| (a) The commission adopts by reference 40 Code of Federal
Regulations (CFR) §257.95 (Assessment monitoring program) as
amended through the April 17, 2015, issue of the Federal Register (80 FR 21301) subject to
the additions in this section.
(b) The owner or operator of the coal combustion residuals
(CCR) unit must establish a groundwater protection standard for each
constituent in Appendix IV adopted by reference in §352.1431
of this title (relating to Appendix IV - Constituents for Assessment
Monitoring) detected in the groundwater. The groundwater protection
standard shall be one of the following.
(1) For constituents for which a maximum contaminant
level (MCL) has been established under 40 CFR §141.62 (Maximum
contaminant levels for inorganic contaminants) and §141.66 (Maximum
contaminant levels for radionuclides), the MCL for that constituent.
(2) For constituents for which an MCL has not been
established, the background concentration for the constituent established
from wells in accordance with §352.911 of this title (relating
to Groundwater Monitoring Systems).
(3) For constituents for which the background level
is higher than the levels identified under paragraphs (1) and (2)
of this subsection, the background concentration.
(c) The owner or operator may return to detection monitoring
only after satisfying the conditions of 40 CFR §257.95(e), and
after obtaining written approval from the executive director.
(d) If one or more constituents in Appendix IV adopted
by reference in §352.1431 of this title are detected at statistically
significant levels above the groundwater protection standard established
in subsection (b) of this section in any sampling event, the owner
or operator shall notify the executive director, and any local pollution
agency with jurisdiction that has requested to be notified, in writing
within 14 days of this determination.
(e) If any of the constituents listed in Appendix IV
adopted by reference in §352.1431 of this title have been detected
at a statistically significant level exceeding the groundwater protection
standards, then the owner or operator may submit an alternative source
demonstration in accordance with 40 CFR §257.95(g)(3) to the
executive director for review. In making a demonstration under this
subsection, the owner or operator must, within 90 days of detecting
a statistically significant level above the groundwater protection
standard of any constituent listed in Appendix IV adopted by reference
in §352.1431 of this title, submit a report prepared and certified
in accordance with §352.4 of this title (relating to Engineering
and Geoscientific Information) to the executive director, and any
local pollution agency with jurisdiction that has requested to be
notified, demonstrating that a source other than a CCR unit caused
the exceedance or that the exceedance resulted from error in sampling,
analysis, statistical evaluation, or natural variation in groundwater
quality.
(f) If the owner or operator does not make an alternative
source demonstration under this section satisfactory to the executive
director, then the owner or operator shall initiate assessment of
corrective measures as required in 40 CFR §257.95(g)(4). The
executive director may require the owner or operator to install additional
monitoring wells to determine whether the demonstration is satisfactory.
If the owner or operator does make an alternative source demonstration
under this section that is satisfactory to the executive director,
then the owner or operator may continue to monitor in accordance with
the assessment monitoring program established under this section.
|
