LAGUNA LAKE DEVELOPMENT AUTHORITY Resource Management and Development Department
Environmental Laboratory and Research Division
Water Quality Assessment Report
Tanay River 2011
WATER QUALITY ASSESSMENT REPORT
TANAY RIVER
2011
Prepared by:
Jonathan U. Nicolas – Aquaculturist II
Christine S. Garcia – Environmental Management Specialist II
Ma. Magdalena T. Almonte – Environmental Management Specialist II
Usman Datu F. Mamadra Jr. – Environmental Management Specialist I
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
Resource Management and Development Department
Laguna Lake Development Authority
Tel No. 286-61-43
Figure 1. Location of Tanay River Sampling Stations.
Stn. 1 – Mouth of Tanay River at Brgy. Wawa. Stn. 2 – Town Proper (Poblacion) Plaza Aldea Stn. 3 – Manila East Road Bridge (National High-way) Stn. 4 – Headwater located near the entrance of Daranak National Park Stn. 5 – Daranak Falls
Introduction :
The Municipality of Tanay is a 1st class municipality in the province of Rizal, Philippines.
It is located 57 kilometers east of Manila, although a typical commute between Manila and
Tanay will take between one to three hours depending upon traffic conditions. It contains
portions of the Sierra Madre Mountains and is bordered by Antipolo City in the northeast,
Baras, Morong and Teresa in the west, General Nakar (Quezon Province) in the east, and
Pililla, Santa Maria (Laguna province) as well as the Laguna de Bay in the south.
According to the latest census (2007), it has a population of 94,460 people in 15,720
households. The majority of the population consists of Tagalogs who live near Laguna de
Bay, though there is also a significant percentage of mountain dwelling people living in the
northern portions of the municipality. (www.tanay.gov.ph)
Tanay municipality has strong hilly to mountainous areas (30 degrees and above) with an
expanse of approximately 4,188 hectares. These are found covering portions of Barangay
Sta. Inez, Mamuyao, Tinukan, Sto. Nino, San Andres, Cayabu, Laiban, Daraitan and
Sampaloc. Strong sloping or strongly rolling land (18-30 degrees) which are found in
portions of Barangays Plaza Aldea, Kaybuto, Katipunan Bayani, Tabing Ilog, Mag-ampon,
Cuyambay, Sampaloc, Daraitan, Laiban, Mamuyao, Sto. Nino, Tinukan, and San Andres
accounts for 8,471 hectares of the total land area. Moderately sloping or rolling land (8-18
degrees) constitutes 3,100 hectares of the municipality’s total land area. These are found
in Barangays Cayabu, San Andres, Cuyambay, Sampaloc, Plaza Aldea, Daraitan, Laiban,
Tandang Kutyo and Katipunan Bayani. The remaining 7,807 hectares have slopes ranging
from level to undulating. Maximum rainfall usually occurs from June to September. The
average rainfall is 135.5 mm with a peak of 322.2 mm in August and a low 5.3 mm in
April. Relative humidity is 79%. This makes the municipality better than the municipalities
of Laguna, which has an average relative humidity of 81%. Portions of Barangays Kay
Buto, San Isidro, Pinagkamaligan, Plaza Aldea, and the whole of Wawa are affected by
moderate to severe seasonal flooding hazard characterized by more frequent and deeper
run-off water. This takes a week or a few months to subside. Based on the land limitation
map, eroded areas comprise about 749 hectares while erosion-prone shallow soil areas
consist of 1,855 hectares.(R.Vicente et.al, 2010)
In support of the River Rehabilitation Program of LLDA, the Environmental Laboratory
and Research Division (ELRD) staff conducted water quality sampling in Tanay River on
June 19, 2011, to represent the wet season and December 1, 2011, to represent the dry
season.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 2
Sampling Stations and Frequency of Sampling:
Monitoring was undertaken on a seasonal basis (wet and dry). Collection of water and
sediment samples for physico-chemical, biological and microbiological analyses was
conducted at the different designated stations identified during the reconnaissance activity
on 17 June 2011 along the stretch of Tanay River. ELRD has established five (5)
sampling stations at various sections of the river and were properly marked using a Global
Positioning System (GPS) device. Sampling stations were named and identified as
follows: Station 1 – Mouth of Tanay River at Barangay Wawa; Station 2 – Plaza Aldea,
Poblacion, beside the Barangay Hall; Station 3 – Manila East Road, National Hi-way;
Station 4 – Headwater, near the entrance of Daranak National Park and Station 5 –
Daranak Falls. The map of the sampling stations is shown in Figure 1.
