Post on 10-Feb-2017
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
1
CABUYAO RIVER
WATER QUALITY ASSESSMENT REPORT
2011
Prepared by:
IRENEO G. BONGCO – Sr. Science Research Specialist
Reviewed by:
JOCELYN G. STA. ANA – OIC, Environmental Laboratory and Research Division
ADELINA C. SANTOS-BORJA – OIC, Resource Management and Development
Department
For more Information, please contact:
Environmental Laboratory and Research Division (ELRD)
Laguna Lake Development Authority
Park and Shop Bldg.
Km. 24, Brgy. San Juan, Taytay, Rizal
Tel. No. 286-61-43
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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CABUYAO RIVER WATER QUALITY ASSESSMENT REPORT
Introduction:
Cabuyao is a first class urbanized city in the province of Laguna, Philippines. It is located
at the western portion of Laguna and about 43 kilometers southeast of Metro Manila. It is
bordered by the Laguna de Bay, the country's largest lake, to the north (N), Calamba City
to the east (E) with Barangays Uwisan (NE), Banlic & San Cristobal (E) and Mapagong
& Canlubang (SE), some portion of Silang, Cavite (Brgy. Puting Kahoy) to the south (S)
and by the Santa Rosa City to the west (W) with the Barangays Malitlit (SW), Dita (W)
and Caingin (NW) respectively. Based on the 2007 Census, the city has a total population
of 205,376.
The City of Cabuyao within the Sta. Rosa and San Cristobal
Micro-watersheds of Laguna de Bay
Cabuyao City was formerly the "Richest Municipality of the Philippines" and it is the
fastest growing municipality in Laguna with large number of migrant workers in the
town's industrial estates (http://www.cityofcabuyao.gov.ph/profile.php).
.
The rivers of Cabuyao are Cabuyao River between the boundary of Santa Rosa City and
Cabuyao, Niugan-Sala River along the boundary of Barangays Niugan and Sala, Tiway-
Tiway River, and San Cristobal River between the boundary of Calamba City and
Cabuyao. The municipality is politically subdivided into eighteen (18) barangays in
which six (6) of them are situated along the lake, namely: Bigaa, Butong, Marinig,
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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Gulod, Baclaran and Mamatid. In 2004, the data from the Municipal Agriculture Office
showed that the municipality had a total of 940.56 hectares riceland (or 9.4056 in square
kilometers) while the total number of farmers for the same year was 468. The
ricefields/ricelands in Cabuyao are found in Barangay Bigaa, Butong, Marinig, Gulod,
Baclaran, Mamatid, San Isidro, Pulo, Banay-Banay, Niugan and Sala. For 2010, the
Land Use Map of City of Cabuyao is presented below:
In support of the River Rehabilitation Program of LLDA, the Environmental Laboratory
and Research Division (ELRD) staff conducted water quality sampling in Cabuyao River
on January 27, 2011, representing the dry season and July 19, 2011, representing the wet
season in order to determine the seasonal variations of the water quality levels in this
river in terms of the biological, chemical and bacteriological parameters. Cabuyao River
was among the six (6) major tributary rivers targeted by LLDA for the River
Rehabilitation Program in 2011 aside from San Pedro, Sta. Cruz, Tanay, Sapang Baho
and Morong-Teresa Rivers after the “Adopt A River Project” was launched by LLDA on
the same year.
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Stn. 1 – Mouth of Cabuyao River at the boundary of Brgy. Bigaa, Cabuyao and Brgy. Caingin, Sta. Rosa. Stn. 2 – Cabuyao River at Sitio Bulihan, Brgy. Sala fronting Purefoods and Villa Susana Subdivision Stn. 3 – Cabuyao River at Brgy. Malitlit, near the entrance of ETON City Stn. 4 – Malitlit tributary located along SLEX near the outlet of ETON City and before confluence with Cabuyao River
3
2
1
4
Figure 1
Location of
Cabuyao River
Sampling
Stations
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Environmental Laboratory and Research Division Laguna Lake Development Authority
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Sampling Stations and Frequency of Sampling:
ELRD has established four (4) sampling stations at various sections of the Cabuyao River
and their locations are depicted in Figure 1. These are the same stations where monitoring
was done in 1997. Specifically, the sampling stations are: Station 1 – Mouth of Cabuyao
River at the boundary of Brgy. Bigaa, Cabuyao and Brgy.Caingin, Sta. Rosa; Station 2 –
Cabuyao River at Sitio Bulihan, Brgy. Sala fronting Purefoods and Villa Susana
Subdivision; Station 3 – Cabuyao River at Brgy. Malitlit, near the entrance of ETON
City; and Station 4 – Malitlit tributary located along SLEX near the outlet of ETON City
and before confluence with Cabuyao River.
