40 CFR Part 264 -- STANDARDS FOR
OWNERS AND OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES
§264.95 Point of compliance.
(a) The Regional Administrator will specify in the facility permit the point of compliance
at which the ground-water protection standard of §264.92 applies and at which monitoring
must be conducted. The point of compliance is a vertical surface located at the
hydraulically downgradient limit of the waste management area that extends down into the
uppermost aquifer underlying the regulated units.
(b) The waste management area is the limit projected in the horizontal plane of the area
on which waste will be placed during the active life of a regulated unit.
(1) The waste management area includes horizontal space taken up by any liner, dike, or
other barrier designed to contain waste in a regulated unit.
(2) If the facility contains more than one regulated unit, the waste management area is
described by an imaginary line circumscribing the several regulated units.
§264.96 Compliance period.
(a) The Regional Administrator will specify in the facility permit the compliance period
during which the ground-water protection standard of §264.92 applies. The compliance
period is the number of years equal to the active life of the waste management area
(including any waste management activity prior to permitting, and the closure period.)
(b) The compliance period begins when the owner or operator initiates a compliance
monitoring program meeting the requirements of §264.99.
(c) If the owner or operator is engaged in a corrective action program at the end of the
compliance period specified in paragraph (a) of this section, the compliance period is
extended until the owner or operator can demonstrate that the ground-water protection
standard of §264.92 has not been exceeded for a period of three consecutive years.
§264.97 General ground-water monitoring requirements.
The owner or operator must comply with the following requirements for any ground-water
monitoring program developed to satisfy §264.98, §264.99, or §264.100:
(a) The ground-water monitoring system must consist of a sufficient number of wells,
installed at appropriate locations and depths to yield ground-water samples from the
uppermost aquifer that:
(1) Represent the quality of background water that has not been affected by leakage from a
regulated unit;
(i) A determination of background quality may include sampling of wells that are not
hydraulically upgradient of the waste management area where:
(A) Hydrogeologic conditions do not allow the owner or operator to determine what wells
are hydraulically upgradient; and
(B) Sampling at other wells will provide an indication of background ground-water quality
that is representative or more representative than that provided by the upgradient wells;
and
(2) Represent the quality of ground water passing the point of compliance.
(3) Allow for the detection of contamination when hazardous waste or hazardous
constituents have migrated from the waste management area to the uppermost aquifer.
(b) If a facility contains more than one regulated unit, separate ground-water monitoring
systems are not required for each regulated unit provided that provisions for sampling the
ground water in the uppermost aquifer will enable detection and measurement at the
compliance point of hazardous constituents from the regulated units that have entered the
ground water in the uppermost aquifer.
(c) All monitoring wells must be cased in a manner that maintains the integrity of the
monitoring-well bore hole. This casing must be screened or perforated and packed with
gravel or sand, where necessary, to enable collection of ground-water samples. The annular
space (i.e., the space between the bore hole and well casing) above the sampling depth
must be sealed to prevent contamination of samples and the ground water.
(d) The ground-water monitoring program must include consistent sampling and analysis
procedures that are designed to ensure monitoring results that provide a reliable
indication of ground-water quality below the waste management area. At a minimum the
program must include procedures and techniques for:
(1) Sample collection;
(2) Sample preservation and shipment;
(3) Analytical procedures; and
(4) Chain of custody control.
(e) The ground-water monitoring program must include sampling and analytical methods that
are appropriate for ground-water sampling and that accurately measure hazardous
constituents in ground-water samples.
(f) The ground-water monitoring program must include a determination of the ground-water
surface elevation each time ground water is sampled.
