Current through Register Vol. 38, No. 18, March 15, 2024
(a) The owner or operator of a C&DLF unit
shall submit a water quality monitoring plan to the Division in the application
for the permit to construct in accordance with Rule .0535(a)(1) of this Section
that shall apply to all C&DLF units. The water quality monitoring plan
shall be prepared in accordance with this Rule, and shall include information
on the proposed groundwater monitoring systems, surface water sampling
locations, sampling and analysis requirements, and detection monitoring
requirements provided in Paragraphs (b) and (c) of this Rule.
(b) Groundwater monitoring shall be as
follows:
(1) A groundwater monitoring system
shall be installed that consists of no less than one background and three
downgradient wells installed at locations and depths that yield groundwater
samples from the uppermost aquifer that:
(A)
represent the quality of the background groundwater that has not been affected
by leakage from the unit. Determination of background water quality shall be
based on sampling of a well or wells that are hydraulically upgradient of the
waste management area. However, the determination of background water quality
may include sampling of wells that are not hydraulically upgradient of the
waste management area where hydrogeologic conditions do not allow the owner and
operator to determine which wells are hydraulically upgradient, or
hydrogeologic conditions do not allow the owner and operator to place a well in
a hydraulically upgradient location, or sampling at other wells will provide an
indication of background groundwater quality that is as representative as that
provided by the upgradient well(s); and
(B) represent the quality of groundwater
passing the relevant point of compliance as approved by the Division. The
downgradient monitoring system shall be installed at the relevant point of
compliance to ensure detection of groundwater contamination in the uppermost
aquifer. The relevant point of compliance shall be established no more than 250
feet from a waste boundary, or shall be at least 50 feet within the facility
property boundary, whichever point is closer to the waste boundary. In
determining the relevant point of compliance, the Division shall consider
recommendations made by the owner and operator based upon consideration of at
least the hydrogeologic characteristics of the facility and surrounding land;
the quantity, quality, and direction of flow of the groundwater; the proximity
and withdrawal rate of the groundwater users; the existing quality of the
groundwater, including other sources of contamination and their cumulative
impacts on the groundwater, and whether the groundwater is currently used or
expected to be used for drinking water; public health, safety, and welfare
effects; and practicable capability of the owner and operator.
(C) A water quality monitoring plan shall
include consistent sampling and analysis procedures that are designed to ensure
monitoring results that provide an accurate representation of groundwater
quality at the background and downgradient wells. The plan shall include
procedures and techniques for sample collection; sample preservation and
shipment; chain-of-custody control; and quality assurance and quality
control.
(D) The detection
groundwater monitoring program shall include sampling and analytical methods
for groundwater sampling that accurately measure target constituents and other
monitoring parameters in groundwater samples. Detection monitoring shall be
conducted at C&DLF units at all groundwater monitoring wells that are part
of the detection monitoring system as established in the approved water quality
monitoring plan. The detection groundwater monitoring program shall include
monitoring for the constituents listed in Appendix I of
40 CFR
258, and the following constituents: mercury,
chloride, manganese, sulfate, iron, specific conductance, pH, temperature,
alkalinity, and total dissolved solids. The monitoring frequency for all
detection monitoring constituents shall be no less than annual during the
active life of the facility, and during closure and the post-closure period. To
establish baseline, no less than four independent samples from each background
and downgradient monitoring well shall be collected within a twelve-month
period and analyzed for the constituents required in this Paragraph, with no
less than one sample collected from each new monitoring well before waste
placement in each new cell or phase. The water quality monitoring plan shall
include a description of the procedures used to establish baseline at the
C&DLF unit. No less than one sample from each background and downgradient
monitoring well shall be collected and analyzed during subsequent annual
sampling events. C&DLF units shall comply with the groundwater quality
standards and interim maximum allowable concentrations (IMACs) set forth in
15A NCAC
02L .0202 and the groundwater protection
standards established in Rule .0545(c) of this Section.
(E) The sampling procedures and frequency
shall be protective of human health and the environment.