Photo documentations of the two (2) samplings conducted are shown in Figures 2 to 5.
Figure 2. Photo of Station 1 in Cabuyao River Mouth at the Boundary of Brgy.
Bigaa, Cabuyao, Laguna and Barangay Caingin, Sta. Rosa, Laguna
Figure 3. Photo of Stn. 2 in Cabuyao River at Sitio Bulihan, Brgy. Sala (fronting
Purefoods and Villa Susana Subdivision
January sampling (dry season) July sampling (wet season)
January sampling (dry season) July sampling (wet season)
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Figure 4. Photo of Stn. 3 of Cabuyao River at Brgy. Malitlit (near the entrance of
ETON City)
Figure 5. Photo of Stn. 4 Malitlit tributary (located along SLEX near the outlet of
ETON City and before the confluence with Cabuyao River)
January sampling (dry season) July sampling (wet season)
January sampling (dry season) July sampling (wet season)
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Field Observations and In-Situ Measurements:
Field observations for the two (2) sampling activities are presented in Tables 1a and 1b.
During the first sampling (dry season), the recorded water temperature was 24oC in all of
the four (4) stations, the weather was sunny, and the color of the water was greenish to
brownish. The presence of garbage was observed at the river mouth (Stn. 1) and in that
section of the river in Sitio Bulihan, Brgy. Sala (Stn. 2).
For the second sampling (wet season), it was also undertaken on a sunny weather. The
observed river flows in all four (4) stations remained the same as the first sampling but
the recorded water temperatures were higher at 27oC. The second sampling also showed
clearing of the water in Stns. 3 and 4 wherein small fish, shrimps and crabs were noted.
The water remained turbid (grayish) in Stns. 1 and 2. Clearing of the water hyacinth was
observed in Stn. 1 and this could be attributed to river flushing during the rainy season.
In Stn. 2, garbage was still present and there were soft shelled turtle and abundant fish fry
seen in the area.
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Table 1a. Field Observations and in-Situ Measurements for the Cabuyao River Sampling on January 27, 2011 (Dry Season)
Sampling Team : Bileynnie Encarnacion, Jonathan Nicolas and Usman Mamadra (ELRD), Reena Buena (CDD) and
Wilson Amoranto (Driver)
Sampling Stations
1 2 3 4
Time 11:35 AM 11:00 AM 10:30 AM 10:00 AM
GPS Reading (UTM) P0298091 P0296580 P0294604 P0294528
1581312 1578360 1577168 1578583
Air Temperature (oC) 25 26 27 27
Water Temperature
(oC) 24 24 24 24
Weather sunny sunny sunny sunny
Color of the Water brownish (turbid) greenish brown greenish greenish brown
Other observations: water slightly flowing,
thick growth of water
hyacinth and presence of
garbage noted, with low
river banks
water moderately
flowing, with sandy
bottom, illegal settlers
noticed along river
banks, presence of
garbage also noted
water fast flowing,
damming of the water
noted for irrigation
purposes, river banks
high with cogon grasses
and other vegetation,
with muddy river bed
water fast flowing,
presence of river bed
with boulders, head-
sized stones and pebbles,
both sides of the river
are high and with cogon
grass and trees
Stn. 1 - Mouth of Cabuyao River at the boundary of Brgy. Bigaa, Cabuyao and Brgy.Caingin, Sta. Rosa
Stn. 2 - Cabuyao River at Sitio Bulihan, Brgy. Sala fronting Purefoods Villa Susana Subdivision
Stn. 3 - Cabuyao River at Brgy. Malitlit, near the entrance of ETON City.
