UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460
James Roewer c/o Edison Electric Institute 701 Pennsylvania Avenue, N.W. Washington, D .C 20004
Douglas Green Margaret Fawal Venable LLP 600 Massachusetts Avenue, N.W. Washington, D.C. 20001
APR 3 o 2018
OFOCE OF SOUP WASTE AND
EMERGENCY RESPONSE
NOW THE OFFICE OF LAND AND EMERGENCY MANAGEMENT
Re: Coal. Combustion Residuals Rule Groundwater Monitoring Requirements
Dear Ms. Fawal, Mr. Green, and Mr. Roewer:
My office has been asked to respond to the letter from the Utility Solid Waste Activities Group (USWAG), dated November 27, 2017, to the U.S, Environmental Protection Agency (EPA), requesting confirmation with regard to your reading o f the timing for two specific requirements in the Coal Combustion Residuals (CCR) Rule's groundwater monitoring provisions: (1) the timing to establish an assessment monitoring program if an owner/operator is unable to successfully make an alternate source demonstration in detection monitoring tinder 40 C.F.R, 257.94(e)(2); and (2) the timing for conducting a statistical evaluation on the data collected under the assessment monitoring program. On January 26, 2018, we provided an initial response that addressed the first issue raised in your letter. This letter responds to the remainder o f that November 27 letter.
USWAG requested confirmation of its reading of the time frame for completing a statistical evaluation o f the groundwater data collected during assessment monitoring in order to determine whether there is an exceedance of the groundwater protection standard. Your letter suggests that January 10. 2019, is the date by which facilities must make their initial determination o f whether there has been the detection o f a statistically significant increase o f an Appendix IV constituent above the relevant groundwater protection standard in the downgradient wells (assuming the facility has elected to take 90 days pursuant to 257.94(e)(2 ) to demonstrate that detection o f the Appendix III constituents) was attributable to sampling error or some other source).
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As explained below, EPA calculates January 14, 2019J as the deadline for facilities*2 to make their initial determination o f whether there has been the detection o f a statistically significant increase o f an Appendix IV constituent above the relevant groundwater protection standard in the downgradient wells (assuming the facility has elected to take advantage o f the 90 day option in g 257.94(e)(2)).
Section 257.95 generally establishes the schedule and framework for conducting the sampling and analysis required for assessment monitoring, but does not include a specific timeframe for completing the statistical eval uation o f these data to determine whether there is an exceedance o f the groundwater protection standard. The timeframe for that requirement instead appears in 40 C.F.R. 257.93(h), which EPA reads to apply to the statistical analyses required under both detection and assessment monitoring. Taken together, these sections establish that the first deadline for completing the statistical evaluation o f the assessment monitoring data to determine whether there is an. exceedance o f the groundwater protection standard Is 90 days after completion o f the re-sampling and analysis in 257.95(d)(1).
Section 257.95(b) provides that: within 90 days o f triggering assessment monitoring (and on an annual basis thereafter) the owner/operator must sample and analyze for all Appendix IV constituents. For any Appendix IV constituents detected in the sampling and analysis required under subsection (b) the owner/operator must: (1) identify ("establish") the relevant groundwater protection .standards specified in 257.95(h); (2) continue assessment monitoring by resampling for all Appendix III and the relevant (detected) Appendix IV constituents and (3) obtain analytical results o f those combined samples within 90 days. 40 C.F.R. 257.95(d)( 1)-(2).
Section 257.93(h) states that art owner or operator "must determine whether there is a statistically significant increase over background values for each constituent required in the particular groundwater monitoring program that applies to the CCR unit, as determined under 257.94(a) or 257.95(a)." 40 C.F.R. 257.93(h). Section (h)(2) in turn specifies that "within 90 days after completing sampling and analysis, the owner or operator must determine whether there has been a statistically significant increase over background for any constituent at each monitoring well." The determination o f whether there has been a statistically significant increase over background is a necessary prerequisite to determining whether there is an exceedance o f the groundwater protection standard. A determination that there has been a statistically significant increase over background indicates that there Is a release from the unit and requires that the release be evaluated further to determine if it also exceeds the ground water protection standard. See 40 C.F.R. 257.95(1).
Thus, 90 days after completing the resampling for the relevant (detected) Appendix IV constituents pursuant to 257.95(d)(1), an owner or operator must conduct a statistical analysis in accordance with 257.93(h)/ For example, assuming that the facility did not take advantage o f the 90 day option in 257.94(e)(2), the first round o f Assessment monitoring would have been completed on April 16, 201,8. In this case, consistent with 257.93(h). the facility would need to complete the
5In calculating this date, EPA extended any deadlines that: fell on a weekend or Federal holiday to the next: business day. 2This excludes those inactive surface impoundments whose deadlines were extended by 81 Fed. Reg. 51,803 (Aug. 5, 2016). Note that conducting the statistical analysis on 2 sets of sampling occurs only on this first: round (the "initial...sampling events" referenced in 257.95(d)(1)) of A'.WNMiient monitoring. All other statistical analyses on subsequent rounds of on-going semi-annual or annual sampling underassessment monitoring must be conducted following the single set of samples obtained during that sampling event.
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statistical analyses on the two rounds o f sampling to determine whether there is a statistically significant increase over the groundwater protection standard no later than October 15, 2018,
E PA 's discussion o f section 257.93(h)(2) in the final rule preamble supports this reading. As ERA explained, "(sjeveral eommenters suggested that once sampling and analysis had been completed, 90 days would be a reasonable amount o f time to complete the statistical analysis to determine whether an exceedance bad occurred. No commenter suggested a longer period o f time was necessary and that timeframe is consistent with the Agency's experience o f the timeframes necessary to complete such analyses. Accordingly, we have revised the provision to require the determination o f a statistically significant increase to he made within 90 days o f sampling and analysis." 80 Fed. 'Reg. at 21,404 (emphases added).
If you ha\e any additional questions regarding this letter, please contact me at Personal Matterss/ jor at Johnson, barnes a epa.gov.
Sincerely,
,,
Barnes Joh n en , Director Office o f Resource Conservation and Recovery
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