In January 2007, EPA Groundwater Rule became effective. The rule provides increased protection against microbial pathogens in public drinking water supplies that use groundwater sources. This rule requires groundwater systems that are at risk of fecal contamination to take corrective action to reduce cases of illness and deaths due to exposure to microbial pathogens. The rule uses the following four major components to determine groundwater is not at risk of fecal contamination:
- Periodic sanitary surveys of groundwater systems that require the evaluation of eight critical elements and identification of significant deficiencies.
- Source water monitoring to test for the presence of E. coli.
- Corrective actions required for any waterworks with a significant deficiency or source water fecal contamination.
- Compliance monitoring to ensure that treatment technologies installed to treat drinking water reliably achieves at least 99.99 perfect (4-log) inactivation or removal of viruses.