The assessment of the water quality was done for the purpose of determining the seasonal
variations of the water quality at different stations of the river in terms of the chemical,
biological and bacteriological parameters.
Field Observations and In-Situ Measurements:
Field observations were recorded during the sampling activities for both wet and dry
seasons and are presented in Tables 2 and 3. During the wet season, moderate to fast
flowing waters were observed with water temperature ranging from 26oC to 28
oC. A
sunny weather occurred at the time of sampling. Air temperature was recorded between
27oC to 31
oC. Dry season registered a lower level of temperature for both water and air
that ranges from 26oC to 29
oC for air and 23
oC to 25
oC for water. Sunny weather and
moderate to fast flowing waters was observed at the time of sampling.
Actual physical condition of all the stations for wet and dry seasons is presented in Figures
2a to 6b.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 3
Stn. 1 – Mouth of Tanay River at Brgy. Wawa.
Stn. 2 – Town Proper (Poblacion) Plaza Aldea
Stn. 3 – Manila East Road Bridge (National High-way)
Stn. 4 – Headwater located near the entrance of Daranak National Park
Stn. 5 – Daranak Falls Figure 1. Location of Tanay River Sampling Stations.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 5
Figure 2a. Tanay River Station 1
Wet Season – June 29, 2011
Field Observations and in-Situ Measurements
Name of Station Mouth – Brgy. Wawa
GPS Reading (UTM)
P0315034
1602589
Time 09:35 AM
Air Temperature (oC) 27
Water Temperature (oC) 26
Weather Sunny
Water Condition Moderately flowing
Color of the Water Greenish
Width Approximately 40m
Depth 1.5m
Other observations: Presence of fish fry along the side,
patches of water hyacinth going to
the lake, floating debris and dried
twigs, residential area
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 6
Figure 2b. Tanay River Station 1
Dry Season - December 1, 2011
Field Observations and in-Situ Measurements
Name of Station Mouth – Brgy. Wawa
GPS Reading (UTM)
P0315034
1602589
Time 09:15 AM
Air Temperature (oC) 29
Water Temperature (oC) 25
Weather Sunny
Water Condition Moderately flowing
Color of the Water Greenish brown
Width Approximately 38m
Depth .75m
Other observations: With floating garbage
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 7
Figure 3a. Tanay River Station 2
Wet Season – June 29, 2011
Field Observations and in-Situ Measurements
Name of Station
Town Proper, Poblacion (Plaza
Aldea)
GPS Reading (UTM)
P0315160
1603451
Time 09:40 AM
Air Temperature (oC) 29
Water Temperature (oC) 27
Weather Sunny
Water Condition Moderately flowing
Color of the Water Greenish
Width Approximately 25m
Depth .75m
Other observations: residential and commercial area,
with floating debris, presence of
fish fry, soil erosion brought by
heavy flushing
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 8
Figure 3b. Tanay River Station 2
Dry Season - December 1, 2011
Field Observations and in-Situ Measurements
Name of Station
Town Proper, Poblacion (Plaza
Aldea)
GPS Reading (UTM)
P0315160
1603451
Time 09:25 AM
Air Temperature (oC) 29
Water Temperature (oC) 25
Weather Sunny
Water Condition Moderately flowing
Color of the Water Greenish
With Approximately 24m
Depth .5m
Other observations: With floating debris, low level of
water
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 9
Figure 4a. Tanay River Station 3
Wet Season – June 29, 2011
Field Observations and in-Situ Measurements
Name of Station
Manila East Road
(National High-way)
GPS Reading (UTM)
P0315920
1604051
Time 10:00 AM
Air Temperature (oC) 31
Water Temperature (oC) 25
Weather Sunny
Water Condition Fast flowing
Color of the Water Greenish
Width Approximately 15m
Depth .75m
Other observations: Residential and commercial area,
pebbles to head size stones river
bed, grasses/cogon on both sides
of the banks, presence of garbage
also noted
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 10
Figure 4b. Tanay River Station 3
Dry Season - December 1, 2011
Field Observations and in-Situ Measurements
Name of Station
Manila East Road
(National High-way)
GPS Reading (UTM)
P0315920
1604051
Time 10:20 AM
Air Temperature (oC) 26
Water Temperature (oC) 25
Weather Sunny
Water Condition Fast flowing
Color of the Water Clear
Width Approximately 13m
Depth .3m
Other observations: Presence of garbage along the
banks