Stn. 4 - Malitlit tributary located along SLEX near the outlet of ETON City and before confluence with Cabuyao River
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Environmental Laboratory and Research Division Laguna Lake Development Authority
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Table 1b. Field Observations and in-Situ Measurements for the Cabuyao River Sampling on July 19, 2011 (Wet Season)
Sampling Team : Bileynnie Encarnacion, Jonathan Nicolas and Reynaldo Zulueta (Driver)
Sampling Stations
1 2 3 4
Time 11:40 AM 11:00 AM 10:20 AM 09:50 AM
GPS Reading (UTM) P0298091 P0296580 P0294604 P0294528
1581312 1578360 1577168 1578583
Air Temperature (oC) 26 28 26 28
Water Temperature
(oC) 27 27 27 27
Weather sunny sunny sunny sunny
Color of the Water grayish (turbid) grayish clear clear
Other observations: water slightly flowing,
absence of water
hyacinth in the area only
patches near the mouth.
water moderately
flowing, garbage on both
sides of the river banks,
presence of soft-shelled
turtle, abundant fish fry
on the side of the river.
water fast flowing,
presence of small fish
and shrimp, river banks
high with cogon grasses
and other vegetation,
with sandy river bed.
water fast flowing,
presence of river bed
with boulders, head-
sized stones and pebbles,
both sides of the river
are high and with cogon
grass and trees. Small
fish, shrimp and crab
present.
Stn. 1 - Mouth of Cabuyao River at the boundary of Brgy. Bigaa, Cabuyao and Brgy.Caingin, Sta. Rosa
Stn. 2 - Cabuyao River at Sitio Bulihan, Brgy. Sala fronting Purefoods Villa Susana Subdivision
Stn. 3 - Cabuyao River at Brgy. Malitlit, near the entrance of ETON City.
Stn. 4 - Malitlit tributary located along SLEX near the outlet of ETON City and before confluence with Cabuyao River
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Table 2. Results of the Physico-Chemical Analysis of Water Samples from Cabuyao River:
Sampling Dates: January 27, 2011 (Dry Season) and July 19, 2011 (Wet Season)
PARAMETERS
STATIONS DENR Class C
Water Quality
Criteria Stn. 1 Stn. 2 Stn. 3 Stn. 4
Dry Wet Dry Wet Dry Wet Dry Wet
pH, units 7 7.4 7 7.6 7.3 7.9 7.6 7.5 6.5-8.5
Total Suspended Solids, mg/L 4 6 7 9 122 6 26 5 <30 (increase)
Total Dissolved Solids, mg/L 242 486 244 371 290 284 291 340 1000
Total Solids, mg.L 246 492 251 380 412 290 317 345 *
Chemical Oxygen Demand,
mg/L
45 14 45 42 37 <4 25 30 *
Biochemical Oxygen
Demand, mg/L
14 8 35 33 5 <2 4 2 10
Dissolved Oxygen, mg/L 1.1 0.4 4.5 2.1 7.8 7.6 7.3 6.6 5 (minimum)
Oil/Grease, mg/L 0.5 <1 0.5 <1 7.8 <1 7.3 <1 2
Ammonia, mg/L NH3-N 3.1 2.307 0.924 2.088 0.029 0.069 0.053 0.055 *
Nitrate, mg/L NO3-N 0.001 <0.002 0.647 0.046 1.739 0.846 0.463 0.544 10
Inorganic Phosphate, mg/L 0.714 0.601 0.602 0.610 0.579 0.785 0.369 0.514 0.4
Total Phosphate, mg/L 0.999 0.904 0.912 0.97 0.922 0.889 0.595 2.47 *
Total Nitrogen, mg/L 6.4 5.5 3.7 5.2 2.9 1.7 2 0.9 *
Chloride, mg/L 74 48 22 22 15 19 22 22 350
Alkalinity, mg CaCO3/L 308 304 212 244 188 172 204 208 *
Calcium Hardness, mg
CaCO3/L
132 88 88 80 80 64 92 88 *
Total Hardness,mg CaCO3/L 212 220 148 172 140 124 156 168 *
Turbidity, NTU 5 6 3 9 20 4 20 3 *
Conductivity, uS/cm 830 720 457 512 396 381 429 457 *
*Note: No set DENR Class C Water Quality Criteria
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WATER QUALITY ASSESSMENT
1. Physico-Chemical Parameters:
The results of the physico-chemical analyses of the collected water samples for
the two (2) sampling dates are summarized in Table 2. The analytical results were
compared to the DENR Water Quality Criteria for Class C Waters as specified in
DENR Administrative Order (DAO) No. 34 and below are the findings:
a) pH
This parameter is a measure of the level of the hydrogen ion concentration. As
observed, measured pH in all of the four (4) stations in Cabuyao River which
ranged from 7.0 to 7.9 for the dry and wet season were found within the
acceptable range of 6.5 to 8.5 for Class C waters.
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b) Solids - Total Suspended Solids (TSS) and Total Dissolved Solids (TDS)
The presence of high amounts of solids will affect water clarity as it will
impede light to pass through the water body.
