via GRAPHIC PLUS | 24 June 2026 — The City Government of San Jose del Monte has uncovered a clean-water line allegedly used to dilute wastewater from a facility formerly operated by PrimeWater Infrastructure Corp. before it underwent testing by the Department of Environment and Natural Resources (DENR).

During an inspection of Septage Treatment Plant 2, the City Engineers’ Office found a plastic pipe inside the tank where wastewater is stored after undergoing the treatment process. The line was allegedly opened to introduce clean water whenever the DENR conducted water testing at the facility.

This allowed the wastewater sample being tested to be mixed with clean water, potentially reducing the concentration of pollutants and making it appear that the treated wastewater complied with prescribed environmental standards.

According to the City Government, PrimeWater’s alleged manipulation may have concealed the true level of pollution and resulted in the discharge of unsafe wastewater that could contaminate waterways, damage the environment, and threaten the health of affected communities.

“While we were inspecting the tank’s discharge point to collect a sample, we found PE tubing, or a plastic pipe, inside. We discovered that PrimeWater would open a line to inject clear water whenever the DENR conducted testing at the septage facility,” said Engr. Renz Christian Casas of the City Engineers’ Office.

According to the City Engineers’ Office’s investigation, the alleged manipulation began in 2024 after the facility repeatedly failed DENR water quality tests.

The City Government continues to investigate the facility’s operations and the possible effects on the quality of wastewater discharged into the environment. The findings will also be submitted to the appropriate regulatory agencies to determine whether environmental regulations were violated and who should be held accountable.