Shallow Tidal Water Restoration Using In-Lieu Fee Mitigation Funds at Paradise Creek on the Elizabeth River in Portsmouth Virginia. The highly industrialized Elizabeth River in Southeastern Virginia is identified as a toxic region of concern by the multi-state Chesapeake Bay Program. Legacy contaminants identified in the sediment of Paradise Creek, a shallow tidal tributary of the Elizabeth River, are being remediated to restore and enhance shallow water habitat using in-lieu fee mitigation funds.
Paradise Creek Mitigation Site PCBs are the primary toxicity driver in Paradise Creek and the IRT-approved mitigation approach addresses PCBs, PAHs and other organic contaminates present in the sediment. PCBs can move up the food chain posing a threat to both marine and human health. PAHs are known to negatively impact marine organisms. Sequestering the PCBs and other organic compounds will improve the Paradise Creek habitat conditions providing an off-set for unavoidable permitted impacts to higher quality shallow water sediment.
Emerging New Mitigation Approach The Living River Trust’s Paradise Creek ILF is the first to address contaminated sediments as permit mitigation. The IRT approved advance credits based on LRT’s sediment remediation track record. The Paradise Creek mitigation site is comprised of sub-areas with varying degrees of contaminant impact. Mitigation consists of one of the following two approaches: 1) Sediment Restoration – The top 1- 1.5 feet of the most highly contaminated areas are dredged, amendment material (activated carbon pellets) is spread on the dredged area, clean sand is back-filled to original contours, and a second amendment layer is spread on the new surface. 2) Sediment Rehabilitation – For lesser contaminated areas, a thin layer of amendment material (activated carbon pellets) is spread over the existing sediment surface. Mitigation construction was initiated in September 2021.
