Preserve at Wye Mills Wastewater Treatment Plant

Talbot County, Maryland

Until 2021, the Preserve at Wye Mills Wastewater Treatment Plant (WWTP) was owned by the property owners association. It was failing and repeatedly violating permit requirements, resulting in the Maryland Department of the Environment (MDE) taking formal action. In 2021 the Talbot County Council passed a resolution authorizing the County to take over management of the plant calling it an “emergency and a public health menace.” The County also entered into a Settlement Agreement and Consent Order with MDE.

RAUCH inc. was retained to conduct a preliminary engineering analysis of the existing facilities at the WWTP. Our analysis revealed that the WWTP was designed for the community’s full buildout of 67 lots with a total design flow of 20,100 GPD; however, only 53 homes were connected generating average flows of 7,367 GPD (approximately 36% of the design flow capacity). Low flow and low organic loading were significant contributors to the operational issues at the plant. Our analysis also evaluated spray field capacity and storage lagoon capacity.

Our environmental services team investigated site feasibility to safely attenuate wastewater from the failing RBC plant to effectively lower nutrient concentrations being observed in background water quality. Our evaluation consisted of preliminary examination of soils from 4” hand augers, converting the bore holes into 2-inch diameter hydraulic conductivity wells for slug testing, surface infiltration testing using a 24” single ring infiltrometer, and reading water levels over the course of this report. We conducted groundwater, slug/percolation, and infiltrometer tests, and conducted a mounding analysis.

After our studies were completed, ProStart was hired as an operator to work under our supervision. As a short-term solution, we implemented process refinements and minor equipment changes that were successful in immediately improving performance at the plant. We were also asked by the County to evaluate long-term options for repairing or replacing the existing WWTP and getting it to ENR treatment. We provided the County with a report making recommendations on MBR treatment add-on units, and addressing permitting, right-of-way, and sustainability concerns. We included total alternative costing (with debt repayments), a life cycle cost analysis, O&M costs, soft costs, and construction cost estimates. Most recently, we have provided the County with 80% design plans for the improvements.