North Dakota Administrative Code, Chapter 33.1-20-08, Section 33.1-20-08-06 - Ground water monitoring and corrective action | North Dakota Administrative Code

1. Applicability.

a. Existing CCR landfills, CCR surface impoundments, and lateral expansions of CCR units are subject to the ground water monitoring and corrective action requirements of this section, except as provided in subdivision f.

b. Initial time frames.

(1) Existing CCR landfills and existing CCR surface impoundments. The owner or operator of the CCR unit shall include with the permit modification application required by subsection 9 of section 33.1-20-08-02, a ground water monitoring plan showing compliance with the following ground water monitoring requirements:

(a) Install the ground water monitoring system as required by subsection 2;

(b) Develop the ground water sampling and analysis program to include selection of the statistical procedures to be used for evaluating ground water monitoring data as required by subsection 3;

(c) Initiate the detection monitoring program to include obtaining a minimum of eight independent samples for each background and downgradient well as required by subsection 4; and

(d) Begin evaluating the ground water monitoring data for statistically significant increases over background levels for the constituents listed in appendix I of this chapter as required by subsection 4.

(2) New CCR landfills, new CCR surface impoundments, and all lateral expansions of CCR units. The owner or operator shall include a ground water monitoring plan with the application for a new permit or permit modification to show compliance with the ground water monitoring requirements specified in subparagraphs a and b of paragraph 1 prior to initial receipt of CCR by the CCR unit. In addition, the owner or operator of the CCR unit shall initiate the detection monitoring program to include obtaining a minimum of eight independent samples for each background well as required by subsection 4.

c. Once a ground water monitoring system and ground water monitoring program has been established at the CCR unit as required by this section, the owner or operator shall conduct ground water monitoring and, if necessary, corrective action throughout the active life and postclosure care period of the CCR unit.

d. In the event of a release from a CCR unit, the owner or operator immediately shall take all necessary measures to control the source of the release so as to reduce or eliminate, to the maximum extent feasible, further releases of contaminants into the environment. The owner or operator of the CCR unit shall comply with all applicable requirements in subsections 6 through 8, or, if eligible, must comply with the requirements in subsection 9.

e. Annual ground water monitoring and corrective action report. For existing CCR landfills and existing CCR surface impoundments, no later than January thirty-first of the year following July 1, 2020, and January thirty-first of each year thereafter, the owner or operator must prepare an annual ground water monitoring and corrective action report. For new CCR landfills, new CCR surface impoundments, and all lateral expansions of CCR units, the owner or operator must prepare the initial annual ground water monitoring and corrective action report no later than January thirty-first of the year following the calendar year a ground water monitoring system has been established, and January thirty-first of each year thereafter. For the preceding calendar year, the annual report must document the status of the ground water monitoring and corrective action program for the CCR unit, summarize key actions completed, describe any problems encountered, discuss actions to resolve the problems, and project key activities for the upcoming year. For purposes of this section, the owner or operator has prepared the annual report when the report is placed in the facility's operating record. The annual report must be submitted to the department for approval and placed on the facility's publicly accessible internet site by March first of each year. At a minimum, the annual ground water monitoring and corrective action report must contain the following information, to the extent available:

(1) A map, aerial image, or diagram showing the CCR unit and all background (or upgradient) and downgradient monitoring wells, to include the well identification numbers, that are part of the ground water monitoring program for the CCR unit;

(2) Identification of any monitoring wells that were installed or decommissioned during the preceding year, along with a narrative description of why those actions were taken;

(3) In addition to all the monitoring data obtained under this section, a summary including the number of ground water samples that were collected for analysis for each background and downgradient well, the dates the samples were collected, and whether the sample was required by the detection monitoring or assessment monitoring programs;

(4) A narrative discussion of any transition between monitoring programs (e.g., the date and circumstances for transitioning from detection monitoring to assessment monitoring in addition to identifying the constituents detected at a statistically significant increase over background levels); and

(5) Other information required to be included in the annual report as specified in this section.

f. Suspension of ground water monitoring requirements.

