Surprisingly and unknowingly, a large amount of septic tanks in Ireland are polluting the very drinking water rural dwellers drink every day. If your drinking water test results have indicated an unacceptable level of fecal coliforms and you have a septic tank or sewage treatment system then you should have it surveyed.
As per the image below, septic tanks don’t treat the waste water to a high standard and if the percolation area is not installed taking into account the original site assessment report it is very possible that it is discharging back to your well.
Discharge from a septic tank is very dangerous and contains fecal coliforms containing E. coli and Kryptos Sporidium among billions of other bacteria. You should immediately stop drinking your tap water until the issue is resolved.
In the vast majority of cases like this, the only option is to replace the sewage system. A site suitability assessment will be need to be completed to design a new system taking into account all the unique features on the site, followed by installation and certification.