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Attachment A wsb July 27, 2020 Todd Blomstrom, PE City of Arden Hills — Public Works Department 1245 Highway 96 West Arden Hills, MN 55112 Re: Scope of Work and Cost— RAP/CCP Development, MPCA Brownfields Program Enrollment Services Old Snelling Avenue and County Road E Improvements Arden Hills, Minnesota o Dear Mr. Blomstrom: U z Outlined below is a scope of work and cost estimate for WSB to provide Response Action m Plan/Construction Contingency Plan (RAP/CCP) Development and Minnesota Pollution Control Agency (MPCA) Brownfields Program Enrollment services for the proposed Old Snelling Avenue and County Road (CR) E Improvements project located in Arden Hills, Minnesota (the Site). The CD Site a north-south segment totaling approximately 0.90 miles in length. The Site extends from co Trunk Highway (TH) 51 at the south end to approximately 600 feet north of CR E (approximately Arden Oaks Drive) at the north end. M WSB completed a Phase I Environmental Site Assessment (ESA) at the Site in February 2020. The Phase I ESA identified the following two recognized environmental conditions (RECs) `° associated with the Site: Lo U) • REC-1: Soil impacted with polycyclic aromatic hydrocarbons (PAHs) and diesel range z organics (DRO) was encountered during the replacement of Bridge 62J17 at the southern �i end of the Site in 2018. J ° 0 REC-2: Petroleum odors were noted during a geotechnical investigation completed at the a a W Site in 2019. z z WSB completed a Field Investigation at the Site in May 2020 to determine if the identified RECs resulted in soil, groundwater, and/or soil vapor impacts at the Site. The Field Investigation CD CD identified PAH and DRO impacted soil above MPCA reuse criteria at multiple locations at the W Site, which will require special management if encountered during construction. No evidence of a Z) release was identified in the groundwater and soil vapor samples. It is our understanding that the proposed underground utility work will include the replacement of W approximately 1,600 feet of watermain between Skiles Lane and Bussard Court. Proposed Z) improvements also include a full depth reclamation of Old Snelling Avenue to a depth of W approximately 12 inches below the roadway surface. a a The purpose of this scope is to prepare a RAP/CCP to manage soil contamination encountered z X during construction and obtain eligible technical assistance and/or contamination liability 0 assurances from the MPCA Brownfields Program. The following tasks will be performed under this scope of work: