(a)
The requirements in this part apply to municipal solid waste landfill
units which are within the town or its extraterritorial jurisdiction.
(b)
Groundwater monitoring requirements under sections 13.02.192 through 13.02.197 of these regulations will be suspended for a landfill unit if the owner/operator can demonstrate to the town that there is no potential for migration of hazardous constituents from that unit to the uppermost aquifer during the active life, including the closure period, of the unit and for the post-closure care period. This demonstration must be certified by a qualified geologist or geotechnical engineer, approved by the town and the owner/operator, and must incorporate reliable site-specific data. If detailed hydrogeologic data is unavailable, the owner/operator must provide an adequate margin of safety in the prediction of potential migration of hazardous constituents by basing such predictions on assumptions that maximize the rate of hazardous constituent migration.
(c)
New municipal solid waste units must comply with this part.
(d)
The town shall specify a schedule for owners/operators of existing
municipal solid waste landfill units to comply with this part. This
schedule will be specified by the town after considering the potential
risks posed by the municipal solid waste landfill unit to human health
and the environment. Compliance with this part will be achieved for
all existing landfill units within two years of the effective date
of this rule.
(e)
Once established at a unit, groundwater monitoring shall be conducted
throughout the active life and post-closure care period of the solid
waste facility as specified in part III of this division.
(1998 Code, sec. 95.75)
(a)
A groundwater monitoring well system approved by the town must be installed at the existing waste management unit boundary, the alternative boundary specified by the town under section 13.02.161, or the closest practical distance from the appropriate boundary. Where subsurface conditions cause hazardous constituents to migrate horizontally past the boundary specified under section 13.02.161 before descending to the uppermost aquifer, the town can designate another appropriate downgradient location for the groundwater monitoring wells.
(b)
A groundwater monitoring system must consist of a sufficient number of wells, installed at appropriate locations and depths, to yield groundwater samples from the uppermost aquifer that represent the quality of background groundwater that has not been affected by leakage from a landfill unit; and represent the quality of groundwater passing the waste management unit boundary specified under subsection (a) of this section.
(1)
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 groundwater 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 groundwater.
(2)
The number, spacing, and depths of monitoring systems shall be proposed
by the owner/operator and approved by the town based upon site-specific
technical information that must be developed by the owner/operator
and must include thorough characterization of:
(1998 Code, sec. 95.76)
(a)
The groundwater monitoring program must 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 installed in compliance with section 13.02.192 of this division. At a minimum the program must include the procedures and techniques for:
(b)
The groundwater monitoring program must include sampling and analytical
methods that are appropriate for groundwater sampling and that accurately
measure hazardous constituents and other monitoring parameters in
groundwater samples.
(c)
Groundwater elevations must be measured in each well immediately
prior to sampling. The owner/operator must determine the rate and
direction of groundwater flow in the uppermost aquifer each time groundwater
gradient changes as indicated by previous sampling period elevation
measurements.
(d)
The owner/operator must establish background groundwater quality in hydraulically upgradient well(s) for each of the monitoring parameters or constituents required in the particular groundwater monitoring program that applies to the municipal solid waste landfill unit, as determined under sections 13.02.194 through 13.02.196 of this division. The minimum number of samples used to establish background groundwater quality must be consistent with the appropriate statistical procedures determined pursuant to subsection (g) of this section.
(e)
Background quality at existing units may be based on sampling of
wells that are not upgradient from the waste management area where:
(f)
The town may determine alternate background groundwater quality on
a site-specific basis if true background groundwater quality cannot
be detected on-site.
(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 sampling procedures and frequency must be protective of human
health and the environment. The sampling requirements must ensure
that the statistical procedure has an acceptably low probability of
failing to detect contamination. The owner/operator will specify one
or more of the following requirements in the permit for each hazardous
constituent to be monitored for:
(1)
Obtain a sequence of daily (or near daily) samples at least twice
a year, unless it is found that this frequency of sampling results
in autocorrelation of the observations that cannot be corrected by
the statistical procedure used.
(2)
Obtain a sequence of weekly samples at least twice a year, provided
that weekly observations are not autocorrelated and that no seasonal
effects are present in the data used in each periodic comparison.
(3)
Obtain monthly samples, provided the data exhibits no seasonal effects.
(4)
Use an alternate sampling procedure specified by the town.
(h)
The owner/operator must determine whether or not there is a statistically significant increase over background values for each parameter or constituent required in the particular groundwater monitoring program that applies to the landfill unit, as determined under sections 13.02.194 through 13.02.196 of this division. The owner/operator must make these statistical determinations each time (s)he assesses groundwater quality at the waste management unit boundary designated under section 13.02.161.
