Thanks for the reply. The pdf that I've attached is all the chemical info that I have. The mines are horizontal, one has 0.5 metres, another 5 metres and the longest one is 30 metres long. There is a 10 X 5 X 1.5 metre open tank and a tube goes from the middle water mine to another closed tank, 2 X 2 X 2 metres that is 70 metres away and near the houses. The water from the larger tank is for agricultural use, the smaller one for punctual human consumption and to fill the swimming pool. I will not use chlorination in water for human consumption. I assume that the coliforms come from the 70 metres pipe or from the mine itself, as the sample I took from the pipe before the smaller, closed tank. The water mine is not used most of the time and the local company water has low chlorine (except for their seasonal system maintenance), as this is a rural area with little industry or major pollution outlets. It is more of a safety option and something that I want to keep an eye on, since they've probably been made thousands of years ago. Thanks!

Published December 30, 2019 12:32 by Manuel Trindade, University of Exeter - One Planet MBA