7 Del. Admin. Code § 1351-E-5.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 1351-E-5.0 - Remedial Action Requirements

5.1 Administrative Option For Remedial Action

5.1.1 The Department may waive the requirement of a hydrogeologic investigation when the Responsible Parties have taken the appropriate initial response steps to eliminate imminent dangers and to prevent any further Release and have chosen to submit a Remedial Action work plan (RAWP) for remediating contaminated soil, groundwater and surface water.

5.1.2 If the Department determines that the implementation of Remedial Actions are not achieving adequate protection of human health, safety or the environment, the Department shall require Responsible Parties to take appropriate action.

5.1.3 Responsible Parties may, in the interest of minimizing environmental contamination and promoting more effective remediation, initiate remediation of soil and groundwater before the Remedial Action work plan is approved provided that the Responsible Parties:

5.1.3.1 Notify the Department of their intention to initiate remediation; and

5.1.3.2 Comply with any conditions imposed by the Department, including halting remediation or mitigating adverse consequences from remedial activities; and

5.1.3.3 Incorporate these self initiated remediation measures in the RAWP that shall be submitted to the Department for approval; and

5.1.3.4 Recognize that any actions taken by the Responsible Parties without prior Department approval is at the risk of the Responsible Parties and does not absolve the Responsible Parties of the obligation to comply with the Remedial Action requirements of Part E.

5.2 Remedial Action Work Plan (RAWP) Requirements

5.2.1 At any point after reviewing the information contained in the hydrogeologic investigation report, the Department may require the Responsible Parties to submit additional information or to develop and submit a RAWP for responding to contaminated soils, surface water and groundwater.

5.2.2 The RAWP shall address the contamination of soils, groundwater, and surface water, including all Occurrences of LNAPL resulting from a Release, and shall be submitted to the Department in a timeframe specified by the Department. The RAWP shall provide for adequate protection of human health, safety, and the environment, and shall establish cleanup goals for the site.

5.2.3 Responsible Parties shall modify any RAWP that does not provide for adequate protection of human health, welfare, safety and the environment, as necessary to meet the requirements of Part E of these Regulations.

5.2.4 The RAWP shall include sufficient design information that demonstrates that the remedial technology shall meet the cleanup goals approved by the Department and shall include an estimated time to cleanup completion for the remediation method proposed in the RAWP.

5.2.5 A RAWP shall propose a Remedial Action method for the site that shall:

5.2.5.1 Reduce the contaminant levels at the site to meet the cleanup goals proposed in the Remedial Action work plan and approved by the Department; or

5.2.5.2 Reduce the contaminant levels to achieve the cleanup goals established by the Department; or

5.2.5.3 Monitor the site over time to provide technically-based assurance that the site contamination is controlled under natural conditions and that those conditions will not now, or at some future time, adversely impact human health, safety or the environment.

5.2.6 The Department shall approve the RAWP when satisfied that implementation of the RAWP provides for measures considered adequate to protect human health, safety, and the environment.

5.2.7 The RAWP shall be organized in report form and signed by a professional geologist or professional engineer registered in the State of Delaware as required in 24 Del.C. Ch. 36 and the Delaware Board of Registration of Geologists Regulations and 24 Del.C. Ch. 28.

5.2.8 The RAWP shall be of site specific design and shall be based on the results of the hydrogeologic investigation, or contain appropriate investigatory steps if submitted without a prior hydrogeologic investigation having been completed.

5.2.9 The RAWP may propose a phased approach to site remediation. If data can justify a no further action determination, Responsible Parties may request a no further action determination in accordance with the requirements of Part E, Section 6.0. Remedial Action will be considered complete only upon the Department's evaluation and approval of a satisfactory no further action request.

5.2.10 The RAWP shall include a summary of past efforts and a description of any new or continued efforts to effectively remove LNAPL as described in Part E, Section 3.0.

5.2.11 The RAWP may include green sustainable remediation practices, processes, and technologies in accordance with ASTM (ASTM International) E2893-16 Standard Guide for Greener Cleanup. ITRC (Interstate Technology & Regulatory council). Green and Sustainable Remediation: State of the Science and Practice. GSR-1 and ITRC (Interstate Technology & Regulatory Council). Green and Sustainable Remediation: A Practical Framework. GSR-2.

5.2.12 The RAWP may include the use of Institutional Controls to reduce the potential for exposure to Regulated Substances. Institutional Controls may include land use restrictions, activity restrictions, groundwater use restrictions, operations and Maintenance requirements, or other Institutional Controls.

5.3 Quality Assurance and Quality Control Requirements

5.3.1 Responsible Parties shall develop and implement a site specific Quality Assurance/Quality Control (QA/QC) plan for the activities to be carried out during implementation of the RAWP and the QA/QC plan shall be included in the RAWP submitted to the Department.

5.4 Site Safety Requirements

5.4.1 Responsible Parties shall develop a site-specific health and safety plan which shall be furnished to the Department upon request and shall cover all Remedial Action tasks. The health and safety plan shall, at a minimum, address site worker protection levels, protection of Persons living near the site, and site access control during the remediation.

5.5 Implementation and Reporting Schedule

5.5.1 Upon approval of the RAWP by the Department, the Responsible Parties shall implement the RAWP, including any modifications to the RAWP made by the Department, within the timeframe approved by the Department.

5.5.2 The Responsible Parties shall monitor, evaluate, and report to the Department the results of implementing the Remedial Action at a minimum of once every 3 calendar months, or within the time schedule approved in the RAWP. Copies of all records documenting the transport and disposal of any free product, contaminated water and soil, or other waste that is generated at the site while investigation and Remedial Action work is being performed shall be included in each report.

5.5.3 The Responsible Parties shall submit a Remedial Action progress report to the Department once every 12 calendar months that includes an evaluation of the effectiveness of the Remedial Action to determine whether additional measures shall be implemented to meet the cleanup goals established in the RAWP. The evaluation shall include an estimate of time to Remedial Action completion.

5.5.4 Responsible Parties shall submit recommendations for optimization and improvement as needed to achieve the cleanup goals established in the RAWP, as part of each Remedial Action progress report.

5.6 Post Remedial Monitoring

5.6.1 Upon completion of Remedial Action activities the Responsible Parties shall perform 4 consecutive quarters of groundwater sampling or other sampling schedule as approved by the Department to ensure the contaminant plume is stable and shrinking and that rebounding does not occur.

7 Del. Admin. Code § 1351-E-5.0

13 DE Reg. 1562 (06/01/10)
23 DE Reg. 581 (1/1/2020)
24 DE Reg. 806 (2/1/2021)
27 DE Reg. 533 (1/1/2024) (Final)