Ecological Risk-Based PCB Cleanup Level in River Sediments
Gradient developed ecologically-based PCB cleanup levels in sediment and upland soils along a seven mile stretch of a small river in the Midwest. We evaluated PCB exposure of fish; aquatic invertebrates; aquatic plants; piscivorous birds; and herbivorous and carnivorous mammals within the local food web. We assessed PCB exposure from direct contact with sediment and soil; as well as by transfer via the food chain. Assessment endpoints selected for evaluation included growth; reproduction; and survival. The small size of the river; combined with the large foraging range of many of the receptors; yielded an area-weighted average cleanup goal of 1.0 mg/kg in sediments. The remedial action level (RAL) to achieve this area-weighted cleanup goal was 10 mg/kg for PCBs in sediments over the full range of the river; sediment RALs over 1-mile averaging areas were approximately 4 mg/kg. We also developed human health based RAL values of 5 mg/kg and 50 mg/kg for PCBs in soils in residential and recreational areas; respective
Project Highlights
- Foraging area-weighted exposures
- Food web modeling
- Area-weighted PCB cleanup levels