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 11
Figure 5a. Tanay River Station 4
Wet Season – June 29, 2011
Field Observations and in-Situ Measurements
Name of Station
Headwater (near entrance of
Daranak National Park)
GPS Reading (UTM)
P031781
1608658
Time 10:58 AM
Air Temperature (oC) 30
Water Temperature (oC) 26
Weather Sunny
Water Condition Fast flowing
Color of the Water Clear
Width Approximately 10m
Depth .3m
Other observations: Presence of few garbage result of
picnic activity, floating
debris/twigs, pebbles to head size
stones river bed, area for
swimming
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 12
Figure 5b. Tanay River Station 4
Dry Season - December 1, 2011
Field Observations and in-Situ Measurements
Name of Station
Headwater (near entrance of
Daranak National Park)
GPS Reading (UTM)
P031781
1608658
Time 10:35 AM
Air Temperature (oC) 27
Water Temperature (oC) 23
Weather Sunny
Water Condition Fast flowing
Color of the Water Clear
Width Approximately 7m
Depth .2m
Other observations: Rock balancing activity was noted
in the area
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 13
Figure 6a. Tanay River Station 5
Wet Season – June 29, 2011
Field Observations and in-Situ Measurements
Name of Station Daranak Falls
GPS Reading (UTM)
P0317865
1608629
Time 10:48 AM
Air Temperature (oC) 28
Water Temperature (oC) 27
Weather sunny
Water Condition Fast flowing
Color of the Water Clear
Width Approximately 8m
Depth .75m
Other observations: Trees on both sides of the river
banks forming shaded areas, dried
leaves/twigs floating, pebbles to
headsize stones river
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 14
Figure 6b. Tanay River Station 5
Dry Season - December 1, 2011
Field Observations and in-Situ Measurements
Name of Station Daranak Falls
GPS Reading (UTM)
P0317865
1608629
Time 11:50 AM
Air Temperature (oC) 27
Water Temperature (oC) 25
Weather Sunny
Water Condition Fast flowing
Color of the Water Clear
Width Approximately 5m
Depth .5m
Other observations: Rock balancing activity was noted
in the area
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 15
Results of Physico-Chemical Analyses:
The results of the physico-chemical analyses of the collected water samples are
summarized in Tables 1 and 2. The analytical results were compared to the DENR
Water Quality Criteria for Class C Waters as specified in the DENR Administrative
Order (DAO) No. 34 and below are the findings:
Dissolved Oxygen
Dissolved Oxygen (Wet/Dry)
0
2
4
6
8
10
Brg
y. W
aw
a
Plaza A
ldea
Manila E
ast
Road
Dara
nak Falls
Tanay H
eadw
ater
Stations
D.O
. m
g/L
D.O.- WET
D.O.- DRY
Class "C" (5mg/L
minimum )
Dissolved Oxygen (DO) is one of the water quality parameters used as an indication of
how polluted the water is and how well the water can support aquatic plant and animal
life. DO is the amount of oxygen that is dissolved in water and is essential to streams
and lakes.
For the wet season, the dissolved oxygen in all the stations met the minimum criterion
of 5mg/L for Class C waters. This is an indication that the river system has good
quality for fish and other organisms to survive. Likewise, all stations passed the
criterion for D.O. for the dry season.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 16
Biochemical Oxygen Demand
Biochemical oxygen demand, or BOD, measures the amount of oxygen consumed by
microorganisms in decomposing organic matter in water. BOD parameter measures the
organic strength of wastes in water; the higher the BOD concentration, the greater the
degree of organic pollution.
For Tanay, all five stations passed the criterion of 10 mg/L for BOD during the wet
and dry season.
pH
pH (WeT/Dry)
0
2
4
6
8
Brg
y. W
aw
a
Plaza A
ldea
Manila E
ast
Road
Dara
nak Falls
Tanay H
eadw
ater
Stations
pH
un
it
pH- WET
pH- DRY
Class "C" ( 6.5, unit )
Class "C" ( 8.5, unit )
The most commonly measured chemical characteristic of water is its pH since its
changes can alter the aspects of water chemistry. Most rivers have a neutral to slightly
basic pH of 6.5 to 8.5. If the river has pH less than 5.5, it may be too acidic for fish to
survive in, while river with a pH greater than 8.6 may be too basic. Sudden shift in pH
can affect aquatic life since this may indicate presence of contaminants in the river.
However, since some rivers are naturally acidic — or basic — pH may not necessarily
indicate pollution (www.cotf.edu).
