USEPA Ground Water Rule

The final USEPA Ground Water Rule (GWR) was published on November 8, 2006. (The rule can be downloaded from http://www.epa.gov/ogwdw/disinfection/gwr/index.html) The GWR applies to an estimated 147,000 community and non-community water systems using groundwater not under the direct influence of surface water. That includes consecutive systems that receive finished groundwater with surface water (or groundwater under the direct influence after the surface water is treated as per Subpart H requirements, if the groundwater is not equally treated. The rule does not apply to systems that combine all of their groundwater and surface water before surface water treatment required under Subpart H. Additionally, neither general variances nor exemptions are applicable given the rule's risk-based approach, and small system variances are not allowed for microbial contaminants.

Systems subject to GWR requirements must comply by December 1, 2000 with five general requirements:

" Requirement 1: Provide states with information necessary to conduct mandated periodic sanitary surveys.
" Requirement 2: Conduct source water monitoring for pathogen indicators when triggered by certain conditions.
" Requirement 3: Comply with treatment technique mandates when found by a state sanitary survey to have a significant deficiency or when source monitoring indicates fecal contamination.
" Requirement 4: Systems that provide at least 4-log virus treatment must conduct compliance monitoring to demonstrate treatment effectiveness.
" Requirement 5: Upon state request, provide information to enable the state to perform a hydrogeologic sensitivity analysis, which is defined as "a determination of whether groundwater systems obtain water from hydrogeologically sensitive settings."

(For further details, please review "Ground Water Rule marked by many unknowns," by Mark Scharfenaker, Journal AWWA, Dec. 2006, pp. 14-20)

A few highlights:

Few changes from the proposed rule:
The risk-based GWR has hardly changed from the proposed version. Risk-based GWR aims to identify systems at risk of delivering fecally contaminated groundwater and correcting the action. The most significant revision is the monitoring of source waters for indicators of fecal contamination. USEPA will not require all groundwater systems using at-risk sources as determined by hydrogeologic sensitivity assessments (HSAs) to monitor them monthly for fecal indicators. The final rule gives states the option to perform HSAs for individual systems.

Monitoring sources for fecal indicators:

Groundwater systems that do not provide 4-log virus treatment (as of December 1, 2009) must sample their sources for fecal indicators whenever a routine TCR sample turns up positive and is not invalidated. Systems that detect a fecal indicator would be immediately required into taking state-defined corrective actions unless first directed to take five follow up samples.

If a periodic state sanitary survey identifies a "significant deficiency" in any of the eight system components, groundwater systems could also be required by the state to take correct actions. The GWR rule requires states to perform periodic sanitary surveys of all groundwater systems and sets deadlines for states to complete initial surveys. The rule requires states to define at least one such deficiency for each element. Correct actions can include one or more of the following alternatives:
" Correct all significant deficiencies,
" Provide an alternative source,
" Eliminate the contaminant source, or
" Provide at least 4-log virus inactivation/removal treatment before or at the first customer. Systems ordered to provide 4-log virus treatment must monitor the effectiveness and reliability of treatment. Systems that currently provide 4-log virus treatment- and exempted from GWR source monitoring- must notify the state and begin monitoring by Dec. 1, 2009.

Utilities have 120 days to implement state-ordered corrective actions. Systems must be in compliance with a state-approved corrective action plan and schedule interim public health protection measures approved by the state. Failure to comply constitutes a treatment technique violation. Systems already providing 4-log virus treatment and fails to correct failures within 4 hours are in violation of the treatment technique.

Systems must also provide appropriate public notice when notified of an indicator-positive sample (not validated) or a significant deficiency. Failure to comply will be a monitoring violation subject to public notice. Neither general variances nor exemptions are applicable, given the risk-based nature of requiring corrective action and small system variances are not allowed fro microbial contaminants.

Vague guidance:

USEPA has promised to provide seven guidance documents to help states and utilities implement the rule's requirements. Scheduled to be published over the next two years, the documents will cover state requirements, HSAs, sanitary surveys, source monitoring, and corrective actions as well as implementation particulars for consecutive systems and small systems. Fact sheets, a quick reference guide and training are also slated for publication.

USEPA calculated the mean annualized present value compliance costs at $61.8 million (with a 3% discount rate) and $62.3 million (with a 7% discount rate). Per-household, the USEPA estimated annual costs for costumers of community systems ranging from $0.21 to $16.52. Annual household costs for community systems expected to implement corrective actions, range from $0.45 to $52.38.

USEPA calculated the estimated mean annualized present value benefits to be $19.7 million (3% discount rate) and $16.8 million (7% discount rate) using an enhanced cost-of-illness approach and $10 million (3% discount rate) and $8.6 million (7% discount rate) using a traditional cost-of-illness approach. USEPA also estimated that the GWR will prevent 42,000 cases from rotavirus and echovirus alone.