N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 373-3.6

Current through Register Vol. 46, No. 45, November 2, 2024

Section 373-3.6 - Ground-water monitoring

(a)Applicability.

(1) The owner or operator of a surface impoundment, landfill or land treatment facility which is used to manage hazardous waste must implement a ground-water monitoring program capable of determining the facility's impact on the quality of ground water in the uppermost aquifer underlying the facility, except as section 373-3.1(a) of this Subpart and paragraph (3) of this subdivision provide otherwise.

(2) Except as paragraphs (3) and (4) of this subdivision provide otherwise, the owner or operator must install, operate and maintain a ground-water monitoring system which meets the requirements of subdivision (b) of this section and must comply with subdivisions (c)-(e). This ground-water monitoring program must be carried out during the active life of the facility, and for disposal facilities, excluding thermal treatment, incineration and energy recovery facilities, during the post-closure care period as well.

(3) All or part of the ground-water monitoring requirements of this section may be waived if the owner or operator can demonstrate that there is a low potential for migration of hazardous waste or hazardous waste constituents from the facility via the uppermost aquifer to water supply wells (domestic, industrial or agricultural) or to surface water. This demonstration must be in writing, and must be kept at the facility. This demonstration must be certified by a qualified geologist or geotechnical engineer and must establish the following:

(i) the potential for migration of hazardous waste or hazardous waste constituents from the facility to the uppermost aquifer, by an evaluation of:

(a) a water balance of precipitation, evapotranspiration, runoff and infiltration; and

(b) unsaturated zone characteristics (i.e., geologic materials, physical properties, and depth to ground water); and

(ii) the potential for hazardous waste or hazardous waste constituents which enter the uppermost aquifer to migrate to a water supply well or surface water, by an evaluation of:

(a) saturated zone characteristics (i.e., geologic materials, physical properties, and rate of ground-water flow); and

(b) the proximity of the facility to water supply wells or surface water.

(4) If an owner or operator assumes (or knows) that ground-water monitoring of indicator parameters in accordance with subdivisions (b) and (c) of this section would show statistically significant increases (or decreases, in the case of pH) when evaluated under subdivision (d) of this section, an alternate ground-water monitoring system (other than the one described in subdivisions [b] and [c]) may be installed, operated and maintained. If the owner or operator decides to use an alternate ground-water monitoring system, the owner or operator must:

(i) prepare and submit to the department a specific plan, certified by a qualified geologist or geotechnical engineer, which satisfies the requirements of subparagraph (d)(4)(iii) of this section for an alternate groundwater monitoring system. This plan is to be placed in the facility's operating record and maintained until closure of the facility;

(ii) initiate the determinations specified in subparagraph (d)(4)(iv) of this section;

(iii) prepare a report in accordance with subparagraph (d)(4)(v) of this section and place it in the facility's operating record and maintain until closure of the facility; and

(iv) continue to make the determinations specified in subparagraph (d)(4)(iv) of this section on a quarterly basis until final closure of the facility; and

(v) comply with the recordkeeping and reporting requirements in paragraph (e)(2) of this section.

(5) The ground-water monitoring requirements of this section may be waived with respect to any surface impoundment that:

(i) is used to neutralize wastes which are hazardous solely because they exhibit the corrosivity characteristic under section 371.3(c) of this Title or are listed as hazardous wastes in section 371.4 of this Title only for this reason; and

(ii) contains no other hazardous wastes, if the owner or operator can demonstrate that there is no potential for migration of hazardous wastes from the impoundment. The demonstration must establish, based upon consideration of the characteristics of the wastes and the impoundment, that the corrosive wastes will be neutralized to the extent that they no longer meet the corrosivity characteristic before they can migrate out of the impoundment. The demonstration must be in writing and must be certified by a qualified professional.

