The Environmental Protection Agency published the Ground Water Rule (GWR) in the Federal Register on Nov. 8, 2006 (Federal Register Volume 71, Number 216, 65574, available at: http://www.epa.gov/safewater/disinfection/gwr/regulation.html).

This rule is part of a series of rules, the “Microbial-Disinfectants/Disinfection Byproducts Cluster” (M-DBP Cluster), which is intended to improve control of microbial pathogens while minimizing public health risks of disinfectants and disinfection byproducts.

The GWR builds upon the Total Coliform Rule by addressing the health risks of fecal contamination in community water systems and noncommunity water systems (e.g., nontransient noncommunity water systems and transient noncommunity water systems) that use ground water. The GWR does not apply, however, to public water systems that combine all of their ground water with surface water before the treatment. These systems must comply instead with requirements for surface water systems and systems using ground water under the direct influence of surface water (Subpart H systems).

Key provisions of the GWR include:

• Periodic on-site reviews and inspections of ground water systems requiring evaluation of eight specific sanitary survey elements and identification of significant deficiencies;
• Requirements to correct significant deficiencies and eliminate fecal contamination through specified actions;
• Triggered source water monitoring to test for the presence of fecal indicators (E. coli, enterococci or coliphage) in the sample; and
• Compliance monitoring to ensure that treatment technologies installed to treat drinking water reliably achieve at least 99.99 percent (4-log) inactivation or removal of viruses.

Guidance and Forms

• 4 log treatment guidance
• 4-log treatment form on Compliance Forms Page
• Representative Source Water Monitoring Guidance
• Corrective Action
  • Corrective Action Proposal Form (MSWord)
  • Correction Action Flowchart - Significant Deficiency (PDF)
  • Correction Action Flowchart - Contamination (PDF)
• Notification Requirements for Wholesale and Purchasing Systems