(1) The department may suspend the ground water monitoring requirements of this section for a CCR unit for up to ten years if the owner or operator provides written documentation that there is no potential for migration of the constituents listed in appendices I and II to this chapter from that CCR unit to the uppermost aquifer during the active life of the CCR unit and the postclosure care period. This demonstration must be certified by a qualified professional engineer and approved by the department, and must be based upon:

(a) Site-specific field collected measurements, sampling, and analysis of physical, chemical, and biological processes affecting contaminant fate and transport, including at a minimum, the information necessary to evaluate or interpret the effects of the following properties or processes on contaminant fate and transport:

[1] Aquifer characteristics, including hydraulic conductivity, hydraulic gradient, effective porosity, aquifer thickness, degree of saturation, stratigraphy, degree of fracturing and secondary porosity of soils and bedrock, aquifer heterogeneity, ground water discharge, and ground water recharge areas;

[2] Waste characteristics, including quantity, type, and origin;

[3] Climatic conditions, including annual precipitation, leachate generation estimates, and effects on leachate quality;

[4] Leachate characteristics, including leachate composition, solubility, density, the presence of immiscible constituents, Eh, and pH; and

[5] Engineered controls, including liners, cover systems, and aquifer controls (e.g., lowering the water table). These must be evaluated under design and failure conditions to estimate their long-term residual performance.

(b) Contaminant fate and transport predictions that maximize contaminant migration and consider impacts on human health and the environment.

(2) The owner or operator of the CCR unit may secure an additional ten years for the suspension of the ground water monitoring requirements provided the owner or operator provides written documentation that there continues to be no potential for migration. The documentation must be supported by, at a minimum, by the same information required for the initial monitoring suspension and must be certified by a qualified professional engineer and approved by the department. The owner or operator shall submit the documentation of their re-demonstration for the department's review and approval of their extension one year before their ground water monitoring suspension is due to expire. If the existing ground water monitoring extension expires, the owner or operator shall begin ground water detection monitoring according to this section within ninety days. The owner or operator may obtain additional ten-year ground water monitoring suspensions provided the owner or operator continues to make the written demonstration. The owner or operator shall place each completed demonstration, if more than one ten-year suspension period is sought, in the facility's operating record.

2. Ground water monitoring systems.

a. Performance standard. The owner or operator of a CCR unit shall install a ground water monitoring system that consists of a sufficient number of wells, installed at appropriate locations and depths, to yield ground water samples from the uppermost aquifer that:

(1) Accurately represent the quality of background ground water that has not been affected by leakage from a CCR unit. A determination of background quality may include sampling of wells that are not hydraulically upgradient of the CCR management area where:

(a) Hydrogeologic conditions do not allow the owner or operator of the CCR unit to determine what wells are hydraulically upgradient; or

(b) Sampling at other wells will provide an indication of background ground water quality that is as representative or more representative than that provided by the upgradient wells; and

(2) Accurately represent the quality of ground water passing the waste boundary of the CCR unit. The downgradient monitoring system must be installed at the waste boundary that ensures detection of ground water contamination in the uppermost aquifer. All potential contaminant pathways must be monitored.

b. The number, spacing, and depths of monitoring systems shall be determined based upon site-specific technical information that must include thorough characterization of:

(1) Aquifer thickness, ground water flow rate, ground water flow direction including seasonal and temporal fluctuations in ground water flow; and

(2) Saturated and unsaturated geologic units and fill materials overlying the uppermost aquifer, materials comprising the uppermost aquifer, and materials comprising the confining unit defining the lower boundary of the uppermost aquifer, including thicknesses, stratigraphy, lithology, hydraulic conductivities, porosities, and effective porosities.

c. The ground water monitoring system must include the minimum number of monitoring wells necessary to meet the performance standards specified in paragraph a, based on the site-specific information specified in paragraph b. The ground water monitoring system must contain:

(1) A minimum of one upgradient and three downgradient monitoring wells; and

(2) Additional monitoring wells as necessary to accurately represent the quality of background ground water that has not been affected by leakage from the CCR unit and the quality of ground water passing the waste boundary of the CCR unit.

d. The owner or operator of multiple CCR units may install a multiunit ground water monitoring system instead of separate ground water monitoring systems for each CCR unit.

(1) The multiunit ground water monitoring system must be equally as capable of detecting monitored constituents at the waste boundary of the CCR unit as the individual ground water monitoring system for each CCR unit based on the following factors:

(a) Number, spacing, and orientation of each CCR unit;

(b) Hydrogeologic setting;

(c) Site history; and

(d) Engineering design of the CCR unit.

e. Monitoring wells must be cased in a manner that maintains the integrity of the monitoring well borehole. 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 borehole and well casing) above the sampling depth must be sealed to prevent contamination of samples and the ground water.

