Abstract

Background: Partially treated wastewater effluent percolating into the soil contaminates groundwater quality. As water percolates through the soil, some degree of disinfection occurs; however, most soil infiltration systems have been traditionally designed for treated wastewater disposal and are not designed with disinfection in mind1. In India, households construct and operate OSS systems in the absence of regulatory supervision and non-compliance with IS 24702 where onsite disposal of liquid is not possible which poses a risk to public health. IS 2470 part II recommending that the disposal system shall be either a dispersion trench or soak pit and recommends disinfecting before the OSS effluent is discharged into the drain. In Tiruchirappalli, Tamil Nadu, nearly two-thirds of the population rely on OSS. Infiltration of partially treated wastewater effluent into the soil is a common practice for many onsite wastewater management systems in the city. The objective of the study was to check the feasibility of low cost and efficient disinfection methods and to determine the performance of disinfection, reliability and constraints in the method, maintenance and frequency, and estimated cost for installation and operation.