Pollutants in two Delaware waterways reduced

DOVER — The Department of Natural Resources and Environmental Control announced it has successfully used an innovative approach to reduce polychlorinated biphenyls in two Delaware waterways.

Newly released scientific data is validating the new method of sequestering pollutants with activated carbon, which render them unavailable for uptake by fish and other aquatic organisms, DNREC said.

The first success was with an activated carbon product called SediMite at Mirror Lake in Dover in 2013. The project is featured in a new article co-authored by several project participants, including two DNREC scientists, and published in the May issue of Journal of Environmental Engineering.
The article, titled “Full-Scale Application of Activated Carbon to Reduce Pollutant Bioavailability in a 5-Acre Lake” presents a summary of the monitoring data collected at the site between 2013 and 2018.

“The recognition by the Journal of Environmental Engineering reflects how Delaware is on the leading edge of environmental technology, an area DNREC is exploring more and more” said DNREC Secretary Shawn Garvin.

“Mirror Lake was a successful pilot, so DNREC’s team sought a second opportunity to try the technology.”

The A Street Ditch project became a focus for DNREC’s Watershed Approach to Toxics Assessment and Restoration (WATAR) team after samples confirmed drainage ditch sediments were a continuing source of PCBs to the Christina River.

The project, in coordination with cleanup efforts at the adjacent South Wilmington Wetland Park site, provided an opportunity to evaluate an enhanced carbon sequestration technology developed by DNREC’s partners at the University of Maryland Baltimore County (UMBC).

Another harbinger for clean water in Delaware is that sequestering or destroying legacy PCBs – the primary risk driver for most of the fish consumption advisories issued by DNREC and the Delaware Division of Public Health – prevents these contaminants from entering the food chain. With increasing confidence in these innovative sediment remediation technologies, DNREC is beginning to plan for larger-scale projects, in key watersheds across Delaware, with similar water quality impairments.