The 20-kilometer Calumpang River that runs through two cities and six towns in Batangas province showed fecal coliform contamination, prompting a major rehabilitation by scientists and local government units (LGUs).
Based on a 2012-2013 study conducted by the School of Environmental Science and Management-University of the Philippines Los Baños (Sesam-UPLB), the water quality tests showed high presence of fecal coliform (2,000 to 130,000 most probable number or mpn per 100 milliliter) as of 2011.
Coliform presence, according to the Department of Environment and Natural Resources (DENR) standard, should stay below 400 mpn/mL.
Another indicator that the river is polluted is the high level of phosphate at 2.1432 milligrams per liter (DENR standard is less than 0.4 mg/L) as of 2013. The river’s dissolved oxygen level, or the amount of oxygen available to marine organisms, is at 0.53-4.71 mg/L, falling below the 5.0 mg/L DENR standard, the study showed.
Polluted water
“Generally, the water is polluted,” said Sesam assistant professor Dr. Rico Ancog in a phone interview on Sunday.
Ancog said the source of phosphate in Calumpang River must be the animal feeds dumped into the water, while the fecal coliform must have come from animal wastes.
Livestock farming is a major industry with at least 324 large-scale swine and poultry farm operators in Batangas City and the towns of Ibaan and Rosario alone. The rest of the eight LGUs that straddle the Calumpang watershed are Lipa City and the towns of Cuenca, Padre Garcia, San Jose and Taysan.
“[Calumpang River] is classified as Class D river, according to the DENR classification, meaning it now serves only as a receiving body of discharges or a catchment,” said Batangas City environment officer Oliver Gonzales in a separate phone interview.
River rehab
Asked if marine products from Calumpang River remained safe for human consumption, Ancog said they had no definitive study on that matter yet.
Gonzales, however, said residents could still catch fish and prawns from the river.
The river’s current state prompted a major rehabilitation project by the city government. The city is at the downstream of Calumpang River.
Gonzales said the city government commissioned the Sesam-UPLB to undertake the study and recommend or undertake measures for the Calumpang River Rehabilitation Project.
On July 8, the Sesam started giving a river basin management training among the eight watershed LGUs. The training sessions will run until September.
“If you don’t work with those [municipalities] in the upstream and midstream, you cannot solve the problem of those in the downstream. So this is an example of an inter-LGU collaboration,” Ancog said.
He said among the possible solutions would be the construction of a wastewater treatment facility and the use of biogas digesters in livestock farms to harvest energy and minimize water pollution.