ASPA puts water disinfection systems project out for bid
The American Samoa Power Authority (ASPA) is currently inviting bids for the construction of UV disinfection systems for the Utulei (Town Area) and Fogagogo (Tafuna Area) wastewater treatment plants.
A one-time pre-bid meeting was held last Tuesday, Feb. 25 and according to ASPA Executive Director, Utu Abe Malae, seven companies were represented during the meeting: RW, Fletcher, PEP, RM Construction, E&W Construction, Tresmel Inc., and APECS.
When asked for a brief insight about the local disinfection systems, Utu explained that there was a chlorine gas disinfection system that was utilized at the Utulei wastewater treatment plant (WWTP) until 1985, when the Environmental Protection Agency (EPA) issued a waiver and the system was shut down.
“There has never been a disinfection system at the Tafuna WWTP since,” Utu continued. “Under the current US-EPA Administrative Order, ASPA is working with the US-EPA in keeping a 301 H waiver that allows ASPA’s WWTPs at Utulei and Tafuna to discharge into the ocean with only primary WW treatment, omitting secondary WW treatment.”
Utu said that in pursuit of maintaining the semi-autonomous agency’s waiver, ASPA and the US-EPA have decided to install disinfection systems for both wastewater treatment plants.
He said there were many disinfection options available, but after a thorough study of those options, a decision was made to install an ultra-violet (UV) disinfection system which, according to him, “was determined to be the most cost effective… and UV disinfection has the added benefit of being the safest disinfection system on the market.”
In addition, Utu added, there is no chlorine residual that may be discharged into the ocean. “The system has a life cycle of about 50 years; however, the electronic and electrical components will need to be replaced more frequently.”
The ASPA Executive Director explained that the two disinfection systems will serve all of the customers—about 5,000 families— connected to the central sewer systems. The Utulei waste water treatment plant will serve current customers from the Fagaalu to Atu’u areas, and is being sized to accommodate future customers, such as Aua village.
On the other hand, the Tafuna waste water treatment plant will serve current customers in the Tualauta area and Nuuuli, and is also being sized to accommodate future customers, such as Leone.
According to Utu, municipal waste water generally requires disinfection to meet specific bacterial limits before being discharged to surface waters. The main objective of disinfection is to reduce the number of waterborne pathogens to safe levels, thereby lowering the risk of exposing the public to infectious diseases.
“The persistence of some pathogens in receiving waters and soils indicate that disinfection of wastewater effluents provide the first line of defense for drinking water from surface water or groundwater,” Utu explained. “Disinfection protects our marine environment, including the reefs and indigenous species.”
All submittals for bids on this project must be received at the ASPA Materials Management Office - Procurement, no later than 2 p.m. on Wednesday, March 19, 2014.