FOR the third straight year, more than half of Guagua Water District’s 13 operating pumping stations failed safety limits set by the Philippine National Standard for Drinking Water (PNSDW) after seven of them posted higher concentrations of arsenic, a cancer-causing element.
The 2020 audit of the Guagua WD released last March 25 showed the seven pumping stations that failed were located in San Nicolas, San Miguel, Samsaman, Sta. Filomena, Bancal, Sta. Clara, and San Matias.
These same seven pumping stations also failed the 2019 tests showing higher arsenic levels than the 0.1 milligrams per liter (mg/L) allowed by PNSDW.
According to the latest audit report, Guagua WD derives its water supply from groundwater source serving 18,938 active concessionaires in the municipality’s 31 barangays.
It has 18 pumping stations in its service area, of which 13 are in operational status as of December 31, 2020.
The presence of the toxic substance in the water and the inability of the water district to address the problem had prompted a warning from the Commission on Audit.
“The control measures set in District’s Water Safety Plan (WSP) may not be properly implemented and the concessionaires may be consuming water with arsenic concentration which is harmful to one’s health,” the audit team said.
“Water contaminants such as arsenic are toxic when high concentrations are present in a human body and may cause health problems,” it added.
Guagua’s water system has been under the management of PrimeWater Infrastructure Corporation “for financing, development, rehabilitation, improvement, expansion and maintenance” since it signed a Joint Venture Agreement (JVA) with Guagua WD on November 3, 2017.
At the exit conference with government auditors, the Operation Head of Primewater for North Luzon said the Water Quality Department of Primewater Central and Euro Products Inc. contractor have started trial activity on arsenic removal using DMI 65 at Pump Station 1 – San Nicolas from March 1, 2021 up to the third week of April.
Primewater said in the event the results are found favorable, the technology will be further tested on other pumping stations for verification and comparison.
The JVA partnership is intended to map out a water development program for the next 25 years to include current concerns regarding sufficient supply, non-revenue water, and water quality. It also covers service expansion, repair, and replacement of aging system and other upgrading activities.
However, while Guagua WD passed the monthly microbial analysis tests conducted by Waterlab Water Testing Laboratory Inc. and Angeles City Water District Laboratory, the arsenic content of water pumped from the seven problem areas persists.
Auditors noted that Primewater has tested four technologies during the year to remove arsenic from the water, two of which showed good results.
Granular Iron Oxide Media Filtration was reported to have removed arsenic content by 100 percent and was first tested in large scale at the Bancal pumping station. While the same result was obtained, the filtering medium used had to be replaced every month, making the system problematic.
The second technology, the Arsenic Selective Media System, was pilot-tested at Sta. Filomena PS from December 06, 2019 to January 30, 2020 and was found consistent in reducing the arsenic concentration well below the PNSDW safe limit. However, the expected life for the filtering medium was only months or less.