(2) Each time groundwater is sampled,
elevations shall be measured in each well prior to purging. Groundwater
elevations in wells which monitor the same waste management area shall be
measured within a 24 hour period of time to avoid temporal variations in
groundwater flow that could preclude accurate determination of groundwater flow
rate and direction. In order to determine accurate groundwater elevations for
each monitoring well, the wells shall have been surveyed by a licensed
professional land surveyor if required by G.S. 89C. The survey of the wells
shall conform to the following levels of accuracy: horizontal location to the
nearest 0.1 foot, vertical control for the ground surface elevation to the
nearest 0.01 foot, and vertical control for the measuring reference point on
the top of the inner well casing to the nearest 0.01 foot. In order to
determine the rate of groundwater flow, the owner or operator shall provide
data for hydraulic conductivity and porosity for the formation materials at
each of the well locations.
(3) The
owner or operator shall establish existing conditions of groundwater quality in
hydraulically upgradient or background well(s) for each of the monitoring
parameters or constituents required in Part (1)(D) of this Paragraph.
Statistical analysis used to establish existing conditions of groundwater
quality shall be in accordance with Subparagraphs (4) and (5) of this Paragraph
and the minimum number of samples required by the statistical method used shall
be met.
(4) Should the owner or
operator choose to perform statistical analysis of groundwater quality data for
the purpose of establishing background concentrations or to determine if there
is an exceedance of the groundwater quality standards and IMACs established in
15A NCAC
02L .0202 or the groundwater protection
standards established in Rule .0545(c) of this Section, the owner or operator
shall select one of the following statistical methods to be used in evaluating
groundwater monitoring data for each constituent of concern. The statistical
test chosen shall be conducted separately for each constituent of concern in
each well.
(A) A parametric analysis of
variance (ANOVA) followed by multiple comparisons procedures to identify
statistically significant evidence of contamination. The method shall include
estimation and testing of the contrasts between each compliance well's mean and
the background mean levels for each constituent.
(B) A parametric analysis of variance (ANOVA)
based on ranks followed by multiple comparisons procedures to identify
statistically significant evidence of contamination. The method shall include
estimation and testing of the contrasts between each compliance well's median
and the background median levels for each constituent.
(C) A tolerance or prediction interval
procedure in which an interval for each constituent is established from the
distribution of the background data, and the level of each constituent in each
compliance well is compared to the upper tolerance or prediction
limit.
(D) A control chart approach
that gives control limits for each constituent.
(E) Another statistical test method that
meets the performance standards of this Rule. The owner or operator shall
submit a justification for an alternative test method to the Division for
approval to determine compliance with this Rule. The justification shall
demonstrate that the alternative statistical test method meets the performance
standards in Subparagraph (5) of this Paragraph. If approved, the owner or
operator shall place a copy of the justification for an alternative test method
in the operating record.
(5) Any statistical method chosen to evaluate
groundwater monitoring data shall comply with the following performance
standards:
(A) The statistical method used to
evaluate groundwater monitoring data shall be appropriate for the distribution
of chemical parameters or constituents of concern. If the distribution of the
chemical parameters or constituents of concern is shown by the owner or
operator or the Division to be inappropriate for a normal theory test, then the
data shall be transformed or a distribution-free theory test shall be used. If
the distributions for the constituents differ, more than one statistical method
shall be considered.
(B) If an
individual well comparison procedure is used to compare an individual
compliance well constituent concentration with background constituent
concentrations or a groundwater protection standard, the test shall be done at
a Type I error level no less than 0.01 for each testing period. If a multiple
comparisons procedure is used, the Type I experiment wise error rate for each
testing period shall be no less than 0.05. However, the Type I error of no less
than 0.01 for individual well comparisons shall be maintained. This performance
standard does not apply to tolerance intervals, prediction intervals, or
control charts.
(C) If a control
chart approach is used to evaluate groundwater monitoring data, the specific
type of control chart and its associated parameter values shall be protective
of human health and the environment. The parameters shall be determined by the
analyst after considering the number of samples in the background data base,
the data distribution, and the range of the concentration values for each
constituent of concern.
(D) If a
tolerance interval or a prediction interval is used to evaluate groundwater
monitoring data, the levels of confidence and, for tolerance intervals, the
percentage of the population that the interval shall contain, shall be
protective of human health and the environment. These parameters shall be
determined by the analyst after considering the number of samples in the
background data base, the data distribution, and the range of the concentration
values for each constituent of concern.
(E) The statistical method shall account for
data below the limit of detection with one or more statistical procedures that
are protective of human health and the environment. Any practical quantitation
limit (pql) that is used in the statistical method shall be the lowest
concentration level that can be reliably achieved within specified limits of
precision and accuracy during routine laboratory operating conditions that are
available to the facility.
