Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

DAVAO RIVER

Davao River may be traced to as far as the mountain ranges within San Fernando, Bukidnon and Davao del Norte on the northern boundary, North Cotabato on the western boundary and the major portion within the territory of Davao City. It flows southward, meandering through the central part of Davao City and finally flows eastward emptying into Davao Gulf on the southern periphery of the city proper.

Suawan River, Tamugan River, Lamanan River and Siao River are the main tributaries; however, there are also creeks that drain into it.

At the estuary portion, a delta exists and siltation is evident along the Magallanes - Bankerohan and Isla Berde reach. The siltation is largely visible usually during low tide and normal level of the river.

The river’s present uses are domestic utilization such as bathing, washing and occasional fishing. The river is also the venue for water rafting. It has become one of the exciting adventures the city could offer to its people and tourists.

It is also utilized for agricultural purposes. Small-scale farmers use the water from the river to irrigate and water their crops. Big banana plantations also utilized the river to irrigate its plantations.

On the river itself could be found small scale as well as large scale sand and gravel quarry operations. This has been a major source for contractors for their sand and gravel needs.

At the downstream portion, the river traverses through the commercial, industrial, agro- industrial and residential areas.

The river is also an alternative pathway for navigation. At the Bankerohan and Bolton areas people cross the river via small water transports. Fishermen make use of the river to and from their homes and the Davao Gulf.

Davao River is classified into:

Class B – Sta. 1-4 (Downstream) Class A - Sta. 5-8 (Upstream)

Monitoring Stations

There were fourteen (14) sampling stations identified as shown in the map below.

There were six (6) additional sampling stations monitored. Four (4) stations were added in between stations 3 and 4. One station each is added upstream of stations 4 and 5. Sampling stations were added in order to get a more accurate water quality data of the river.

In addition to the primary parameters monitored, Nitrate-N, Phosphate-P, Cadmium, Copper, Lead and Zinc were also monitored in selected stations due to financial constraints. These parameters were analyzed in one of EMB’s recognized laboratories. Total and Fecal Coliforms were also monitored.

Davao River is designated as one of the Priority Rivers and proposed to be designated as Water Quality Management Area (WQMA).

Interpretation of Data

The parameters monitored are Color, Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), Nitartes-N, Phosphates-P, Total Coliform, Fecal Coliform, Cadmium, Lead, Copper and Zinc. Total Dissolved Solids is also monitored for Class A water. The frequency of monitoring is on a monthly basis except for heavy metals which is monitored quarterly.

Stations 1-4 (Class B water)

Average values for Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Cadmium and Lead are within the water quality criteria for Class B water except for Total and Fecal Coliforms and Phosphates-P as prescribed in Table 1, Section 69 of DAO 34. There are no numerical water quality criteria for TSS, Nitrates, Copper and Zinc for Class B water. High TSS value obtained could be attributed to soil erosion after a rainfall. Summary of Results is shown in the table below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 7 100 27 No Abnormal Discoloration Temperature °C 26 30 27 max. of 3 ْ C rise pH 7.7 8.5 8.1 6.5-8.5 Dissolved Oxygen ,mg/L 1.3 7.9 7.0 5.0 Biochemical Oxygen Demand, 0.5 7.2 2.7 5 mg/L Total Suspended Solids, mg/L 24 4,851 1,063 Not more than 30 % increase Total Coliform, MPN/100ml 45x102 16x104 11x104 1,000 Fecal Coliform, MPN/100ml 14x102 16x104 52x103 200 Nitrate-N, mg/L <0.10 0.90 0.23 nr Phosphates-P, mg/L 0.09 1.16 0.36 0.2 Cadmium, mg/L <0.001 0.019 0.005 0.01 Lead, mg/L <0.01 0.06 0.02 0.05 Copper, mg/L 0.01 0.13 0.04 - Zinc, mg/L 0.01 0.06 0.03 -

During the one-year sampling, all samples collected passed the water quality criteria for Color, Temperature and pH.

Ninety Nine percent of the samples collected passed the water quality criteria for DO while 95.4% of the samples collected passed the water quality criteria for BOD. There was only one instance that DO level did not meet the water quality criteria of 5.0 mg/L for Class B water while for BOD, there were five instances that BOD level did not meet the water quality criteria but some BOD values obtained were near the maximum value as shown in Fig. 1.

There are houses located along the river bank of the said stations. There are also discharge outfalls of the city’s drainage located along the river bank. Wastewater coming from these sources is high in organic waste which contributes to an increase in BOD level.

Only 27.4% of the samples collected for Phosphates-P passed the water quality criterion of 0.2 mg/L as shown in Fig. 2. Potential sources of phosphorus are agricultural run-off, industrial, commercial and domestic wastes. There are agricultural plantations, industrial, commercial and residential establishments located along the river.

For heavy metals, only 93.8% of the samples monitored passed the water quality criteria of 0.05 mg/L for Lead while 87.5 % passed the water quality criteria for Cadmium. There was only one instance that Lead concentration exceeded the water quality criteria and two

instances that exceedance in Cadmium were observed. Potential sources of Cadmium are batteries and paints while potential sources of Lead are paints, solders, corrosions from water distribution system and pesticides.

For Total and Fecal Coliforms, all samples collected did not pass the water quality criteria of 1,000 MPN/100ml and 200 MPN/100ml, respectively. Sources of Coliform bacteria are from domestic and industrial wastewater discharges, septic tanks, animals and wildlife. Fecal Coliform comes from human and animal wastes. It serves as an indicator of fecal contamination that causes water borne diseases. There are houses located near the river and at present, the city has no sewerage system, all domestic wastewater drains into the river. There are houses that have no toilets, some have toilets but septic tanks are not frequently desludge.

Fig. 1

BIOCHEMICAL OXYGEN DEMAND

WQ Criteria 5 mg/L mg/L mg/L Class B

Station No.Station No.