(1)
In determining whether a statistically significant increase has occurred, the owner/operator must compare the groundwater quality of each parameter or constituent at each monitoring well designated pursuant to section 13.02.192 to the background value of that parameter or constituent, according to the statistical procedures specified under subsection (g) of this section.
(2)
The owner/operator must determine whether there has been a statistically
significant increase over background at each monitoring well within
30 days after completing sampling.
(1998 Code, sec. 95.77)
(b)
At a minimum, a Phase I monitoring program must include the following
monitoring parameters or constituents:
(c)
The town will determine an appropriate monitoring frequency on a site-specific basis by considering aquifer flow rate and resource value of the groundwater. The minimum monitoring frequency for parameters (1) through (14) of subsection (b) of this section is semiannual, except during the post-closure care period, when a minimum monitoring frequency shall be determined by the town on a site-specific basis. The minimum monitoring frequency for appendix I constituents is annual, except during the post-closure period, when minimum monitoring frequency shall be determined by the town on a site-specific basis.
(d)
If the owner/operator determines, pursuant to section 13.02.193(g) of this division, that there is a statistically significant increase over background for two or more of parameters (1) through (14) under subsection (b) of this section at any monitoring well at the waste management unit boundary, he/she:
(1)
Must notify the town within 14 days of this finding. The notification
must indicate what Phase I parameters have shown statistically significant
increases over background levels.
(2)
Within 30 days, must establish a Phase II monitoring program meeting the requirements of section 13.02.195 of this division.
(3)
May demonstrate that a source other than a municipal solid waste
landfill caused the contamination, or that the contamination resulted
from error in sampling, analysis, or evaluation. While the owner/operator
may make a demonstration under this subsection in lieu of establishing
a Phase II monitoring program, he/she is not relieved of the requirement
to establish a Phase II monitoring program within 30 days unless the
demonstration made under this subsection successfully shows that a
source other than a municipal solid waste landfill caused the increase,
or that the increase resulted from error in sampling, analysis, or
evaluation. In making a demonstration under this subsection, the owner/operator
must:
(A)
Notify the town in writing within seven days of determining statistically
significant evidence of contamination that (s)he intends to make a
demonstration under this subsection;
(B)
Within 90 days, submit to the town a report that demonstrates that
a source other than a municipal solid waste landfill unit caused the
contamination or that the contamination resulted from error in sampling,
analysis, or evaluation; and
(C)
Continue to monitor in accordance with the Phase I monitoring program.
(e)
If the owner/operator determines, pursuant to section 13.02.193(h), that there is a statistically significant increase over background for any one or more of the appendix I constituents at any monitoring well at the waste management unit boundary, he or she:
(1)
Must notify the town within 14 days of this finding. The notification
must indicate what constituents have shown statistically significant
increases over background levels.
(1998 Code, sec. 95.78)
(a)
Phase II monitoring is required whenever statistically significant increases over background have been detected for two or more of the non-VOC Phase I parameters under section 13.02.194(b).
(c)
The town shall determine an appropriate monitoring frequency on a
site-specific basis by considering aquifer flow rate. The minimum
monitoring frequency is semiannual for Phase II parameters, except
during the post-closure care period, when monitoring frequency shall
be determined by the town on a site-specific basis.
(d)
If, after conducting Phase II monitoring for an appropriate time period approved by the town, the owner/operator determines that there has not been a statistically significant increase of parameters or constituents specified pursuant to subsection (b)(1) or (2) of this section at any monitoring well, that unit may return to Phase I monitoring. The following factors should be considered by the town when determining an appropriate time period for sampling before allowing a unit to return to Phase I monitoring:
(e)
If the owner/operator determines, pursuant to section 13.02.193(h), that there is a statistically significant increase over background for any one or more constituents specified pursuant to subsection (b)(1) or (2) of this section at any monitoring well, he/she:
(1)
Must notify the town of this finding in writing within 14 days. The
notification must indicate what Phase II parameters or constituents
have shown statistically significant increases over background levels.
(2)
Must, within 30 days, establish a Phase III monitoring program meeting the requirements of section 13.02.196 of this division.
(3)
May demonstrate that a source other than a municipal solid waste
landfill caused the contamination, or that the contamination resulted
from error in sampling, analysis, or evaluation. While the owner/operator
may make a demonstration under this subsection in lieu of establishing
a Phase III monitoring program[, a Phase III monitoring program shall
be established] within 30 days unless the demonstration made under
this subsection successfully shows that a source other than a municipal
solid waste landfill caused the increase, or that the increase resulted
from an error in sampling, analysis, or evaluation. In making a demonstration
under this subsection, the owner/operator must:
(A)
Notify the town in writing within seven days of determining statistically
significant evidence of contamination that he or she intends to make
a demonstration under this subsection;
(B)
Within 90 days, submit to the town a report that demonstrates that
a source other than a municipal solid waste landfill caused the contamination
or that the contamination resulted from error in sampling, analysis,
or evaluation; and
(C)
Continue to monitor in accordance with the Phase II monitoring program.
