Deanna Dunseith  I think if ...

Deanna Dunseith  I think if animals are the cause than there will be an increase in nitrates.

Tendai H. Madzaramba  E Coli is from Human sewage. If it is a rural area where you sampled then I think lots of unlined septic tanks which are leaking into the groundwater. Sometimes residents even go for very deep septic tanks so that they don't have to empty them quite often and this results in groundwater contamination. Also rainy season may be resulting in carryover of sewage into the groundwater. So I think you should focus more on prevention of groundwater contamination. Simultaneously, boiling of water and chlorine tablets are the best idea. And all this should be done immediately as this is a very serious issue. All the Best!