Fig. 2

Phosphates-P J 1.4 F 1.2 M 1 A 0.8 M mg/L Jun 0.6 WQ Criteria 0.4 0.2 mg/L Jul A 0.2 Class B S 0 1 2 3 4 4a O N D

Stations 5-8 (Class A)

Average values for Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Total Dissolved Solids, Nitrates-N, Lead, Cadmium and Copper are within the water quality criteria for Class A water except for Total Suspended Solids, Phosphates-P, Total Coliform and Fecal Coliform as prescribed in Table 1, Section 69 of DAO 34. There is no water quality criterion for Zinc for Class A water. Summary of Results is shown in the table below.

Parameter Min Max Ave Water Quality Criteria Class A water Color 1 70 22 No Abnormal Discoloration Temperature, ⁰C 22 30 27 max of 3 ْ C rise pH 7.8 8.6 8.2 6.5-8.5 Dissolved Oxygen, mg/L 6.5 8.2 7.3 5.0 BOD (5-day) mg/L 0.8 6.2 1.9 5 Total Dissolved Solids, mg/L 63 742 227 1,000 Total Suspended Solids, mg/L 3 3,440 572 50 Total Coliform, MPN/100ml 200 35x104 13x103 1,000 Fecal Coliform, MPN/100ml 179 17x104 81x102 200 Nitrates-N, mg/L <0.10 1.4 0.27 10 Phosphates-P, mg/L <0.01 0.93 0.21 0.1 Lead, mg/L <0.01 0.06 0.03 0.05 Cadmium, mg/L <0.001 0.008 0.003 0.01 Copper, mg/L <0.01 0.04 0.02 1.0 Zinc, mg/L <0.01 0.05 0.03 -

During the one year sampling, all samples collected passed the water quality criteria for Color, Temperature, Dissolved Oxygen, Total Dissolved Solids, Nitrate-N, Cadmium and Copper.

For pH and BOD, 98.3% of the total samples collected passed the water quality criteria. There was only one instances that exceedance was both observed for pH and BOD.

For TSS, only 23.3 % of the total samples collected passed the water quality criterion of 50 mg/L for Class A water. However, for the entire sampling period Total Suspended Solids at station 7 consistently passed the water quality criterion as shown in Fig. 3.

Only 25 % of the total samples collected passed the water quality criteria of 0.1 mg/L for Phosphates-P as shown in Fig.4. The river is surrounded with agricultural plantations.

Whereas, all samples collected for Total Coliform and Fecal Coliform did not meet the water quality criteria of 1,000 MPN/100ml and 200 MPN/100ml respectively. Sources of Coliform bacteria are domestic and industrial wastewater discharges, septic tank, animal and wildlife. Fecal Coliform comes from human and animal wastes. It serves as an indicator of fecal contamination that causes water borne diseases. There are houses located near the river and at present, the city has no sewerage system, all domestic wastewater drains into the river. There are houses that have no toilets or septic tanks are

not frequently desludge. There are also poultry and hog farms that discharge its wastewater into the river.

Fig. 3

Total Suspended Solids J 3000 F 2800 2600 M 2400 2200 A 2000 M 1800 1600 Jun mg/L 1400 1200 Jul 1000 800 A 600 WQ Criteria 400 50 mg/L S 200 O 0 Class A 5 5A 6 7 8 N Station No. D

Fig. 4

J 1 Phosphates-P F 0.9 0.8 M 0.7 A 0.6 M mg/L 0.5 0.4 Jun 0.3 WQ Criteria Jul 0.2 0.1 mg/L 0.1 A 0 Class A S 5 6 7 8 O Station No. N

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of Davao River at the downstream portion conforms to its present classification except at this time; it does not meet the water quality criteria for Phosphates-P, Total Coliform and Fecal Coliform. At the upstream portion of the river, the water quality conforms to the classification for Class A water except for Total and Fecal Coliforms, Phosphates-P and Total Suspended Solids.

Alteration in the water quality could be attributed to organic wastes discharged into the river, agricultural run-off and surface run-off.

Monitoring should be continued in order to determine the trend and water quality of the river. Data gathered in the monitoring could be used as a basis for the formulation of policy relevant to the protection and preservation of the river.

To maintain or improve the water quality of the river, the following are recommended:

1. De-silt the river; 2. Trees and cover crops should be planted not only along the riverbank but also in areas prone to soil erosion; 3. Proper quarrying procedure should be strictly imposed; 4. Agricultural activities that tend to cause soil erosion should be discouraged and the concept of soil and water conservation should be imparted to farmers; 5. Strict monitoring of WTF of industries; 6. Provision of standard septic tanks for all residential and commercial buildings located along the river bank; 7. Provision of a sewerage / septage system; 8. Encourage households / dwellings/ institutional / establishments to desludge septic tanks regularly; and 9. Proper solid waste management.

It is also recommended that Davao River be designated as Water Quality Management Area so that above approaches will be implemented through a holistic approach and with proper delegation and coordination.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

TALOMO RIVER

Talomo River is a waterway which originates from Mt. Talomo and adjoining Apo Range located at the eastern portion of Davao City. It is generally characterized by a semi-rough topography with gradient from gradual steep to steep slope. A number of creeks are connected to it such as Tagakpan Creek in Barangay Tagakpan, Wangan Creek at Barangay Wangan and the creeks at Barangays Baguio and Malagos, all in Davao City. It flows east-southerly direction, curves out and finally empties into Talomo Bay.

Big boulders can be found at the upper reaches of the river towards Mintal area. Abundant sand materials can be found downstream of the said river particularly from Mintal towards Brgys. Ulas and Bangkal. The estuarine portion of the said river is characterized predominantly with muddy soil.

The river is used for domestic purposes such as bathing and swimming. It also traverses through agro-industrial, industrial, hydropower plant and residential areas.

