Originally Posted by
Klondyke
Actually, when Donald says "high limestone content": Last 2 years I had abandoned my bore well (some 8 m deep under my garden), fed up by the iron problems. I had excavated a well (diam. 1m, some 6 m deep) at the bank of the river - some 100 m under my house - hoping that the river water will be cleaned by the sand bed, pushing the water to the house by a submersible pump.
This to substitute the iron water from the bore well. However, after more than 1 year pumping the water had not is been clean either, instead of the iron it is contaminated by some limestone or clay sediments. The ground around Lampang is well known for abundance of various kinds of clay for ceramic industry.
So after a year I had come back to the bore water with iron, pumping both of them onto my settle tank. And I have found that obviously the iron water likes the alkalines and settle quite more easily that without it.