(1998 Code, sec. 95.79)
(a)
Phase III monitoring is required whenever any parameter under section 13.02.194(b) and section 13.02.195(b) has been detected at statistically significant levels above background concentrations.
(b)
Phase III monitoring parameters must include all constituents in
appendix II.
(c)
Within 90 days of triggering a Phase III monitoring program, or an alternative time period approved by the town, the owner/operator must sample the groundwater in all monitoring wells identified pursuant to section 13.02.192 of this division and analyze those samples for all constituents identified in appendix II.
(d)
If any appendix II constituents are detected at statistically significant levels above background in response to subsection (c) of this section, the owner/operator must, within 90 days, submit a report to the town containing:
(e)
The minimum monitoring frequency under the active life and closure period of the unit is quarterly for those constituents in appendix II that are determined to be present at levels above background concentrations at the waste management unit boundary or the alternative boundary as specified in section 13.02.161 of these regulations.
(f)
The town shall determine an appropriate minimum monitoring frequency for all parameters listed in appendix II that are not being monitored at the frequency designated under subsection (e) of this section.
(g)
During the post-closure period, the town shall determine an appropriate
minimum monitoring frequency for all appendix II constituents.
(h)
If any appendix II parameters or constituents are identified under subsection (g) of this section that had not previously been identified under subsection (d)(1) of this section, then, within 90 days or an alternate time period approved by the town, the owner/operator must:
(1)
Submit to the town a report on the concentration of any appendix
II constituents detected at statistically significant levels above
background concentrations; and
(i)
If, after conducting Phase III monitoring for an appropriate time period approved by the town, the owner/operator determines that there has not been a statistically significant increase of parameters or constituents specified pursuant to subsection (b) of this section at any monitoring well at the waste management unit boundary or at the alternative boundary, that unit may return to Phase II monitoring. The following factors will be considered by the town when determining an appropriate time period for sampling before allowing a unit to return to Phase II monitoring:
(j)
If one or more hazardous constituents identified under subsection (h)(1) or (2) of this section exceed the groundwater protection standard established under section 13.02.197 of this division, the owner/operator must:
(1)
Notify the town of this finding in writing within 14 days. The notification
must indicate what Phase III parameters or constituents have exceeded
the groundwater protection standard.
(2)
Within 90 days, or an appropriate time period approved by the town,
submit a report to the town containing:
(A)
Any proposed changes to the groundwater monitoring system at the facility necessary to meet the requirements of section 13.02.198.
(B)
Any proposed changes to the monitoring frequency, sampling and analysis procedures or methods, or statistical procedures used at the facility necessary to meet the requirements of section 13.02.198.
(C)
An engineering feasibility plan for a corrective action program necessary
to meet the requirements of this section.
(3)
Within a time period determined by the town, establish a corrective action program meeting the requirements of section 13.02.198 of this division.
(4)
Continue to monitor in accordance with the Phase III monitoring program
established under this section.
(1998 Code, sec. 95.80)
(a)
Groundwater protection standards (GWPS) will be established by the town for any of the constituents listed in appendix II that have been detected at statistically significant levels above background during the Phase III monitoring program as required under section 13.02.196(e).
(b)
The concentration levels established for the GWPS shall be protective
of human health and the environment, to be specified as:
(1)
Maximum contaminant level (MCL) promulgated under section 1412 of
the Safe Drinking Water Act, being 42 USC 300g-1 (regulations codified
under 40 CFR part 141, subpart B); or
(2)
For constituents for which MCLs have not been promulgated, an appropriate
health-based level established by the town which satisfies the following
criteria:
(A)
The level is derived in a manner consistent with the agency guidelines
for assessing the health risks of environmental pollutants (FR 33992,
34006, 34014, 34028).
(B)
For carcinogens, the level represents a concentration associated
with an excess lifetime cancer risk level (due to continuous lifetime
exposure) within the 10-4 to 10-7 range.
(C)
For systematic toxicants, the level represents a concentration which
the human population (including sensitive subgroups) could be exposed
to on a daily basis that is likely to be without appreciable risk
or deleterious effects during a lifetime.
(3)
For constituents for which no health-based level is available or
for which background levels are higher than the health-based levels,
the background concentration.
(d)
The town may establish alternatives to the concentration limits required under subsection (b) of this section if:
(1)
The aquifer underlying the unit is not a current or potential source
of underground drinking water, or water which could be used for agricultural,
industrial, or other beneficial human purposes;
(2)
The aquifer underlying the unit is not interconnected with any other
aquifer, unless all other interconnected aquifers are also unsuitable
for human consumption or other beneficial human purposes; and
(3)
The aquifer underlying the unit is not hydraulically connected with
surface waters to which the hazardous constituents could migrate in
concentrations that could pose a threat to human health and the environment.