At Brgy. Mintal, the river is diverted through a diversion canal and used to service the hydro power plants of the Hedcor, Inc.

Talomo River is classified as Class B water.

Monitoring Stations

There were four (4) sampling stations identified as shown in the map below.

Sta.1 – Mouth of the river Sta. 2- Ulas Bridge Sta.3 – NPC Area, Mintal Sta.4 – Angalan Bridge III, Tugbok

Interpretation of Data

The parameters monitored are Color, Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS). The frequency of monitoring is on a monthly basis. Talomo River is designated as one of the Priority Rivers.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class B water as prescribed in Table 1, Section 69 of DAO 34. . TSS level ranges from 18 mg/L – 178 mg/L. For Class B water, there is no numerical water quality criterion for TSS. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 10 70 26 No Abnormal Discoloration Temperature ْ C 25 30 27 max of 3 °C rise pH 7.4 8.0 7.7 6.5-8.5 Dissolved Oxygen, mg/L 5.3 7.9 7.1 5.0 BOD (5-day), mg/L 0.6 7.0 2.4 5 Total Suspended Solids, mg/L 18 178 55 Not more than 30 % increase

One Hundred percent of the total samples collected passed the water quality criteria for Color, Temperature, pH and Dissolved Oxygen.

For BOD, only 95.8% of the total samples collected passed the water quality criterion of 5.0 mg/L for Class B water. There were only two instances that exceedance was observed; one at station 1 and the other at station 4. Potential causes of high BOD are discharges from residential, industrial, agro-industrial and commercial establishments.

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of Talomo River still conforms to its present classification.

Monitoring should be continued in order to determine the trend and water quality of the river. Data gathered in the monitoring could be used in formulating policy relevant to the protection and preservation of the river.

To improve the water quality of Talomo River, the following are recommended:

5. Provision of septic tanks for all residential and commercial buildings located along the river bank; 6. Provision of a sewerage / septage system; 7. Encourage households / dwellings/ institutional / establishments to desludge septic tanks regularly; and 8. Proper solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

LIPADAS RIVER

Lipadas River is a waterway which originates from the upper reaches of Mt. Talomo passing through Brgys. Baracayo, Bangkas, Manambulan, Alambre and Mulig. It is joined by a main tributary which is the Lubogan River with sources coming from the upstream tributaries such as the Tagluno River, Kilate River and Bato River. It then continues to meander further downstream and joined at Brgy. Lezada by another tributary which is the Marapangi Creek. It then finally empties itself into Davao Gulf.

The river traverses through agricultural, agro-industrial and residential areas.

The river’s uses are for domestic utilization such as bathing and washing of clothes. It is also use for bathing and drinking of domesticated animals and irrigation purposes. Sand and gravel extraction is also done at the said river.

Lipadas River has multiple classifications such as:

Class AA - Upstream from National Park to Brgy. Baracayo Class A - Brgy. Baracayo to Brgy. Bangkas Class B - Midstream (Brgy. Bangkas to Brgy. Alambre Class C - Downstream ( Brgy. Alambre to confluence of Davao Gulf.

Monitoring Stations

Monitoring of Lipadas River is only at the downstream portion because of accessibility. Monitoring at Station 4 was no longer included because it is no longer significant; however, four sampling stations were added to give representative samples of the stretch of the river being monitored.

Data Interpretation

The parameters monitored are Color, Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS). Lipadas River is designated as one of the Priority Rivers. The frequency of monitoring is on a monthly basis.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class C water as prescribed in Table 1, Section 69 of DAO 34. . TSS level range from 2 mg/L – 126 mg/L. There is no water quality criterion for TSS for Class C water. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class C water Color 1 30 12 No Abnormal Discoloration Temperature ْ C 24 28 26 max of 3 ْ C rise pH 6.7 8.3 7.7 6.5-8.5

Dissolved Oxygen, mg/L 0 8.5 6.8 5.0

BOD (5-day), mg/L 0.5 48.0 5.8 7

Total Suspended Solids, mg/L 2 126 18 Not more than 30 mg/L increase

One hundred percent of the total samples collected passed the water quality criteria for Color, Temperature and pH.

For Dissolved Oxygen, only 88 % of the total samples collected meet the water quality criteria of 5 mg/L. Exceedances were observed at stations 1, 2 and 6 as shown in Fig.1.

Similarly, of the total samples collected, only 78.7 % meet the water quality criteria for BOD. Exceedances were observed at stations 1, 2, 3 and 6 as shown in Fig.2.

Low Dissolved Oxygen level and high BOD values indicates organic wastes were being discharged into the river. Sources of organic wastes are domestic wastes and discharges of wastewater from industries and piggery farms located within the area.

Fig. 1

Dissolved Oxygen

WQ Criteria 5.0 mg/L mg/L Class C

Fig.2

Biochemical Oxygen Demand 50 J 45 F 40 M 35 30 A mg/L 25 M 20 WQ Criteria Jun 15 7 mg/L 10 Jul Class C 5 A 0 1 2 3 5 6 7 8 9 10 S Station No. O

Conclusion and Recommendations:

Based on the parameters monitored, the water quality of the river still conforms to its present classification except that DO and BOD level at stations 1 and 2 exceeded the water quality criteria.

Alteration in the water quality of the river could be attributed to organic wastes discharged into the river.

Sta.No. Monitoring should be continued in order to determine trend and water quality of the river. Data gathered in the monitoring could be used in formulating policy relevant to the protection and preservation of the river.

