Rule 3745-535-830 | Groundwater quality assessment monitoring program.
(A) Upon determining a statistically significant increase above background in a groundwater monitoring well pursuant to rule 3745-535-820 of the Administrative Code, the owner or operator shall implement a groundwater quality assessment program and submit a groundwater quality assessment plan to the director as follows:
(1) Not later than one hundred eighty days after withdrawing a groundwater sample from the monitoring well that upon analysis demonstrates a statistically significant increase above background.
(2) Not later than ninety days after notification by the director that the report submitted under paragraph (D) of rule 3745-535-820 of the Administrative Code does not successfully make the necessary demonstration.
(B) The owner or operator may undertake activities necessary to prevent the continued release of waste-derived constituents from the regulated unit to groundwater during the implementation of the groundwater quality assessment program.
(C) The groundwater quality assessment program plan submitted in accordance with paragraph (A) of this rule shall include at a minimum detailed descriptions of the following:
(1) Hydrogeologic conditions at the facility.
(2) The detection monitoring program implemented by the owner or operator at the facility, including the following:
(a) The number, location, depth, and construction of detection monitoring wells with documentation.
(b) A summary of detection monitoring groundwater analytical data with documentation of the results.
(c) A summary of statistical analyses applied to the data.
(3) The investigatory approach to be followed during the assessment, including but not limited to the following:
(a) The proposed number, location, depth, installation method, and construction of assessment monitoring wells.
(b) The proposed methods for gathering additional hydrogeologic information.
(c) The planned use of supporting methodology.
(4) The techniques, procedures, and analytical equipment to be used for groundwater sampling and analysis during the assessment as specified in paragraph (B) of rule 3745-535-810 of the Administrative Code.
(5) Data evaluation procedures, including but not limited to the following:
(a) Planned use of computer models.
(b) Planned use of previously gathered information.
(c) Criteria that will be utilized to determine if additional assessment activities are warranted.
(6) A schedule of implementation that is executed as soon as practical following an unsuccessful demonstration in accordance with paragraph (D) of rule 3745-535-820 of the Administrative Code and incorporates the requirements specified in paragraph (D) of this rule.
(7) Provisions for installing additional wells, as necessary, for determining the nature and extent of any release of waste-derived constituents pursuant to paragraph (E) of this rule.
(8) Provisions for installing at least one additional monitoring well at the facility boundary in the direction of downgradient groundwater flow from the affected well and as many additional wells as necessary to meet the requirements specified in paragraph (E) of this rule.
(D) The owner or operator shall monitor all assessment monitoring wells in accordance with the following:
(1) Not later than the due date of the groundwater quality assessment plan specified in paragraph (A) of this rule, sample the affected monitoring wells including any background monitoring wells within the flow path or closest to the affected monitoring well and screened within the same geologic unit and analyze the samples for all parameters listed in rules 3745-535-801 and 3745-535-802 of the Administrative Code.
(2) Not later than seventy-five days after commencing the sampling specified in paragraph (D)(1) of this rule, sample all monitoring wells screened within the same geologic units at the facility as the affected monitoring well and not sampled under paragraph (D)(1) of this rule. These samples shall be analyzed for those waste-derived constituents found to be above background levels in the affected monitoring wells sampled pursuant to paragraph (D)(1) of this rule.
(3) Sample all monitoring wells used to meet the paragraph (E) of this rule as follows:
(a) At least semiannually for the following:
(i) All parameters contained in rule 3745-535-801 of the Administrative Code or the alternative parameter list approved pursuant to rule 3745-535-825 of the Administrative Code.
(ii) All the constituents reported to the director in accordance with paragraph (D)(4) of this rule.
(b) At least annually for one of the following.
(i) All parameters contained in rule 3745-535-802 of the Administrative Code.
(ii) The remaining parameters contained in rule 3745-535-802 of the Administrative Code if the director has deleted one or more parameters in accordance with paragraph (D)(6) of this rule.
(4) Not later than seventy-five days after sampling the groundwater monitoring wells in accordance with paragraph (D)(1) of this rule and after all subsequent samplings, the owner or operator shall place a notice in the operating record identifying all parameters that have been detected and submit a copy to the appropriate Ohio EPA district office and the approved health district.
(5) Not later than one hundred eighty days after implementing the groundwater quality assessment plan, the owner or operator shall collect a minimum of four additional statistically independent samples from any background well sampled pursuant to paragraph (D)(1) of this rule that does not have at least four independent analysis results of each waste-derived constituent detected in the monitoring wells demonstrating a statistically significant increase.
(6) Upon the written request of the owner or operator, the director may delete any of the monitoring parameters contained in rule 3745-535-802 of the Administrative Code for a facility if the owner or operator can demonstrate that the deleted parameters are not reasonably expected to be in or derived from the waste contained in the unit.
