Case Study

SALF Leachate Project

Challenge:

A power plant client needed to redirect ash contact water from an on-site landfill to wet scrubbers for pollution mitigation to comply with a consent degree. The client was faced with a challenge of improving existing conditions to comply with the environmental requirements agreed upon with their state government.

Solution:

Valdes assumed responsibility for the detail engineering and filled in numerous gaps from the initial project study phase. This allowed our utility client to save significantly on material and installation costs during the execution phase of this project.

Valdes ultimately engineered and designed all associated systems to redirect ash contact water from an on-site landfill to wet scrubbers for pollution mitigation, per the consent decree with the State of Indiana. Valdes repurposed the existing storm water pond to handle the hazardous material - utilizing a new pond design, addition of pond liner, new electrical and controls systems, and new forwarding pumps. The wastewater is to be processed at the power plant and disposed of via the plant’s wet scrubbers.

Valdes also performed the layout and routing of approximately 15,000 feet of mostly underground 12” HDPE pipe on plant property to convey the ash leachate contact water to the main plant for disposal. Additionally, Valdes designed and routed two underground 14kV power distribution lines and fiber optic lines, along with separate concrete duct banks, to provide power to the new electrical building (following the same routing as the transfer piping).

Valdes provided significant cost savings to the client by reusing an existing storm water pond to hold ash leachate. Valdes designed a new impermeable liner, and it was installed to prevent contaminated water from reaching the ground water supply. Valdes designed this pond to handle back-to-back 25-year rain events and is designed with redundant HDPE liners.

Impact:

Valdes provided a significant cost savings to the client by reusing an existing storm water pond to hold ash leachate. It was designed to handle back-to-back, 25-year rain events and with redundant HPDE liners. A new impermeable liner was designed and installed to prevent contaminated water from reaching the ground water supply.