Spatial Comparison of Persistent Organic Pollutants in the Boardman River Following Impoundment Removal and Channel Restoration.

Semi-permeable membrane devices (SPMDs) were used to quantify dissolved concentrations of persistent organic pollutants (POPs) along a 40-km reach of the Boardman River in Traverse City, Michigan that has recently undergone dam and impoundment pond sediment removal. Concentrations of polychlorinated biphenyls (ΣPCBs; 7.7-65.0 pg/L), dichloro-diphenyl-trichloroethane and metabolites (ΣDDTs; 7.6-202.5 pg/L) and cyclodiene compounds (3.7-220.7 pg/L) were below regulatory guidelines considered to pose chronic risks to aquatic health. POP concentrations estimated from SPMD monitoring were not representative of potential residual contamination from legacy sediment impoundments. Spatial patterns in POP profiles were present among the different deployment sites and were reflective of differences in land-use patterns along the rural to urban gradient of the monitored area of the river. These results represent baseline POP data prior to the removal of remaining dam infrastructure in the Boardman River. Overall, this study supports the utility of SPMDs for monitoring trace environmental contamination and helps assess the efficacy of environmental remediation for mitigating legacy pollutant releases following dam and impoundment pond sediment removal.