(1) The owner or operator of the CCR unit shall document and include in the ground water monitoring plan and the operating record the design, installation, development, and decommissioning of any monitoring wells; piezometers; and other measurement, sampling, and analytical devices.

(2) The monitoring wells; piezometers; and other measurement, sampling, and analytical devices must be operated and maintained so that they perform to the design specifications throughout the life of the monitoring program.

f. The owner or operator shall provide documentation in the ground water monitoring plan that the ground water monitoring system has been designed and constructed to meet the requirements of this section. If the ground water monitoring system includes the minimum number of monitoring wells specified in this subsection, the ground water monitoring plan must document the basis for supporting this determination. Any proposed changes to the ground water monitoring plan must be submitted to, and approved by, the department.

3. Ground water sampling and analysis requirements.

a. The ground water monitoring program must include consistent sampling and analysis procedures that are designed to ensure monitoring results that provide an accurate representation of ground water quality at the background and downgradient wells. The owner or operator of the CCR unit must develop a sampling and analysis program that includes procedures and techniques for:

(1) Sample collection;

(2) Sample preservation and shipment;

(3) Analytical procedures;

(4) Chain of custody control; and

(5) Quality assurance and quality control.

b. The ground water monitoring program must include sampling and analytical methods that are appropriate for ground water sampling and that accurately measure hazardous constituents and other monitoring parameters in ground water samples. For purposes of this section, the term constituent refers to both hazardous constituents and other monitoring parameters listed in either appendix I or II of this chapter.

c. Ground water elevations must be measured in each well immediately prior to purging, each time ground water is sampled. The owner or operator of the CCR unit shall determine the rate and direction of ground water flow each time ground water is sampled. ground water elevations in wells which monitor the same CCR management area must be measured within a period of time short enough to avoid temporal variations in ground water flow which could preclude accurate determination of ground water flow rate and direction.

d. The owner or operator of the CCR unit shall establish background ground water quality in hydraulically upgradient or background wells for each of the constituents required in the particular ground water monitoring program that applies to the CCR unit as determined under subsections 4 or 5. Background ground water quality may be established at wells that are not located hydraulically upgradient from the CCR unit if it meets the requirements of paragraph 1 of subdivision a of subsection 2.

e. The number of samples collected when conducting detection monitoring and assessment monitoring, for both downgradient and background wells, must be consistent with the statistical procedures chosen under subdivision f and the performance standards under subdivision g of this subsection. The sampling procedures must be those specified under subsection 4 for detection monitoring, subsection 5 for assessment monitoring, and subsection 6 for corrective action monitoring.

f. The owner or operator of the CCR unit shall select one of the statistical methods specified in paragraphs 1 through 5 to be used in evaluating ground water monitoring data for each specified constituent. The statistical test chosen must be conducted separately for each constituent in each monitoring well.

(1) A parametric analysis of variance followed by multiple comparison 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 based on ranks followed by multiple comparison 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 background 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 that meets the performance standards of subdivision g.

(6) The owner or operator of the CCR unit shall include documentation in the ground water monitoring plan showing that the selected statistical method is appropriate for evaluating the ground water monitoring data for the CCR management area. The documentation must include a narrative description of the statistical method selected to evaluate the ground water monitoring data.

g. Any statistical method chosen must comply with the following performance standards, as appropriate, based on the statistical test method used:

(1) The statistical method used to evaluate ground water monitoring data must be appropriate for the distribution of constituents. Normal distributions of data values m use parametric methods. Nonnormal distributions must use nonparametric methods. If the distribution of the constituents is shown by the owner or operator of the CCR unit to be inappropriate for a normal theory test, then the data must be transformed or a distribution-free (nonparametric) theory test must 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 must be done at a type I error level no less than 0.01 for each testing period. If a multiple comparison procedure is used, the type I experiment wise error rate for each testing period must 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 must be such that this approach is at least as effective as any other approach in this section for evaluating ground water data. The parameter values must be determined after considering the number of samples in the background database, the data distribution, and the range of the concentration values for each constituent of concern.

