Projects

COAL-FIRED GENERATING STATION CCR POND CLOSURE ACTIVITIES

Industry: Utilities

Location: Midwest

Coal-fired generating station CCR pond closure and maintenance

ENTACT was engaged to perform pond closure, repurposing, and maintenance activities at this coal-fired power plant located along a major river system in the Midwest. Based on the successful completion of the East Bottom Ash Pond Closure, ENTACT was awarded additional work at the facility, as outlined below, on a competitive or sole-sourced basis. Highlighted projects include:

East Bottom Ash Pond Closure
The EBAP was closed in compliance with CCR Rule 40 CFR Part 257 and Effluent Limit Guidelines 40 CFR Part 423. Scope of work included:

Bulk dewatering of the 26-acre pond
Managing 47,200,000 gallons of water over the course of the project
Excavating 348,000 cubic yards of CCR and 52,000 cubic yards of native material
Constructed measures to promote existing habitat for the Least Tern and discourage entry into the construction zone

On-Site Landfill Soil Cover
Concurrent with the activities outlined above, ENTACT was engaged to install a temporary soil cover over the on-site landfill at this at this coal-fired power plant to facilitate germination. Scope of work included:

Managing 47,000 cubic yards of soil on the constructed landfill subgrade
Placing 4,500 square yards of geotextile and 2,200 tons of rip rap in seven drainage channels
Installing erosion control measures
Hydroseeding 28 acres of the landfill area

West and East Bottom Ash Pond Repurposing
The West Bottom Ash Pond (WBAP) was closed by removal and the East Bottom Ash Pond (EBAP) was retrofitted with a CCR-compliant composite liner system. Scope of work included:

Bulk dewatering of the WBAP
Managing 310,000 cubic yards of CCR, 60,000 cubic yards of underlying native soil
Placing, conditioning, and compacting 250,000 cubic yards of low permeable fill materials and installing the new geosynthetic liner system at the EBAP
Continuous dewatering and treatment of 148,000,000 gallons of water, along with site restoration, environmental protection measures, and supporting construction activities