An owner of a coal-fired power plant, committed to complying with the Federal Coal Combustion Residuals (CCR) Rule for its CCR storage impoundments, requested high resolution characterization (HRSC) and remediation of a release to groundwater adjacent to the impoundments.
Geosyntec’s Scope of Services
Geosyntec completed HRSC and then fast‐tracked design and construction of a groundwater extraction and conveyance system to meet a stringent regulatory-driven deadline. The remedial system included the installation of nine extraction wells with a total flow rate up to 250 gallons per minute (gpm). Extracted groundwater is treated on-site before ultimate disposal in a Class I deep injection well system.
Groundwater characterization began in a stepwise fashion using multiple HRSC techniques (e.g., surface and borehole geophysics, direct push technology). Our staff used two- and three-dimensional visualizations to inform the development of a conceptual site model (CSM) that supplemented our understanding of groundwater conditions near the impoundments. The CSM was used to guide the design and installation of an expanded groundwater monitoring network and as the basis for remedial alternatives evaluation, regulatory negotiation of a remedial action plan, and remedial design.
Following regulatory approval, our team developed intermediate, final, and certified-for-construction engineering design packages that covered the extraction wells, pumps, wellhead fixtures, conveyance forcemains, electrical, and controls. Due to concentrations of groundwater constituents, corrosion/scaling issues were predicted by geochemical modeling and subsequently observed during system operation. The potential for scaling was addressed through flexible system design and routine system operation and maintenance (O&M).
During design and before construction, Geosyntec developed an aggressive project schedule to meet regulatory deadlines. During preliminary design, capital and operational cost estimates were developed to assist the client with cash flow management. We also provided construction engineering, coordination of communication among multiple subcontractors/vendors and on-site personnel, and quality assurance support during system construction. Geosyntec performed system startup testing, developed as-built drawings and an operations and maintenance manual, and currently assist with system operation, performance evaluation, optimization, and reporting.
Geosyntec’s ability to work as part of a unified, interdisciplinary team with the client and subcontractors was critical in achieving ultimate project success. This cohesion allowed the team to meet tight project deadlines based on regulatory requirements, and used HRSC tools to assess, design, and implement corrective measures. These activities allowed our client to meet their desired remedy implementation deadlines.
- Location: Confidential
- Client: Confidential Client
- Project Practice Areas: Water and Natural Resources
- Type of Facility: Confidential Coal-Fired Power Plant
- Services Provided: High‐resolution site characterization, Conceptual site model development, Regulatory negotiation, Groundwater extraction system design and installation oversight, Cost forecasting, Schedule development and management, Construction quality assurance
- Type of Work: groundwater treatment design and construction
- Governing Regulation: State and local