Current through Supplement No. 394, October, 2024
An owner or operator subject to sections
33.1-24-05-160 through
33.1-24-05-175 shall establish
an unsaturated zone monitoring program to discharge the following
responsibilities:
1. The owner or
operator shall monitor the soil and soil-pore liquid to determine whether
hazardous constituents migrate out of the treatment zone.
a. The department will specify the hazardous
constituents to be monitored in the facility permit. The hazardous constituents
to be monitored are those specified under subsection 2 of section
33.1-24-05-161.
b. The department may require monitoring for
principal hazardous constituents in lieu of the constituents specified under
subsection 2 of section
33.1-24-05-161. Principal
hazardous constituents are hazardous constituents contained in the waste to be
applied at the unit that are the most difficult to treat, considering the
combined effects of degradation, transformation, and immobilization. The
department will establish principal hazardous constituents if the department
finds, based on waste analyses, treatment demonstrations, or other data that
effective degradation, transformation, or immobilization of the principal
hazardous constituents will assure treatment of at least equivalent levels for
the other hazardous constituents in the wastes.
2. The owner or operator must install an
unsaturated zone monitoring system that includes soil monitoring using soil
cores, and soil-pore liquid monitoring using devices such as lysimeters. The
unsaturated zone monitoring system must consist of a sufficient number of
sampling points at appropriate locations and depths to yield samples that:
a. Represent the quality of background
soil-pore liquid quality and the chemical makeup of soil that has not been
affected by leakage from the treatment zone; and
b. Indicate the quality of soil-pore liquid
in the chemical makeup of the soil below the treatment zone.
3. The owner or operator shall
establish a background value for each hazardous constituent to be monitored
under subsection 1. The permit will specify the background values for each
constituent or specify the procedures to be used to calculate the background
values.
a. Background soil values may be
based on a one-time sampling at a background plot having characteristics
similar to that of the treatment zone.
b. Background soil-pore liquid values must be
based on at least quarterly sampling for one year at a background plot having
characteristics similar to those of the treatment zone.
c. The owner or operator shall express all
background values in a form necessary for the determination of statistically
significant increases under subsection 6.
d. In taking samples used in the
determination of all background values, the owner or operator shall use an
unsaturated zone monitoring system that complies with subdivision a of
subsection 2.
4. The
owner or operator shall conduct soil monitoring and soil-pore liquid monitoring
immediately below the treatment zone. The department will specify the frequency
and timing of soil and soil-pore liquid monitoring in the facility permit after
considering the frequency, timing, and rate of waste application and the soil
permeability. The owner or operator shall express the results of the soil and
soil-pore liquid monitoring in a form necessary for the determination of
statistically significant increases under subsection 6.
5. The owner or operator shall use consistent
sampling and analysis procedures that are designed to ensure sampling results
that provide a reliable indication of soil-pore liquid quality and the chemical
makeup in the soil below the treatment zone. At a minimum, the owner or
operator shall implement procedures and techniques for:
a. Sample collection;
b. Sample preservation and
shipment;
c. Analytical procedures;
and
d. Chain of custody
control.
6. The owner or
operator shall determine whether there is a statistically significant change
over background values for any hazardous constituent to be monitored under
subsection 1 below the treatment zone each time the owner or operator conducts
soil monitoring and soil-pore liquid monitoring under subsection 4.
a. In determining whether a statistically
significant increase has occurred, the owner or operator shall compare the
value of each constituent as determined under subsection 4 to the background
value for that constituent according to the statistical procedures specified in
the facility permit under this subsection.
b. The owner or operator shall determine
whether there has been a statistically significant increase below the treatment
zone within a reasonable time period after completion of sampling. The
department 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 the soil and soil-pore liquid
samples.
c. The owner or operator
shall determine whether there is a statistically significant increase below the
treatment zone using a statistical procedure that provides reasonable
confidence that migration from the treatment zone will be identified. The
department will specify a statistical procedure in the facility permit that the
department finds:
(1) Is appropriate for the
distribution of data used to establish background values; and
(2) Provides a reasonable balance between the
probability of falsely identifying migration from the treatment zone and the
probability of failing to identify real migration from the treatment
zone.
7. If the
owner or operator determines pursuant to subsection 6 that there is a
statistically significant increase of hazardous constituents below the
treatment zone, the owner or operator shall:
a. Notify the department of this finding in
writing within seven days. The notification must indicate what constituents
have shown statistically significant increases.
b. Within ninety days submit to the
department an application for a permit modification to modify the operating
practices at the facility in order to maximize the success of degradation,
transformation, or immobilization processes in the treatment zone.
8. If the owner or operator
determines pursuant to subsection 6 that there is a statistically significant
increase of hazardous constituents below the treatment zone, the owner or
operator may demonstrate that a source other than regulated units caused the
increase or that the increase resulted from an error in sampling, analysis, or
evaluation. While the owner or operator may make this demonstration in addition
to, or in lieu of, submitting a permit modification application under
subdivision b of subsection 7, the owner or operator is still required to
submit a permit modification within the time specified in subdivision b of
subsection 7 should the demonstration be unsuccessful. In making this
demonstration the owner or operator shall:
a.
Notify the department in writing within seven days of determining a
statistically significant increase below the treatment zone that the owner or
operator intends to make a determination under this subsection;
b. Within ninety days submit a report to the
department demonstrating that a source other than the regulated units caused
the increase or that the increase resulted in error in sampling, analysis, or
evaluation;
c. Within ninety days
submit to the department an application for permit modification to make any
appropriate changes to the unsaturated zone monitoring program at the facility;
and
d. Continue to monitor in
accordance with the unsaturated zone monitoring program established under this
section.
General Authority: NDCC 23.1-04-03; S.L.
2017, ch. 199, § 1
Law Implemented: NDCC 23.1-04-03,
23.1-04-05; S.L. 2017, ch. 199, §
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