(g) In detection monitoring or where appropriate in compliance monitoring, data on each
hazardous constituent specified in the permit will be collected from background wells and
wells at the compliance point(s). The number and kinds of samples collected to establish
background shall be appropriate for the form of statistical test employed, following
generally accepted statistical principles. The sample size shall be as large as necessary
to ensure with reasonable confidence that a contaminant release to ground water from a
facility will be detected. The owner or operator will determine an appropriate sampling
procedure and interval for each hazardous constituent listed in the facility permit which
shall be specified in the unit permit upon approval by the Regional Administrator. This
sampling procedure shall be:
(1) A sequence of at least four samples, taken at an interval that to the greatest extent
technically feasible, that an independent sample is obtained, by reference to the
uppermost aquifer's effective porosity, hydraulic conductivity, and hydraulic gradient,
and the fate and transport characteristics of the potential contaminants, or
(2) an alternate sampling procedure proposed by the owner or operator and approved by the
Regional Administrator.
(h) The owner or operator will specify one of the following statistical methods to be used
in evaluating ground-water monitoring data for each hazardous constituent which, upon
approval by the Regional Administrator, will be specified in the unit permit. The
statistical test chosen shall be conducted separately for each hazardous constituent in
each well. Where practical quantification limits (pql's) are used in any of the following
statistical procedures to comply with 264.97(i)(5), the pql must be proposed by the owner
or operator and approved by the Regional Administrator. Use of any of the following
statistical methods must be protective of human health and the environment and must comply
with the performance standards outlined in paragraph (i) of this section.
(1) A parametric analysis of variance (ANOVA) followed by multiple comparisons procedures
to identify statistically significant evidence of contamination. The method must include
estimation and testing of the contrasts between each compliance well's mean and the
background mean levels for each constituent.
(2) An analysis of variance (ANOVA) based on ranks followed by multiple comparisons
procedures to identify statistically significant evidence of contamination. The method
must include estimation and testing of the contrasts between each compliance well's median
and the median levels for each constituent.
(3) 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.
(4) A control chart approach that gives control limits for each constituent.
(5) Another statistical test method submitted by the owner or operator and approved by the
Regional Administrator.
(i) Any statistical method chosen under §264.97(h) for specification in the unit permit
shall comply with the following performance standards, as appropriate:
(1) The statistical method used to evaluate ground-water monitoring data shall be
appropriate for the distribution of chemical parameters or hazardous constituents. If the
distribution of the chemical parameters or hazardous constituents is shown by the owner or
operator to be inappropriate for a normal theory test, then the data should be transformed
or a distribution-free theory test should be used. If the distributions for the
constituents differ, more than one statistical method may be needed.
(2) If an individual well comparison procedure is used to compare an individual compliance
well constituent concentration with background constituent concentrations or a
ground-water 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
experimentwise 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 must be maintained. This
performance standard does not apply to tolerance intervals, prediction intervals or
control charts.
(3) If a control chart approach is used to evaluate ground-water monitoring data, the
specific type of control chart and its associated parameter values shall be proposed by
the owner or operator and approved by the Regional Administrator if he or she finds it to
be protective of human health and the environment.
(4) 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 must contain, shall be proposed by the owner or operator
and approved by the Regional Administrator if he or she finds these parameters to be
protective of human health and the environment. These parameters will be determined 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.
(5) 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 quantification limit (pql) approved by the Regional Administrator under
264.97(h) 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.
(6) 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.
(j) Ground-water monitoring data collected in accordance with paragraph (g) of this
section including actual levels of constituents must be maintained in the facility
operating record. The Regional Administrator will specify in the permit when the data must
be submitted for review.
(Approved by the Office of Management and Budget under control number 2050-0033)
(47 FR 32350, July 26, 1982, as amended at 50 FR 4514, Jan. 31, 1985; 53 FR 39728, Oct.
11, 1988)
§264.98 Detection monitoring program.
