Location: Marple Township, Delaware County, PA
In support of a Pennsylvania Department of Environmental Protection (PADEP) Act 2 Remedial Investigation Report (RIR) and Cleanup Plan (CP), Brickhouse performed a Baseline Human Health Risk Assessment (HHRA) for a future residential development in Marple Township, Delaware County, PA. The property formerly operated as a pre-Mining Act quarry in the early 1900s, and most recently, was used by a construction company for equipment storage and maintenance. The currently unused property is proposed to be redeveloped by 26 residential homes. The HHRA was unique in that the property is surrounded by woodlands on all sides. A tributary to Darby Creek flows from west to east through the northern edge of the Site and the banks of the stream dip steeply down to the channel five to ten feet below surrounding grade.
The HHRA was conducted in order to characterize the potential exposure and risks associated with Site soil, bank soil, sediment, surface water, and soil vapor to all potential current and future human health receptors. Brickhouse used Site-specific conditions to consider individual and cumulative risks to both future construction/utility workers and child and adult residents. Recreational users and trespassers were considered in the evaluation and Brickhouse conservatively assumed that future Site residents would also recreate along and within the tributary and may potentially be exposed to bank soils, sediment, and surface water, in addition to Site soil and indoor air. Brickhouse employed upper-bound conservative exposure parameters to ensure that early lifetime exposure to mutagenic carcinogens was accounted for the residential child/recreator. Brickhouse was able to conclude that under baseline conditions, there are no adverse impacts to current- and potential future-use receptors at the Site and the original plan to include a two-foot engineered clean soil cap was no longer needed.