SCOPE_OF_WORK_FOR_DRIWR_Vapor_Intrusion_Evaluation.pdf

SCOPE OF WORK

Detroit River International Wildlife Refuge 5437 West Jefferson Ave.

Trenton, MI 48183

Visitor Center Headquarters – Vapor Intrusion Sampling Plan

Monitoring of potential vapor intrusion of the Detroit River IWR Visitor Center is requested because of concerns raised. The Detroit River IWR Visitor Center was built on a brownfield site (Old Chrysler Manufacturing Site). The 4-acre site was tested and cleared as clean and acceptable for building. During the excavation of the site, 55-gallon drums and old building parts were found where the foundation of the Visitor Center was to be placed. Based on this information the Service installed vapor barrier and two passive pipes into the floor below grade. The passive pipes have been retrofitted with fans to actively remove subfloor gases.

The existing grade when we started to build was about 582, 582.5 or 583 depending on the location. The elevation of the finished floor slab is 586.50 we essentially built the foundation and footings on top of the existing grade and at the most excavated 3 inches to a 1 foot depending on the exact location just for the spread footings. The foundation walls are all above existing grade and backfilled with granular sandy fill from off site. There is a perimeter exterior foundation drain that daylights to the pond which I assume will also allow these new recently discovered gases to escape.

Michigan Department of Environmental Quality installed Vapor Wells around the building in 2019.

Sampling events occurred on August 20, January 15, 2020, and November 6, 2019. See attachments for the results of previous samples.

Vapor Well Sampling: GPS Table Below for Locations

Conduct sampling of Vapor Wells installed around the perimeter of the building:

VP1-4.5 – Sampled 11/6/2019, 1/15/2020, 8/20/2020 VP2- 7.5 - Water VP3 – 7 - Water VP4 – 5– Sampled 11/6/2019, 8/20/2020 VP5 – 6.5 – Water, 1/15/2020, VP6 – 6.25 – Sampled 11/6/2019, 1/15/2020, VP7 – 2.75 – Sampled 11/6/2019, 1/15/2020, 8/20/2020 VP8 – 3 – Sampled 11/6/2019, 8/20/2020 VP9 – 3.5 – Sampled 11/6/2019, 8/20/2020

Vapor Pin Sampling: See Building Drawing for Pin Location

19VPSS-1- 8/20/2020

19VPSS-2 - 8/20/2020

19VPSS-3 - 8/20/2020

Ambient – None Taken Previously (Would like to discuss locations of Samples)

Multi-Purpose Room – 116A/B Exhibit Area – 101B Video Theater 105 Open Office – 136 Office 159 Pipe exterior foundation drain which daylights to the pond.

Exhaust from through Floor Ventilation #1 Exhaust from Through Floor Ventilation #2

The location of samples will be discussed during the kick-off phase of the project.

Vapor Well Sampling Plan:

1) Perform leak test on each well to ensure that there are no leaks in the fitting that may affect test. (Wells that are identified to produce water during the purge test will not be sampled)

2) Collect 1-Liter Vacuum Bottle with a 100 to 200-ml/minute regulator to collect air samples.

3) Samples shall be analyzed using:

A) Environmental Protection Agency (EPA) Method TO-15 for volatile organic compounds

(VOC’S)

B) Environmental Protection Agency (EPA) Method 8015 for methane and ethylene

4) Analytical results shall be compared to:

A) Recommended Interim Action Screening Levels (RIASL), B) Time-Sensitive Interim Action Screening Levels (TRIASL), and C) Non-Residential Soil Vapor

Vapor Pin Sampling Plan:

1) Conduct test to determine if pin is under negative pressure and record pressure reading.

2) Perform leak test on each vapor pin to ensure that there are no leaks in the fitting that may affect test.

3) Collect 1-Liter Vacuum Bottle with a 100 to 200-ml/minute regulator to collect air samples.

4) Samples shall be analyzed using:

A) Environmental Protection Agency (EPA) Method TO-15 for volatile organic compounds

(VOC’S)

B) Environmental Protection Agency (EPA) Method 8015 for methane and ethylene

5) Analytical results shall be compared to:

A) Recommended Interim Action Screening Levels (RIASL), Ambient Sampling Plan:

1) Collect 1-Liter Vacuum Bottle with a 100 to 200-ml/minute regulator to collect air samples.

2) Samples shall be analyzed using:

A) Environmental Protection Agency (EPA) Method TO-15 for volatile organic compounds

(VOC’S)

B) Environmental Protection Agency (EPA) Method 8015 for methane and ethylene

3) Analytical results shall be compared to:

A) Recommended Interim Action Screening Levels (RIASL), Task 1: Conduct sampling per sampling:

a. Provide copy of sampling plan to EGLE to review prior to conducting samples for comments.

b. Conduct sampling in October, January, April, and July

c. Provide results of each sampling event to U.S. FWS within two weeks of sampling event.

Task 2: Evaluate Vapor Intrusion Potential

Task 3: Provide report to EGLE with following information:

a. Summary of results from sampling conducted in October, January, April, July

b. Evaluation of Vapor Intrusion Potential

c. Recommendation if additional controls are needed to mitigate Vapor Intrusion Potential