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 17
The pH for all the stations in Tanay is within the acceptable range for Class C waters
for the wet season. As for the dry season, the stations in Daranak Falls and Tanay
Headwater with pH values of 8.6 slightly exceeded the required range.
Oil and Grease
The concentration of dispersed oil and grease in water is an important parameter in
water quality. These can cause surface films and shoreline deposits leading to
environmental degradation, which can result to human health risks when discharged to
surface and ground water.
Both stations in Brgy. Wawa and Manila East Road failed to comply with the criterion
for Oil and Grease during the wet season. This may be due to wastes coming from
nearby community. But for the dry season, all stations passed the criterion for oil and
grease.
Nitrate and Inorganic Phosphate
Nitrate (Wet/Dry)
0
2
4
6
8
10
12
Brg
y. W
aw
a
Plaza A
ldea
Manila E
ast
Road
Dara
nak Falls
Tanay H
eadw
ater
Stations
Nit
rate
, m
g-N
/L
Nitrate-WET
Nitrate-DRY
Class "C" (10 mg/L)
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 18
Inorganic Phosphate (Wet/Dry)
0
0.1
0.2
0.3
0.4
0.5
Brg
y. W
aw
a
Plaza A
ldea
Manila E
ast
Road
Dara
nak Falls
Tanay H
eadw
ater
Stations
Ino
rgan
ic P
ho
sp
hate
, m
g-P
/L
Inorganic Phosphate-
WET
Inorganic Phosphate-
DRY
Class "C" (0.4 mg/L)
Phosphates and nitrates are required to maintain the growth and metabolism of plants
and animals. However, in excess amounts, these nutrients are proven harmful.
Nutrients enrichment or eutrophication is a main cause in the destruction of bodies of
water. This causes phytoplankton to grow and reproduce more rapidly, resulting in
algal blooms which disrupt normal ecosystem functioning and cause many problems
like depletion of dissolved oxygen, blocking of sunlight from photosynthetic marine
plants and producing toxins that are harmful to higher forms of life (www.water-
pollution.org.uk/eutophica).
All stations passed the criteria for nitrates and phosphates for the wet and dry season.
Chloride
Chloride (Wet/Dry)
0
50
100
150
200
250
300
350
Brg
y. W
aw
a
Plaza A
ldea
Manila E
ast
Road
Dara
nak Falls
Tanay H
eadw
ater
Stations
Ino
rgan
ic P
ho
sp
hate
, m
g-P
/L
Chloride-WET
Chloride-DRY
Class "C" (350 mg/L)
Chlorides are salts resulting from the combination of the gas chlorine with a metal.
Some common chlorides are sodium chloride (NaCl) and magnesium chloride
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 19
(MgCl2). Chlorine which is commonly used as a disinfectant is highly toxic. In
combination with a metal such as sodium it becomes essential for life. Small amounts
of chlorides are required for normal cell functions in plant and animal life. Chlorides
may get into surface water from several sources like rocks containing chlorides;
agricultural runoff; wastewater from industries; oil well wastes; effluent wastewater
from wastewater treatment plants, and road salting. High level of chlorides can
contaminate fresh water streams and lakes wherein fish and aquatic communities
cannot survive. (www.state.ky.us/nrepc/water/ncpel.htm)
All the stations for Tanay showed low concentration of chloride during the wet and dry
season, thus passing the criterion for chloride which is 350 mg/L.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 21
Table 1. Results of the Physico-Chemical Analysis of Water Samples from Tanay River: WET season
PARAMETERS STATIONS DENR Class C Water
Quality Criteria Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
pH, units 7.0 7.0 7.1 7.5 7.0 6.5-8.5
Total Suspended Solids, mg/L 15 17 17 9 14 <30 (increase)
Total Dissolved Solids, mg/L 248 253 223 217 211 *
Total Solids, mg.L 263 270 240 226 225 *
Chemical Oxygen Demand, mg/L <4 <4 <4 <4 <4 *
Biochemical Oxygen Demand,
mg/L
3 4 2 <2 2 10
Dissolved Oxygen, mg/L 6.8 7.2 7.3 7.8 8.1 5 (minimum)
Oil/Grease, mg/L 3 2 3 2 1 2
Ammonia, mg/L NH3-N 0.1312 0.1225 0.1598 0.0458 0.0141 *
Nitrate, mg/L NO3-N 0.9510 1.0446 0.8773 0.5057 0.3455 10
Inorganic Phosphate, mg/L 0.3061 0.2740 0.3265 0.0843 0.0044 0.4
Total Phosphorus, mg/L 0.3061 0.277 0.3265 0.1089 0.0216 *
Total Nitrogen, mg/L 3.9 5.6 3.9 4.3 3.2 *
Chloride, mg/L 11 11 11 11 7 350
