According to my experiences with arsenic contents along the Ganga, I can say, that from a certain depth on -increasing depth from West to East- the groundwater is arsenic-free. The depth is best / easiest determined by an old land-surface about 12 000 years old and identifiable by reddish sediments coming up when drilling beyond 50 meters or so. The water below is older, than 12 000 years and the aesenic has been washed out, so the water ist safe for drinking. Problem is the poor quality delivered by local enterprises who do not use modern equipment and are thus inapt to install a safe hydraulic bull plug between the surface-near water and the deeper seated arsenic-free water. The use of bad casing, gravel pack etc. are another deficit. A hydrogeological survey would be needed to identify the extension of the "good" and "bad" groundwater and the separating layers of old continental surface. Thereupon, we'd need standards about building safe wells and then - just putting the norms into gear, administratively and otherwise.
Published by Jürgen Tümmler
According to my experiences with arsenic contents along the Ganga, I can say, that from a certain depth on -increasing depth from West to East- the groundwater is arsenic-free. The depth is best / easiest determined by an old land-surface about 12 000 years old and identifiable by reddish sediments coming up when drilling beyond 50 meters or so. The water below is older, than 12 000 years and the aesenic has been washed out, so the water ist safe for drinking. Problem is the poor quality delivered by local enterprises who do not use modern equipment and are thus inapt to install a safe hydraulic bull plug between the surface-near water and the deeper seated arsenic-free water. The use of bad casing, gravel pack etc. are another deficit. A hydrogeological survey would be needed to identify the extension of the "good" and "bad" groundwater and the separating layers of old continental surface. Thereupon, we'd need standards about building safe wells and then - just putting the norms into gear, administratively and otherwise.