Section 665.0093. Preparation, evaluation and response.

 

(1)  By August 1, 1982, the owner or operator shall prepare an outline of a groundwater quality assessment program. The outline shall describe a more comprehensive groundwater monitoring program (than that described in ss. NR 665.0091 and 665.0092 ) capable of determining all of the following:

(a) Whether hazardous waste or hazardous waste constituents have entered the groundwater.

(b) The rate and extent of migration of hazardous waste or hazardous waste constituents in the groundwater.

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

(2)  For each indicator parameter specified in s. NR 665.0092 (2) (c) , the owner or operator shall calculate the arithmetic mean and variance, based on at least 4 replicate measurements on each sample, for each well monitored in accordance with s. NR 665.0092 (4) (b) , and compare these results with its initial background arithmetic mean. The comparison shall consider individually each of the wells in the monitoring system, and shall use the Student's t-test at the 0.01 level of significance (see ch. NR 665 Appendix IV ) to determine statistically significant increases (and decreases, in the case of pH) over initial background.

(3)  

(a) If the comparisons for the upgradient wells made under sub. (2) show a significant increase (or pH decrease), the owner or operator shall submit this information in accordance with s. NR 665.0094 (1) (b) 2.

(b) If the comparisons for downgradient wells made under sub. (2) show a significant increase (or pH decrease), the owner or operator shall then immediately obtain additional groundwater samples from those downgradient wells where a significant difference was detected, split the samples in 2 and obtain analyses of all additional samples to determine whether the significant difference was a result of laboratory error.

(4)  

(a) If the analyses performed under sub. (3) (b) confirm the significant increase (or pH decrease), the owner or operator shall provide written notice to the department—within 7 days of the date of the confirmation—that the facility may be affecting groundwater quality.

(b) Within 15 days after the notification under par. (a) , the owner or operator shall develop and submit to the department a specific plan, based on the outline required under sub. (1) and certified by a qualified geologist or geotechnical engineer, for a groundwater quality assessment program at the facility.

(c) The plan to be submitted under s. NR 665.0090 (4) (a) or (b) shall specify all of the following:

1. The number, location and depth of wells.

2. Sampling and analytical methods for those hazardous wastes or hazardous waste constituents in the facility.

3. Evaluation procedures, including any use of previously-gathered groundwater quality information.

4. A schedule of implementation.

(d) The owner or operator shall implement the groundwater quality assessment plan which satisfies the requirements of par. (c) , and, at a minimum, determine all of the following:

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

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

(e) The owner or operator shall make the first determination under par. (d) as soon as technically feasible, and, within 15 days after that determination, submit to the department a written report containing an assessment of the groundwater quality.

(f) If the owner or operator determines, based on the results of the first determination under par. (d) , that no hazardous waste or hazardous waste constituents from the facility have entered the groundwater, then the owner or operator may reinstate the indicator evaluation program described in s. NR 665.0092 and sub. (2) . If the owner or operator reinstates the indicator evaluation program, the owner or operator shall so notify the department in the report submitted under par. (e) .

(g) If the owner or operator determines, based on the first determination under par. (d) , that hazardous waste or hazardous waste constituents from the facility have entered the groundwater, then the owner or operator:

1. Shall continue to make the determinations required under par. (d) on a quarterly basis until final closure of the facility, if the groundwater quality assessment plan was implemented prior to final closure of the facility.

2. May cease to make the determinations required under par. (d) , if the groundwater quality assessment plan was implemented during the long-term care period.

(5)  Notwithstanding any other provision of this subchapter, any groundwater quality assessment to satisfy the requirements of sub. (4) (d) which is initiated prior to final closure of the facility shall be completed and reported in accordance with sub. (4) (e) .

(6)  Unless the groundwater is monitored to satisfy the requirements of sub. (4) (d) , at least annually the owner or operator shall evaluate the data on groundwater surface elevations obtained under s. NR 665.0092 (5) to determine whether the requirements under s. NR 665.0091 (1) for locating the monitoring wells continues to be satisfied. If the evaluation shows that s. NR 665.0091 (1) is no longer satisfied, the owner or operator shall immediately modify the number, location or depth of the monitoring wells to bring the groundwater monitoring system into compliance with s. NR 665.0091 (1) .

History: CR 05-032 : cr. Register July 2006 No. 607 , eff. 8-1-06; correction in (2) made under s. 13.92 (4) (b) 7. , Stats., Register March 2013 No. 687 .