(F) If
necessary, the statistical method shall include procedures to control or
correct for seasonal and spatial variability as well as temporal correlation in
the data.
(6) Within 120
days of completing a groundwater sampling event, the owner or operator shall
submit to the Division a monitoring report in an electronic format that is
accessible and viewable by the Division that includes information from the
sampling event including field observations relating to the condition of the
monitoring wells; field data; a summary of the laboratory analytical data
report; statistical analysis (if utilized), field sampling methods and quality
assurance and quality control data; information on groundwater flow direction;
calculations of groundwater flow rate; and for each well, any constituents that
exceed groundwater quality standards and IMACs set forth in
15A NCAC
02L .0202 or the groundwater protection
standards established in Rule .0545(c) of this Section.
(7) If the owner or operator determines upon
evaluation of laboratory data or by a verification sampling event that there is
an exceedance of the groundwater quality standards and IMACs established in
accordance with
15A NCAC
02L .0202, or the groundwater protection
standards established in accordance with Rule .0545(c) of this Section for one
or more of the constituents being monitored at any monitoring well, the owner
or operator:
(A) shall, within 14 days of this
finding, report to the Division and place a notice in the operating record
indicating which constituents have exceeded groundwater quality standards and
IMACs established in accordance with
15A NCAC
02L .0202, or the groundwater protection
standards established in accordance with Rule .0545(c) of this
Section;
(B) shall establish an
assessment monitoring program in accordance with Rule .0545 of this Section
except as provided for in Part (C) of this Subparagraph; and
(C) may demonstrate that a source other than
a C&DLF unit caused the exceedance, or the exceedance resulted from an
error in sampling, analysis, statistical evaluation, or natural variation in
groundwater quality. A report documenting this demonstration shall be submitted
to the Division for review. If required by G.S. 89C or G.S. 89E, a licensed
professional engineer or licensed geologist shall prepare these documents.
[Note: The North Carolina Board of Examiners for Engineers and Surveyors and
the Board of Licensing of Geologist has determined, via letters dated July 16,
2010 and November 30, 2010 respectively, that preparation of documents pursuant
to this Paragraph constitutes practicing engineering or geology under G.S. 89C
and G.S. 89E.] A copy of this report shall also be placed in the operating
record. If a successful demonstration is made, documented, and approved by the
Division, the owner or operator may continue detection monitoring. If after 90
days of the initial determination of exceedance, a successful demonstration is
not made, the owner or operator shall initiate an assessment monitoring program
as required by Rule .0545 of this Section.
(8) Monitoring wells shall be designed and
constructed in accordance with
15A NCAC
02C.
(A)
Owners and operators shall obtain approval from the Division for the design,
installation, development, and decommission of any monitoring well or
piezometer. Documentation shall be placed in the operating record and provided
to the Division.
(B) The monitoring
wells and piezometers shall be operated, maintained, and accessible so that
they perform to design specifications throughout the life of the monitoring
program.
(9) The number,
spacing, and depths of groundwater monitoring points shall be determined based
upon site-specific technical information that shall include an investigation
of:
(A) aquifer thickness, groundwater flow
rate, and groundwater flow direction, including seasonal and temporal
fluctuations in groundwater flow; and
(B) thickness, stratigraphy, lithology,
hydraulic conductivities, porosities, and effective porosities of the saturated
and unsaturated geologic units, including fill materials, overlying and
comprising the uppermost aquifer,
(10) In addition to groundwater monitoring
wells, the use of alternative monitoring systems may be:
(A) required by the Division at sites where
the owner or operator does not control the property from any landfill unit to
the groundwater discharge features; or
(B) allowed by the Division at sites with
hydrogeologic conditions favorable to detection monitoring by alternative
methods.
(11) Owners and
operators of C&DLF units shall comply with the groundwater monitoring,
assessment, and corrective action requirements under Rules .0544 and .0545 of
this Section according to the following schedule:
(A) new C&DLF units shall be in
compliance with the requirements before waste can be placed in the unit;
and
(B) lateral expansions to
existing C&DLF units shall be in compliance with the requirements before
waste can be placed in the expansion area.
(12) Groundwater quality standards and IMACs
established under
15A NCAC
02L .0202 and groundwater protection
standards established in accordance with Rule .0545(c) of this Section shall
not be exceeded.
(c)
Surface water monitoring shall meet the following criteria:
(1) The monitoring shall include sample
collection from surface water features on or bordering the facility property
and include no less than one upstream and one downstream sampling location.
