Sagasser & Associates, Inc.
Environmental Assessment & Engineering Services
Sagasser & Associates, Inc.
SOMERS MOBIL GAS STATION, LINCOLN, MICHIGAN

Client: Clayton Environmental Services - DEQ Project Management Firm
Contact/Reference: Michelle Arsenault [Clayton] 248-344-7742 / Randy Rothe [DEQ] 989-705-3416
Site Location: 307 South Second Street, Lincoln, Michigan
Project Dates: 04/00 - Present

Sagasser & Associates, Inc. was subcontracted by a State of Michigan Contract Management firm to complete ARA, Site, FFS and FAR of a known contaminated facility. The project involved identification of three potentially co-mingled sources of contamination, UST removal specifications, vapor monitoring of indoor air and substructures, soil and groundwater contaminant (and free product) delineation utilizing direct push technology and installation of permanent monitor wells with a truck-mounted drill rig and progressed toward remediation of the Site.

The Site is an inactive gas station situated on the east side of South Second Street, mid-way between Traverse Bay Road and Hawley Street. Six registered underground storage tanks (USTs) exist at the Site, which were utilized by multiple dispensers. Additional USTs and above-ground storage tanks (ASTs) containing varying petroleum products were observed and reported at the Site. Historical records information for the Site indicated that two separate releases had been reported; however, Sagasser & Associates, Inc. conducted plume degradation and timeline differentiation analyses for three separate releases in the vicinity of the Site.

Sagasser & Associates, Inc. completed soil borings utilizing an all-terrain direct-push drilling rig, soil and groundwater sampling, and UST removal specification development. Soil and groundwater contamination consisting of VOCs, PNAs and lead have been identified at and down gradient of the Site. Soils consist of fine to medium silty sands to approximately 40 feet below ground surface (bgs). A unique peat lithology was identified at approximately 4 feet bgs, beneath a former riverbed, contributing as a secondary source of groundwater contamination after exposure from seasonal groundwater fluctuations. Groundwater is located 6 to 8 feet bgs, and flows in a southwesterly direction.

The UST removal specifications were prepared to facilitate the selection of a contractor for proper closure of the six registered USTs and dispenser islands. Sagasser & Associates, Inc. has completed free product monitoring and recovery. Sagasser & Associates, Inc. also conducted vapor monitoring activities on-Site and potable water well sampling at down gradient structures. Site Investigation activities, Focused Feasibility Study and the Final Assessment Report have been completed. Additional feasibility analyses were conducted and a Corrective Action Plan (CAP) was prepared that primarily consisted of excavation and disposal of 21,000 tons of impacted media.

Sagasser & Associates, Inc. prepared soil excavation specifications that included contaminated media removal to greater than 14 feet bgs, demolition of two town buildings, Class A roadway and right of way replacement and dewatering in excess of 10,000,000 gallons.

During the excavation activities, VSR sampling techniques according to new Op Memo #2 requirements and Tier II (e.g. SPLP and foc) evaluations were conducted. In addition, Sagasser & Associates, Inc. provided a temporary drinking and other use water supply to three local businesses that had insufficient water supply wells to access the depressed water table. Coordination was required between the State and local units of government, the Village Downtown Development Authority and multiple on-Site and adjacent owners. The project is currently in the Site restoration phase to be followed by performance monitoring.

Numerous reports have been prepared for this project including SI, FFS, FAR, Remedial Design, Construction Specifications, Free Product Monitoring and Quarterly Monitoring Reports.