(4) If a tolerance interval or a predictional interval is used to evaluate ground water monitoring data, the levels of confidence and, for tolerance intervals, the percentage of the population that the interval must contain, must be such that this approach is at least as effective as any other approach in this section for evaluating ground water data. These parameters must be determined after considering the number of samples in the background database, the data distribution, and the range of the concentration values for each constituent of concern.

(5) The statistical method must account for data below the limit of detection with one or more statistical procedures that shall be at least as effective as any other approach in this section for evaluating ground water data. Any practical quantization limit that is used in the statistical method must 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 must include procedures to control or correct for seasonal and spatial variability as well as temporal correlation in the data.

h. The owner or operator of the CCR unit shall determine if there is a statistically significant increase over background values for each constituent required in the particular ground water monitoring program that applies to the CCR unit.

(1) In determining whether a statistically significant increase has occurred, the owner or operator shall compare the ground water quality of each constituent at each downgradient monitoring well to the background value of that constituent, according to the statistical procedures and performance standards specified under subdivisions f and g.

(2) Within ninety days after completing sampling and analysis, the owner or operator shall determine whether there has been a statistically significant increase over background for any constituent at each monitoring well.

i. The owner or operator must measure "total recoverable metals" concentrations in measuring ground water quality. Measurement of total recoverable metals captures both the particulate fraction and dissolved fraction of metals in natural waters. ground water samples may not be field-filtered prior to analysis.

4. Detection monitoring program.

a. The owner or operator of a CCR unit shall conduct detection monitoring at all ground water monitoring wells consistent with this subsection. At a minimum, a detection monitoring program must include ground water monitoring for all constituents listed in appendix I to this chapter.

b. Except as provided in subdivision d, the monitoring frequency for the constituents listed in appendix I to this chapter must be at least semiannual during the active life of the CCR unit and the postclosure period. For existing CCR landfills and existing CCR surface impoundments, a minimum of eight independent samples from each background and downgradient well must be collected and analyzed for the constituents listed in appendices I and II to this chapter no later than six months after July 1, 2020. For new CCR landfills, new CCR surface impoundments, and all lateral expansions of CCR units, a minimum of eight independent samples for each background well must be collected and analyzed for the constituents listed in appendices I and II to this chapter during the first six months of sampling, if not already completed.

c. The number of samples collected and analyzed for each background well and downgradient well during subsequent semiannual sampling events must be consistent with subdivision e of subsection 3 and must account for any unique characteristics of the site, but must be at least one sample from each background and downgradient well.

d. 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 I to this chapter during the active life and the postclosure care period based on the availability of ground water. If there is not adequate ground water 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 and approved by the department. The demonstration must be supported by:

(1) Information documenting that the need for less frequent sampling. The alternative frequency must be based on consideration of the following factors:

(a) Lithology of the aquifer and unsaturated zone;

(b) Hydraulic conductivity of the aquifer and unsaturated zone; and

(c) Ground water 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 time frame that will not materially delay establishment of an assessment monitoring program.

(3) The owner or operator must obtain approval by the department for an alternative ground water sampling and analysis frequency. The owner or operator shall include the demonstration providing the basis for the alternative monitoring frequency in the annual ground water monitoring and corrective action report required by this section.

e. If the owner or operator of the CCR unit determines that there is a statistically significant increase over background levels for one or more of the constituents listed in appendix I to this chapter at any monitoring well at the waste boundary the owner or operator shall:

(1) Except as provided for in paragraph 2, within ninety days of detecting a statistically significant increase over background levels for any constituent, notify the department and establish an assessment monitoring program meeting the requirements of subsection 5.

(2) The owner or operator may demonstrate that a source other than the CCR unit caused the statistically significant increase over background levels for a constituent or that the statistically significant increase resulted from error in sampling, analysis, statistical evaluation, or natural variation in ground water quality. The owner or operator shall complete the written demonstration within ninety days of detecting a statistically significant increase over background levels. If a successful demonstration is completed within the ninety-day period, the owner or operator of the CCR unit shall continue with a detection monitoring program under this section, with approval by the department. If a successful demonstration is not completed within the ninety-day period, the owner or operator of the CCR unit shall initiate an assessment monitoring program as required under subsection 5. The owner or operator also shall include the demonstration in the annual ground water monitoring and corrective action report.

(3) The owner or operator of a CCR unit shall prepare a notification stating that an assessment monitoring program has been established. The owner or operator has completed the notification when the notification is submitted to the department and placed in the facility's operating record.

