The Thua Thien Hue Water Supply and Construction Company (HueWACO) is a state-owned water utility that supplies the cities and towns of Thua Thien Hue Province in central Vietnam. In response to a decision by the Provincial Peoples’ Committee (PPC) of Thua Thien Hue and in line with the national government’s directive on decentralization, HueWACO will also assume responsibility for providing water services to rural populations.
With support from the Asian Development Bank’s Pilot Demonstration Activity program, Aquaya collaborated with HueWACO on the design and management of four rural water treatment systems. Our objective was to develop appropriate rural water treatment and management models that HueWACO can implement on a province-wide scale as it assumes increasing responsibility for rural water services.
Each system was designed to produce high quality treated drinking water distributed through household connections or standpipes. Local community members were employed as paid system operators and fee collectors, with HueWACO providing oversight and responsibility for system maintenance and repair.
We began the project by helping to identify appropriate candidate communes in two districts within Thua Thien Hue Province and by providing initial hardware designs. HueWACO convened public hearings at the first two candidate sites in November 2010 and an additional two sites in the summer of 2011, with the assistance of a Vietnamese community mobilization professional. After finalizing formal agreements with local authorities, hardware installation at all sites was completed in August 2011.
Three of the projects involved water treatment upgrades of existing piped water distribution systems, while the fourth was a new construction of a gravity-fed kiosk-style system and a series of community taps. For the piped systems, we opted for locally-manufactured, manually backwashable pressure sand filters (PSFs) with capacity of 200m3/day (see Figure 1). In each case the PSF stage is followed by chlorination using flow-driven chlorine tablet feeders. (These low-cost feeders are in wide use for swimming pool chlorination in the United States and other industrialized countries).
The kiosk system also utilized a gravity-feed from an upland stream through a buried pipeline to the installation pictured in Figures 2 and 3. Again, taking
advantage of gravity pressure, all physical and biological impurities are retained as water flows from the elevated feed tank through
an AquaSentry module filled with MEMCOR brand ultrafiltration membranes manufactured by Siemens (and supplied by AquaSolutions of Australia). As with the PSF installations, a disinfection dose of chlorine is automatically added through a chlorine tablet feeder before the water passes through to a “product”
tank, from which the water is dispensed through a series of community taps. Villagers pick up their water in their own containers, and the chlorine dose in the water protects it from recontamination during transport and storage.
Each system is operated by a locally-nominated community member whose salary is paid by HueWACO. The operator also collects monthly fees from the village water users and passes the revenues on to HueWACO. The water fee charged is the standard bulk rate set by HueWACO – approximately $0.35 per cubic meter ($0.00035 per liter).
An essential component of this project is the use of a formal quality control/quality assurance protocol for system operation and maintenance. The protocol, known as a Water Safety Plan, has been developed and adopted by a number of public water utilities in Australia and has been officially endorsed by the World Health Organization (WHO) for reducing and mitigating hazard risks. Aquaya worked with HueWACO to develop and implement Water Safety Plans for each installation.