Coastal, River, & Wetland Restoration
- Herrick Hollow Creek — Richardson Hill Road Landfill SFS, EPA Region 2 Superfund Site
Sidney Center, New York
the challengeThe Bioengineering Group was retained by Amphenol Corporation to develop design measures to restore Herrick Hollow Creek at the Richardson Hill Road Landfill Superfund Site. Herrick Hollow Creek eventually discharges via Trout Creek to the West Branch of the Delaware River and the Cannonsville Reservoir operated by the New York City Department of Environmental Protection (NYCDEP). Previous stream restoration measures designed by others had failed multiple times and much of the fill material placed in the stream corridor had been washed downstream into the municipal drinking water reservoir. The situation was very tense due to the need for the NYCDEP to comply with EPA regulations limiting turbidity in the reservoir, and the NY Attorney General’s office was involved. Two prior designers were no longer involved in the work.
the interdisciplinary approach As an immediate short-term remedy, several field engineered interim measures designed to reduce sediment mobility and prevent further stream channel incision were installed. Next, a meeting of stakeholders was convened to establish the goals and objectives for the restoration effort. A key to achieving consensus was for all to understand the trade-offs involved and to establish specific and measurable ecological restoration priorities. The design for complete stream restoration was based on site-specific hydrologic data combined with use of data referencing geomorphically appropriate nearby stream reaches that were known to perform the prioritized habitat functions. After ecological performance was clearly linked to earth science parameters such as channel geometry and base flow, full geotechnical and hydraulic engineering analysis was conducted to validate and refine the treatment designs.
the results The Bioengineering Group brought a level of stakeholder communication and engineering rigor to the project which served to maintain constructive interaction even in the face of severe weather and construction delays. The design approach received support of the stakeholder group, and the consensus process allowed clear communication when change was needed. The Bioengineering Group provided support during construction of various phases and follow-up monitoring of the performance of the restoration and all work was conducted under the close scrutiny of multiple agencies.