THE MANY SHADES OF THE HENRY WOOD’S SONS PAINT FACTORY SITE, WELLESLEY, MA; A SITE CHARACTERIZATION CASE STUDY

The Former Henry Wood’s Sons Paint Factory operated on a large, rural parcel in Wellesley, MA between 1848 and the 1920’s. The paint factory abutted the campus of Wellesley College, who purchased the land in 1932.

As part of paint pigment production, the factory disposed of metal-laden wastewater and solids on the property, including what appear to have been “off-spec” pigments, which were stockpiled on the site. The primary site contaminants (lead, chromium and hexavalent chromium) have impacted soil, groundwater, and surface water and sediments of surrounding surface water bodies. To complicate matters further, the stockpiled waste material provided a readily available and inexpensive source of fill. Pigments have been identified adjacent to foundations both on and off the site, and beneath parking areas at the site.

Site characterization efforts, initiated in the early 1980’s, were hampered by the heavily overgrown site conditions, and by the historic redistribution of contaminants used as fill on and off the site. Traditional means of site characterization, including installation of soil borings and monitoring wells, excavation of test pits, and sampling of soil, sediment, and groundwater provided as many questions as answers. For instance, the nature and extent of groundwater contamination was still uncertain after 15 years of assessment.

Although much information was gained from these investigations, recent site characterization studies have revised the site conceptual model. For example, the use of SEM/EDX technology allowed differentiation between soluble and insoluble chromium compounds, enabling the delineation of areas in which pigments were capable of leaching to groundwater. In addition, an extensive groundwater profiling program was initiated in 2001, which has provided a better understanding of site groundwater conditions, and has identified at least two previously unknown sources of groundwater contamination.

Approximately 150,000 cubic yards of contaminated soil and sediment will be excavated and placed under an engineered barrier constructed at the site. Subsequently, an extensive monitoring well network will be installed to monitor the effects of source removal on the groundwater quality and to assess the feasibility of implementing a groundwater remedy, if required.