Surface water samples shall be analyzed for constituents that include those
listed in Part (b)(1)(D) of this Rule. The monitoring frequency shall be no
less than annual during the active life of the facility, and no less than
annual during the closure and post-closure care period.
(2) Responsibility for sample collection and
analysis shall be defined as a part of the monitoring plan.
(3) Information used for the development of
the surface water monitoring system shall include:
(A) drainage patterns and other hydrological
conditions in the area;
(B)
proximity of surface water to the facility;
(C) uses that are being or may be made of any
surface water that may be affected by the facility; and
(D) any other factors that relate to the
potential for surface water impacts from the facility.
(4) The C&DLF unit shall not cause an
exceedance of the surface water standards established under
15A NCAC
02B .0200.
(d) The owner or operator of a C&DLF unit
shall submit a landfill gas monitoring plan to the Division prepared in
accordance with this Rule that shall apply to all C&DLF units. Landfill gas
monitoring shall be as follows:
(1) Owners
and operators of C&DLF units shall ensure that:
(A) the concentration of explosive gases
generated by the facility does not exceed 25 percent of the lower explosive
limit in on-site facility structures, excluding gas control or recovery system
components; and
(B) the
concentration of explosive gases does not exceed the lower explosive limit at
the facility property boundary.
(2) Owners and operators of all C&DLF
units shall implement a routine landfill gas monitoring program to ensure that
the standards of Subparagraph (1) of this Paragraph are met as follows:
(A) The type of monitoring shall be
determined based on soil conditions, the hydrogeologic conditions under and
surrounding the facility, the hydraulic conditions on and surrounding the
facility, the location of facility structures and property boundaries, and the
location of all off-site structures adjacent to property boundaries.
(B) The concentration of methane in landfill
gas shall be monitored. The monitoring shall be conducted at a frequency of no
less than quarterly.
(C) The
Division may also require quarterly monitoring of landfill gas for explosive
gases other than methane, such as hydrogen sulfide, if it is necessary to
ensure compliance with Subparagraph (1) of this Paragraph. If the Division
requires monitoring of additional explosive gases, the Division shall provide
written notice to the facility of the requirement.
(3) If explosive gas levels exceeding the
limits specified in Subparagraph (1) of this Paragraph are detected, the owner
and operator shall:
(A) upon discovery of
detection, notify the Division and take any steps that may be necessary to
ensure protection of human health, such as evacuation or monitoring of offsite
structures for explosive gases;
(B)
within seven days of detection, place in the operating record the explosive gas
levels detected and a description of the steps taken to protect human health;
and
(C) within 60 days of
detection, implement a remediation plan for the explosive gas releases, place a
copy of the plan in the operating record, and notify the Division that the plan
has been implemented. The plan shall describe the nature and extent of the
problem and the proposed remedy.
(4) The owner or operator may submit a
request in writing to the Division for an extension or alternate schedule for
compliance with Parts (3)(B) and (3)(C) of this Paragraph, and the request
shall include a justification for the alternate schedule. In making the
determination on approval of the request, the Division shall consider the
following factors:
(A) the justification
submitted by the owner or operator;
(B) actions taken by the owner or operator
upon discovery of the exceedances;
(C) the explosive gas levels measured and
reported; and
(D) the circumstances
and use of properties surrounding the facility.
(e) Owners or operators of C&DLF units
shall develop and implement a waste screening plan as required by
G.S.
130A-295.6(g) in accordance
with the effective date and applicability requirements of S.L. 2007-550, s.
9.(b). The plan shall meet the same requirements as municipal solid waste
landfills set forth in 40
CFR 258.20 and shall include screening for
the wastes prohibited by Rule .0542(e) of this Section. Owners and operators of
MSWLF units that are not subject to
G.S.
130A-295.6(g) shall develop
and implement a waste screening plan that shall comply with
40 CFR
258.20, and shall include screening and a
contingency plan for the wastes prohibited by Rule .0542(e) of this
Section.
(g) Water quality monitoring plans and
landfill gas monitoring plans shall be prepared under the charge of and bear
the seal of a licensed professional engineer or licensed geologist if required
by G.S. 89C or 89E, respectively.
(h) Water quality monitoring plans and
landfill gas monitoring plans shall be capable of providing detection of any
release of monitored constituents from any point in a disposal cell or leachate
surface impoundment to the uppermost aquifer, air, surface waters, or proximal
area.