An owner or operator required to establish a detection monitoring program under this
subpart must, at a minimum, discharge the following
(a) The owner or operator must monitor for indicator parameters (e.g., specific
conductance, total organic carbon, or total organic halogen), waste constituents, or
reaction products that provide a reliable indication of the presence of hazardous
constituents in ground water. The Regional Administrator will specify the parameters or
constituents to be monitored in the facility permit, after considering the following
factors:
(1) The types, quantities, and concentrations of constituents in wastes managed at the
regulated unit;
(2) The mobility, stability, and persistence of waste constituents or their reaction
products in the unsaturated zone beneath the waste management area;
(3) The detectability of indicator parameters, waste constituents, and reaction products
in ground water; and
(4) The concentrations or values and coefficients of variation of proposed monitoring
parameters or constituents in the ground-water background.
(b) The owner or operator must install a ground-water monitoring system at the compliance
point as specified under §264.95. The ground-water monitoring system must comply with
§264.97(a)(2), (b), and (c).
(c) The owner or operator must conduct a ground-water monitoring program for each chemical
parameter and hazardous constituent specified in the permit pursuant to paragraph (a) of
this section in accordance with §264.97(g). The owner or operator must maintain a record
of ground-water analytical data as measured and in a form necessary for the determination
of statistical significance under §264.97(h).
(d) The Regional Administrator will specify the frequencies for collecting samples and
conducting statistical tests to determine whether there is statistically significant
evidence of contamination for any parameter or hazardous constituent specified in the
permit under paragraph (a) of this section in accordance with §264.97(g). A sequence of
at least four samples from each well (background and compliance wells) must be collected
at least semi-annually during detection monitoring.
(e) The owner or operator must determine the ground-water flow rate and direction in the
uppermost aquifer at least annually.
(f) The owner or operator must determine whether there is statistically significant
evidence of contamination for any chemical parameter of hazardous constituent specified in
the permit pursuant to (a) of this section at a frequency specified under paragraph (d) of
this section.
(1) In determining whether statistically significant evidence of contamination exists, the
owner or operator must use the method(s) specified in the permit under §264.97(h). These
method(s) must compare data collected at the compliance point(s) to the background
ground-water quality data.
(2) The owner or operator must determine whether there is statistically significant
evidence of contamination at each monitoring well as the compliance point within a
reasonable period of time after completion of sampling. The Regional Administrator will
specify in the facility permit what period of time is reasonable, after considering the
complexity of the statistical test and the availability of laboratory facilities to
perform the analysis of ground-water samples.
(g) If the owner or operator determines pursuant to paragraph (f) of this section that
there is statistically significant evidence of contamination for chemical parameters or
hazardous constituents specified pursuant to paragraph (a) of this section at any
monitoring well at the compliance point, he or she must:
(1) Notify the Regional Administrator of this finding in writing within seven days. The
notification must indicate what chemical parameters or hazardous constituents have shown
statistically significant evidence of contamination;
(2) Immediately sample the ground water in all monitoring wells and determine whether
constituents in the list of appendix IX of Part 264 are present, and if so, in what
concentration.
(3) For any appendix IX compounds found in the analysis pursuant to paragraph (g)(2) of
this section, the owner or operator may resample within one month and repeat the analysis
for those compounds detected. If the results of the second analysis confirm the initial
results, then these constituents will form the basis for compliance monitoring. If the
owner or operator does not resample for the compounds found pursuant to paragraph (g)(2)
of this section, the hazardous constituents found during this initial appendix IX analysis
will form the basis for compliance monitoring.
(4) Within 90 days, submit to the Regional Administrator an application for a permit
modification to establish a compliance monitoring program meeting the requirements of
§264.99. The application must include the following information:
(i) An identification of the concentration or any appendix IX constituent detected in the
ground water at each monitoring well at the compliance point;
(ii) Any proposed changes to the ground-water monitoring system at the facility necessary
to meet the requirements of §264.99;
(iii) Any proposed additions or changes to the monitoring frequency, sampling and analysis
procedures or methods, or statistical methods used at the facility necessary to meet the
requirements of §264.99;
(iv) For each hazardous constituent detected at the compliance point, a proposed
concentration limit under §264.94(a) (1) or (2), or a notice of intent to seek an
alternate concentration limit under §264.94(b); and
(5) Within 180 days, submit to the Regional Administrator:
(i) All data necessary to justify an alternate concentration limit sought under
§264.94(b); and
(ii) An engineering feasibility plan for a corrective action program necessary to meet the
requirement of §264.100, unless:
(A) All hazardous constituents identified under paragraph (g)(2) of this section are
listed in Table 1 of §264.94 and their concentrations do not exceed the respective values
given in that Table; or
(B) The owner or operator has sought an alternate concentration limit under §264.94(b)
for every hazardous constituent identified under paragraph (g)(2) of this section.
