Current through Bulletin 2024-06, March 15, 2024
(a) Assessment
monitoring is required whenever a statistically significant increase over
background levels has been detected for one or more of the constituents listed
in appendix III to Rule R315-319.
(b) Within 90 days of triggering an
assessment monitoring program, and annually thereafter, the owner or operator
of the CCR unit shall sample and analyze the groundwater for all constituents
listed in appendix IV to Rule R315-319. The number of samples collected and
analyzed for each well during each sampling event shall be consistent with
Subsection R315-319-93(e), and shall account for any unique characteristics of
the site, but shall be at least one sample from each well.
(c) The owner or operator of a CCR unit may
demonstrate the need for an alternative monitoring frequency for repeated
sampling and analysis for constituents listed in appendix IV to Rule R315-319
during the active life and the post-closure care period based on the
availability of groundwater. If there is not adequate groundwater flow to
sample wells semiannually, the alternative frequency shall be no less than
annual. The need to vary monitoring frequency shall be evaluated on a
site-specific basis. The demonstration shall be supported by, at a minimum, the
information specified in Subsections R315-319-95(c)(1) and (2).
(1) Information documenting that the need for
less frequent sampling. The alternative frequency shall be based on
consideration of the following factors:
(i)
Lithology of the aquifer and unsaturated zone;
(ii) Hydraulic conductivity of the aquifer
and unsaturated zone; and
(iii)
Groundwater flow rates.
(2) Information documenting that the
alternative frequency will be no less effective in ensuring that any leakage
from the CCR unit will be discovered within a timeframe that will not
materially delay the initiation of any necessary remediation
measures.
(3) The owner or operator
shall obtain a certification from a qualified professional engineer stating
that the demonstration for an alternative groundwater sampling and analysis
frequency meets the requirements of Section R315-319-95. The owner or operator
shall include the demonstration providing the basis for the alternative
monitoring frequency and the certification by a qualified professional engineer
in the annual groundwater monitoring and corrective action report required by
Subsection R315-319-90(e).
(d) After obtaining the results from the
initial and subsequent sampling events required in Subsection R315-319-95(b),
the owner or operator shall:
(1) Within 90
days of obtaining the results, and on at least a semiannual basis thereafter,
resample all wells that were installed pursuant to the requirements of Section
R315-319-91, conduct analyses for all parameters in appendix III to Rule
R315-319 and for those constituents in appendix IV to Rule R315-319 that are
detected in response to Subsection R315-319-95(b), and record their
concentrations in the facility operating record. The number of samples
collected and analyzed for each background well and downgradient well during
subsequent semiannual sampling events shall be consistent with Subsection
R315-319-93(e), and shall account for any unique characteristics of the site,
but shall be at least one sample from each background and downgradient
well;
(2) Establish groundwater
protection standards for all constituents detected pursuant to Subsection
R315-319-95(b) or (d). The groundwater protection standards shall be
established in accordance with Subsection R315-319-95(h); and
(3) Include the recorded concentrations
required by Subsection R315-319-95(d)(1), identify the background
concentrations established under Subsection R315-319-94(b), and identify the
groundwater protection standards established under Subsection R315-319-95(d)(2)
in the annual groundwater monitoring and corrective action report required by
Subsection R315-319-90(e).
(e) If the concentrations of all constituents
listed in appendices III and IV of Rule R315-319 are shown to be at or below
background values, using the statistical procedures in Subsection
R315-319-93(g), for two consecutive sampling events, the owner or operator may
return to detection monitoring of the CCR unit. The owner or operator shall
prepare a notification stating that detection monitoring is resuming for the
CCR unit and submit the notification to the Director for approval. The owner or
operator has completed the notification when the notification is placed in the
facility's operating record as required by Subsection
R315-319-105(h)(7).
(f) If the
concentrations of any constituent in appendices III and IV to Rule R315-319 are
above background values, but all concentrations are below the groundwater
protection standard established under Subsection R315-319-95(h), using the
statistical procedures in Subsection R315-319-93(g), the owner or operator
shall continue assessment monitoring in accordance with Section
R315-319-95.