5. Assessment monitoring program.

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 I to this chapter.

b. Within ninety days of triggering an assessment monitoring program, and annually thereafter, the owner or operator of the CCR unit shall sample and analyze the ground water for all constituents listed in appendix II to this chapter. The number of samples collected and analyzed for each well during each sampling event must be consistent with subdivision e of subsection 3, and must account for any unique characteristics of the site, but must 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 II to this chapter during the active life and the postclosure care period based on the availability of ground water. If there is not adequate ground water flow to sample wells semiannually, the alternative frequency shall be no less than annual. The need to vary monitoring frequency must be evaluated on a site-specific basis. The demonstration must be supported by:

(1) Information documenting the need for less frequent sampling. The alternative frequency must be based on consideration of the following factors:

(a) Lithology of the aquifer and unsaturated zone;

(b) Hydraulic conductivity of the aquifer and unsaturated zone; and

(c) Ground water 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 time frame that will not materially delay the initiation of any necessary remediation measures.

(3) The owner or operator shall obtain approval by the department for an alternative ground water sampling and analysis frequency. The owner or operator shall include the demonstration providing the basis for the alternative monitoring frequency in the annual ground water monitoring and corrective action report required by this section.

d. After obtaining the results from the initial and subsequent sampling events required in subdivision b, the owner or operator must:

(1) Within ninety days of obtaining the results, and on at least a semiannual basis thereafter, resample all wells in the monitoring system, conduct analyses for all parameters in appendices I and II to this chapter that are detected in response to subdivision 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 must be consistent with subdivision e of subsection 3, and must account for any unique characteristics of the site, but must be at least one sample from each background and downgradient well;

(2) Establish ground water protection standards for all constituents detected pursuant to subdivision b or d. The ground water protection standards must be established in accordance with subdivision h of this subsection; and

(3) Include the recorded concentrations required by the assessment monitoring program, identify the background concentrations established under the detection monitoring program, and identify the ground water protection standards in the annual ground water monitoring and corrective action report.

e. If the concentrations of all constituents listed in appendices I and II to this chapter are shown to be at or below background values, using the statistical procedures in subdivision g of subsection 3, for two consecutive sampling events, the owner or operator may return to detection monitoring of the CCR unit with approval by the department. The owner or operator shall prepare a notification stating that detection monitoring is resuming for the CCR unit. The owner or operator has completed the notification when the notification is submitted to the department and placed in the facility's operating record.

f. If the concentrations of any constituent in appendices I and II to this chapter are above background values, but all concentrations are below the established ground water protection standard, using the statistical procedures in subdivision g or subsection 3, the owner or operator must continue assessment monitoring in accordance with this section.

g. If one or more constituents in appendix II to this chapter are detected at statistically significant levels above the established ground water protection standard in any sampling event, the owner or operator shall prepare a notification identifying the constituents in appendix II to this chapter that have exceeded the ground water protection standard. The owner or operator has completed the notification when the notification is submitted to the department and placed in the facility's operating record. 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 must 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 6. Characterization of the release includes the following minimum measures:

(a) Install additional monitoring wells necessary to define the contaminant plume or plumes;

(b) Collect data on the nature and estimated quantity of material released including specific information on the constituents listed in appendix II to this chapter and the levels at which they are present in the material released;

(c) Install at least one additional monitoring well at the facility boundary in the direction of contaminant migration and sample this well in accordance with paragraph 1 of subdivision d; and

(d) Sample all wells in accordance with paragraph 1 of subdivision d 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 offsite. The owner or operator has completed the notifications when they are placed in the facility's operating record.

(3) Within ninety days of finding that any of the constituents listed in appendix II to this chapter have been detected at a statistically significant level exceeding the ground water protection standards the owner or operator must either:

(a) Initiate an assessment of corrective measures as required by subsection 6; or

(b) 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 ground water quality. Any such demonstration must be supported by a report that includes the factual or evidentiary basis for any conclusions and must be approved by the department. If a successful demonstration is made, the owner or operator shall continue monitoring in accordance with the assessment monitoring program pursuant to this subsection and may return to detection monitoring if the constituents in appendices I and II to this chapter are at or below the established background. The owner or operator also shall include the demonstration in the annual ground water monitoring and corrective action report.

(4) If a successful demonstration has not been made at the end of the ninety-day period provided by subparagraph b of paragraph 3, the owner or operator of the CCR unit shall initiate the assessment of corrective measures requirements under subsection 6.

