LWUA: Angeles City Water District spends P28M yearly on 'ineffective' UV disinfectant
PAMPANGA, Philippines – The Angeles City Water District (ACWD) has been wasting P28 million yearly on a water disinfection system that does not effectively kill harmful bacteria.
This was disclosed by the Local Water Utilities Administration (LWUA) in a recent letter to Vice Mayor Vicenta Vega Cabigting, in response to the earlier request of the Angeles City Council for clarification on the effectivity of ultraviolet (UV) disinfection as ACWD's main method of treating the water it sells and distributes to households, business establishments, and government offices.
"The Angeles City Water District has shifted from chlorination to the use of ultraviolet disinfection to get rid of microbiological contaminants and comply with the drinking standards (2017 Philippine Standards for Drinking Water)," LWUA acting administrator Jeci Lapus said in the letter.
He added, "Unfortunately, the microbial quality after the UV treatment was not completely addressed as laboratory results showed the reported significant levels of heterotrophic plate count, a key indicator for bacterial regrowth."
Heterotrophic plate count is a procedure for estimating the number of live bacteria in water during water treatment and distribution.
"Besides, the intended use of UV as a disinfectant is negated because the presence of mineral contents that impedes the radiation was not adequately removed prior to the UV radiation exposure," he said.
Lapus said the ACWD initially contracted Texin Incorporated to supply and install UV Hydro Optic Disinfection for the central pumping station in Barangay Santo Domingo at a cost of P29,940,320.
But the ACWD later opted to outsource the installation and maintenance of UV disinfection units for 20 other pumping stations, paying P3 per cubic meter of UV-treated water to Texin for 25 years.
"This cost the ACWD P32,287,932 per year for the UV treatment plus the added P4,172,110 per year for chlorine. A substantial saving of P28,115,821 per year could have been achieved if chlorine was used as the disinfectant. Thus, the failure of the ACWD to make a thorough engineering study and post-project evaluation on the beneficial use of UV disinfectant had cost the government more," Lapus disclosed.
LWUA said the procurement of UV disinfection machines without sufficient data on the efficacy of the system "is not well understood."
"It may be interred that the introduction of UV disinfection for water disinfection alone did not improve the water quality and more importantly, it ate up additional operational and maintenance cost," it added.
Late last year, LWUA dispatched a team to evaluate ACWD's UV disinfection system.
A copy of the report by the LWUA team that inspected ACWD's pumping stations on December 2, 2019, stated: "The team decided to recommend the use of chlorination as the main disinfectant and suggested to cease operation of UV disinfection facilities to avoid unnecessary expenses on water supply disinfection and maintenance, as UV is not ideal disinfection for the present setup. Immediate termination of service contract with Texin contractor would be very beneficial to the water district in terms of operational cost and attaining full disinfection of water supply."
The LWUA team said that while ultraviolet disinfection for water supply is internationally accepted, the "new breed of UV disinfection installed at Angeles City Water District is relatively not suitable considering raw water contains iron, manganese, TDS (total dissolved solids), odor and color that are not addressed effectively prior to UV exposure."
Rappler tried to get comments on the LWUA letter from ACWD board chairman Bernardo Cruz and ACWD general manager Reynaldo Liwanag through emails sent to the water district's email addresses (firstname.lastname@example.org and email@example.com) on February 20. Both have not responded as of this posting.
LWUA sent copies of the letter to Liwanag, Angeles City Mayor Carmelo Lazatin Jr, Commission on Audit Chairperson Michael Aguinaldo, Ombudsman Samuel Martires, and Commissioner Greco Belgica of the Presidential Anti-Crorruption Commission. – Rappler.com