Ala. Admin. Code r. 335-14-6-.06 - Groundwater Monitoring

(1) Applicability.

(a) The owner or operator of a surface impoundment, landfill, or land treatment facility which is used to manage hazardous waste must implement a groundwater monitoring program capable of determining the facility's impact on the quality of groundwater in the uppermost aquifer underlying the facility, except as 335-14-6-.01(1) and 335-14-6-.06(1)(c) provides otherwise.

(b) Except as 335-14-6-.06(1)(c) and (d) provide otherwise, the owner or operator must install, operate, and maintain a groundwater monitoring system which meets the requirements of 335-14-6-.06(2), and must comply with 335-14-6-.06(3), (4), and (5). This groundwater monitoring program must be carried out during the active life of the facility, and for disposal facilities, during the post-closure care period as well.

(c) All or part of the groundwater monitoring requirements of 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 licensed professional geologist and/or registered professional engineer and must establish the following:

1. The potential for migration of hazardous waste or hazardous waste constituents from the facility to the uppermost aquifer, by an evaluation of:

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

(ii) Unsaturated zone characteristics (i.e., geologic materials, physical properties, and depth to groundwater); and

2. 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:

(i) Saturated zone characteristics (i.e., geologic materials, physical properties and rate of groundwater flow); and

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

(d) If an owner or operator assumes (or knows) that groundwater monitoring of indicator parameters in accordance with 335-14-6-.06(2) and (3) would show statistically significant increases (or decreases in the case of pH) when evaluated under 335-14-6-.06(4)(b), he may, install, operate, and maintain an alternate groundwater monitoring system (other than the one described in 335-14-6-.06(2) and (3)). If the owner or operator decides to use an alternate groundwater monitoring system he must:

1. Within one year after the effective date of these regulations, develop a specific plan, certified by a qualified geologist or geotechnical engineer, which satisfies the requirements of 335-14-6-.06(4)(d)3., 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;

2. Initiate the determinations specified in 335-14-6-.06(4)(d)4.;

3. Prepare a report in accordance with 335-14-6-.06(4)(d)5. and place it in the facility's operating record and maintain until closure of the facility;

4. Continue to make the determinations specified in 335-14-6-.06(4)(d)4. on a quarterly basis until final closure of the facility; and

5. Comply with the recordkeeping and reporting requirements in 335-14-6-.06(5)(b).

(e) The groundwater monitoring requirements of 335-14-6-.06 may be waived with respect to any surface impoundment that:

1. Is used to neutralize wastes which are hazardous solely because they exhibit the corrosivity characteristic under 335-14-2-.03(3) or are listed as hazardous wastes in 335-14-2-.04 only for this reason; and

2. 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 an independent engineer.

(f) The Department may replace all or part of the requirements of applying to a regulated unit (as defined in 335-14-5-6-.06(1)), 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 335-14-8-.01(1)(c)7.), where the Department determines that:

1. 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

2. It is not necessary to apply the requirements of because the alternative requirements will protect human health and the environment. The alternative standards for the regulated unit must meet the requirements of 335-14-5-.06(12)(a).

(2) Groundwater monitoring system.

(a) A groundwater monitoring system must be capable of yielding groundwater samples for analysis and must consist of:

1. 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 groundwater samples that are:

(i) Representative of background groundwater quality in the uppermost aquifer near the facility; and

(ii) Not affected by the facility; and

2. 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.

3. 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 groundwater scientist and establish that:

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

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

(iii) 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.

(iv) Lateral expansion, new, or replacement units are not eligible for an alternate downgradient location under 335-14-6 -.06(2).

(b) 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.

1. 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).

2. 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.

(c) All monitoring wells must be cased in a manner that maintains the integrity of the monitoring well bore hole. This casing must be screened or perforated, and packed with gravel or sand where necessary, to enable 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 groundwater. Monitoring wells must be operated and maintained in a manner to prevent soil, surface water, and/or groundwater contamination. This requirement includes the installation of protective barriers around monitoring wells where necessary to prevent damage to the well from traffic or other causes or as required on a case-by-case basis by the Department. All monitoring wells must have functional key or combination locks on the wellhead covers to prevent unauthorized access. All monitoring wells must be assigned an identifying number by the facility, and such numbers must be permanently affixed to the outer casing of each monitoring well.

(3) Sampling and analysis.