(5) If an assessment of corrective measures is required and if the CCR unit is an existing unlined CCR surface impoundment, then the CCR unit is subject to the closure requirements under subdivision a of subsection 2 of section 33.1- 20-08-07 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 ground water protection standard for each constituent in appendix II to this chapter detected in the ground water must be:

(1) The maximum contaminant level for constituents for which an maximum contaminant level has been established under chapter 33.1-17-01; or

(2) For the following constituents:

(a) Cobalt - 6 micrograms per liter (ug/ l);

(b) Lead - 15 ug/l;

(c) Lithium - 40 ug/l; and

(d) Molybdenum - 100 ug/l.; or

(3) The background concentration for constituents for which the background level is higher than the maximum contaminant level or the levels identified in paragraph 2 of this subdivision.

6. Assessment of corrective measures.

a. Within ninety days of finding that any constituent listed in appendix II to this chapter has been detected at a statistically significant level exceeding the ground water protection standard, or immediately upon detection of a release from a CCR unit, the owner or operator shall initiate an assessment of corrective measures to prevent further releases, to remediate any releases and to restore affected areas to original conditions. The assessment of corrective measures must be completed within ninety days, unless the owner or operator demonstrates the need for additional time to complete the assessment of corrective measures due to site-specific conditions or circumstance and obtains approval by the department. The ninety-day deadline to complete the assessment of corrective measures may be extended for no longer than sixty days. The owner or operator also shall include the demonstration and approval in the annual ground water monitoring and corrective action report.

b. The owner or operator of the CCR unit shall continue to monitor ground water in accordance with the assessment monitoring program.

c. The assessment of corrective measures must include an analysis of the effectiveness of potential corrective measures in meeting all of the requirements and objectives of the remedy as described under subsection 7, addressing at least the following:

(1) The performance, reliability, ease of implementation, and potential impacts of appropriate potential remedies, including safety impacts, cross-media impacts, and control of exposure to any residual contamination;

(2) The time required to begin and complete the remedy;

(3) The institutional requirements, such as state or local permit requirements or other environmental or public health requirements that may substantially affect implementation of the remedy.

d. The assessment has been completed when it is approved by the department and placed in the facility's operating record.

e. The owner or operator shall discuss the results of the corrective measures assessment at least thirty days prior to the selection of remedy, in a public meeting with interested and affected parties.

7. Selection of remedy.

a. Based on the results of the corrective measures assessment, the owner or operator shall, as soon as feasible, select a remedy. This requirement applies to, not in place of, any applicable standards under the Occupational Safety and Health Act of 1970 [ Public Law 91-596; 84 Stat. 1590]. The owner or operator shall prepare a semiannual report describing the progress in selecting and designing the remedy. Upon selection of a remedy, the owner or operator shall prepare a final report describing the selected remedy and how it meets the standards specified in this subsection. The report has been completed when it is approved by the department and placed in the operating record.

b. Remedies must:

(1) Be protective of human health and the environment;

(2) Attain the ground water protection standard as specified pursuant to subdivision h of subsection 5, or attain a risk-based ground water concentration that is protective of human health and the environment;

(3) Control the sources of releases so as to reduce or eliminate, to the maximum extent feasible, further releases of constituents in appendix II to this chapter into the environment;

(4) Remove from the environment as much of the contaminated material that was released from the CCR unit as is feasible, taking into account factors such as avoiding inappropriate disturbance of sensitive ecosystems;

(5) Comply with standards for management of wastes as specified in subdivision d of subsection 8.

c. In selecting a remedy that meets the standards of this subsection, the owner or operator of the CCR unit shall consider the following evaluation factors:

(1) The long- and short-term effectiveness and protectiveness of the potential remedies, along with the degree of certainty that the remedy will prove successful based on consideration of the following:

(a) Magnitude of reduction of existing risks;

(b) Magnitude of residual risks in terms of likelihood of further releases due to CCR remaining following implementation of a remedy;

(c) The type and degree of long-term management required, including monitoring, operation, and maintenance;

(d) Short-term risks that might be posed to the community or the environment during implementation of such a remedy, including potential threats to human health and the environment associated with excavation, transportation, and redisposal of contaminant;

(e) Time until full protection is achieved;

(f) Potential for exposure of humans and environmental receptors to remaining wastes, considering the potential threat to human health and the environment associated with excavation, transportation, redisposal, or containment;

(g) Long-term reliability of the engineering and institutional controls; and

(h) Potential need for replacement of the remedy.

