Contamination from metals, chlorinated solvents and petroleum can create challenges in redeveloping industrial properties for higher uses.
On a tree-lined street nestled between duplexes and single-family homes between Davis and Porter Squares, a former industrial dry cleaning plant sat covered in graffiti and weeds.
A mile up the road, in a dense residential neighborhood two blocks from Harvard University, sat a former metal plating facility with plywood shuttering the windows.
The underutilized parking lot of a 1950s mall near The Pentagon in desirable Arlington, Virginia, shared an entire city block with a gas station and auto repair shops.
Despite top-tier locations, sites like these can be a hard sell to investors because of pre-existing contamination. But remediation and reuse of properties doesn’t have to be daunting if you work with the right environmental team. Enterprising developers who choose to invest in remediating such sites can see returns that are doubled, even quadrupled with time.
A Notorious Problem in Somerville
In the Spring Hill neighborhood of Somerville, redevelopment of a former dry cleaning plant into mixed commercial and residential use is under way. Dry cleaners are notorious for chemical contamination, which can discourage investors from the outset.
In this case, soil and groundwater impacts from chlorinated volatile organic compounds (CVOCs) or dry cleaning solvents, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were identified above state reportable concentrations. However, because of the dense soil and high clay content, the extent of the impacts was isolated.
For this project, a cost-effective method called in situ chemical oxidation was used to destroy CVOCs in soil and groundwater. Eight thousand pounds of potassium permanganate, the most effective oxidant for this project, was mixed into the soil at each treatment zone with a drum rotary mixing head. The process took six days and was confined to the building interior, overcoming numerous logistic and structural challenges. Within three months, data indicated that remediation efforts have been effective in significantly reducing CVOC concentrations to achieve a permanent solution without conditions and a condition of no significant risk for current and potential future receptors.
A Toxic Trifecta in Cambridge
The former metals plating facility located a short walk from Harvard Square in Cambridge had been shuttered for years. Now it is a 3-story, mixed-use residential development with 17 units selling from $800,000 to $1.25 million and ground-level retail. At former industrial sites, contamination from metals, chlorinated solvents and petroleum are concerning. This site contained all three.
As part of the redevelopment plans, any structures were demolished and contaminated soils were excavated and removed, followed by bioremediation to further remedy groundwater impacts. A sub–slab depressurization system was also installed to eliminate exposures in the air, and throughout the excavation and demolition, vapor suppressing foam and air monitoring was applied to ensure containment. This cost-effective approach allowed development to move forward and achieve a permanent solution without conditions.
Redevelopment of the former gas station in Alexandria, Virginia created 178 apartments renting from $1,800 to $4,500, 4,500 square feet of retail and nearly 200 parking spaces. Gas stations have unique, but predictable environmental challenges.
Dan Spinogatti
In this particular instance, the gas station had been in operation since the 1970s and had open pollution complaints against it. A corrective action plan was created which included the removal of underground storage tanks and structures and remediation of petroleum-contaminated soil and groundwater. The contaminated soil was excavated and disposed of, effectively eliminating the source of the onsite contamination. The onsite groundwater impacts were addressed through the use of municipally supplied water, and proposed engineering (vapor barrier) and institutional (deed restriction) controls.
While the upfront investment in these types of properties can be discouraging, the long-term benefits stretch even beyond financial gains. The social and economic revitalization in neighborhoods like Spring Hill is a direct result of redeveloping industrial sites into uses that support residents. Investing in urban cores also mitigates sprawl and remediating soil and groundwater contamination contributes to a healthier environment. Pre-existing contamination doesn’t have to be intimidating. Experienced environmental consultants will always look for the most cost-effective and efficient methods to meet your goals.
Dan Spinogatti is senior vice president of national sales and marketing for Burlington-based EBI Consulting.