In Stns. 3 and 4, the TSS levels decreased from 122 to 6 mg/l and from 26 to 5
mg/l, respectively. This could possibly be explained by the comparatively
higher volume of water flow in these two (2) sampling stations during the
second sampling (wet season). Thus, dilution of the water resulted to low TSS
levels.
For TDS, Stn 4 obtained the highest concentration at 291 mg/l in January and
while in Stn. 1 at 486 mg/l in July. Nevertheless, measured TDS
concentrations in all stations were found within the Class B criterion of 1000
mg/l.
Total Suspended Solids
Cabuyao River
0
20
40
60
80
100
120
140
Stn. 1 Stn. 2 Stn.3 Stn. 4
mg
/L
Dry
Wet
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c) Biochemical Oxygen Demand (BOD)
This parameter is a measure of the approximate amount of oxygen needed by
the microorganisms for the aerobic decomposition of organic matter. For the
first sampling, results of the analysis for BOD showed that measured
concentrations in Stns. 1 and 2 at 14 and 35 mg/l, respectively, exceeded the 10
mg/l criterion for Class C. Comparison of the BOD levels obtained during the
two (2) sampling dates indicated that in Stn. 1, it improved to 8 mg/l in the
second sampling from 14 mg/l in the first sampling but in Stn. 2, Class C
criterion remained exceeded at 33 mg/l from 35 mg/l because of the presence
of garbage in the area. For both Stns. 3 and 4, measured BOD concentrations
for the two (2) sampling dates were low and conformed to the Class C
criterion. The adequate supply of oxygen due to the moderate flow of the
water in Stn. 3 and the fast flow of the water in Stn. 4 as well as the presence of
cogon grasses along the river banks in these two (2) stations during the water
quality samplings done in January and July could possibly be the reasons for
the low BOD levels.
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d) Dissolved Oxygen (DO)
Dissolved oxygen is required by aquatic organisms for their metabolism and is
needed for the oxidation and removal of organic wastes in water. In polluted
waters, large amount of available dissolved oxygen is consumed by aerobic
bacteria, thus, depriving aquatic organisms of the dissolved oxygen they need
to breathe and live. In both Stns. 3 and 4, the dissolved oxygen concentrations
measured in January and July which ranged from 6.6 to 7.8 mg/l conformed to
the water quality criterion for Class C set at a minimum of 5 mg/l. However,
this criterion was not met in Stns. 1 and 2 as measured DO concentrations
appeared to be low for the two (2) sampling dates ranging from 0.4 to 4.5 mg/l.
The observed low DO might be due to the high organic loading at the river
mouth and the garbage undergoing decomposition in Stn. 2.
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e) Oil and Grease
Oil may injure aquatic organisms by direct contact, by poisoning with various
soluble toxic substances that may be leached from it or by emulsions which
may cause clogging of the gills of the fish. Under DAO 34, the oil and grease
concentration of 2 mg/l is the set criterion for Class C waters. During the first
sampling in January, the results of oil and grease analysis showed that
measured concentrations in Stns. 1 and 2 both at 0.5 mg/l were within the
criterion while in Stns. 3 and 4 at 7.8 mg/l and 7.3 mg/l., respectively, failed
the criterion. However, recorded oil and grease concentrations in all of the
four (4) stations for the July sampling ranging from <1 to 0.5 mg/l passed the
Class C criterion.
f) Nitrate (NO3-)
Nitrate is the most highly oxidized form of nitrogen. It is an important plant
nutrient that in some cases, acts as growth-limiting nutrient. The DENR Class
C water quality criterion for nitrate was set at 10 mg/l while for ammonia, there
is no water quality criterion. Based on the analytical results, very low levels of
nitrates as compared to the 10 mg/l Class C criterion were recorded in all four
(4) stations for the two (2) sampling dates wherein the concentrations only
ranged from <0.002 to 1.739 mg/l.
Nitrate Cabuyao River
00.10.20.30.40.50.60.70.80.9
11.11.21.31.41.51.61.71.81.9
Stn. 1 Stn. 2 Stn.3 Stn. 4
mg
/L
Dry
Wet
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g) Inorganic Phosphate (IPO4-3
)
Phosphorus is found in natural waters and in wastewaters chiefly as
phosphates. Phosphorus is also an important plant nutrient and a primary
element in the metabolic reactions of both plants and animals. In events where
phosphate is a growth-limiting nutrient, the discharge of raw or treated
wastewater, agricultural drainage or industrial wastes with large quantity of
phosphorus into the body of water may enhance the growth of algae in
nuisance density, thus, may cause bloom or cultural eutrophication. For the
January sampling, Stn. 4 was the only station whose measured inorganic
phosphate concentration at 0.369 mg/l passed the 0.4 mg/l Class C criterion.