DO, mg/L

To improve the water quality of Lipadas River, the following are recommended:

1. Trees and cover crops should not only be planted along the river bank but also in areas prone to soil erosion; 2. Proper quarrying procedure should be strictly imposed; 3. Agricultural activities that tend to cause soil erosion should be discouraged and the concept of soil and water conservation should be imparted to the farmers; 4. Strict Monitoring of the WTF of industries and livestock farms; 5. Provision of appropriate specifications of septic tanks for all residential and commercial buildings; 6. Require the desludging of septic tanks every three years through an enactment of a city ordinance on sewage and septage management ; 7. Provision of a sewerage/ septage system; and 8. Proper solid waste management.

Further, it is also recommended that the river be designated as Water Quality Management Area so that the above proposal will be implemented through proper delegation and coordination.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

DIGOS RIVER

Digos River is a combination of two upper branching rivers namely Napan River and Ruparan River with headwater or source both at Mt. Ruparan.

It traverses through agricultural, industrial, commercial and residential areas. It flows downward and finally empties to Davao Gulf at Chapter 3, Abuno, Brgy. Aplaya.

Digos River is classified into : Class B – Sta. 1-2 (Downstream ) Class A - Sta. 3-6 (Upstream)

Monitoring Stations

There were six (6) sampling stations identified as shown in the map.

Sta. 1 – Mouth of the river Sta. 1a –At Digos Bridge II Sta. 2 – At Caños Bridge Sta. 3 - Below Ebreo Bridge (formerly Power Bridge) Sta. 4- Digos River, approx. 100 meters downstreamfrom confluence of Napan and Ruparan Rivers Sta. 5- Napan River at Purok Labander Sta.6- Napan River at Scriptures Park, Bo. Goma

Data Interpretation:

Sta. 1-2 (Class C)

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Total Suspended Solids. Monitoring is conducted quarterly.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class C water as prescribed in Table 1, Section 69 of DAO 34. . TSS level range from 10 mg/L – 111 mg/L. There is no water quality criterion for TSS for Class C water. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class C water Color 1 30 13 No Abnormal Discoloration Temperature ᵒC 23 32 26 max of 3 ْ C rise pH 7.6 8.5 7.9 6.5-8.5 Dissolved Oxygen, mg/L 6.4 7.8 7.4 5.0 BOD (5-day), mg/L 1.1 2.0 1.8 7 Total Suspended Solids, mg/L 10 111 36 Not more than 30 mg/L increase

All samples collected passed the water quality criteria for Color, Temperature, Dissolved Oxygen and Biochemical Oxygen Demand except for pH. There was one instance that pH exceeded the maximum pH value of 8.5.

Sta. 3-6 (Class B)

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Total Suspended Solids. Monitoring is conducted quarterly.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class B water as prescribed in Table 1, Section 69 of DAO 34. . TSS level range from 4 mg/L – 80 mg/L. There is no water quality criterion for TSS for Class B water. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 1 30 13 No Abnormal Discoloration Temperature ᵒ C 23 29 26 max of 3 ⁰C rise pH 7.9 8.6 8,2 6.5-8.5 Dissolved Oxygen, mg/L 5.8 7.8 7.3 5.0 BOD (5-day), mg/L 1.1 2.6 1.9 5 Total Suspended Solids, mg/L 4 80 29 Not more than 30 % increase

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of the river conforms to the standards for Class B & C waters.

Alteration in the water quality of the river could be attributed to the wastewater coming from industry, slaughterhouse, residential, hospital, institutional and commercial establishments, agricultural run-off and improper solid waste management.

Monitoring should be continued in order to determine trend and water quality of the river. Data gathered in the monitoring could be used in formulating policy relevant to the protection and preservation of the river. More parameters should be included in the monitoring to get a true picture of the water quality of the river.

To improve or maintain the water quality of Digos River, the following are recommended:

1. Planting of trees and cover crops not only along the riverbank but also in areas prone to soil erosion; 2. Best agricultural practices should be strictly implemented and promote organic farming; 3. Strict monitoring of WTF of industries and livestock farms; 4. Provision of appropriate specification of septic tanks for all residential and commercial buildings not only those located along the river bank; 5. Require the desludging of septic tanks once in every three years through the enactment of a city ordinance on septage management; 6. LGU should put up Septage Facility or community- based technologies for Domestic Wastewater Treatment and Reuse; and 7. Strict implementation of LGU’s ordinance on solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

PADADA RIVER

Padada River originates at its headwater at Matanao, Davao del Sur. It flows, meanders and joined downstream by Mainit River. It finally empties to Davao Gulf at Guihing, Hagonoy, Davao del Sur.

It traverses through ricefields, banana and mango plantations, sugar mill and residential areas at the downstream portion of the river.

The river is used as source of irrigation water of NIA servicing ricefields nearby. Banana and mango plantations also use the river to irrigate their plantations. The river is also use as cooling water. Sand and gravel extraction is also present in the area.

Padada River is classified as Class D water.

Monitoring Stations There were three (3) monitoring stations identified as shown in the map.

Sta. 1 – Mouth of the river Sta. 2 – At Padada Bridge Sta. 3 – NIA Dam

Data Interpretation:

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Total Suspended Solids. Monitoring is conducted quarterly.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class D water as prescribed in Table 1, Section 69 of DAO 34. . TSS level range from 40 mg/L – 420 mg/L. There is no water quality criterion for TSS for Class D water. Summary of Results is shown below. Parameter Min Max Ave Water Quality Criteria Class D water Color 20 50 30 No Abnormal Discoloration Temperature ᵒC 22 31 26 max of 3 ᵒC rise pH 7.6 8.2 7.9 6.0-9.0 Dissolved Oxygen, mg/L 6.4 7.5 7.0 3.0 BOD (5-day), mg/L 1.6 3.0 2.4 10 Total Suspended Solids, 40 420 213 Not more than mg/L 60 mg/L increase

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of the river conforms to its present classification.

Alteration in the water quality of the river could be attributed to the effluent of the existing Wastewater Treatment Facility of a sugar mill, domestic wastes, agricultural run-off and improper solid waste management.

