Louisiana Administrative Code
Title 33 - ENVIRONMENTAL QUALITY
Part V - Hazardous Wastes and Hazardous Materials
Subpart 1 - Department of Environmental Quality-Hazardous Waste
Chapter 43 - Interim Status
Subchapter E - Groundwater Monitoring
Section V-4373 - Preparation, Evaluation, and Response

Universal Citation: LA Admin Code V-4373

Current through Register Vol. 50, No. 9, September 20, 2024

A. The owner or operator must have an outline of a groundwater quality assessment program. The outline must describe a more comprehensive groundwater monitoring program (than that described in LAC 33:V.4369 and 4371) 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 LAC 33:V.4371.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 LAC 33:V.4371.E.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 LAC 33:V.3309.A.3, Table 1) to determine statistically significant increases (and decreases in the case of pH) over initial background.

C. If the comparisons for the upgradient wells made under LAC 33:V.4373.B show a significant increase (or decrease in pH), the owner or operator must submit this information in accordance with LAC 33:V.4375.A.2.

D. If the comparison for downgradient wells made under LAC 33:V.4373.B shows a significant increase (or decrease in pH), 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.

E. If the analyses performed under LAC 33:V.4373 confirm the significant increase (or pH decrease), the owner or operator must provide written notice to the administrative authority, within seven days of the date of such confirmation, that the facility may be affecting groundwater quality.

F. Within 15 days after the notification required in Subsection E of this Section, the owner or operator must develop a specific plan, based on the outline required in Subsection A of this Section and certified by a qualified geologist or geotechnical engineer, for a groundwater quality assessment program at the facility. This plan must be placed in the facility operating record and be maintained until closure of the facility.

G. The plan to be submitted under LAC 33:V.4367.C.1 or 4373.F must specify:

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; and

4. a schedule of implementation.

H. The owner or operator must implement the groundwater quality assessment plan which satisfies the requirements of LAC 33:V.4373.G, and, at a minimum, determine:

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

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

I. The owner or operator must make his first determination required in Subsection H of this Section as soon as technically feasible and prepare a report containing an assessment of the groundwater quality. This report must be placed in the facility operating record and be maintained until closure of the facility.

J. If the owner or operator determines, based on the results of the first determination under LAC 33:V.4373.H, 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 LAC 33:V.4371 and 4373.B. If the owner or operator reinstates the indicator evaluation program, he must notify the Office of Environmental Services, in the report submitted under LAC 33:V.4373.I.

K. Notwithstanding any other provision of this Chapter, the administrative authority may order such corrective action measures as may be necessary for groundwater protection. When it is determined, based on the groundwater quality assessment plan, that hazardous waste or hazardous waste constituents from the facility have entered the groundwater, the administrative authority shall establish a groundwater protection standard including:

1. a list of hazardous constituents, concentration limits, the compliance points and the compliance period. The administrative authority may establish alternative risk-assessment-based concentration limits. Any alternative risk-assessment-based concentration limit must be protective of human health and the environment, as demonstrated in accordance with LAC 33:I.Chapter 13;

2. within 30 days or other schedule required by the administrative authority, after the establishment of the groundwater protection standard, the owner or operator shall submit to the Office of Environmental Services a corrective action and monitoring plan;

3. within a reasonable time set by the administrative authority, corrective action measures shall be instituted by the owner or operator that prevents hazardous constituents from exceeding their respective concentration limits at the compliance point by removing the hazardous waste constituents or treating them in place;

4. if the owner or operator determines, based on the first determination under LAC 33:V.4373 that hazardous waste or hazardous waste constituents from the facility have entered the groundwater, he:
a. must continue to make the determinations required under LAC 33:V.4373 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; or

b. may cease to make the determination required under LAC 33:V.4373 if the groundwater quality assessment plan was implemented during the post-closure care period.

L. Notwithstanding any other provision of this Subchapter, any groundwater quality assessment to satisfy the requirements of LAC 33:V.4373.H, which is initiated prior to final closure of the facility, must be completed and reported in accordance with LAC 33:V.4373.I.

M. Unless the groundwater is monitored to satisfy the requirements of LAC 33:V.4373.H, the owner or operator must evaluate the data on groundwater surface elevations obtained under LAC 33:V.4371.F at least annually to determine whether the requirements under LAC 33:V.4369.A for locating the monitoring wells continue to be satisfied. If the evaluation shows that LAC 33:V.4369.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.

AUTHORITY NOTE: Promulgated in accordance with R.S. 30:2180 et seq.

Disclaimer: These regulations may not be the most recent version. Louisiana may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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