provide well development by pumping and surging with turbine pump (est. 60 hrs/well) 180 hrs $ 250 $ 45,000 28 Provide pumping tests for yield and drawdown (40 hrs/well) 120 hrs $ 250 $ 30,000 29 Provide static and dynamic spinner surveys 3 set $ 4,000 $ 12,000 30 Provide plumbness and alignment gyroscopic deviation survey 3 each $ 2,800 $ 8,400 31 Title 22 water quality analysis (3 wells) 3 each $ 3,500 $ 10,500 32 Well disinfection, wellhead completion and capping, site clean-up 3 each $ 2,800 $ 8,400 33 Provide Dual-Cam video survey on DVD (3 wells) 3 each $ 1,250 $ 3,750 34 Abandonmnet of pilot hole in accordance with county standards, if required 1800 ft $ 25 $ 45,000 TOTAL ESTIMATED BID PRICE (3 WELLS) - ITEM 1 - 33 $ 1,633,650
Appendix A
Summary of Existing Wells in the Chino Creek Area Well Construction Details
I-1 I-2 I-3 I-4 I-5 I-8 I-9 I-10 I-16 I-18 290 ‐ 300 260 ‐ 330 235 ‐ 275 200 ‐ 280 160 ‐ 245 180 ‐ 275 190 ‐ 220 180 ‐ 270 100 ‐ 140 100 ‐ 176 Upper 320 ‐ 400 ‐ 360 ‐ 470 ‐ ‐ ‐ 260 ‐ 340 ‐ ‐ ‐ Middle Intervals Perforated 480 ‐ 500 406 ‐ 456 500 ‐ 525 390 ‐ 480 345 ‐ 385 340 ‐ 416 390 ‐ 430 280 ‐ 340 ‐ 196 ‐ 312 Lower Diameter 18 18 18 18 18 16 16 16 18 18 Depth 520 485 546 500 405 435 450 360 170 332
Layer 1 0% 0% 0% 0% 66% 33% 26% 60% 100% 47% *
Layer 2 100% 100% 100% 100% 44% 67% 74% 40% ‐ 53% in Aquifer Systems in Aquifer Layer 3 ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ ‐ Estimated Proportion of Screen Screen Proportion of Estimated
* All estimates based on Chino Basin cross‐sections developed by Wildermuth (2007) Production Rate Statistics
Initial Production Well Minimum1 Maximum1 Average1 Actual2 Period of Record Testing digital analog AFD gpm AFD gpm AFD gpm gpm ft drawdown From To gpm gpm I-1 0.44 101 3.22 730 1.87 423 401 400 970 160 7/1/2001 6/30/2010 I-2 0.04 8.54 0.91 207 0.65 147 264 140 368 160 10/1/2001 6/30/2010 I-3 1.78 405 2.47 558 2.22 503 546 560 908 135 4/1/2005 6/30/2010 I-4 0.06 13.7 1.5 341 1.02 231 262 220 560 120 7/1/2001 6/30/2010 I-5 0.13 29 6.19 1401 3.3 748 1040 25 7/1/2010 6/30/2010 I-8 0.03 7.59 5.07 1147 2.49 563 650 697 1200 50 7/1/2001 6/30/2010 I-9 0.61 137.9 4.92 1115 2.72 615 837 837 1200 35 4/1/2002 6/30/2010 I-10 0.22 49 5.38 1218 3.23 779 1100 23 7/1/2002 6/30/2010
1 Accuracy limited. Estimated from quarterly data assuming constant production rate. 2 Good accuracy. Based on actual reading from flow meter. Water Level Statistics
I-1 I-2 I-3 I-4 I-5 I-8 I-9 I-10 Minimum 107 93 72 55 79.2 87.8 64 92.9 Maximum 179 282 124 170 92 113 111 139
S W L Average 129.7 118.6 78 92.05 85.3 99.1 102.4 107.4
Count 9 241 513 215 12 16 275 415
From 4/25/2002 7/26/2000 11/7/2001 7/26/2000 6/19/2001 6/19/2001 8/9/2000 7/12/2000 Record Record
Period of To 4/3/2003 2/26/2007 3/15/2004 6/28/2003 1/27/2011 1/27/2011 2/26/2007 10/25/2006
Minimum 78.7 115 82 103 79.8 93.9 95 110.9 Maximum 269.6 289 257 284 172 236.6 143 128
P W L Average 246.3 270.4 179.7 191.5 142 146.4 127 122
Count 895 542 269 549 782 782 380 86
From 6/16/2000 6/16/2000 11/7/2001 1/17/2001 6/16/2000 6/16/2000 7/12/2000 3/3/2003 Record Record Period of To 9/30/2008 9/30/2008 3/15/2004 4/15/2008 2/23/2011 2/23/2011 11/5/2008 5/18/2007
Appendix B
Hydraulic Control Monitoring Well Water Level Graphs
HCMP 1 0 HCMP1/1 10 HCMP1/2 20 HCMP1/3 30 bgs)
(ft 40 Level 50 Water 60
70 Ground
80
90
100 1/1/2005 1/1/2006 1/1/2007 1/1/2008
12/31/2008 12/31/2009 12/31/2010
HCMP 2
0 HCMP 2‐1 10 HCMP 2‐2 20
30 bgs)
(ft 40 Level 50 Water 60
70 Ground
80
90
100 1/1/2005 1/1/2006 1/1/2007 1/1/2008 12/31/2008 12/31/2009 12/31/2010 12/31/2011
HCMP 3 0
10
20
30 bgs)
(ft 40 Level 50 Water 60
70 Ground HCMP 3‐1
80 HCMP 3‐2
90 HCMP 3‐3
100 1/1/2005 2/9/2009 5/16/2006 9/28/2007 6/24/2010 11/6/2011