(6) If the owner or operator determines, pursuant to paragraph (f) of this section, that
there is a statistically significant difference for chemical parameters or hazardous
constituents specified pursuant to paragraph (a) of this section at any monitoring well at
the compliance point, he or she may demonstrate that a source other than a regulated unit
caused the contamination or that the detection is an artifact caused by an error in
sampling, analysis, or statistical evaluation or natural variation in the ground water.
The owner operator may make a demonstration under this paragraph in addition to, or in
lieu of, submitting a permit modification application under paragraph (g)(4) of this
section; however, the owner or operator is not relieved of the requirement to submit a
permit modification application within the time specified in paragraph (g)(4) of this
section unless the demonstration made under this paragraph successfully shows that a
source other than a regulated unit caused the increase, or that the increase resulted from
error in sampling, analysis, or evaluation. In making a demonstration under this
paragraph, the owner or operator must:
(i) Notify the Regional Administrator in writing within seven days of determining
statistically significant evidence of contamination at the compliance point that he
intends to make a demonstration under this paragraph;
(ii) Within 90 days, submit a report to the Regional Administrator which demonstrates that
a source other than a regulated unit caused the contamination or that the contamination
resulted from error in sampling, analysis, or evaluation;
(iii) Within 90 days, submit to the Regional Administrator an application for a permit
modification to make any appropriate changes to the detection monitoring program facility;
and
(iv) Continue to monitor in accordance with the detection monitoring program established
under this section.
(h) If the owner or operator determines that the detection monitoring program no longer
satisfies the requirements of this section, he or she must, within 90 days, submit an
application for a permit modification to make any appropriate changes to the program.
(Approved by the Office of Management and Budget under control number 2050-0033)
(47 FR 32350, July 26, 1982, as amended at 50 FR 4514, Jan. 31, 1985; 52 FR 25946, July 9,
1987; 53 FR 39729, Oct. 11, 1988)
§264.99 Compliance monitoring program.
An owner or operator required to establish a compliance monitoring under this subpart
must, at a minimum, discharge the following responsibilities:
(a) The owner or operator must monitor the ground water to determine whether regulated
units are in compliance with the ground-water protection standard under §264.92. The
Regional Administrator will specify the ground-water protection standard in the facility
permit, including:
(1) A list of the hazardous constituents identified under §264.93;
(2) Concentration limits under §264.94 for each of those hazardous constituents;
(3) The compliance point under §264.95; and
(4) The compliance period under §264.96.
(b) The owner or operator must install a ground-water monitoring system at the compliance
point as specified under §264.95. The ground-water monitoring system must comply with
§264.97(a)(2), (b), and (c).
(c) The Regional Administrator will specify the sampling procedures and statistical
methods appropriate for the constituents and the facility, consistent with §264.97 (g)
and (h).
(1) The owner or operator must conduct a sampling program for each chemical parameter or
hazardous constituent in accordance with §264.97(g).
(2) The owner or operator must record ground-water analytical data as measured and in form
necessary for the determination of statistical significance under §264.97(h) for the
compliance period of the facility.
(d) The owner or operator must determine whether there is statistically significant
evidence of increased contamination for any chemical parameter or hazardous constituent
specified in the permit, pursuant to paragraph (a) of this section, at a frequency
specified under paragraph (f) under this section.
(1) In determining whether statistically significant evidence of increased contamination
exists, the owner or operator must use the method(s) specified in the permit under
§264.97(h). The methods(s) must compare data collected at the compliance point(s) to a
concentration limit developed in accordance with §264.94.
