A04_Crab_Orchard_NWR_LUST_Project_SOW_1.docx

United States Department of the Interior Fish and Wildlife Service Crab Orchard National Wildlife Refuge

Scope of Work Closure of Leaking Underground Storage Tanks (LUSTs) Number 941970

Background

Leaking Underground Storage Tank (LUST) Incident number 941970 was reported to the Illinois Emergency Management Agency (IEMA) on August 30, 1994: According to the IEMA field report, two tanks, one 10,000-gallon gasoline and one 8,000-gallon diesel fuel were part of this release. The amount of product released, and cause of release was unknown. An evaluation of the site was conducted by United Science Industries on July 13, 2000. The sampling completed per the report can be utilized for future investigatory work. Due to the nature of the release, Benzene, Toluene, Ethylbenzene, and Total Xylenes (BTEX) in addition to Polynuclear Hydrocarbons (PNAs) were listed as indicator contamination and all samples were analyzed for these compounds.

Results from the Site Classification Completion Report and addendum illustrate the extent of contamination has been adequately defined both horizontally and vertically. Further, the extent of contamination, both soil and groundwater, is confined to the site boundaries. However, contaminant of concern concentrations is present on-site exceeding the most stringent Tier 1 Class I remediation objectives. Thus, a Corrective Action Plan (CAP) must be completed to address the remaining contamination.

Since this work has been done, Crab Orchard NWR has enclosed the area from the old building to the pump station to use this space as a garage/storage area.

Per that sampling conducted by United Science Industries on July 13, 2000, the following samples exhibited elevated concentrations.

Soil:

• B-9 (20'): Benzene and Toluene

– Possible Exposure Outdoor inhalation/soil component/construction worker inhalation

• B-11 (10'): Benzene, Ethylbenzene, and Toluene

– Possible Exposure Outdoor inhalation/soil component/construction worker inhalation

• BH-12 (22'): Benzene, Ethylbenzene, and Toluene

– Possible Exposure Outdoor inhalation/soil component/construction worker inhalation

• BH-13A (23'): Benzene

– Possible Exposure Soil component

• BH-13B (12'): Benzene

– Possible Exposure Outdoor inhalation/soil component

• BH-18B (17'): Benzene

– Possible Exposure Soil component Groundwater:

• MW-4: Benzene, Toluene, Ethyl-benzene, Naphthalene

Work to be Performed

The Contractor shall perform the following work:

1. Additional Sampling

Due to the long duration in which the site has been dormant in the LUST program, it is assumed the contamination due to the release would have attenuated in the soil. Additional sampling approved by the LUST program that satisfies requirements in Section 734 of Petroleum Underground Storage Tanks regarding the definition of the contamination plume.

A. Sample existing wells that can be located. (Note: Additional gravel has been added to the site burying some of the pervious wells.

1. MW-1 Well was located on 6/13/2023, but no well collar or well cap.

2. MW-2, MW-5, MW-8 – Wells were located on 6/13/2023 and wells were intact and accessible.

3. MW-4 and MW-6 could not be located and are covered by several inches of gravel.

4. MW-3, MW-7, MW-9 could not be located in the grass.

B. Install new wells where pervious wells cannot be located or at an appropriate location approved by the Illinois Environmental Protection Agency (ILEPA).

C. Soil samples to be taken to document current soil levels (expectation of lower chemical concentrations).

D. Vapor Intrusion study to address the enclosure of the previous pump station to part of the building.

2. Develop work plan to sample site and have it reviewed and approved by ILEPA and U.S. Fish and Wildlife Service.

3. Develop a Corrective Action Completion Report (CACR) and submit it to the ILEPA that addresses:

A. Results of the current round of sampling shall be provided in a spreadsheet with previous data collected (2000 report) and displayed on a map showing results and location of sample.

B. For the purposes of the CACR, the specific pathways in which exceedances are present must be addressed. The pathways in question are:

1. Soil ingestion and inhalation pathways;

2. Soil component to the groundwater ingestion exposure pathway; Note: Groundwater plume must be modeled using SSL and RBCA modeling equations; as described in Sections 742.805 and 742.810.

3. Indoor inhalation pathway (Vapor Intrusion);

4. Construction worker inhalation pathway; and

5. Groundwater ingestion pathway.

C. The CACR shall develop a Corrective Action Plan that discusses the cost and pros/cons of mitigating the site using active remediation, engineered barriers, institutional controls (Land Use Control Plan), or a combination of these methods. The contractor shall provide a final recommendation based on this evaluation.

D. If Institutional Controls (Land Use Control Plan) is selected, work with U.S. Fish and Wildlife Service to develop and submit Land Use Control Plan to ILEPA.

E. Respond to all comments received from U.S. Fish and Wildlife and ILEPA.

*It must be noted that industrial commercial remediation objectives can be utilized during the CAP phase. This will amount to a Land Use Control Plan that will be maintained at the station as the Federal Government do not place land-use limitation on the deed of Federal Government property. This may be noted in the No Further Remediation Letter received by the state. However, per Illinois EPA all contamination must be defined to Tier 1 residential values - the most stringent remediation objectives - before an industrial commercial land-use restriction can be utilized.

Requirements

1) Contractor performing work must be licensed in State of Illinois.

2) Corrective Action Completion Report must be signed off by a Licensed Professional Engineer licensed to work in Illinois.

Applicable Standards

ILEPA Title 35.G.I.d. Part 734 – Petroleum Underground Storage Tanks ILEPA Title 35.G.I.f. Part 742 – Tiered Approach to Corrective Action Objectives

Site Location

The worksite is located on Crab Orchard National Wildlife Refuge. The nearest street address is: 8203 Route 148, Marion, IL 62959