GOVERNMENT auditors have warned that water samples from 21 pumping stations of the Calamba Water District (CWD) registered high levels of Coliform, Thermotolerant Coliform, and Heterotrophic Plate Count (HPC) according to laboratory test results conducted in various months last year.
In a Compliance Audit report released last June 26, the Commission on Audit said the flagged pumping stations supply water to 12 barangays of Calamba City with a total of 4,558 connections, including households and business establishments.
The high level of bacteria was attributed to the non-chlorination of the water supply in the said pumping stations. Chlorination of water is a process that eliminates microorganisms from the water supply or to address contamination, making the water safe for consumption.
Based on the Philippine National Standards for Drinking Water (PNSDW), the safe or acceptable level of total coliform and thermotolerant coliform/E. coli was less than 1.1 MPN (most probable number) per 100 milliliter of sample water or <1.1MPN/100mL.
On the other hand, the PNSDW recommends that the heterotrophic plate count should be at <500 CFU (colony forming unit) per milliliter or 500 CFU/mL.
The CWD stations that failed the laboratory tests were identified in the report as Bunggo Pumps 1 to 4; Maunong Purok Pumps 1 to 3; Bubuyan Pump 3 (new); Ulango Pumps 1 and 2; Gumamela pump in Barangay Laguerta; Laguna Hills pump in Brgy. Pansol; Homalan Pumps 1 to 3; Ciudad Verde and Woodlands Pump in Brgy. Makiling; Saimsim Pump; Don Abelardo Pump in Brgy. Lawa; Gawad Kalinga Calambeño Ville in Brgy Majada Labas; and Tibagan Pump in Barangay Sirang Lupa.
The lab results showed these pumping stations registered total coliform and thermotolerant coliform or E.coli ranging from 1.1 MPN/100 mL to 8 MPN/100 mL in several months of sampling.
On the other hand, 15 of the 21 pumping stations showed heterotrophic plate counts of >6500 CFU/mL. These were Bunggo 1 to 3; Maunong 1 to 3; Bubuyan 3; Ulango 2; Gumamela; Laguna Hills; Homalan 1 to 3; Don Abelardo; Gawad Kalinga Calambeño Ville, and Tibagan.
“Evaluation of the monthly microbiological test results showed that these PSs exceeded the allowable level for the HPC, total coliform, and thermotolerant coliform/E.coli parameters in various months,” the COA said.
According to auditors, the water district officials “claimed that chlorination was not applied to the 21 PS (pumping stations) because the concessionaires rejected the addition of chlorine due to its odor and taste.”
The audit team, however, pointed out that no written complaint or request for non-chlorination was submitted to it in support of the assertion.
State auditors recommended that the general manager instruct the Water Safety Plan chairperson to conduct monitoring and to chlorinate the 21 PS to eliminate microorganisms and bring microbiological levels within the allowable threshold set by the PNSDW of 2017.
The CWD management said it will meet with the affected concessionaires to clarify if they still prefer non-chlorination.
Those who would refuse the installation of chlorination equipment would be made to sign a memorandum of agreement with the CWD, where they will be made to acknowledge the risks and assume accountability for their decision.