(2) The effectiveness of the remedy in controlling the source to reduce further releases based on consideration of the following factors:

(a) The extent to which containment practices will reduce further releases; and

(b) The extent to which treatment technologies may be used.

(3) The ease or difficulty of implementing a potential remedy based on consideration of the following types of factors:

(a) Degree of difficulty associated with constructing the technology;

(b) Expected operational reliability of the technologies;

(c) Need to coordinate with and obtain necessary approvals and permits from other agencies;

(d) Availability of necessary equipment and specialists; and

(e) Available capacity and location of needed treatment, storage, and disposal services.

(4) The degree to which community concerns are addressed by a potential remedy.

d. The owner or operator shall specify as part of the selected remedy a schedule for implementing and completing remedial activities. Such a schedule must require the completion of remedial activities within a reasonable period of time, taking into consideration:

(1) Extent and nature of contamination;

(2) Reasonable probabilities of remedial technologies in achieving compliance with ground water protection standards and other objectives of the remedy;

(3) Availability of treatment or disposal capacity for CCR managed during implementation of the remedy;

(4) Potential risks to human health and the environment from exposure to contamination prior to completion of the remedy;

(5) Resource value of the aquifer, including:

(a) Current and future uses;

(b) Proximity and withdrawal rate of users;

(c) Ground water quantity and quality;

(d) The potential damage to wildlife, crops, vegetation, and physical structures caused by exposure to CCR constituents;

(e) The hydrogeologic characteristic of the facility and surrounding land; and

(f) The availability of alternative water supplies; and

(6) Other relevant factors.

e. The department may determine that remediation of a release of a constituent listed in appendix II to this chapter from a CCR unit is not necessary if the owner or operator demonstrates to the satisfaction of the department that:

(1) The ground water is additionally contaminated by substances that have originated from a source other than a CCR unit and those substances are present in concentrations such that cleanup of the release from the CCR unit would provide no significant reduction in risk to actual or potential receptors; or

(2) The constituent is present in ground water that:

(a) Is not currently or reasonably expected to be a source of drinking water; and

(b) Is not hydraulically connected with waters to which the constituent is migrating or are likely to migrate in a concentration that would exceed the ground water protection standards; or

(3) Remediation of the release is technically impracticable; or

(4) Remediation results in unacceptable cross-media impacts.

f. A determination by the department that remediation of a release is not necessary may not affect the requirement under subdivision b for the owner or operator to undertake source control measures or other measures, including closure if triggered, that may be necessary to eliminate or minimize further releases to the ground water, to prevent exposure to the ground water, or to remediate the ground water to concentrations that are technically feasible and significantly reduce threats to human health or the environment.

8. Implementation of the corrective action program.

a. Within ninety days of selecting a remedy under subsection 7, the owner or operator shall initiate remedial activities. Based on the schedule established under subdivision d of subsection 7, for implementation and completion of remedial activities the owner or operator shall:

(1) Establish and implement a corrective action ground water monitoring program that:

(a) Meets the requirements of an assessment monitoring program under subsection 5;

(b) Documents the effectiveness of the corrective action remedy; and

(c) Demonstrates compliance with the ground water protection standards.

(2) Implement the selected corrective action remedy; and

(3) Take any interim measures necessary to reduce the contaminants leaching from the CCR unit and potential exposures to human or ecological receptors. Interim measures must, to the greatest extent feasible, be consistent with the objectives of, and contribute to the performance of, any remedy that may be required pursuant to subsection 7. The following factors must be considered by an owner or operator in determining whether interim measures are necessary:

(a) Time required to develop and implement a final remedy;

(b) Actual or potential exposure of nearby populations or environmental receptors to any of the constituents listed in appendix II to this chapter;

(c) Actual or potential contamination of drinking water supplies or sensitive ecosystems;

(d) Further degradation of the ground water that may occur if remedial action is not initiated expeditiously;

(e) Weather conditions that may cause any of the constituents listed in appendix II to this chapter to migrate or be released;

(f) Potential for exposure to any of the constituents listed in appendix II to this chapter as a result of an accident or failure of a container or handling system; and

(g) Other situations that may pose threats to human health and the environment.

