Revitalizing the Old Yellowstone District Using Brownfield Funding
The City of Casper (City) received a US Environmental Protection Agency (EPA) Brownfields Assessment Grant to redevelop the Old Yellowstone District, an area adjacent to the heart of downtown with abandoned and blighted properties and underutilized commercial and industrial sites.
Trihydro assisted the City in prioritizing properties in the Old Yellowstone District for assessment. Before starting work, Trihydro drafted a Quality Assurance Project Plan and a Sampling and Analysis Plan, both of which the EPA approved. Our team hosted collaborative public engagements, including open house sessions and one-on-one meetings with property owners.
Conducting Environmental Site Assessments
Trihydro conducted 17 Phase I Environmental Site Assessments (ESAs) and 10 Phase II ESAs on a diverse portfolio of commercial and industrial properties, including a former railyard, historical service stations, an old ice factory, and a paint and auto body shop. Technical challenges included impacts from a large former refinery next to the investigation area and a comingled perchloroethylene plume next to and within the Old Yellowstone District.
Preparing for Construction
Our team also conducted a Phase I ESA for the State of Wyoming on five parcels with nine buildings scheduled for demolition to clear the property for the construction of a new state office building. Phase I ESA results indicated that the buildings likely had asbestos-containing material (ACM). As part of a Phase II ESA, Trihydro inspected the buildings and identified ACM for abatement.
The Phase II ESA also included a vapor intrusion study to evaluate if existing groundwater impacts on the property would cause indoor air quality concerns for the future office building. In addition, Trihydro collected radon measurements from soil gas to evaluate if radon concentrations would be predicted to exceed EPA action levels. The Phase II ESA vapor intrusion and radon assessment results helped the State of Wyoming select an appropriate vapor intrusion barrier for the 110,000-square-foot office building.
Revitalizing Old Yellowstone District
Altogether, the project team assessed 34 acres within the grant period and under the grant budget. Phase I ESAs conducted under the grant assisted in the sale of three commercial properties in the Old Yellowstone District, helping previously unused properties re-enter the tax base and revitalizing the area for community use. After completing Phase I and II ESAs for over nine acres, the state completed construction of the Thyra Thomson State Office Building. The building is in the heart of the Old Yellowstone District and will serve as an anchor for redevelopment in the area.