(1998 Code, sec. 95.81)
(a)
A corrective action program is required whenever the groundwater protection standard under section 13.02.197 is exceeded.
(b)
A corrective action monitoring program must comply with the Phase III monitoring requirements under section 13.02.196 of this division. Additional monitoring must be implemented as necessary to:
(1)
Determine the areal extent of any plume of contamination for each constituent under section 13.02.197 that has been measured at concentrations that exceed limits established under section 13.02.197(b) or (c); and
(2)
Demonstrate the effectiveness of the corrective action program.
(c)
The owner/operator must design and implement a corrective action program, approved by the town, to achieve the groundwater protection standard established in section 13.02.197 by removing or heating [sealing] in place and/or eliminating the releases of any appendix II hazardous constituent released by the municipal solid waste landfill unit at levels that exceed the groundwater protection standards.
(1)
Corrective action programs under this subsection must achieve the groundwater protection standard established in section 13.02.197 at all points within the plume of contamination that lie beyond the groundwater monitoring well system established under section 13.02.192(a).
(2)
Corrective action programs under this subsection must be initiated
and completed within 90 days. The town may shorten or lengthen the
time allowed for completion of a corrective action program under this
subsection after consideration of the following factors:
(A)
Potential risks to human health and the environment from exposure
to contamination prior to completion of the corrective action program;
(B)
Extent and nature of contamination;
(C)
Resource value of the aquifer including:
(i)
Current and future uses;
(ii)
Proximity and withdrawal rates of users;
(iii)
Groundwater quantity and quality;
(iv)
The potential drainage [damage] to wildlife, crops, vegetation,
and physical structures caused by exposure to waste constituents;
(v)
The hydrogeologic characteristics of the facility and surrounding
land;
(vi)
Groundwater removal and treatment costs; and
(vii)
The cost and availability of alternative water supplies.
(D)
Availability of treatment of disposal capacity for waste managed
during implementation of the program;
(E)
Desirability of utilizing technologies which are not currently available,
but which may offer significant advantages over already available
technologies in terms of effectiveness, reliability, safety, or ability
to achieve program objectives;
(F)
Practicable capabilities of remedial technologies in achieving compliance with the groundwater protection standard established under section 13.02.197 and other objectives of the remedy; and
(G)
Practicable capability of the owner/operator.
(3)
Corrective action programs under this section must comply with all
applicable federal, state, and local regulations and requirements.
(4)
If, in the judgment of the town, the most desirable overall corrective remedy action is one that does not meet the groundwater protection standard established under section 13.02.197, but does meet an alternative level that is also protective of human health and the environment, the town may accept the most desirable remedy.
(5)
Corrective action programs that do not achieve the groundwater protection standard under section 13.02.197 may be accepted by the town in the following situations:
(A)
It is not technically feasible to achieve the groundwater protection
standard;
(B)
Available methods will result in undesirable cross-media effects,
including, but not limited to, irreparable damages to scenic areas,
surface waters, air quality, interconnected aquifers, and habitats
of endangered or threatened species; or
(C)
Available methods will result in high hazard situations such as unacceptable
air contamination, dangers to cleanup personnel, or dangers to the
surrounding community from weakening of structural support of roads,
building, and other structures.
(d)
The owner/operator must implement as soon as is practical a corrective
action program to:
(1)
Notify all persons who own the land or reside on the land that directly overlies any part of the plume defined in subsection (c)(1) of this section; and
(2)
Replace any currently used sources of groundwater that lie within any part of the plume as defined in subsection (c)(1) of this section by making water available that is of appropriate quality for its current use and that has been approved by the town. The amount of water supplied under this subsection must be equal to the usage rates of the replaced groundwater. The town may waive this replacement requirement if the current usage is not adversely affected by the contaminated groundwater.
(e)
The owner/operator must implement any interim measures deemed necessary
by the town to ensure the protection of human health and the environment.
The following factors may be considered by the town in determining
whether interim measures are necessary:
(1)
Actual or potential exposure of nearby populations or animals to
hazardous constituents;
(2)
Actual or potential contamination of drinking water supplies or sensitive
ecosystems;
(3)
Weather conditions that may cause hazardous constituents to migrate
or be released; and
(4)
Risks of fire or explosion, or potential for exposure to hazardous
constituents as a result of an accident or failure of a container
or handling system.
(f)
A corrective action program is completed when the groundwater protection standard under section 13.02.197 is achieved as specified in subsection (c)(1) of this section for three consecutive years unless a corrective action program described under subsection (c)(5) is implemented. Completion of corrective action programs under subsection (c)(5) shall be determined on a site-specific basis by the town.
(1998 Code, sec. 95.82)