Alkalinity, mg CaCO3/L 188 180 176 180 172 *
Calcium Hardness, mg CaCO3/L 128 116 112 100 100 *
Total Hardness,mg CaCO3/L 192 188 188 184 168 *
Turbidity, NTU 9 11 9 6 7 *
Conductivity, uS/cm 405 399 385 375 358 *
*Note: No set DENR Class C Water Quality Criteria
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 22
Table 2. Results of the Physico-Chemical Analysis of Water Samples from Tanay River: DRY season
PARAMETERS STATIONS DENR Class C Water
Quality Criteria Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
pH, units 7.9 8.1 8.4 8.6 8.6 6.5-8.5
Total Suspended Solids, mg/L 4 5 8 10 6 <30 (increase)
Total Dissolved Solids, mg/L 272 284 262 261 226 *
Total Solids, mg.L 276 289 270 271 232 *
Chemical Oxygen Demand, mg/L 8 12 16 16 12 *
Biochemical Oxygen Demand,
mg/L
2 2 <2 <2 <2 10
Dissolved Oxygen, mg/L 5.6 8.2 8.0 8.0 8.1 5 (minimum)
Oil/Grease, mg/L <1 <1 <1 <1 <1 2
Ammonia, mg/L NH3-N 0.2329 0.2626 0.1447 0.1464 0.2031 *
Nitrate, mg/L NO3-N 1.4822 1.662 1.5902 0.4387 0.7227 10
Inorganic Phosphate, mg/L 0.2585 0.2559 0.1876 0.0680 0.0079 0.4
Total Phosphorus, mg/L 0.2585 0.2559 0.1876 0.156 0.2342 *
Total Nitrogen, mg/L 4.6 4.0 3.9 4.5 4.7 *
Chloride, mg/L 11 15 11 15 4 350
Alkalinity, mg CaCO3/L 192 184 184 184 160 *
Calcium Hardness, mg CaCO3/L 120 112 88 116 96 *
Total Hardness,mg CaCO3/L 196 200 208 200 200 *
Turbidity, NTU 2 2 2 2 1 *
Conductivity, uS/cm 366 360 341 335 331 *
*Note: No set DENR Class C Water Quality Criteria
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 23
Results of Biological Analyses:
Table 6a to 6d present the algal and benthic population of Tanay River and its water
quality assessment.
Phytoplankton or Microscopic Algae (Dry and Wet Season)
Phytoplankton also known as microalgae, are similar to terrestrial plants that contain
chlorophyll and requires sunlight in order to live and grow. Most phytoplankton are
buoyant and occupies the upper portion of the water column where sunlight
penetrates the water and requires inorganic nutrients such as nitrates, phosphates, and
sulfur which in effect are converted into proteins, fats, and carbohydrates.
In a balanced ecosystem, phytoplankton provides food for a wide range of aquatic life
including fish, shrimps and snails. When too many nutrients are available,
phytoplankton may grow out of control and form harmful algal blooms (HABs). These
blooms can produce extremely toxic compounds that have harmful effects on fish,
shellfish, mammals, birds, and even to people.
Phytoplankton is also considered as water quality indicator of an ecosystem such as
lakes and rivers. Phytoplankton communities are sensitive to changes in their
environment and, therefore, phytoplankton total biomass and many phytoplankton
species are used as indicators of water quality (e. g. Olrik, 1994; Reynolds et al., 2002;
Brettum and Andersen, 2005).
Based on the results of quantitative and qualitative analysis of phytoplankton samples
collected in Tanay River during the dry season, three (3) stations were classified as
polluted in terms of algal composition and percentage contribution. Stations 2, 3 and 5
gave a total of 3171, 45784 and 1364 counts per ml of polluted algae identified as
Nitzchia sp.and Gomphonema sp. with percent contribution of 75, 90.6 and 50
respectively. Station 5 was also classified as polluted water with only 50% algal
contribution from polluted water indicator since 50% from unclassified algae was
identified. However, only station 4 (Headwater) was classified as clean water based on
the algal composition identified as Navicula sp. Station 1 was dominated by
Glenodinium sp. with total counts of 1110 per ml. It was however observed that based
on the water quality condition during the wet season, no significant difference was
recorded in the stretch of Tanay River.. It is worth mentioning that Station 4
maintained its classification as clean water. The algal population is mainly clean water
indicator. Stations 1,2,3 and 5 were all classified as polluted waters since polluted
water indicators dominate the algal population. Nitzchia sp. was the only algae
recorded in Stations 2 and 5 as compared to only 75 and 50 percent in same stations
during the dry season, respectively.