To improve or maintain the water quality of Padada River, the following are recommended:

1. Re-classify the river; 2. Planting of trees and cover crops not only along the riverbank but also in areas prone to soil erosion; 3. Best agricultural practices should be strictly implemented and promote organic farming; 4. Strict monitoring of WTF of industries and livestock farms; 5. Provision of appropriate specification of septic tanks for all residential and commercial buildings not only those located along the river bank; 6. Require the desludging of septic tanks once in every three years through the enactment of a city ordinance on septage management; 7. LGU should put up Septage Facility or community- based technologies for Domestic Wastewater Treatment and Reuse; and 8. Strict implementation of LGU’s ordinance on solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

TUGANAY RIVER

Tuganay River is a waterway which originates from the mountain range at the boundary of Davao City, Municipalities of Carmen, B.E. Dujali and Sto. Tomas, Davao del Norte with lots of tributaries connected to it. It flows in a southwesterly direction, curved out and finally empties to Davao Gulf. It is generally characterized by semi-rough topography with gently sloping gradient.

Sand and gravel are abundant at its upper reaches (Sta. 3 & 4) while its lower reaches are characterized predominantly with muddy soil due to presence of silt materials. A big sand bar is present at the mouth of the river forming an island which is reforested with mangrove.

The upper reaches of the river is generally use for bathing, domestic uses and drinking water for domesticated animals

Tuganay River is classifies as Class B water.

Sta. 1 - At the foot of Tuganay-Taba Bridge, approx. 500 meters upstream from the mouth of the river

Sta. 2 – At the foot of Tuganay Bridge

Sta. 3 – At the foot of Apitong Bridge, La Libertad, Sto.Tomas, Davao del Norte

Sta. 4 – At the foot of Menzi Bridge, Brgy. Menzi, Sto. Tomas, Davao del Norte

Sta. 5 – Anibongan River, at the foot of Anibongan Bridge, approx. 600 meters upstream from the confluence with Tuganay River

Sta. 6 – At the foot of Tanglaw Bridge, Brgy. Tanglaw, B. Dujali, Davao del Norte

Interpretation of Data

The parameters monitored are Color, Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD) and Total Suspended Solids (TSS). Tuganay River is designated as one of the Priority Rivers. The frequency of monitoring is on a monthly basis.

Average values for Color, Temperature, pH, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class B water as prescribed in Table 1, Section 69 of DAO 34. . TSS level range from 2 mg/L – 6,883 mg/L. There is no water quality criterion for TSS for Class B water. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 7 20 13 No Abnormal Discoloration Temperature ْ C 24 28 27 max of 3 ْ C rise pH 7.4 8.5 8.0 6.5-8.5

Dissolved Oxygen, mg/L 5.0 8.2 6.6 5.0

BOD (5-day), mg/L 0.9 8.4 2.4 5

Total Suspended Solids, mg/L 2 6,883 561 Not more than 30 % increase

One hundred percent of the total samples collected passed the water quality criteria for Color, Temperature pH and Dissolved Oxygen. Although DO level passed the water quality criteria, it can be observed that some of the DO level in some stations were almost near the minimum value as shown in Fig. 1. Potential causes of DO depletion is the discharged of organic wastes into the river.

For BOD, 98.6% of the total samples collected passed the water quality criteria for Biochemical Oxygen Demand. There was only one instance that exceedance was observed for BOD; but BOD level in some stations were also near the maximum value of 5 mg/L as shown in Fig.2.

Fig.1

Dissolved Oxygen 9 J 8 F 7 WQ Criteria M 6 5.0 mg/L A

5 Class B M mg/L 4 Jun 3 Jul 2 A 1 S 0 O 1 2 3 4 5 6 N Station No. D

Fig. 2

Biochemical Oxygen Demand

WQ Criteria 5 mg/L

mg/L Class C

Station No.

Conclusion and Recommendation

Based on the parameters monitored, the water quality of the river still conforms to its present classification.

To improve the water quality of Tuganay River, the following are recommended:

1. Trees and cover crops should not only be planted along the river bank but also in areas prone to soil erosion; 2. Proper quarrying procedure should be strictly imposed; 3. Agricultural activities that tend to cause soil erosion should be discouraged and the concept of soil and water conservation should be imparted to the farmers; 4. Strict Monitoring of the WTF of industries and livestock farms; 5. Provision of appropriate specifications of septic tanks for all residential and commercial buildings; 6. Require the desludging of septic tanks every three years through an enactment of an ordinance on septage management ; 7. Provision of a septage system; and 8. Proper solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

HIJO RIVER

Hijo River is a combination of the two upper branching medium-sized rivers. The Tagum River which is located along the Lingdan Mountain Range and the Masara River located along the Amacan Mountain Range.

It is also partly bounded by two mountain ranges and flows toward the north-west direction going to the municipality of Mawab, meanders westward along the National Road and finally empties into Davao Gulf at the southern periphery of Brgy. Hijo, Apokon, Tagum City.

It traverses through mining , agricultural and residential areas.

Hijo River is reclassified as Class C water.

Sta. 1 – Mouth of the river Sta. 4- Approx. 100 meters upstream

Sta. 2 – At Hijo Bridge of Minex Mining Corp. Sta. 3- Approx. 100 m downstream Sta. 5 – At Sawangan Bridge Of Granscor-Kimpro Sta. 6 – At Hangin Bridge (10 MVA), Masara, Maco

Sta. 4- Approx. 100 meters upstream of Minex Mining Corp. Sta. 5 – At Sawangan Bridge Sta. 6 – At Hangin Bridge

Data Interpretation:

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Total Suspended Solids, Cyanide and Mercury. Monitoring is conducted quarterly.