For the other three (3) stations, the inorganic phosphate levels were notably
higher than the Class C criterion at 0.7139 mg/l in Stn. 1, 0.6017 mg/l in Stn. 2,
and 0.5793 mg/l in Stn. 3. The analytical results for the July sampling revealed
that all of the four (4) sampling stations yielded inorganic phosphate levels
higher than the Class C criterion. Possible main sources of phosphorus are
from leaching of soil and from domestic wastes or sewage effluents.
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h) Chloride
Chloride is present nearly in all waters, but most are in combination with
sodium as sodium chloride (NaCl) or common salt and to a lesser extent with
calcium and magnesium. Intrusion of saline water during Pasig river backflow
which usually occurs during summer months increases the chloride level of the
lake. The assessment of the Cabuyao River’s water quality in terms of chloride
showed that measured concentrations in all four (4) stations for the two (2)
sampling periods which ranged from 15 to 74 mg/l, were very much within the
350 mg/l criterion for Class C Waters.
i) Ammonia
Among the chemical parameters analyzed without the set DENR criteria,
ammonia concentrations appeared to be within alarming levels. According to
the Environmental Studies Board (1973) of U.S. Environmental Protection
Agency (EPA), a level of 0.02 mg/l un-ionized ammonia (NH3) should not be
exceeded for the protection of aquatic life. However, high concentrations of
ammonia in Stns. 1 to 4 were recorded ranging from 0.0289 to 3.099 in
January, 2011 and from 0.055 to 2.307 in July, 2011. High ammonia
concentrations could have emanated from the decomposition of nitrogenous
organic materials at various sections of the river.
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2. Biological Parameters:
a) Phytoplankton or Microscopic Algae
Based on the results of quantitative and qualitative analysis of phytoplankton
samples collected in Cabuyao River last January, 2011, the percentage
contributions of polluted water algae appeared to be significantly higher than
the percentage contribution of clean water algae in all four (4) sampling
stations, thus, all of them are assessed as polluted (see Table 3A).
In Table 3B, it can be seen that the most dominant algae identified in Stns. 1
to 4 was a polluted water species, specifically, Nitzschia sp. from Division
Bacillariophyta (diatom). In July, 2011, all of the four (4) sampling stations
remained polluted wherein the polluted algae were predominated again by
Nitzschia sp.
The results of the qualitative and quantitative analyses of algae are shown in
Table 3B while for the benthic fauna analysis, are in Table 3D.
Table 3. Results of Biological Analyses of Water Samples
3A. Summary of Water Quality Assessment in Cabuyao River Based on
Phytoplankton/Algal Population
Table 3A.1
Date of Sampling - January 27, 2011 (Dry Season)
Stations Location
Counts (organism/sq.m.) % Contribution Water
Quality
Assessment CWA PWA OTHERS TOTAL
%
CWA
%
PWA
%
OTHERS
1
Mouth of
Cabuyao
River 12209 45505 360712 418426 2.9 10.9 86.2 Polluted
2 Sitio Bulihan,
Brgy. Sala 5777 168353 10728 184858 3.1 91.1 5.8 Polluted
3
Brgy. Malitlit
(near ETON City
entrance) 16505 166703 1651 184859 8.9 90.2 0.9 Polluted
4 Malitlit
Tributary (along SLEX) 7177 169357 828848 1005382 0.7 16.8 82.4 Polluted
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Table 3A.2
Date of Sampling – July 19, 2011 (Wet Season)
Stations Location
Counts (organism/sq.m.) % Contribution Water
Quality
Assessment CWA PWA OTHERS TOTAL
%
CWA
%
PWA
%
OTHERS
1 Mouth of
Cabuyao
River 9302 46509 22091 77902 11.9 59.7 28.4 Polluted
2 Sitio Bulihan,
Brgy. Sala 17941 205270 2871 226082 7.9 90.8 1.3 Polluted
3
Brgy. Malitlit
(near ETON
City
entrance) 0 36168 4305 40473 0 89.4 10.6 Polluted
4 Malitlit
Tributary (along SLEX) 9867 162361 211697 383925 2.6 42.3 55.1 Polluted
Notes:
CWA - Clean Water Algae
PWA - Polluted Water Algae
Others - Algae not classified as CWA or PWA
3B. Qualitative and Quantitative Analysis of Phytoplankton or Algae
Table 3B.1.