(a) The owner or operator must obtain and analyze samples from the installed groundwater monitoring system. The owner or operator must develop and follow a groundwater sampling and analysis plan. He must keep this plan at the facility. The plan must include procedures and techniques for:

1. Sample collection;

2. Sample preservation and shipment;

3. Analytical procedures; and

4. Chain of custody control.

(b) The owner or operator must determine the concentration or value of the following parameters in groundwater samples in accordance with 335-14-6-.06(3)(c) and (d):

1. Parameters characterizing the suitability of the groundwater as a drinking water supply, as specified in 335-14-6 -Appendix III;

2. Parameters establishing groundwater quality:

(i) Chloride;

(ii) Iron;

(iii) Manganese;

(iv) Phenols;

(v) Sodium;

(vi) Sulfate;

3. Parameters used as indicators of groundwater contamination:

(i) pH;

(ii) Specific Conductance;

(iii) Total Organic Carbon; and

(iv) Total Organic Halogen.

(c)

1. For all monitoring wells, the owner or operator must establish initial background concentrations or values of all parameters specified in 335-14-6-.06(3)(b). He must do this quarterly for one year.

2. For each of the indicator parameters specified in 335-14-6-.06(3)(b)3., 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.

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

1. Samples collected to establish groundwater quality must be obtained and analyzed for the parameters specified in 335-14-6 -.06(3)(b)2. at least annually.

2. Samples collected to indicate groundwater contamination must be obtained and analyzed for the parameters specified in 335-14-6-.06(3)(b)3. at least semi-annually.

(e) Elevation of the groundwater surface at each monitoring well must be determined each time a sample is obtained.

(4) Preparation, evaluation, and response.

(a) The owner or operator must prepare an outline of a groundwater quality assessment program. The outline must describe a more comprehensive groundwater monitoring program (than that described in 335-14-6-.06(2) and (3)) capable of determining:

1. Whether hazardous waste or hazardous waste constituents have entered the groundwater;

2. The rate and extent of migration of hazardous waste or hazardous waste constituents in the groundwater; and

3. The concentrations of hazardous waste or hazardous waste constituents in the groundwater.

(b) For each indicator parameter specified in 335-14-6-.06(3)(b)3., 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 335-14-6-.06(3)(d)2., 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 335-14-6 -Appendix IV) to determine statistically significant increases (and decreases, in the case of pH) over initial background.

(c)

1. If the comparisons for the upgradient wells made under 335-14-6-.06(4)(b) show a significant increase (or pH decrease), the owner or operator must submit this information in accordance with 335-14-6-.06(5) (a)2.(ii).

2. If the comparisons for downgradient wells made under 335-14-6-.06(4)(b) show a significant increase (or pH decrease), the owner or operator must then immediately obtain additional groundwater 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.

(d)

1. If the analyses performed under 335-14-6 -.06(4)(c)2. confirm the significant increase (or pH decrease), the owner or operator must provide written notice to the Department--within seven days of the date of such confirmation--that the facility may be affecting groundwater quality.

2. Within 15 days after the notification under 335-14-6-.06(4)(d)1., the owner or operator must develop a specific plan, based on the outline required under 335-14-6-.06(4)(a) and certified by a qualified geologist or geotechnical engineer, for a groundwater quality assessment at the facility. This plan must be placed in the facility operating record and be maintained until closure of the facility.

3. The plan to be submitted under 335-14-6-.06(1)(d)1. or 335-14-6-.06(4)(d)2. must specify:

(i) The number, location, and depth of wells;

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

(iii) Evaluation procedures, including any use of previously gathered groundwater quality information; and

(iv) A schedule of implementation.

(v) Include provisions for modification of the plan in the event the plan, when implemented, does not achieve the objectives of 335-14-6-.06(4)(d)4.

4. The owner or operator must implement the groundwater quality assessment plan which satisfies the requirements of 335-14-6-.06(4)(d)3., and, at a minimum, determine:

(i) The rate and extent of migration of the hazardous waste or hazardous waste constituents in the groundwater; and

(ii) The concentrations of the hazardous waste or hazardous waste constituents in the groundwater.

5. The owner or operator must make his first determination under 335-14-6-.06(4)(d)4. as soon as technically feasible, and prepare a report containing an assessment of groundwater quality. This report must be placed in the facility operating record and be maintained until closure of the facility.