Average values for Color, pH, Temperature, Dissolved Oxygen, Biochemical Oxygen Demand and Cyanide are within the water quality criteria as prescribed in Table 1, Section 69 of DAO 34. Total Suspended Solids range from 43 mg/L – 1,057 mg/L. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class C water Color 7 30 15 No Abnormal Discoloration Temperature °C 23 30 28 max of 3 ْ C rise pH 7.7 8.5 8.2 6.5-8.5 DO, mg/L 6.7 8.8 7.4 5.0 BOD(5-day),mg/L 0.8 2.8 1.7 7 Total Suspended 43 1,057 265 Not more than 30 mg/L Solids, mg/L increase Cyanide, mg/L <0.03 <0.03 <0.03 0.05 (Test Kit) Mercury, mg/L <0.001 0.008 0.002 0.002

All samples collected passed the water quality criteria for all parameters monitored except for Mercury as shown in the graph below. There are mining firms in the area. There are also panning activities in the river.

Mercury 0.009 0.008 0.007 0.006 0.005 WQ Criteria mg/L 0.004 0.002 mg/L 0.003 0.002 Class C 0.001 1st Qtr 0 2nd Qtr 1 2 3 4 5 6 3rd Qtr Station No. 4th Qtr

Conclusion and Recommendations:

Based on the parameters monitored, the water quality of the river conforms to its present classification.

The monitoring of Cyanide is conducted on site using a Microquant Cyanide Test Kit. Specific Ion Electrode Method should be used as per approved Methods of Analysis.

Alteration in the water quality of the river could be attributed to the mining activities in the upstream and tributaries of the river, domestic wastes and agricultural run-off.

Monitoring should be continued in order to determine the trend and water quality of the river. Continuous monitoring could determine pathways of pollution sources. Data gathered in the monitoring could be used as a basis for the rehabilitation of the river as well as in the formulation of policy relevant to the protection and preservation of the river.

To improve or maintain the water quality of Hijo River, the following are recommended:

1. Rehabilitate the tributary rivers that contribute pollution to Hijo River. Concerted efforts should be undertaken between the LGU and miners in the area. River rehabilitation could be started through the” Adopt-an-Estero/waterbody” Program of the Department; 2. Relocate the mining processors located along the tributaries of Hijo River to a designated mining processing zone provided with a Mine Tailings Disposal Facility; or 3. Regulate the mining operations and processors in the area; 4. Best agricultural practices should be strictly implemented and promote organic farming; 5. Planting of trees along the riverbank and on gullies to prevent soil erosion; and 6. Strict implementation on solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

AGUSAN RIVER

Agusan River is a long meandering river originating from the mountains in the southwestern part of Compostela Valley Province and flowing northward to its main outlet, the Butuan Bay.

The basin is divided into three: Lower Agusan River Basin; Middle Agusan River Basin and Upper Agusan River Basin which comprises upstream reach from Sta. Josefa to Compostela Valley Province.

Agusan River passes through the Municipalities of New Bataan, Compostela, Nabunturan and Monkayo, Compostela Valley Province and then to Agusan Sur.

It traverses through agricultural and residential areas. It also serves as catchment of tributaries affected by the mining industry.

Agusan River is classified as Class C water.

Monitoring Stations

Sta. 1 - Batutu River, at the foot of Batutu Dam, Sta. 4 – Agusan River, at Sta. Josefa Brdige Camanlangan, New Bataan Sta. 5 – Naboc River, at Naboc Dam Sta. 2 - Agusan River, at the foot of the bridge at Sta. 6 – Agusan River, at the foot of Monkayo Compostela Proper Bridge Sta. 3 - Ngan River, passageway to Valderama Sta. 7 – Manat River, at the confluence of Agusan River, at Banlag, Monkayo

Interpretation of Data

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Total Suspended Solids, Cyanide and Mercury. Monitoring is conducted quarterly.

Average values for Color, pH, Temperature, Dissolved Oxygen, Biochemical Oxygen Demand, Mercury and Cyanide are within the water quality criteria for Class C water as prescribed in Table 1, Section 69 of DAO 34. Total Suspended Solids range from 89 mg/L – 427 mg/L. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 1 30 12 No Abnormal Discoloration Temperature ᵒC 26 28 27 max of 3 ْ C rise pH 7.3 8.5 7.9 6.5-8.5 Dissolved Oxygen, 5.4 8.3 6.9 5.0 mg/L BOD (5-day), mg/L 1.4 2.9 2.1 7 Total Suspended 33 563 227 Not more than Solids, mg/L 30 mg/L increase Cyanide, mg/L <0.03 <0.03 <0.03 0.05 (Test Kit) Mercury, mg/L <0.001 0.004 0.001 0.002

All samples collected are within the water quality criteria for all parameters monitored except for Mercury as shown in the graph below. The river is the receiving body of tributaries that are affected by the mining industry.

Mercury 0.006

0.005

0.004 WQ Criteria mg/L 0.003 0.002 mg/L

0.002 Class C

0.001 1st Qtr 0 2nd Qtr 1 2 3 4 5 6 7 3rd Qtr Station No. 4th Qtr

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of the river still conforms to its present classification.

The monitoring of Cyanide is conducted on site using a Microquant Cyanide Test Kit. Specific Ion Electrode Method should be used as per approved Methods of Analysis.

Alteration in the water quality of the river could be attributed to the mining activities that discharge its mine wastes at the tributaries of the river, domestic wastes and agricultural run-off.