Date of Sampling - January 27, 2011 (Dry Season)
Phytoplankton/Algae
Identified (counts per
square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Clean Water Indicator
Division Bacillariophyta
Navicula sp. 12209 5777 16505 6459
Pinnularia sp. 718
Sub Total 12209 5777 16505 7177
Polluted Water Indicator
Division Cyanophyta
Oscillatoria sp. 825 2476 1435
Division Bacillariophyta
Gomphonema sp. 1110 1435
Nitzschia sp. 44395 167528 164227 166487
Sub Total 45505 168353 166703 169357
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Phytoplankton/Algae
Identified (counts per
square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Others
Division Cyanophyta
Anabaenopsis sp. 2220 274130
Division Chlorophyta
Actinastrum sp. 3330 5741
Coelastrum sp. 8879 5741
Cosmarium sp. 2870
Closterium sp. 718
Crucigenia sp. 204218 9903 80373
Oocystis sp. 4440 2870
Pediastrum sp. 5023
Scenedesmus sp. 116537 442770
Selenastrum sp. 3330
Division Bacillariophyta
Amphora sp. 1435
Rhopalodia sp.
Stauroneis sp. 825 718
Stephanodiscus sp. 13318 6459
Synedra sp. 2220 1651
Division Pyrrophyta
Glenodinium sp. 2220
Sub Total 360712 10728 1651 828848
TOTAL 418426 184858 184859 1005382
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Table 3B.2.
Date of Sampling – July 19, 2011 (Wet Season)
Phytoplankton/Algae
Identified (counts
per square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Clean Water
Indicator
Division Bacillariophyta
Cladophora sp 718
Navicula sp. 3488 718 9867
Pinnularia sp. 5814 17223
Sub Total 9302 17941 0 9867
Polluted Water
Indicator
Division Cyanophyta
Lyngbya sp. 2153
Oscillatoria sp. 1163 156072 2691
Division Chlorophyta
Spirogyra sp 3488
Division
Bacillariophyta
Gomphonema sp. 3488 718 11661
Nitzschia sp. 38370 48480 36168 148009
Sub Total 46509 205270 36168 162361
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Phytoplankton/Algae
Identified (counts
per square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Others
Division Chlorophyta
Closterium sp. 718
Cosmarium sp. 1794
Golenkinia sp. 897
Division
Bacillariophyta
Amphora sp. 2325 1722 2691
Cymbella ap 861
Melosira sp. 17441 204521
Stauroneis sp. 1722
Stephanodiscus sp. 2325 718 1794
Division Pyrrophyta
Glenodinium sp. 1435
Sub Total 22091 2871 4305 211697
TOTAL 77902 226082 40473 383925
b) Benthic Fauna
Table 3C shows the water quality assessments based on the identified benthic
fauna population. Stns. 1 and 4 were moderately polluted while Stns. 2 and 3
were polluted during the January sampling. The moderately polluted benthic
fauna indicators in Stns. 1 and 3 are from Families Thiaridae (Tarebia
granifera, Tiara scabra and Melanoides tuberculatus), Planorbidae (Gyralus
sp.), Stenothyridae (Stenothyra Formosa), Conidae and Corbiculidae
(Corbicula manilensis) while in Stns. 2 and 4, the polluted water indicators
are from Families Chironomidae (chironomid larvae and pupae),
Ceratopogonidae (ceratopogonid larvae), Psychodidae (Psychoda pupae) and
Tubificidae as well as from Class Hirudinea. For the July sampling, obtained
water quality assessments for benthic fauna were moderately polluted for Stn.
1, polluted for Stn. 2 and clean for both Stns. 3 and 4. The moderately
polluted algae in Stn. 1 belong to Families Thiaridae (Thiara riqueti, Thiara
scabra and Semisulcospira libertine) and Planorbidae (Hippeutis umbicalis).
The polluted algae in Stn. 2 are from Family Chironomidae (chironomid
larvae and chironomid pupae). The clean water species of benthic fauna found
in Stns. 3 and 4 are from Families Gerridae (water strider), Baetidae (Baetis
sp.), Caenidae (Caenis sp.), Hydropsychidae (Hydropsyche sp.),
Hydrophilidae (Hydrochus sp.), Potamidae (freshwater crab) and Crustacea
(freshwater shrimp).
