Let me first state that I am not a sanitation engineer or a hydraulics engineer but this is a subject that interests me greatly. Over the years, mostly in foreign countries I have observed how effluent from leaky septic tanks and soak pits make their way down to the water table and underground aquifers, contaminating the water supply of the surrounding area. This is particularly true in areas along the coastline where the soil is sandy and porous. In Goa the Health department has made it a requirement that a soak pit should be at least 15 meters from an open well. I think that a lot of factors would impact this rule of thumb including the water table in low lying areas and the type of soil prevalent in the area. The well known Springs in Merces in Tiswadi, which used to be a prominent picnic spot and a place where people used to drink the pure spring water, now bears a sign that the water is contaminated and not fit for human consumption. Could it be because of the military installation with staff quarters and their septic tanks and soak pits up-hill from the Springs ? During my working career in the USA, I was a Director of Facilities for a very large School district which spanned both urban and rural areas. Schools in the rural areas depended on bore wells for their water supply. The Health department tested the water from the bore wells every 6 months and disallowed the use of water in the rural areas, for drinking and cooking purposes because they were contaminated by sulphates and nitrates from fertilizers used by farmers upto 3 miles from the schools. If fertilzers used in distant fields seep into underground aquifers and contaminate drinking water supplies several miles away, imagine the contamination of wells from leaky septic tanks and soak pits along the congested coastal belt of Goa.