To improve the water quality of Agusan River, the following are recommended:

1. Rehabilitate the rivers that contribute pollution to Agusan River thru the “Adopt- an-Estero/waterbody” program of the Department; 2. Relocate the mining processors located along the tributaries of Agusan River to a designated mining processing zone and it has to be provided with a Mine Tailings Disposal Facility or regulate the mining operations in the area; 3. Best agricultural practices should be strictly implemented and promote organic farming; 4. Provision of appropriate specification of septic tanks for all residential and commercial buildings not only those located along the river bank; 5. Require the desludging of septic tanks once in every three years through the enactment of an ordinance on septage management; 6. LGU should put up Septage Facility or community- based technologies for Domestic Wastewater Treatment and Reuse; and 7. Strict implementation of LGU’s ordinance on solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

KINGKING RIVER

Kingking River is located in the North-East part of Pantukan, Compostela Valley Province. It is about 26,650 kilometer stretch and emanates from the mountain ranges of Boringot and being carried downslopes leading to the gold rush areas of Diaat, Pangasanon, etc. From these areas, creeks and tributaries formed this river which accumulates and empties into Davao Gulf.

The river functions as channel for wastewater of mining activities in the area. There are also panning activities in the river.

Kingking River is classified as Class C.

Monitoring Stations

Sta. 1- Mouth of the river Sta. 2 – At Kingking Bridge Sta. 3 - At Sitio Balanban, Kapoc, Pantukan

Data Interpretation:

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Total Suspended Solids, Cyanide and Mercury. Monitoring is conducted quarterly.

Average values for Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand and Cyanide are within the water quality criteria for Class C water except for Mercury as prescribed in Section 69 of DAO 34. Total Suspended Solids range from 113 mg/L – 1,990 mg/L. There is no water quality criterion for Class C water. Summary of Results of Analyses is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 15 30 20 No Abnormal Discoloration Temperature °C 27 30 29 max of 3 ْ C rise pH 7.5 8.6 8.1 6.5-8.5 Dissolved Oxygen, mg/L 5.8 8.3 7.2 5.0 BOD (5-day), mg/L 1.1 4.0 2.1 7 Total Suspended Solids, 113 1990 817 Not more than mg/L 30 mg/L increase Cyanide, mg/L (Test Kit) <0.03 <0.03 <0.03 0.05 Mercury, mg/L <0.001 0.011 0.004 0.002

All samples collected passed the water quality criteria for all parameters monitored except for Mercury as shown in Fig. 1. Potential sources of Mercury are from the wastewater coming from the mining activities that drains into the river. There are also panning activities in the river. TSS concentration as shown in Fig. 2 showed that the river is silted.

Mercury 1st Qtr 0.02 2nd Qtr 0.018 3rd Qtr 0.016 0.014 4th Qtr 0.012 0.01 mg/L 0.008 0.006 WQ Criteria 0.004 0.002 mg/L 0.002 0 Class C 1 2 3 Station No.

Total Suspended Solids 2500

2000

1500 mg/L 1000

500 1st Qtr 2nd Qtr 0 1 2 3 3rd Qtr Station No. 4th Qtr

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of the river conforms to its present classification except for Mercury. Based on the concentration of TSS and visual observation of the physical condition of the river will show that it is silted.

The monitoring of Cyanide is conducted on site using a Microquant Cyanide Test Kit. However, Specific Ion Electrode Method should be used as per approved Methods of Analysis.

Possible sources of pollution could be attributed to the mining activities in the area, domestic wastes and agricultural run-off.

To improve or maintain the water quality of Kingking River, the following are recommended:

1. Relocate the ore processing plant at Diaat, Pangasanon and neighboring areas to a designated mining processing zone and provide with an appropriate Mine Tailings Disposal Facility; 2. After relocating the mining operations; de-silt the river. Concerted effort should be undertaken between the LGU and miners in the area. River rehabilitation could be started through the” Adopt-an-Estero/waterbody” Program of the Department; 3. Provide a common sedimentation basin to address siltation (generated from mining operation ;

4. Regulate the mining operations in the area; 5. Provision of appropriate specification of septic tanks for all residential and commercial buildings not only those located along the river bank; 8. Require the desludging of septic tanks once in every three years through the enactment of an ordinance on septage management; 9. LGU should put up Septage Facility or community- based technologies for Domestic Wastewater Treatment and Reuse; and 10. Strict implementation of LGU’s ordinance on solid waste management; and 11. Planting of trees along the riverbank and on gullies to prevent soil erosion.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

MATIAO RIVER

Matiao River is located in the North-East part of Pantukan, Compostela Valley Province. It is the main drainage of Sitios Boringot, Biasong, Lit-ag, Mabarus and Mangapispis gold rush areas. It is joined by a tributary river, Napnapan River at the downstream portion of the river. It then empties to Davao Gulf.

The river is used for domestic utilization such as bathing and washing of clothes. It is also used as source of irrigation water servicing ricefields. It also functions as a channel for wastewater of some mining activities in the area. Panning activities also exists in the river.

Matiao River is classified as Class C water.

Monitoring Stations

Sta. 1 – Mouth of the river Sta. 4- Napnapan River, approx.. 50 m upstream from confluence with Sta. 2 – At the foot of Matiao Bridge Matiao River Sta. 3 – Approx. 100 m downstream Sta. 5 –Matiao River, approx.. 50 m upstream from confluence with from confluence of Matiao and Napnapan River Napnapan Rivers Sta. 10- Approx. 20m upstream of Binogsayan Bridge

Data Interpretation:

Parameters monitored are Color, Temperature, pH, Dissolved Oxygen, Biochemical Oxygen Demand, Total Suspended Solids, Cyanide and Mercury. Monitoring is conducted quarterly.

Average values for Color, Temperature, Dissolved Oxygen, Biochemical Oxygen Demand and Cyanide are within the water quality criteria for Class C water prescribed in Section 69 of DAO 34. Total Suspended Solids range from 52 mg/L – 305 mg/L. There is no water quality criterion for Class C water. Summary of Results of Analyses is shown below.

