Assessment of the impact of on-site sanitation systems on groundwater pollution in two diverse geological settings—a case study from India

Abstract

On-site sanitation has emerged as a preferred mode of sanitation in cities experiencing rapid urbanization due to the high cost involved in off-site sanitation which requires conventional sewerages. However, this practice has put severe stress on groundwater especially its quality. Under the above backdrop, a study has been undertaken to investigate the impact of on-site sanitation on quality of groundwater sources in two mega cities namely Indore and Kolkata which are situated in two different geological settings. The parameters for the studies are distance of groundwater source from place of sanitation, effect of summer and monsoon seasons, local hydro-geological conditions, and physico-chemical parameters. NO(3) and fecal coliform concentrations are considered as main indexes of pollution in water. Out of many conclusions which can be made from this studies, one major conclusion is about the influence of on-site sanitation on groundwater quality is minimal in Kolkata, whereas it is significant in Indore. This difference is due to the difference in hydrogeological parameters of these two cities, Kolkata being on alluvium quaternary and Indore being on Deccan trap of Cretaceous to Paleogene age.

Pit Latrines and Their Impacts on Groundwater Quality: A Systematic Review

“…Concentrations of nitrate in well water near latrines are highly variable. Although a number of studies that detected total or fecal coliforms did not detect elevated nitrate concentrations in wells (Ahmed et al 2002; Dzwairo et al 2006; Howard et al 2002; Padmasiri et al 1992; Still and Nash 2002), other studies have reported nitrate concentrations > 100 mg/L (Banks et al 2002; Girard and Hillaire-Marcel 1997; Lewis et al 1980; Mafa 2003; Pujari et al 2012; Tandia et al 1999). Frequently, groundwater nitrate concentrations near latrines were above local background levels, even if they remained below or near the WHO guideline (Baars 1957; Caldwell and Parr 1937; Chidavaenzi et al 2000; Jacks et al 1999; Zingoni et al 2005).…”

“…At a study site in India characterized by a shallow water table and fractured rock aquifer, high concentrations of fecal coliforms were found in domestic wells located near pit latrines and septic tanks (Pujari et al 2012). At a contrasting site, characterized by alluvial formations, the authors detected no or low levels of fecal contamination (Pujari et al 2012).…”

“…At a study site in India characterized by a shallow water table and fractured rock aquifer, high concentrations of fecal coliforms were found in domestic wells located near pit latrines and septic tanks (Pujari et al 2012). At a contrasting site, characterized by alluvial formations, the authors detected no or low levels of fecal contamination (Pujari et al 2012). In a georeferenced spatial study of viral contamination, Verheyen et al (2009) sampled 287 drinking-water sources (247 water wells, 25 pumps, and 15 surface water samples) proximate to 220 latrines.…”

Detection of human adenovirus, rotavirus and enterovirus in water samples collected on dairy farms from Tenente Portela, Northwest of Rio Grande do Sul, Brazil

“…This may be an effect of the poor construction of latrines and wells on these farms, which can permit the infiltration of the subsoil by microorganisms, and viruses may thus accumulate on the groundwater resources (Jung et al , 2011; Pujari et al , 2012; Steyer et al , 2011; Wilcock et al , 2011). The concern is that water from artesian wells and springs is often thought to be free of contaminants and the farmers and families living on these locations have been using this as the solely source of drinking water.…”

On-site Sanitation Influence on Nitrate Occurrence in the Shallow Groundwater of Mahitsy City, Analamanga Region, Madagascar

“…Several authors reported that inadequate on-site sanitation design and the hydrogeological conditions of terrain are potential sources of groundwater pollution, including fecal contamination (ARGOSS, 2001;Dzwairo, Hoko, Love, Guzha, 2006;Pujari, Padmakar, Labhasetwar, Mahore, Ganguly, 2011). In Botswana, Staudt (2003) found that eleven out of thirty-one sampled boreholes in the Ramotswa area had nitrate concentrations exceeding the nitrate concentration guideline value of 45 mg/L for drinking water (World Health Organization [WHO], 2006).…”