(6) The department may replace all or part of the requirements of this Subpart applying to a regulated unit (as defined in section 373-2.6[a] of this Part), with alternative requirements developed for groundwater monitoring set out in an approved closure or post-closure plan or in an enforceable document (as defined in section 373-1.2[e][3] of this Part), where the department determines that:

(i) a regulated unit is situated among solid waste management units (or areas of concern), a release has occurred, and both the regulated unit and one or more solid waste management unit(s) (or areas of concern) are likely to have contributed to the release; and

(ii) it is not necessary to apply the requirements of this section because the alternative requirements will protect human health and the environment. The alternative standards for the regulated unit must meet the requirements of section 373-2.6(l)(1) of this Part.

(b)Ground-water monitoring system.

(1) A ground-water monitoring system must be capable of yielding ground-water samples for analysis and must consist of:

(i) monitoring wells (at least one) installed hydraulically upgradient (i.e., in the direction of increasing static head) from the limit of the waste management area. Their number, locations and depths must be sufficient to yield ground-water samples that are:

(a) representative of background ground-water quality in the uppermost aquifer near the facility; and

(b) not affected by the facility; and

(ii) monitoring wells (at least three) installed hydraulically downgradient (i.e., in the direction of decreasing static head) at the limit of the waste management area. Their number, locations and depths must ensure that they immediately detect any statistically significant amounts of hazardous waste or hazardous waste constituents that migrate from the waste management area to the uppermost aquifer.

(iii) The facility owner or operator may demonstrate that an alternate hydraulically downgradient monitoring well location will meet the criteria outlined below. The demonstration must be in writing and kept at the facility. The demonstration must be certified by a qualified ground-water scientist and establish that:

(a) an existing physical obstacle prevents monitoring well installation at the hydraulically downgradient limit of the waste management area; and

(b) the selected alternate downgradient location is as close to the limit of the waste management area as practical; and

(c) the location ensures detection that, given the alternate location, is as early as possible of any statistically significant amounts of hazardous waste or hazardous waste constituents that migrate from the waste management area to the uppermost aquifer; and

(d) lateral expansion, new or replacement units are not eligible for an alternate downgradient location under this paragraph.

(2) Separate monitoring systems for each waste management component of a facility are not required, provided that provisions for sampling upgradient and downgradient water quality will detect any discharge from the waste management area. The commissioner may require separate monitoring systems for separate waste management components.

(i) In the case of a facility consisting of only one surface impoundment, landfill or land treatment area, the waste management area is described by the waste boundary (perimeter).

(ii) In the case of a facility consisting of more than one surface impoundment, landfill or land treatment area, the waste management area is described by an imaginary boundary line which circumscribes the several waste management components.

(3) 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 sample collection at depths where appropriate aquifer flow zones exist. The annular space (i.e., the space between the bore hole and well casing) above the sampling depth must be sealed with a suitable material (e.g., cement grout or bentonite slurry) to prevent contamination of samples and the ground water.

(c)Sampling and analysis.

(1) The owner or operator must obtain and analyze samples from the installed ground-water monitoring system. The owner or operator must develop and follow a ground-water sampling and analysis plan. This plan must be kept at the facility. The plan must include procedures and techniques for:

(i) sample collection;

(ii) sample preservation and shipment;

(iii) analytical procedures; and

(iv) chain of custody control.

Note:

See "Procedures Manual For Groundwater Monitoring At Solid Waste Disposal Facilities," EPA-530/SW-611, August 1977, and "Methods for Chemical Analysis of Water and Wastes," EPA-600/4-79-020, March 1979, for discussions of sampling and analysis procedures (see 6 NYCRR 370.1[e]).

(2) The owner or operator must determine the concentration or value of the following parameters in ground-water samples in accordance with paragraphs (3) and (4) of this subdivision:

(i) parameters characterizing the suitability of the ground water as a drinking water supply, as specified in Appendix 27, infra; and

(ii) parameters establishing ground-water quality:

(a) chloride;

(b) iron;

(c) manganese;

(d) phenols;

(e) sodium; and

(f) sulfate; and

(iii) parameters used as indicators of ground-water contamination:

(a) pH;

(b) specific conductance;

(c) total organic carbon; and

(d) total organic halogen.

Note:

These parameters are to be used as a basis for comparison in the event a ground-water quality assessment is required under paragraph (d)(4) of this section.

