The Ecosystems Research and Development Bureau (ERDB) through the Watershed and Water Resources Research, Development and Extension Center (WWRRDEC) communicated the results of the study on “Water Quality Assessment in Benguet: A Time Series Analysis” during the 2nd Quarterly Meeting Regional Development Council – Cordillera Administrative Region Sectoral Committee (RDC-CAR SeCom) on Watershed and Environmental Management at the DENR Conference Hall, Gibraltar Road, Baguio City on May 27, 2022.
Balili River (BR) is one of the Water Quality Monitoring Areas (WQMA) in the Cordillera as it is one of the major river systems traversing the City of Baguio and La Trinidad, Benguet.
According to CEPMO in 2014, the BR system runs along 70 (full) and 5 (partial) barangays out of the 128 barangays of Baguio City in which 40% of the whole Baguio population of Baguio is served by the river catchment.
The said river was classified in 2013 as “Class A” by virtue of DENR Department Administrative Order No. 34 of 1990 which means that the river is intended for public water supply source provided that it has to undergo conventional treatment to meet the Philippine National Standards for Drinking Water.
However, BR was reclassified last May of this year into “Class B” by virtue of DENR Memorandum Circular 2022-08 since it has long been considered a biologically dead river especially during the dry season as reflected by the monitoring results of various agencies.
Results of the study conducted by ERDB-WWRRDEC confirm accounts that BR is continuously degrading in terms of its health and water quality.
This was validated through various statistical analyses of six-year water quality parameters data gathered by the Environmental Management Bureau – Cordillera Administrative Region (EMB-CAR) from 2014-2019 in the 21 sampling stations within the river.
Water Quality Indices (WQI) of all sampling stations showed significantly high values ranging from 3,369 to 63,796 quarterly and 600 to 67,839 annually compared to the WQI standard limit of 100.
In terms of trend analysis, individual water quality parameter revealed that only 5 out of 9 have accurate trends.
These are the Power of Hydrogen (pH) and Phosphates which showed decreasing trend while Ammonia, Biological Oxygen Demand (BOD) and Total Suspended Solids (TSS) showed an increasing trend. Among these, only the trend of phosphates indicates improvement in water quality of BR while the rest revealed otherwise.
Moreover, a decreasing trend of pH denotes that BR is becoming acidic over time which may negatively affect aquatic life such as the hatching of fish eggs and survival of macroinvertebrates.
The increasing trend in ammonia is an alarming result since high levels of ammonia are toxic to aquatic organisms and cause eutrophication. High levels of BOD mean more dissolved oxygen requirement which implies a large quantity of microorganisms in the water.
Lastly, high concentrations of suspended solids reduce the clarity of the water that also affects the health of BR.
Meanwhile, water quality parameters and WQI of each sampling station have varying forecasts while the annual WQI forecast showed increasing prediction up to 32,412.48 for three years which is significantly high compared to the WQI standard limit of 100.
These results provide pertinent information for decision-making and appropriate action by the Governing Board of Balili River Water Quality Monitoring Area (WQMA), Local Government Units (LGUs), policy makers, stakeholders, and other agencies in continuing efforts to enhance the management of Balili River. Shirley Jaene S. Valdez, Winston P. Manongyao, WWRRDEC