Benefit - cost analysis of wastewater management options for Vientiane Capital, Lao PDR

Abstract

ABSTRACT:

The paper presents a cost-benefit analysis (CBA) as a basis for selecting the most feasible among two wastewater management options for the central area of Vientiane Capital, Lao PDR, with an area of 26km2, a population of 225,035 people. Option 1, applying centralized wastewater management scheme, can collect and treat 62% of wastewater, equal to 28,000 m3/day to meet quality of column A of effluent standard, The remaining 38% of population uses on-site treatment in septic tanks. Option 2, applying the combination of centralized and decentralized scheme, enables to collect 80% of wastewater and treat to column A. Among remaining 20% of population, 10% can use low-cost clustered wastewater treatment systems for BOD and TSS removal, while the remaining 10% use on-site septic tanks. Research results show that every 1 USD invested in wastewater collection and treatment could bring averted economic benefits related to environment improvement, health protection, water quality improvement, time saving, tourism and other investment opportunities, as much as 4.93 USD for the option 1, and 6,50 USD for the option 2.

Keywords: Centralized and decentralized wastewater management model; Benefit-Cost analysis; CAPEX; OPEX; wastewater treatment; Vientiane capital.