Parameter Min Max Ave Water Quality Criteria Class B water Color 7 20 16 No Abnormal Discoloration Temperature ᵒC 27 29 28 max of 3 ْ C rise pH 8.0 8.7 8.3 6.5-8.5 Dissolved Oxygen, mg/L 7.2 9.5 8.0 5.0 BOD (5-day), mg/L 1.0 2,4 1.5 7 Total Suspended Solids, 52 305 93 Not more than mg/L 30 mg/L increase Cyanide, mg/L (Test Kit) <0.03 <0.03 <0.03 0.05 Mercury, mg/L <0.001 0.008 0.002 0.002

All samples collected passed the water quality criteria for all parameters monitored except for Mercury. Only 90.5% of the samples collected passed the water quality criteria of 0.002 mg/L. There were two instances that exceedance for Mercury was observed as shown below. The river receives mine wastes coming from the mining activities in the area. There are also panning activities in the river.

Conclusion and Recommendation:

Based on the parameters monitored, the water quality of the river conforms to its present classification.

The monitoring of Cyanide is conducted on site using a Microquant Cyanide Test Kit. However, Specific Ion Electrode Method should be used as per approved Methods of Analysis.

Sources of Pollution could be attributed to the mining activities in the area, agricultural run-off and domestic wastes.

To improve or maintain the water quality of Matiao River, the following are recommended:

1. Relocate the ore processing plant at Buringot and neighboring areas to a designated mining processing zone and provide with an appropriate Mine Tailings Disposal Facility; 2. Provide common Sedimentation basin to address the mining wastes generated from tunneling operation; 3. Regulate the mining operations in the area; 4. Planting of trees along the riverbank and on gullies to prevent soil erosion; 5. Provision of Septic Tanks for all residential houses located along the river bank; and 6. Strict implementation on solid waste management.

Republic of the Philippines Department of Environment and Natural Resources ENVIRONMENTAL MANAGEMENT BUREAU Region XI, Davao City

WATER QUALITY ASSESSMENT REPORT (CY 2012)

NABOC RIVER

Naboc River is located in the North-East part of Monkayo, Compostela Valley Province. It originates from the uppermost slope of Mt. Diwata and from various tributaries particularly Busay, Balite and Buenas-Tinago creeks. It passes through the barangays of Naboc, Tubo-tubo, Babag and Mamunga, all of which are noted to be agricultural settlements. It finally empties to Agusan River.

The river is primarily used for agricultural purposes. An ogee-shaped dam is constructed at Brgy. Naboc by NIA to irrigate the ricefileds within the area. It also functions as a channel for effluents of some illegal mining activities in the area. Panning activities also exist in the river.

Naboc River is classified as Class C water

Monitoring Stations

There were five (5) sampling stations identified as shown in the map below.

Sta.1 – Mouth of Naboc River Sta. 4 – At Naboc River, approx. 50 m upstream Sta.2 – At the foot of Naboc Bridge from confluence of Naboc River and Sta.3 – At Naboc River, foot of NIA Dam Tabaka River Sta. 5 - Tabaka River, approx.. 50 m upstream from confluence of Naboc River and Tabaka River

Interpretation of Data

The parameters monitored are Color, Temperature, pH, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), Cyanide (using Field Test Kit) and Mercury. The frequency of monitoring is quarterly.

Average values for Color, pH, Temperature, Dissolved Oxygen and Biochemical Oxygen Demand are within the water quality criteria for Class C waters except for Mercury as prescribed in Table 1, Section 69 of DAO 34. Total Suspended Solids range from 2 mg/L – 7,664 mg/L. For Class C water, there is no numerical water quality criterion for TSS. Summary of Results is shown below.

Parameter Min Max Ave Water Quality Criteria Class C water Color <1 20 10 No Abnormal Discoloration Temperature ⁰C 23 27 26 max of 3 ⁰C rise pH 7.7 8.4 8.1 6.5-8.5 Dissolved Oxygen 5.7 8.7 7.0 5.0 BOD (5-day), mg/L 1.1 34.7 5.2 7 Cyanide, mg/L (Field Test <0.03 <0.03 <0.03 0.05 using Cyanide Test Kit) Mercury, mg/L <0.001 0.25 0.026 0.002 Total Suspended Solids, mg/L 2 7664 991 Not more than 30 mg/L increase

For one year monitoring, 100% of the total samples collected passed the water quality criteria for Color, Temperature, pH, Dissolved Oxygen and Cyanide.

For BOD, 90% of the total samples collected passed the water quality criteria of 7 mg/L for Class C water. There were two instances that exceedance was observed for BOD as shown in Fig.1. Potential sources of organic wastes are from domestic use.

For Mercury, 25% of the total samples collected passed the water quality criterion of 0.002 mg/L for Class C water. Mercury level in all station except station 5 exceeded the water quality criterion; however, Mercury level in station 4 were higher compared to other station as shown in Fig. 2. Similarly, TSS level at this station were extremely high compared to other stations as shown in Fig. 3. The river water in station 4 has its sources coming from different streams and creeks where mining operations exist. There is no specific water quality criterion for TSS for Class C water

Fig. 1

Fig. 2

Fig. 3

Conclusion and Recommendations:

Based on the parameters monitored, the water quality of the river conforms to its present classification except for mercury level required under this classification.

Alteration in the water quality of the river could be attributed to domestic waste coming from households and the mining activities in the area.

To improve the water quality of Naboc River, the following are recommended:

1. Relocate the ore processing plant at Diwalwal to MABATAS Area where an existing Tailings Impounding Pond is located; 2. After relocating the mining operations; de-silt / desludge the river; 3. Provide a common sedimentation basin for various mining operations (tunneling) to mitigate siltation of the river; 4. Agricultural activities that tend to disturb the soil should be discouraged and the concept of soil and water conservation should be imparted to the farmers; 5. Provision of septic tanks for all residential houses located along the river bank; and; 6. Encourage households / dwellings/ institutional / establishments to desludge septic tanks regularly; and 7. Planting of trees along the riverbank and on gullies to prevent soil erosion.