(3)

(i) For all monitoring wells, the owner or operator must establish initial background concentrations or values of all parameters specified in paragraph (2) of this subdivision. This must be done quarterly for one year.

(ii) For each of the indicator parameters specified in subparagraph (2)(iii) of this subdivision, at least four replicate measurements must be obtained for each sample, and the initial background arithmetic mean and variance must be determined by pooling the replicate measurements for the respective parameter concentrations or values in samples obtained from upgradient wells during the first year.

(4) After the first year, all monitoring wells must be sampled and the samples analyzed with the following frequencies:

(i) Samples collected to establish ground-water quality must be obtained and analyzed for the parameters specified in subparagraph (2)(ii) of this subdivision at least annually.

(ii) Samples collected to indicate ground-water contamination must be obtained and analyzed for the parameters specified in subparagraph (2)(iii) of this subdivision at least semiannually.

(5) Elevation of the ground-water surface at each monitoring well must be determined each time a sample is obtained.

(d)Preparation, evaluation, and response.

(1) The owner or operator must prepare an outline of the ground-water quality assessment program. The outline must describe a more comprehensive ground-water monitoring program (than that described in subdivisions [b] and [c] of this section), capable of determining:

(i) whether hazardous waste or hazardous waste constituents have entered the ground water;

(ii) the rate and extent of migration of hazardous waste or hazardous waste constituents in the ground water; and

(iii) the concentrations of hazardous waste or hazardous waste constituents in the ground water.

(2) For each indicator parameter specified in subparagraph (c)(2)(iii) of this section, the owner or operator must calculate the arithmetic mean and variance, based on at least four replicate measurements on each sample, for each well monitored in accordance with subparagraph (c)(4)(ii), and compare these results with its initial background arithmetic mean. The comparison must consider individually each of the wells in the monitoring system, and must use the student's t-test at the 0.01 level of significance (see Appendix 28, infra) to determine statistically significant increases (and decreases, in the case of pH) over initial background.

(3)

(i) If the comparisons for the upgradient wells made under paragraph (2) of this subdivision show a significant increase (or pH decrease), the owner or operator must submit this information in accordance with clause (e)(1)(ii)(b) of this section.

(ii) If the comparisons for downgradient wells made under paragraph (2) of this subdivision show a significant increase (or pH decrease), the owner or operator must then immediately obtain additional ground-water samples from those downgradient wells where a significant difference was detected, split the samples in two, and obtain analyses of all additional samples to determine whether the significant difference was a result of laboratory error.

(4)

(i) If the analyses performed under subparagraph (3)(ii) of this subdivision confirm the significant increase (or pH decrease), the owner or operator must provide written notice to the commissioner, within seven days of the date of such confirmation, that the facility may be affecting ground-water quality.

(ii) Within 15 days after the notification under subparagraph (i) of this paragraph, the owner or operator must develop and submit to the department a specific plan, based on the outline required under paragraph (1) of this subdivision and certified by a qualified geologist or geotechnical engineer, for a ground-water quality assessment the facility. This plan must be placed in the facility operating record and be maintained until closure of the facility.

(iii) The plan to be submitted under subparagraph (a)(4)(i) of this section, or subparagraph (ii) of this paragraph, must specify:

(a) the number, location and depth of wells;

(b) sampling and analytical methods for those hazardous wastes or hazardous waste constituents in the facility;

(c) evaluation procedures, including any use of previously gathered ground-water quality information; and

(d) a schedule of implementation.

(iv) The owner or operator must implement the ground-water quality assessment plan which satisfies the requirements of subparagraph (iii) of this paragraph and, at a minimum, determine:

(a) the rate and extent of migration of the hazardous waste or hazardous waste constituents in the ground water; and

(b) the concentrations of the hazardous waste or hazardous waste constituents in the ground water.

(v) The owner or operator must make the first determination under subparagraph (iv) of this paragraph as soon as technically feasible, and, within 15 days after that determination, submit to the department a written report containing an assessment of the ground-water quality. This report must be placed in the facility operating record and be maintained until closure of the facility.