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Environmental Laboratory and Research Division Laguna Lake Development Authority
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3C. Summary of Water Quality Assessment in Cabuyao River Based on Benthic
Fauna Population
Table 3C.1
Date of Sampling - January 27, 2011 (Dry Season)
Station
Counts (individuals per square meter) % Contribution Water
Quality
Assessment CWI MPWI PWI Others Total %CWI %MPWI %PWI %Others
Stn. 1 95 334 95 571 1095 8.7 30.5 8.7 52.1 Moderately
Polluted
Stn. 2 0 55 555 33 643 0 8.6 86.3 5.1 Polluted
Stn. 3 110 33 166 11 320 34.4 10.3 51.9 3.4 Polluted
Stn. 4 166 233 67 0 466 35.6 50 14.4 0 Moderately
Polluted
Table 3C.2
Date of Sampling – July 19, 2011 (Wet Season)
Station
Counts (individual per square meter) % Contribution Water
Quality
Assessment CWI MPWI PWI Others Total %CWI %MPWI %PWI %Others
Stn. 1 0 192 95 - 287 0 66.9 33.1 - Moderately
Polluted
Stn. 2 11 11 578 - 600 1.8 1.8 96.3 - Polluted
Stn. 3 111 33 22 - 166 66.9 19.9 13.3 - Clean
Stn. 4 132 0 11 - 143 92.3 0 7.7 - Clean
Notes:
Stn. 1 - Cabuyao River mouth
Stn. 2 - Cabuyao River in Sitio Bulihan, Brgy. Sala
Stn.. 3 - Cabuyao River in Brgy. Malitlit (near ETON City)
Stn. 4 - Malitlit tributary (along SLEX) CWI - Clean Water Indicator
MPWI - Moderately Polluted Water Indicator
PWI - Polluted Water Indicator
Others - Organisms not classified as either CWI, MPWI or PWI
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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3D. Qualitative and Quantitative of Benthic Fauna
Table 3D.1 Date of Sampling - January 27, 2011 (Dry Season)
Organisms (individual
per square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Clean Water Indicator
(CWI)
Class Arachnida
Hydracarina
Hydracnellae 95
Order Ephemeroptera
Family Baetidae
Baetis sp. 33
Family Caenidae
Caenis sp. 33
Order Trichoptera
Family
Hydropsychidae
Hydropsyche 44 22
Family
Helicopsychidae 144
TOTAL CWI 95 0 110 166
Moderately Polluted
Indicator (MPWI)
Class Gastropoda
Family Thiaridae 56
Tarebia granifera 48 22 33
Thiara scabra 95 11 44
Melanoides tuberculatus
11 22
Family Planorbidae
Gyralus sp. 95
Family Stenothyridae
Stenothyra formosa 48 11
Family Viviparidae
Viviparus viviparus 11
Bellamya angularis 67
Family Conidae 11
Class Pelecypoda
Family Corbiculidae
Corbicula manilensis 48
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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Organisms Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Class Insecta
Order Odonata
Sub-order Zygoptera 22
Family Viviparidae
Viviparus viviparus
Bellamya angularis
TOTAL MPWI 334 55 33 233
Polluted Water
Indicator (PWI)
Class Gastropoda
Family Physidae
Physa gyrina 95
Class Insecta
Order Diptera
Family Chironomidae
chironomid larva 322 111 56
chironomid pupa 233 11
Family
Ceratopogonidae
ceratopogonid larva 11
Family Psychodidae
Psychoda (pupa) 11
Class Oligochaeta
Family Tubificidae 22
Class Hirudinea 11
TOTAL PWI 95 555 166 67
Others
Class Crustacea
Order Ostracoda
Family Cyprididae
Cypricercus
cypricercus 571 11
Class Insecta
Unidentified insecta 22 11
TOTAL OTHERS 571 33 11 0
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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Table 3D.2 Date of Sampling - July 19, 2011 (Wet Season)
Organisms (individual
per square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Clean Water Indicator
(CWI)
Order Hemiptera
Family Gerridae
Water strider 11
Order Ephemeroptera
Family Baetidae
Baetis sp. 67 22
Family Caenidae
Caenis sp. 33
Order Trichoptera
Family
Hydropsychidae
Hydropsyche 44 44
Order Coleoptera
Family Hydrophilidae
Hydrochus sp. 11
Family Potamidae
Freshwater crab 11
Family Crustacea
Freshwater shrimp 11
TOTAL CWI 0 11 111 132
Moderately Polluted
Indicator (MPWI)
Class Gastropoda
Family Thiaridae
Thiara riqueti 48
Thiara scabra 48 11
Thiara sp. 11 22
Semisulcospira
libertina 48
Family Planorbidae
Hippeutis
umbicalis 48
TOTAL MPWI 192 11 33 0
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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Organisms (individual
per square meter)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4
Polluted Water
Indicator (PWI)
Class Gastropoda
Family Physidae
Physa gyrina 95
Class Insecta
Order Diptera
Family Chironomidae
378 22
chironomid larva 200 11
chironomid pupa
TOTAL PWI 95 578 22 11
Others
Class Crustacea
Order Ostracoda
Family Cyprididae
Cypricercus
cypricercus
TOTAL OTHERS 0 0 0 0
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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4. Bacteriological Parameters:
The results of the bacteriological analyses of the water samples are indicated in
Table 4.