Benthic Fauna (Dry and Wet Season)
Benthic fauna are organisms that dwell in the bottom of any water body. Tanay River
was classified according to the benthic populations as Clean Water Indicator (CWI),
Moderately Polluted Indicator (MPWI), and Polluted Water Indicator (PWI).
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 24
During the dry season, Station 1 was relatively the most diversified with five (5)
species identified with a total of 808 counts per liter with Physa gyrina as the most
dominant. Station 1 was classified as polluted with 82.30 percent of the population
belonging to the Polluted Water Indicator. Station 2 was classified as moderately
polluted with 100 percent moderately polluted benthic indicators with Melonoides
tuberculatus as the dominant species. Station 3, 4 and 5 were classified as clean water
with 75, 100 and 100 percent clean water indicator identified respectively with Caenis
sp and Baetis sp as the dominant species.
Likewise, during the wet season it was observed that Station 1 has improved its water
quality from polluted to moderately polluted based on the identified benthic fauna
population .Stations 2,3,4 and 5 maintained its classifications as moderately polluted
and as clean water, respectively. In terms of water quality, Tanay River has shown a
little bit of improvement especially in Station 1 from polluted during the dry season to
moderately polluted during the wet season.
Table 3. Results of Biological Analyses of Water Samples
3a. Summary of Water Quality Assessment in Tanay River Based on
Phytoplankton/Algal Population
Wet Season
Stations Location Counts (organism/sq.m.) % Contribution Water Quality
Assessment
CWA PWA OTHER
S TOTAL %
CWA %
PWA % OTHERS
1 Mouth, Brgy. Wawa 718 2153 0 2871 25.0 75.0 0.0 Polluted
2 Plaza Aldea 0 789 0 789 0.0 100.0 0.0 Polluted
3 Manila East Road 2153 2871 0 5024 42.9 57.1 0.0 Polluted
4 Headwater 753 0 0 753 100.0 0.0 0.0 Clean
5 Daranak Falls 0 861 0 861 0.0 100.0 0.0 Polluted
Dry Season
Stations Location Counts (organism/sq.m.) % Contribution Water Quality
Assessment
CWA PWA OTHER
S TOTAL %
CWA %
PWA % OTHERS
1 Mouth, Brgy. Wawa 0 0 1110 1110 0.0 0.0 100.0 Not Classified
2 Plaza Aldea 1057 3171 0 4228 25.0 75.0 0.0 Polluted
3 Manila East Road 2368 45784 2368 50520 4.7 90.6 4.7 Polluted
4 Headwater 2153 0 718 2871 75.0 0.0 25.0 Clean
5 Daranak Falls 0 1364 1364 2728 0.0 50.0 50.0 Polluted
Notes:
CWA - Clean Water Algae
PWA - Polluted Water Algae
Others - Algae not classified as CWA or PWA
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 25
3b. Qualitative and Quantitative Analysis of Phytoplankton or Algae
Wet Season
Phytoplankton/Algae Identified
(counts/sq.m.)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Clean Water Indicator
Division Bacillariophyta
Navicula sp. 718 0 2153 783 0
Sub Total 718 0 2153 783 0
Polluted Water Indicator
Division Bacillariophyta
Nitzschia sp. 2153 789 2871 0 861
Sub Total 2153 789 2871 0 861
TOTAL 2871 789 5024 783 861
Dry Season
Phytoplankton/Algae Identified
(counts/sq.m.)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Clean Water Indicator
Division Bacillariophyta
Navicula sp. 0 1057 2368 2153 0
Sub Total 0 1057 2368 2153 0
Polluted Water Indicator
Division Cyanophyta
Spirogyra sp. 0 1057 0 0 0
Division Bacillariophyta
Gomphonema sp. 0 1057 2368 0 0
Nitzschia sp. 0 1057 43416 0 1364
Sub Total 0 3171 45784 0 1364
Division Bacillariophyta
Stephanodiscus sp. 1110 0 1579 0 0
Synedra sp. 0 0 789 0 682
Division Pyrrophyta
Glenodinium sp. 0 0 0 718 682
Sub Total 1110 0 2368 718 1364
TOTAL 1110 4228 50520 2871 2728
Note: Number of algae is expressed in organism per square meter.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 26