(vi) If the owner or operator determines, based on the results of the first determination under subparagraph (iv) of this paragraph, that no hazardous waste or hazardous waste constituents from the facility have entered the ground water, then the owner or operator may reinstate the indicator evaluation program described in subdivision (c) of this section and paragraph (2) of this subdivision; the owner or operator must so notify the commissioner in the report submitted under subparagraph (v) of this paragraph.

(vii) If the owner or operator determines, based on the first determination under subparagraph (iv) of this paragraph, that hazardous waste or hazardous waste constituents from the facility have entered the ground water, then the owner or operator:

(a) must continue to make the determinations required under subparagraph (iv) of this paragraph on a quarterly basis until final closure of the facility, if the ground-water quality assessment plan was implemented prior to final closure of the facility; or

(b) may cease to make the determinations required under subparagraph (iv) of this paragraph, if the ground-water quality assessment plan was implemented during the post- closure care period.

(5) Notwithstanding any other provision of this section, any ground-water quality assessment to satisfy the requirements of subparagraph (4)(iv) of this subdivision which is initiated prior to final closure of the facility must be completed and reported in accordance with subparagraph (4)(v).

(6) Unless the ground water is monitored to satisfy the requirements of subparagraph (4)(iv) of this subdivision, at least annually the owner or operator must evaluate the data on ground-water surface elevations obtained under paragraph (c)(5) of this section to determine whether the requirements under paragraph (b)(1) of this section for locating the monitoring wells continue to be satisfied. If the evaluation shows that paragraph (b)(1) is no longer satisfied, the owner or operator must immediately modify the number, location or depth of the monitoring wells to bring the ground-water monitoring system into compliance with this requirement.

(e)Recordkeeping and reporting.

(1) Unless the ground water is monitored to satisfy the requirements of subparagraph (d)(4)(iv) of this section, the owner or operator must:

(i) keep records of the analyses required in paragraphs (c)(3) and (4) of this section, the associated ground-water surface elevations required in paragraph (c)(5), and the evaluations required in paragraph (d)(2) throughout the active life of the facility, and, for disposal facilities, throughout the post-closure care period as well; and

(ii) report the following ground-water monitoring information to the commissioner;

(a) during the first year when initial background concentrations are being established for the facility: concentrations or values of the parameters listed in subparagraph (c)(2)(i) of this section for each ground-water monitoring well within 15 days after completing each quarterly analysis. The owner or operator must separately identify for each monitoring well any parameters whose concentration or value has been found to exceed the maximum contaminant levels listed in Appendix 27, infra;

(b) annually: concentrations or values of the parameters listed in subparagraph (c)(2)(iii) of this section for each ground-water monitoring well, along with the required evaluations for these parameters under paragraph (d)(2). The owner or operator must separately identify any significant differences from initial background found in the upgradient wells, in accordance with subparagraph (d)(3)(i). During the active life of the facility, this information must be submitted as part of the annual report required under section 373-3.5(e) of this Subpart; and

(c) as a part of the annual report required under section 373-3.5(e) of this Subpart: results of the evaluations of ground-water surface elevations under paragraph (c)(5) of this section, and a description of the response to that evaluation, where applicable.

(2) If the ground water is monitored to satisfy the requirements of subparagraph (d)(4)(iv) of this section, the owner or operator must:

(i) keep records of the analyses and evaluations specified in the plan, which satisfy the requirements of subparagraph (d)(4)(iii) of this section, throughout the active life of the facility, and, for disposal facilities, throughout the post-closure care period as well; and

(ii) annually, until final closure of the facility, submit to the commissioner a report containing the results of his or her ground water quality assessment program which includes, but is not limited to, the calculated (or measured) rate of migration of hazardous waste or hazardous waste constituents in the ground water during the reporting period. This information must be submitted no later than March 1st of the following calendar year.

N.Y. Comp. Codes R. & Regs. Tit. 6 §§ 373-3.6

Amended New York State Register March 4, 2020/Volume XLII, Issue 09, eff. 4/18/2020