With the current smelter demolition work underway in Goldendale, Washington, Envirocon will demonstrate its versatility in remediation services by carrying out the NPDES Ponds Cleanup Action associated with the Columbia Gorge Aluminum (CGA) plant located in Goldendale, Washington.
The NPDES ponds are four ponds that were used for detention of wastewaters from the aluminum plant. The ponds were constructed by installing earthen dikes across a natural surface water drainage that extended from the plant to the Columbia River. Two of the ponds were constructed in 1971 to remove suspended sediment from plant wastewater. In 1972 and 1973, two additional ponds were constructed downstream from the first two ponds to increase wastewater detention capacity.
The Envirocon crew will be excavating all pond sediment and underlying soil with elevated levels of polycyclic aromatic hydrocarbons (PAHs) and excavating sediment in the ditches connecting the ponds. The removal of contaminated sediment within the ponds and ditches will require dewatering and/or drying of sediment to minimize landfill tipping fees as well as the blending of the sediment to maximize the amount disposed of as a solid waste and minimize the amount disposed of as a hazardous waste. All contaminated sediment will be disposed of at commercial solid waste and hazardous waste landfills.