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 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. 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 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 28oC. A sunny weather occurred at the time of sampling. Air temperature was recorded between 27oC to 31oC. Dry season registered a lower level of temperature for both water and air that ranges from 26oC to 29oC for air and 23oC to 25oC 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. Environmental Laboratory and Research Division 2 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River 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. Environmental Laboratory and Research Division 3 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 2a. Tanay River Station 1 Wet Season – June 29, 2011 Field Observations and in-Situ Measurements Name of Station Mouth – Brgy. Wawa P0315034 GPS Reading (UTM) 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 Environmental Laboratory and Research Division 5 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 2b. Tanay River Station 1 Dry Season - December 1, 2011 Field Observations and in-Situ Measurements Name of Station Mouth – Brgy. Wawa P0315034 GPS Reading (UTM) 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 Environmental Laboratory and Research Division 6 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 3a. Tanay River Station 2 Wet Season – June 29, 2011 Field Observations and in-Situ Measurements Town Proper, Poblacion (Plaza Name of Station Aldea) P0315160 GPS Reading (UTM) 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 Environmental Laboratory and Research Division 7 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 3b. Tanay River Station 2 Dry Season - December 1, 2011 Field Observations and in-Situ Measurements Town Proper, Poblacion (Plaza Name of Station Aldea) P0315160 GPS Reading (UTM) 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 Environmental Laboratory and Research Division 8 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 4a. Tanay River Station 3 Wet Season – June 29, 2011 Field Observations and in-Situ Measurements Manila East Road Name of Station (National High-way) P0315920 GPS Reading (UTM) 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 Environmental Laboratory and Research Division 9 Laguna Lake Development Authority Water Quality Assessment Report –Tanay River Figure 4b. Tanay River Station 3 Dry Season - December 1, 2011 Field Observations and in-Situ Measurements Manila East Road Name of Station (National High-way) P0315920 GPS Reading (UTM) 1604051 Time 10:20 AM Air Temperature (oC) 26 Water Temperature (oC) 25 Weather Sunny Water Condition Fast flowing Color of the Water Clear