(7) After sampling in accordance with paragraph (D)(1) of this rule, the owner or operator may delete 1,2- Dibromoethane (EDB) and 1,2-Dibromo-3-chloropropane (DBCP) from the parameters used to meet paragraph (E) of this rule upon demonstration that there has never been a confirmed detection of EDB or DBCP in the groundwater at the facility.
(E) The owner or operator shall implement the groundwater quality assessment plan that satisfies the requirements of paragraphs (C) and (D) of this rule and at a minimum determines the following:
(1) The rate and extent of migration of the waste-derived constituents in groundwater, including portions of the contaminant plume that exist beyond the facility boundary in accordance with paragraph (F) of this rule.
(2) The concentrations of the waste-derived constituents in groundwater.
(F) The determination specified in paragraph (E) of this rule includes portions of the contaminant plume that exists beyond the facility boundary, unless the owner or operator demonstrates to the director that the owner or operator was unable to obtain the necessary permission to undertake an investigation of the off-site property migration of the contaminant plume. The owner or operator shall submit a copy of the written access request and if a response is provided, a copy of the written statement from the off-site property owner indicating that off-site access is denied. The owner or operator is not relieved of all responsibility to clean up a release that has migrated beyond the facility boundary where off-site access is denied. On-site measures to address such releases will be determined on a case-by-case basis.
(G) The owner or operator shall make a determination in accordance with paragraph (E) of this rule within the timeframe specified in the submitted groundwater quality assessment plan and submit a written groundwater quality assessment report to the director that contains at a minimum the following not later than fifteen days after making the determination:
(1) An assessment of the groundwater quality including all data generated as part of implementation of the groundwater quality assessment plan.
(2) Groundwater remediation standards developed in accordance with rule 3745-535-860 of the Administrative Code.
(H) Alternatives to corrective measures.
(1) If the owner or operator determines that the concentrations of all waste-derived constituents are shown to be at or below background values at the monitoring wells within the assessment monitoring program, or for those wells within a specific assessment monitoring area within an assessment monitoring program using the statistical procedures described in paragraph (A) of rule 3745-535-815 of the Administrative Code for two consecutive sampling events, then the owner or operator may reinstate the detection monitoring program described in rule 3745-535-820 of the Administrative Code by notifying the director.
(2) The owner or operator may demonstrate that a source other than the facility caused the contamination, or that the statistically significant increase resulted from error in sampling, analysis, or statistical evaluation, or from natural variation in groundwater quality. A report documenting this demonstration shall be submitted to director and request that the director approve reinstatement of the detection monitoring program described in rule 3745-535-820 of the Administrative Code. Until the director approves reinstatement of the detection monitoring program, the owner or operator shall comply with paragraph (I) of this rule.
(3) If the owner or operator determines that the concentrations of all waste-derived constituents are shown to be below groundwater remediation standards pursuant to rule 3745-535-860 of the Administrative Code at the monitoring wells within the assessment monitoring program, or for those monitoring wells within a specific assessment monitoring area, for two consecutive sampling events, then the owner or operator may enter into a compliance monitoring program described in paragraph (A)(1) of rule 3745-535-840 of the Administrative Code by notifying the director.
(I) If the owner or operator determines, based on the determination made in accordance with paragraph (E) of this rule, that waste-derived constituents from the facility have entered the groundwater, then the owner or operator shall continue to make the determination pursuant to paragraph (E) of this rule on a semiannual basis until released from this obligation by the director or unless an alternate time interval is established by the director. The owner or operator shall submit documentation of the semiannual determination of rate, extent, and concentration with the reports submitted in accordance with paragraph (K) of this rule.
(J) After the determination of rate, extent, and concentration in accordance with paragraph (E) of this rule, the owner or operator shall notify by certified mail or any other form of mail accompanied by a receipt all persons who own land or reside on the land that directly overlies, or is reasonably expected to overlie, any part of the plume of the contamination, as determined in accordance with paragraph (D) of this rule, of the rate, extent, and concentration of the waste-derived constituents in the groundwater. The owner or operator shall place the return receipts or other evidence of notification into the operating record. Annually, the owner or operator shall re-notify persons or notify additional persons based on the results of the determinations of rate, extent, and concentration in accordance with paragraph (D) of this rule until released from this obligation by the director.
(K) The owner or operator shall continue to comply with all monitoring and reporting requirements contained this rule until the director releases the owner or operator from this obligation or approves a corrective measure in accordance with paragraph (H) of rule 3745-535-850 of the Administrative Code or approves a compliance monitoring plan in accordance with rule 3745-535-840 of the Administrative Code.
Last updated March 1, 2026 at 4:06 AM
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