Groundwater is a major source of water for a large number of Indians with 66 percent rural households and 27 percent urban households directly depending on it for drinking purposes, as per Census 2011. There is a greater daily dependence on groundwater for non-potable uses.

Almost 75 percent of Indian households with toilets within premises rely on onsite sanitation systems. Under the Swachh Bharat Mission, an additional 80 million toilets have been built in the last four years. Most are presumably onsite sanitation systems.

These two statistics may seem unconnected but that’s only because the impact of groundwater and sanitation on health have not been studied well. “The linkage between groundwater and sanitation and its impact on health are poorly understood, and there is a dearth of field studies in the Indian context,” says Harshvardhan Dhawan, senior manager, Programmes, Arghyam, in his opening remarks at a workshop based on a study on groundwater-sanitation nexus held recently in New Delhi. According to him, water security cannot be looked at without exploring water quality. Research in this domain has not necessarily translated into policy and practice.

The study, supported by Arghyam, points to emerging evidence of groundwater contamination, highlighting linkages between groundwater quality and sanitation systems. The outcome of the study was presented by the Indian Institute of Human Settlements (IIHS), Arghyam’s knowledge partner, during this workshop.

Geetika Anand, senior associate, IIHS, while presenting the study, says that faecal contamination is found in both shallow as well as deep aquifers in all the study sites. Some key factors influencing contamination were settlement type and density, hydrogeological settings, groundwater levels, seasonal variations, and household practices including those related to design, construction, management and behaviour.

The research partners included IIHS, Indian Institute of Science (IISc), IIT Madras, PSI, ACT, WASSAN and ATREE. Different hydrogeological settings in both rural and urban areas are represented in the study.

More contamination in dense areas

The study found out that contamination is more likely in dense areas, whether urban or dense villages. In Mulbagal and Neelamangala, both in Karnataka, borewells inside the towns with higher density of soak pits had higher faecal coliforms levels when compared to borewells in peripheral rural areas. Seasonal variations in contamination levels were considerable. Other unsanitary conditions also lead to groundwater contamination.

The pathways of contamination are complex, indicating a link between surface and groundwater contamination. Even the springs at Almora in Uttarakhand, normally considered pristine, received contaminants through direct discharge in the drainage channels. Other sources of groundwater contamination like solid waste, grey water, drainage channels, industrial waste, etc also need to be addressed.

“The contamination of shallow groundwater has opened up newer contamination problems in the deeper layers which take longer time to activate but are irreversible mostly. Nature had its biogeochemical processes through which organic contaminants would get reduced but not any longer,” says G.C. Pati, member, Central Ground Water Board at the panel discussion following the presentation of study findings.

What are the solutions to the problem?

Adequate attention needs to be paid to type, design and construction of toilets and containment systems and their maintenance as per standards. This implies that while technology is key, equal attention needs to be given to operations and management as well.

Selection of onsite systems and their designs should be based on the hydrogeological characteristics of the area. For example, soak pits may not be feasible in areas with shallow water table or in fractured hard rock systems. The full cycle of contamination (containment, conveyance, treatment and disposal), and not just the construction of toilets, needs to be planned well. The planning and implementation of these stages should not be put off.

The research programme highlights the need to integrate all faecal contamination concerns of large-scale water and sanitation programmes like Swachh Bharat Mission, AMRUT (Atal Mission for Rejuvenation and Urban Transformation) and Atal Bhujal Yojana. While these programmes focus on access and service delivery, quality remains a key concern, and hence relevant quality improvement indicators need to be added as a part of outcome measurements.

Households must be made aware of the link between groundwater quality and sanitation systems, and the benefits of properly constructed toilets.

“There is a need to define areas with critical levels of groundwater contamination owing to onsite sanitation systems as a basis for regulation in terms of safe separation and maximum pumping rates. There is a need to explore effective communication strategies for influencing the design and operation of onsite sanitation systems,” says Deepak Sanan, visiting faculty, IIHS and former additional chief secretary, Government of Himachal Pradesh.

“Since interactions with in-situ sanitation can cause public health hazard and can make any waterborne epidemic more difficult to control and potentially hazardous, public policy should focus more on the health sector for epidemic prevention. More so, because groundwater quality status, primarily the level and type of pathogenic contamination are hard to monitor at a wide scale,” says Sunderrajan Krishnan, executive director, INREM Foundation, a research institution probing societal issues.