by Lee Rosberg, PG, Weston & Sampson

The Vermont Farmers Food Center (VFFC) is a 501(c)3 nonprofit organization that is committed to increasing access to locally produced food in the Rutland region. They are able to do this by expanding markets and market access, aggregation, and distribution of locally produced and value-added agricultural products throughout Vermont. 

VFFC purchased a 3-acre former industrial property in downtown Rutland to use for their operations and an indoor winter farmers’ market. First developed in 1868 as the Lincoln Iron Works foundry, the property had a long industrial history. Other past uses have included the manufacturing of stone cutting machinery, tin cans, furniture, forgings for titanium and other metals, and finally as a machine shop from the late 1950s to the early 1970s. That industrial past resulted in legacy contamination issues that remain to this day.

A few years later, the VFFC campus redevelopment plans hit a significant hurdle when that legacy contamination became apparent when the chlorinated solvent, trichloroethene (TCE), was identified in the facility’s indoor air. TCE levels were high enough to force the closure of the Farmer’s Hall building, their hub for food distribution, program space, commercial food production, and Vermont’s largest indoor farmers’ market.   

The project team kept the redevelopment plans in focus while dealing with the reality of the temporary facility closure and the financial strain of assessment and remediation costs, compounded by the loss in revenue faced by VFFC and its market vendors. This involved setting up key partnerships between VFFC, the Vermont Department of Environmental Conservation (VTDEC), Vermont Agency of Commerce and Community Development, the Rutland Regional Planning Commission, and Weston & Sampson.  

The state agencies and regional planning commission stepped up efforts to fund assessments and work with VFFC to communicate the health risks posed by exposure to TCE in the indoor air to the vendors as well as to the larger Rutland community. 

Weston & Sampson developed assessment strategies that balanced site-wide assessment with the need for a timely solution that would allow VFFC to reoccupy the Farmer’s Hall. We prioritized identifying the source of TCE and completing pilot testing to determine feasible vapor intrusion mitigation strategies. Access limitations in the TCE source area complicated the assessment process and typical subslab depressurization or soil vapor extraction were not feasible due to the presence of tight soils, old building foundations, and thickened machine bases. 

With these limitations in mind, Weston & Sampson presented VFFC with a comparison of potential cleanup alternatives. Comparison criteria for each alternative included 

• long-term effectiveness,
• permanence,
• reduction of contaminants,
• technical feasibility,
• cost,
• protection of human health,
• compliance with legal requirements,
• environmental impact, and
• community acceptance.

Our recommended vapor intrusion mitigation strategy selected by VFFC included the installation of a low permeability vapor barrier throughout the Farmer’s Hall, which was protected by a new radiant heated concrete slab, subslab depressurization in a portion of the building, and sealing potential vapor intrusion pathways. 

Since then, our remedial approach has reduced TCE indoor air concentrations several fold to levels that have allowed the indoor farmers market to open once again and thrive. Once faced with an uncertain future, the farmer’s market has returned and VFFC is expanding with the construction of a produce washing and packing center and renovations to the commercial kitchens.

The Author:

Lee Rosberg, PG (NH, VA), is an Assessment and Remediation Team Leader at Weston & Sampson in Waterbury, Vermont. He has 20 years of experience conducting site characterizations and has been responsible for their design and implementation for brownfields and remediation projects in Vermont and elsewhere. He can be reached at rosberg.lee@wseinc.com.