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Ground Water Rule (GWR)

The Groundwater Rule (GWR) requirements became effective December 1, 2009. The GWR applies to all public water systems that serve groundwater. The rule also applies to any system that combines surface and groundwater if the groundwater is provided to consumers without treatment under the surface water treatment rule. In addition, systems purchasing groundwater from another system are required to comply with certain requirements of the rule.


Final Rulemaking: Safe Drinking Water Amendments (25 Pa Code, Chapter 109). In addition to the Groundwater Rule the amendments also incorporate the provisions of the federal Stage 2 Disinfectants and Disinfection Byproduct Rule (Stage 2 DBPR) and the Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). These revisions were initially proposed in three separate packages that have been merged for clarity and consistency.

Related Documents:


Groundwater Rule Compliance Training 2022 – In-person training (2 contact hours): This training is targeted to small community groundwater systems and circuit riders (contract operators).

If you missed the Groundwater Rule training in 2011, or just need a refresher, the information-packed workbook from the training course is available here:

EPA Information on the Groundwater Rule (GWR)*

This link will take you to EPA's website on the EPA Groundwater Rule*. You can view or download technical guidance manuals, obtain fact sheets, and see the federal version of the rule.

* Please note there are provisions of Pennsylvania’s GWR which differ from the Federal GWR.