THE Commission on Audit (COA) has called out the Dasmariñas Water District (DWD) over failed chlorine residual tests in 2024 even as it assured consumers that the overall water supply remains generally safe.
Based on the Compliance Audit Report on DWD released on June 26, 2025, the COA said the water district obtained a Certificate of Acceptance of its Water Safety Plan from the Department of Health last year.
The DWD is providing water supply services to 125,424 service connections as of the year-end 2024, making it one of the country’s biggest water districts.
During the year, the water district also conducted drinking-water quality surveillance in coordination with joint venture partner Primewater Infrastructure Corp., including microbiological tests, physical and chemical tests, and chlorine residual tests.
The microbiological test results showed 852 samples were collected from January to December 2024, numbering between 68 to 73 per month.
Of the said total, 736 passed the total coliform and thermotolerant coliform/ E. Coli safety levels set by the Philippine National Standards for Drinking Water (PNSDW) at less than 1.1 MPN (most probable number) per 100 milliliters of sample water or <1.1MPN/100mL.
On the other hand, 762 samples passed the heterotrophic plate count, also set by the PNSDW.
The COA noted that the average of 71 samples per month “significantly exceeded the minimum requirement.”
Water quality physical and chemical tests involving 949 samples also scored 100 percent compliance with 11 out of 13 parameters of the PNSDW, with the remaining two- color and turbidity – scoring 98.7 percent passing rates.
It was the chlorine residual test that caused a concern among auditors involving 860 samples, wherein failed levels were recorded between 35 percent to 92 percent during the year.
A table of the results attached as Annex C to the COA report showed 92 percent failed the limit of 0.3 parts per million to 1.5 ppm in January 2024, 86 percent in October and November, 84 percent in September, 83 percent in February, and 80 percent in July.
“This non-compliance was primarily attributed to non-functional chlorinators and inadequate disinfection practices. These operational deficiencies compromised the maintenance of proper chlorine levels throughout the distribution system,” the COA noted.
The DWD management said it had issued notices of violation to PrimeWater on June 13, October 31, and November 19, 2024 informing it of the deficiencies cited.
The COA said as of December 31, 2024, the DWD has not received any feedback from PrimeWater.