(g) If one or more
constituents in appendix IV to Rule R315-319 are detected at statistically
significant levels above the groundwater protection standard established under
Subsection R315-319-95(h) in any sampling event, the owner or operator shall
prepare a notification identifying the constituents in appendix IV to Rule
R315-319 that have exceeded the groundwater protection standard. The owner or
operator has completed the notification when the notification is placed in the
facility's operating record as required by Subsection R315-319-105(h)(8). The
owner or operator of the CCR unit also shall:
(1) Characterize the nature and extent of the
release and any relevant site conditions that may affect the remedy ultimately
selected. The characterization shall be sufficient to support a complete and
accurate assessment of the corrective measures necessary to effectively clean
up all releases from the CCR unit pursuant to Subsection R315-319-96.
Characterization of the release includes the following minimum measures:
(i) Install additional monitoring wells
necessary to define the contaminant plume(s);
(ii) Collect data on the nature and estimated
quantity of material released including specific information on the
constituents listed in appendix IV of Rule R315-319 and the levels at which
they are present in the material released;
(iii) Install at least one additional
monitoring well at the facility boundary in the direction of contaminant
migration and sample this well in accordance with Subsection R315-319-95(d)(1);
and
(iv) Sample all wells in
accordance with Subsection R315-319-95(d)(1) to characterize the nature and
extent of the release.
(2) Notify all persons who own the land or
reside on the land that directly overlies any part of the plume of
contamination if contaminants have migrated off-site if indicated by sampling
of wells in accordance with Subsection R315-319-95(g)(1). The owner or operator
has completed the notifications when they are placed in the facility's
operating record as required by Subsection R315-319-105(h)(8).
(3) Within 90 days of finding that any of the
constituents listed in appendix IV to Rule R315-319 have been detected at a
statistically significant level exceeding the groundwater protection standards
the owner or operator shall either:
(i)
Initiate an assessment of corrective measures as approved by the Director and
as required by Subsection R315-319-96; or
(ii) Demonstrate that a source other than the
CCR unit caused the contamination, or that the statistically significant
increase resulted from error in sampling, analysis, statistical evaluation, or
natural variation in groundwater quality. Any such demonstration shall be
submitted to and has received approval from the Director and supported by a
report that includes the factual or evidentiary basis for any conclusions and
shall be certified to be accurate by a qualified professional engineer. If a
successful demonstration is made, the owner or operator shall continue
monitoring in accordance with the assessment monitoring program pursuant to
Section R315-319-95, and may return to detection monitoring if the constituents
in appendices III and IV to Rule R315-319 are at or below background as
specified in Subsection R315-319-95(e). The owner or operator shall also
include the demonstration in the annual groundwater monitoring and corrective
action report required by Subsection R315-319-90(e), in addition to the
certification by a qualified professional engineer.
(4) If a successful demonstration has not
been made at the end of the 90 day period provided by Subsection
R315-319-95(g)(3)(ii), the owner or operator of the CCR unit shall initiate the
assessment of corrective measures requirements under Subsection
R315-319-96.
(5) If an assessment
of corrective measures is required under Subsection R315-319-96 by either
Subsection R315-319-95(g)(3)(i) or (g)(4), and if the CCR unit is an existing
unlined CCR surface impoundment as determined by Subsection R315-319-71(a),
then the CCR unit is subject to the closure requirements under Subsection
R315-319-101(a) to retrofit or close. In addition, the owner or operator shall
prepare a notification stating that an assessment of corrective measures has
been initiated.
(h) The
owner or operator of the CCR unit shall establish a groundwater protection
standard for each constituent in appendix IV to Rule R315-319 detected in the
groundwater. The groundwater protection standard shall be:
(1) For constituents for which a ground water
protection standard has been estaliblished in rule R315-308, the ground water
protection standard in Rule R315-308;
(2) For constituents for which a ground water
protection standard has not been established in Rule R315-308, the background
concentration for the constituent established from wells in accordance with
Section R315-319-91; or
(3) For
constituents for which the background level is higher than the ground water
protection standard identified under Subsection R315-319-95(h)(1), the
background concentration.
(i) The owner or operator of the CCR unit
shall comply with the recordkeeping requirements specified in Subsection
R315-319-105(h), the notification requirements specified in Subsection
R315-319-106(h), and the Internet requirements specified in Subsection
R315-319-107(h).