6. If the owner or operator determines, based on the results of the first determination under 335-14-6-.06(4)(d)4., that no hazardous waste or hazardous waste constituents from the facility have entered the groundwater, then he may reinstate the indicator evaluation program described in 335-14-6-.06(3) and 335-14-6-.06(4)(b). If the owner or operator reinstates the indicator evaluation program, he must so notify the Department in the report submitted under 335-14-6-.06(4)(d)5.

7. If the owner or operator determines, based on the first determination under 335-14-6-.06(4)(d)4., that hazardous waste or hazardous waste constituents from the facility have entered the groundwater, then he:

(i) Must continue to make the determinations required under 335-14-6-.06(4)(d)4. on a quarterly basis until final closure of the facility, if the groundwater assessment plan was implemented prior to final closure of the facility; or

(ii) May cease to make the determinations required under 335-14-6-.06(4)(d)4., if the groundwater quality assessment plan was implemented during the post-closure care period.

(e) Notwithstanding any other provision of 335-14-6-.06, any groundwater quality assessment to satisfy the requirements of 335-14-6-.06(4)(d)4. which is initiated prior to final closure of the facility must be completed and reported in accordance with 335-14-6 -.06(4)(d)5.

(f) Unless the groundwater is monitored to satisfy the requirements of 335-14-6-.06(4)(d)4., at least annually the owner or operator must evaluate the data on groundwater surface elevations obtained under 335-14-6-.06(3)(e) to determine whether the requirements under 335-14-6-.06(2)(a) for locating the monitoring wells continues to be satisfied. If the evaluation shows that 335-14-6-.06(2)(a) is no longer satisfied, the owner or operator must immediately modify the number, location, or depth of the monitoring wells to bring the groundwater monitoring system into compliance with this requirement.

(5) Recordkeeping and reporting.

(a) Unless the groundwater is monitored to satisfy the requirements of 335-14-6-.06(4)(d)4., the owner or operator must:

1. Keep records of the analyses required in 335-14-6-.06(3)(c) and (3)(d), the associated groundwater surface elevations required in 335-14-6-.06(3)(e), and the evaluations required in 335-14-6-.06(4)(b) throughout the active life of the facility, and, for disposal facilities, throughout the post-closure care period as well; and

2. Report the following groundwater monitoring information to the Department:

(i) During the first year when initial background concentrations are being established for the facility: concentrations or values of the parameters listed in 335-14-6-.06(3)(b)1. for each groundwater 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 335-14-6 -Appendix III.

(ii) Annually: Concentrations or values of the parameters listed in 335-14-6-.06(3)(b)3. for each groundwater monitoring well, along with the required evaluations for these parameters under 335-14-6 -.06(4)(b). The owner or operator must separately identify any significant differences from initial background found in the upgradient wells, in accordance with 335-14-6-.06(4)(c)1. During the active life of the facility, this information must be submitted no later than March 1 following each calendar year.

(iii) No later than March 1 following each calendar year: Results of the evaluations of groundwater surface elevations under 335-14-6-.06(4)(f), and a description of the response to that evaluation, where applicable.

(b) If the groundwater is monitored to satisfy the requirements of 335-14-6-.06(4)(d)4., the owner or operator must:

1. Keep records of the analyses and evaluations specified in the plan, which satisfies the requirements of 335-14-6 -.06(4)(d)3., throughout the active life of the facility, and, for disposal facilities, throughout the post-closure care period as well; and

2. Annually, until final closure of the facility, submit to the Department a report containing the results of his groundwater 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 groundwater during the reporting period. This information must be submitted no later than March 1 following each calendar year.

Notes

Ala. Admin. Code r. 335-14-6-.06

November 19, 1980. Amended: April 9, 1986; September 29, 1986; August 24, 198 9; December 6, 1990; January 25, 1992; January 1, 1993. Amended: Filed November 30, 1994; effective January 5, 1995. Amended: Filed February 20, 1998; effective March 27, 1998. Amended: Filed February 26, 1999; effective April 2, 1999. Amended: Filed February 25, 2000; effective March 31, 2000. Amended: Filed March 9, 2001; effective April 13, 2001. Amended: Filed February 27, 2007; effective April 3, 2007. Amended: February 24, 2009; effective March 31, 2009.

Authors: Stephen C. Maurer; Steven O. Jenkins; Amy P. Zachry; Theresa A. Maines

Statutory Authority: Code of Ala. 1975, §§ 22-30-11, 22-30-12, 22-30-16.