b. If an owner or operator of the CCR unit, determines, at any time, that compliance with the requirements of subdivision b of subsection 7 is not being achieved through the remedy selected, the owner or operator shall implement other methods or techniques that could feasibly achieve compliance with the requirements.

c. Remedies selected pursuant to subsection 7 must be considered complete when:

(1) The owner or operator of the CCR unit demonstrates that compliance with the ground water protection standards has been achieved at all points within the plume of contamination that lie beyond the ground water monitoring well system established under subsection 2;

(2) Except as provided by paragraph 4, compliance with the ground water protection standards has been achieved by demonstrating that concentrations of constituents listed in appendix II to this chapter have not exceeded the ground water protection standards for a period of three consecutive years using the statistical procedures and performance standards in subdivisions f and g of subsection 3; and

(3) All actions required to complete the remedy have been satisfied.

(4) The department may specify an alternative length of time to that specified in paragraph 2 during which the owner or operator must demonstrate that concentrations of constituents listed in appendix II to this chapter have not exceeded the ground water protection standards taking into consideration:

(a) Extent and concentration of the release;

(b) Behavior characteristics of the constituents in the ground water;

(c) Accuracy of monitoring or modeling techniques, including any seasonal, meteorological, or other environmental variabilities that may affect the accuracy; and

(d) Characteristics of the ground water.

d. All CCR that are managed pursuant to a remedy required under subsection 7, or an interim measure required under paragraph 3 of subdivision a, shall be managed in a manner that complies with all applicable requirements under this article and North Dakota Century Code chapter 23.1-08.

e. Upon completion of the remedy, the owner or operator shall prepare a notification stating that the remedy has been completed. The owner or operator shall obtain a certification from a qualified professional engineer or a qualified environmental professional that the remedy has been completed. The report has been completed when it is approved by the department and placed in the operating record.

9. Corrective action procedures to remedy eligible nonground water releases.

a. General. This subsection specifies the corrective action requirements that apply to nonground water releases from CCR units that can be completely remediated within one hundred eighty days from the detection of the release. A release is completely remediated when a qualified professional engineer or a qualified environmental professional completes the certification required in paragraph 3 of subdivision c and the corrective action report is approved by the department. If the owner or operator determines, at any time, that the release will not be completely remediated within this one hundred eighty-day time frame, the owner or operator shall comply with all additional requirements specified in subsections 6, 7, and 8.

b. Corrective action requirements. Upon detection of a nonground water release from a CCR unit, the owner or operator shall comply with all of the following requirements:

(1) Immediately take all necessary measures to control all sources of releases so as to reduce or eliminate, to the maximum extent feasible, further releases of contaminants into the environment;

(2) Determine the corrective measures that will meet the substantive standards in subdivision a of subsection 6 to prevent further releases, to remediate any releases, and to restore the affected area to original conditions;

(3) Analyze the effectiveness of potential corrective measures in meeting all of the requirements and objectives of the remedy as described in subdivision c of subsection 6;

(4) Select the corrective action that will remedy the nonground water release, taking into account the results of the assessment in this subdivision and the factors specified in subdivision c of subsection 7;

(5) Remediate the nonground water release to meet the standards specified in subdivision b of subsection 7; and

(6) Complete the remedy within one hundred eighty days of the date of discovery of the release.

c. Required notices and reports. An owner or operator of a CCR unit that complies with the requirements of this subsection to remediate a nonground water release shall ensure that the notices and reports specified in this subdivision are completed. All required notices and reports must be signed by the owner or operator.

(1) Within fifteen days of discovering a nonground water release, the owner or operator shall prepare a notification of discovery of a nonground water release. The owner or operator has completed the notification when it has been placed in the facility's operating record and submitted to the department.

(2) Within fifteen days of completing the analysis of the effectiveness of potential corrective measures, place the completed analysis in the facility's operating record and submit to the department.

(3) Within thirty days of completion of a corrective action of a nonground water release, the owner or operator shall prepare a report documenting the completion of the corrective action. The report must describe the nature and extent of the nonground water release, the CCR units responsible for the nonground water release, and how the remedy selected achieves the corrective action requirements specified in this subsection. The notification must include a certification by a qualified professional engineer or a qualified environmental professional that the corrective action has been completed. The owner or operator has completed the report when it has been approved by the department and placed in the facility's operating record.