3c. Summary of Water Quality Assessment in Tanay River Based on Benthic
Population
Wet Season
Station Counts % Contribution Water Quality Assessment
CWI MPWI PWI Total %CWI %MPWI %PWI
Stn. 1 0 286 0 286 0 100 0 Moderately
Polluted
Stn. 2 0 334 48 382 0 87.43 12.57 Moderately
Polluted
Stn. 3 33 0 11 44 75 0 25 Clean
Stn. 4 99 0 0 99 100 0 0 Clean
Stn. 5 55 0 0 55 100 0 0 Clean
Dry Season
Station Counts % Contribution Water Quality Assessment
CWI MPWI PWI Total %CWI %MPWI %PWI
Stn. 1 0 143 665 808 0 17.70 82.30 Polluted
Stn. 2 0 381 0 381 0 100 0 Moderately
Polluted
Stn. 3 22 0 11 33 75 0 25 Clean
Stn. 4 77 0 0 77 100 0 0 Clean
Stn. 5 55 0 0 55 100 0 0 Clean
Notes:
Stn. 1 - Tanay River mouth
Stn. 2 - Plaza Aldea, Tanay, Rizal
Stn. 3 - Manila East Road (National Hi-way)
Stn. 4 - Headwater (near entrance of Daranak National Park)
Stn. 5 - Daranak Falls
CWI - Clean Water Indicator
MPWI - Moderately Polluted Water Indicator
PWI - Polluted Water Indicator
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 27
3d. Qualitative and Quantitative of Benthic Fauna
Wet Season
Organisms
(# of individual/sq.m.)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Clean Water Indicator (CWI)
Order Ephemeroptera
Family Baetidae
Baetis sp. 33 33
Family Caenidae
Caenis sp. 22
Order Plecoptera
Family Perlidae 33 22
Order Hemiptera
Family Gerridae 44 22
TOTAL CWI 33 99 77
Moderately Polluted Indicator (MPWI)
Class Gastropoda
Family Thiaridae
Melanoides tuberculatus 48 48
Thiara sp. 95 190
Family Viviparidae
Viviparus viviparous 143 48
Family Planorbidae
Hippeutis umbilicalis 48
TOTAL MPWI 286 334
Polluted Water Indicator (PWI)
Class Gastropoda
Family Physidae
Physa gyrina 48
Class Insecta
Order Diptera
Family Chironomidae
Diamesa sp. 11
TOTAL PWI 48 11
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 28
Dry Season
Organisms
(# of individual/sq.m)
Sampling Stations
Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Clean Water Indicator (CWI)
Order Ephemeroptera
Family Baetidae
Baetis sp. 22 22 33
Family Caenidae
Caenis sp. 33
Order Trichoptera
Family Hydropsychidae
Hydropsyche 22
Order Hemiptera
Family Gerridae 22
TOTAL CWI 22 77 55
Moderately Polluted Indicator (MPWI)
Class Gastropoda
Family Thiaridae
Thiara scabra 95
Melanoides tuberculatus 95 143
Thiara sp.
Family Planorbidae
Hippeutis umbilicalis 48 48
Family Pleuroceridae
Brotia costulata 95
TOTAL MPWI 143 381
Polluted Water Indicator (PWI)
Class Gastropoda
Family Physidae
Physa gyrina 285
Class Insecta
Order Diptera
Family Chironomidae
Diamesa sp 237 11
Class Oligochaeta
Family Tubificidae 143
TOTAL PWI 665 11
Note: Results of quantitative analysis is expressed in number of individuals per square meter.
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 29
Table 4. Results of Bacteriological Analyses of Water Samples
Wet Season
Parameters Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Total Coliform
(MPN/100 ml) 110,000 30,000 5,000 5,000 2,200
Fecal Coliform
(MPN/100 ml) 50,000 23,000 5,000 5,000 1,700
Detection of
Escherichia coli + + + + +
Dry Season
Parameters Stn. 1 Stn. 2 Stn. 3 Stn. 4 Stn. 5
Total Coliform
(MPN/100 ml) 350,000 540,000 92,000 35,000 35,000
Fecal Coliform
(MPN/100 ml) 110,000 240,000 24,000 1,300 35,000
Detection of
Escherichia coli + + - + +
Note: DAO 34, DENR 1990 Class C Water Quality Criterion for Total Coliforms (TC) is 5,000
MPN/100 ml while none for fecal coliforms
Results of Bacteriological Analyses:
0
20,000
40,000
60,000
80,000
100,000
120,000
1 2 3 4 5
MP
N/1
00
mL
Stations
Wet
Dry
WQ Criteria (TC=5000 MPN/100 mL)
350 540
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 30
The results of the microbiological analysis of Tanay River is presented in Table 4.