Based on the total coliform concentrations in all of four (4) stations in Cabuyao
River last January 2011, all of them significantly exceeded the DENR Class C
water quality criterion of 5000 MPN/100 ml for total coliforms. The total
coliform levels in Stns. 1 and 2 considerably increased in July to 1,600,000 and
>1,600,000 MPN/100ml, respectively, which further exceeded the Class C DENR
criterion. In Stn. 3, the total coliform concentration at 54 MPN/100 ml remained
higher than the 5,000 MPN/100 ml criterion but in Stn. 4, low total coliform level
was noted at 1,300 MPN/100 ml. For both the dry and wet seasons sampling, all
stations were found contaminated with Escherichia coli, a bacterium that can
cause diseases such as diarrhea and urinary tract infections. For fecal coliforms,
DENR has no set criterion for Class C Waters. However, the data on fecal
coliforms showed high levels in all of the four (4) stations in January. For July,
the fecal coliforms remained high in Stns. 1, 2 and 3 while obtained concentration
in Stn. 4 reduced considerably from 90,000 MPN/100 ml in January to only 330
MPN/100ml.
Table 4. Results of Bacteriological Analyses of Water Samples
Sampling Dates: January 27, 2011 (Dry Season) and July 19, 2011 (Wet Season)
Parameters Stn. 1 Stn. 2 Stn. 3 Stn. 4
Dry Wet Dry Wet Dry Wet Dry Wet Total Coliform (MPN/100 ml)
>160000 1600000 160000 >1600000 >160000 54000 90000 1300
Fecal Coliform
(MPN/100 ml) >160000 920000 160000 1600000 >160000 54000 90000 330
Detection of
Escherichia coli Present Present Present Present Present Present Present Present
Note: DENR Class C Water Quality Criterion for total coliforms is 5,000 MPN/100 ml.
There is no set criterion for fecal coliforms.
Total Coliform
Cabuyao River
0
200000
400000
600000
800000
1000000
1200000
1400000
1600000
1800000
Stn. 1 Stn. 2 Stn.3 Stn. 4
MP
N/1
00m
l
Dry
Wet
Cabuyao River Water Quality Assessment Report
Environmental Laboratory and Research Division Laguna Lake Development Authority
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Conclusion and Recommendations:
From the above findings, it is very evident that Cabuyao River is polluted to some extent
based on BOD, dissolved oxygen (DO), oil and grease and inorganic phosphate levels.
The observed high inorganic phosphate and ammonia levels in the four (4) river stations
in January and July indicate high organic loadings. The polluted condition of the river
both in the dry and wet seasons was also reflected on the assessments using algae as
water quality indicators. However, in spite of the observed varying levels of pollution in
Cabuyao River, low total coliform level relative to the DENR Class C criterion was noted
in July in Stn. 4 and the benthic fauna population was dominated by clean water species
in Stns 3 and 4 during the same period. The natural purification due to dilution by rain
during the wet season could somehow be the reason for the improved water quality
condition in Stn. 4 in July in terms of total coliform counts and the dominant benthic
fauna identified.
Overall, Cabuyao River is recommended for clean-up/rehabilitation. In order for the
improvement of the river’s water quality to be sustainable, it is strongly recommended
that this activity be initiated by LLDA and its implementation must have full support
from the Local Government of Cabuyao. The community must also be actively involved
because of their big role in the rehabilitation activity. Through the community
participation component, the government can run on the ground activities and workshops
for the public and involve them in decision-making processes. The participation of the
private/industrial sector, river council and environmental army is equally very vital. In
addition, saturation drives should be done to track down and control the pollution source