HCMP 4
0
10
20
bgs) 30
(ft 40 Level 50 Water
60
70
Ground HCMP 4‐1 80 HCMP 4‐2 90
100 1/1/2005 1/1/2006 1/1/2007 1/1/2008 12/31/2008 12/31/2009 12/31/2010 12/31/2011
HCMP 5
0
10
20
bgs) 30
(ft 40 Level 50 Water
60
70
Ground HCMP 5‐1 80 HCMP 5‐2 90
100 1/1/2005 2/9/2009 5/16/2006 9/28/2007 6/24/2010 11/6/2011
HCMP 6
0
10
20
30 bgs)
(ft 40 Level 50 Water 60
70
Ground HCMP 6‐1 80 HCMP 6‐2
90 HCMP 6‐3
100 1/1/2005 1/1/2006 1/1/2007 1/1/2008 12/31/2008 12/31/2009 12/31/2010 12/31/2011
HCMP 7
0
10 HCMP 7‐1 HCMP 7‐2 20
30 bgs)
(ft 40 Level 50 Water 60
70 Ground 80
90
100 1/1/2005 1/1/2006 1/1/2007 1/1/2008 12/31/2008 12/31/2009 12/31/2010 12/31/2011 Well Statistics
Reference Perforated SWL No. of Data Well No. Average SWL Point Elevation Depth Interval SD Points ft asl ft below reference point ft Mean Median 1/1 618.52 135 - 175 70 70.1 2.04 1904 1/2 618.52 300 - 320 75.3 74.9 3.5 1907 1/3 618.52 410 - 430 75.7 75.5 3.4 1907
2/1 608.65 124 - 164 62.5 62.4 2.1 3668 2/2 608.64 296 - 316 66.9 66.8 3.1 2397
3/1 582.02 110 - 150 37.2 37.5 2.9 2787 3/2 582.04 344 - 364 38.7 38.6 3.6 2080 3/3 582.04 560 - 580 39 39.2 3.5 2058
4/1 553.23 65 - 105 30.3 29.5 7.4 2329 4/2 553.22 240 - 260 58.2 58.4 14 13092
5/1 572.6 90 - 130 33.5 33.9 2.2 2855 5/2 572.6 160 - 180 36.8 37 1.5 3388
6/1 541.78 60 - 100 31.1 31.4 2 2190 6/2 541.77 276 - 296 27.6 27.3 2 2251 6/3 541.74 462 - 482 30.8 30.7 1.9 2059
7/1 597.31 70 - 110 49.1 51 4.2 1873 7/2 597.31 200 - 220 51.2 52.3 3.3 6280
Appendix C
Anticipated Filter Pack Design
ANTICIPATED FILTER PACK DESIGN
A properly installed gravel pack provides a filter for formation particles to allow for the production of relatively sand-free water from the completed well. Careful design is required to select an appropriate blend that will enhance the natural hydraulic conductivity of the formation materials without diminishing the potential hydraulic efficiency of the completed well.
Ultimately, the final recommended design for the filter pack envelope will be based on mechanical gradation analysis (sieving) of samples collected from at least eight different depth intervals for each well. The samples selected for sieve analysis will be the finest formation materials that are likely to yield sufficient ground water.
Based on our interpretation from the available driller’s and lithologic logs in the area of proposed wells I-19, I-20 and I-21, it is anticipated that the filter pack design will be similar to 4 x 16 custom blend, as summarized on the table below. However, because the final design depends heavily on the actual formations encountered, the final recommended design may be different from what is shown below. The filter pack envelope shall consist of clean, well-rounded particles with low calcareous content (< 5%), with an average specific gravity of at least 2.5.
U.S. Standard Sieve No. Sieve Opening (in) Cumulative Percent Passing ¼-in 0.25 100 4 0. 187 99 6 0. 132 76 8 0.0 94 40 12 0.0 66 10 16 0.0 47 4 20 0.0 33 0
The following will be considered when preparing the final recommended filter pack design:
- Mid-size of the filter pack will be approximately 4 to 6 times greater than that of the finest formation;
- Uniformity co-efficient of the filter pack will be no greater than about 2.5. The uniformity co-efficient is defined as the ratio of the 60% passing size to the 10% passing size;
- The sieve curve for the filter pack shall be parallel to the central part of the sieve curve resulting from mechanical gradation analysis of formation samples;
- The recommended perforation aperture will, in turn, depend on the selected filter pack design with an estimated range of 20% to 35% of filter pack material permitted to pass through during well development.