Water quality assessment for microbiological parameters is based on the Water Quality
Criteria for Class C Waters (DAO 34, 1900) which is set at 5,000 MPN/100 mL.
Based on the results, Stations 1 and 2 exceeded the criterion during the wet season.
Station 1which is located within the residential area wherein the domestic wastes are
discharged directly to the river registered the highest total coliform concentration of
110,000 MPN/100 mL, while station 2 is located in the town proper and within the
residential area also. Station 5 gave the lowest coliform concentration of 2,200
MPN/100 mL. It is located in Daranak Falls, whereby less visitors are coming during
the wet season.
During the dry season, all stations exceeded the set criterion. Station 2 recorded the
highest total coliform with the concentration of 540,000 MPN/100 mL while stations 4
and 5 recorded the lowest both at 35,000 MPN/100 mL. Higher concentration was
recorded during the dry season due to low level of water ( 0.3 m for station 4 and 0.5
m for station 5) occurring due to occasional rains and coliform bacteria are
concentrated during summer.
There is no set criterion for fecal coliforms. Station 1 recorded the highest (50,000
MPN/100 mL) while Station 5 recorded the lowest (1,700 MPN/100 mL) during the
wet season. In the dry season, Station 2 recorded the highest concentration at 240,000
MPN/100 mL while Station 4 recorded the lowest concentration of 1,300 MPN/100
mL for the dry season. Escherichia coli is present in all the stations in both wet and
dry season except in Station 3 in the dry season.
Coliforms are class of bacteria found in our environment, including the feces of man
and other warm-blooded animals. Coliform bacteria are commonly used
as bacterial indicator of water since their presence in water may indicate the possible
presence of harmful, disease-causing organisms. Fecal coliforms are the group of the
total coliforms that are considered to be present specifically in the gut and feces of
warm-blooded animals. Because the origin of fecal coliforms are more specific than the
origin of the more general total coliform group of bacteria, fecal coliforms are
considered a more accurate indication of animal or human waste than the total
coliforms. Escherichia coli (E. coli) is the major species in the fecal coliform group. E.
coli is considered to be the species of coliform bacteria that is the best indicator of
fecal pollution and on the possible presence of pathogens (Standard Methods for the
Examination of Water and Wastewater, 21st ed.)
Conclusion and Recommendations:
Based on the results of the chemical analyses, only Station 1 (Brgy. Wawa) and Station
3 (Manila East Road, National Highway) representing the wet season failed to meet
the water quality criterion set in the Department of Environment and Natural
Resources (DENR) Administrative Order (DAO) 34 in terms of oil and grease with a
measured value of 3 mg/L. All other remaining stations passed the criteria. Water
quality assessment based on the result of biological parameter showed that only station
4 (Headwater) recorded as clean for both wet and dry season. Stations 1, 2, 3 and 5
appeared to be polluted in terms of algal counts and moderately polluted in benthic
Water Quality Assessment Report –Tanay River
Environmental Laboratory and Research Division
Laguna Lake Development Authority 31
population. However, Station 5 (Daranak falls) also indicates clean water in terms of
its invertebrates community. Among the five (5) stations identified along the stretch of
Tanay river, Station 5 (Daranak falls) during the wet season was able to comply with
the DAO water quality criterion for Total Coliform with a recorded value of 2,200
MPN/100 mL . All other stations failed to meet the set criterion.
With the presented results based on chemical, biological and microbiological analysis,
Stations 4 and 5 are considered to be clean though Station 5 (wet season) gave an
indication of pollution in terms of phytoplankton analysis. This could be attributed to
the improper use of the Daranak resort. This is an indication that the river system of
Tanay needs to be addressed for a restoration program.
In order to save the deteriorating water quality in some part of Tanay River, it is
strongly recommended that continuous effort to clean up the river must be done
devotedly not only by LLDA and Local Government Unit but also by the community.
Indiscriminate dumping of garbage from the people living along the river banks must
be given strict compliance with corresponding penalties.
Information/Education/Communication campaign must be strengthened by the local
government. The ―Adopt a River‖ program /project and the People’s Organizations in
Tanay must work hand in hand to help in the awareness in realizing the importance of
rehabilitation of Tanay River System.
LAGUNA LAKE DEVELOPMENT AUTHORITY Resource Management and Development Department
Environmental Laboratory and Research Division
Water Quality
Assessment Report
Tanay River 2011
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