(2) The owner or operator must determine whether there is statistically significant
evidence of increased contamination at each monitoring well at the compliance point within
a reasonable time period after completion of sampling. The Regional Administrator will
specify that time period in the facility permit, after considering the complexity of the
statistical test and the availability of laboratory facilities to perform the analysis of
ground-water samples.
(e) The owner or operator must determine the ground-water flow rate and direction in the
uppermost aquifer at least annually.
(f) The Regional Administrator will specify the frequencies for collecting samples and
conducting statistical tests to determine statistically significant evidence of increased
contamination in accordance with §264.97(g). A sequence of at least four samples from
each well (background and compliance wells) must be collected at least semi-annually
during the compliance period of the facility.
(g) The owner or operator must analyze samples from all monitoring wells at the compliance
point for all constituents contained in appendix IX of Part 264 at least annually to
determine whether additional hazardous constituents are present in the uppermost aquifer
and, if so, at what concentration, pursuant to procedures in §264.98(f). If the owner or
operator finds appendix IX constituents in the ground water that are not already
identified in the permit as monitoring constituents, the owner or operator may resample
within one month and repeat the appendix IX analysis. If the second analysis confirms the
presence of new constituents, the owner or operator must report the concentration of these
additional constituents to the Regional Administrator within seven days after the
completion of the second analysis and add them to the monitoring list. If the owner or
operator chooses not to resample, then he or she must report the concentrations of these
additional constituents to the Regional Administrator within seven days after completion
of the initial analysis and add them to the monitoring list.
(h) If the owner or operator determines pursuant to paragraph (d) of this section that any
concentration limits under §264.94 are being exceeded at any monitoring well at the point
of compliance he or she must:
(1) Notify the Regional Administrator of this finding in writing within seven days. The
notification must indicate what concentration limits have been exceeded.
(2) Submit to the Regional Administrator an application for a permit modification to
establish a corrective action program meeting the requirements of §264.100 within 180
days, or within 90 days if an engineering feasibility study has been previously submitted
to the Regional Administrator under §264.98(h)(5). The application must at a minimum
include the following information:
(i) A detailed description of corrective actions that will achieve compliance with the
ground-water protection standard specified in the permit under paragraph (a) of this
section; and
(ii) A plan for a ground-water monitoring program that will demonstrate the effectiveness
of the corrective action. Such a ground-water monitoring program may be based on a
compliance monitoring program developed to meet the requirements of this section.
(i) If the owner or operator determines, pursuant to paragraph (d) of this section, that
the ground-water concentration limits under this section are being exceeded at any
monitoring well at the point of compliance, he or she may demonstrate that a source other
than a regulated unit caused the contamination or that the detection is an artifact caused
by an error in sampling, analysis, or statistical evaluation or natural variation in the
ground water. In making a demonstration under this paragraph, the owner or operator must:
(1) Notify the Regional Administrator in writing within seven days that he intends to make
a demonstration under this paragraph;
(2) Within 90 days, submit a report to the Regional Administrator which demonstrates that
a source other than a regulated unit caused the standard to be exceeded or that the
apparent noncompliance with the standards resulted from error in sampling, analysis, or
evaluation;
(3) Within 90 days, submit to the Regional Administrator an application for a permit
modification to make any appropriate changes to the compliance monitoring program at the
facility; and
(4) Continue to monitor in accord with the compliance monitoring program established under
this section.
(j) If the owner or operator determines that the compliance monitoring program no longer
satisfies the requirements of this section, he must, within 90 days, submit an application
for a permit modification to make any appropriate changes to the program.
(Approved by the Office of Management and Budget under control number 2050-0033)
(47 FR 32350, July 26, 1982, as amended at 50 FR 4514, Jan. 31, 1985; 52 FR 25946, July 9,
1987; 53 FR 39730, Oct. 11, 1988)