Coal combustion byproducts (CCBs), though not considered hazardous waste under the Resource Conservation and Recovery Act, have the potential to impact the environment, particularly groundwater and surface water. Potentially toxic heavy metals such as arsenic, cadmium, lead, mercury, and chromium are present in trace quantities in CCBs, and rainwater can cause these constituents to leach into groundwater and surface water.
Geosyntec’s client owns and operates multiple coal combustion byproduct storage and management facilities, two of which are located on the East Coast of the United States. The sites, each covering hundreds of acres, are used to manage CCBs, or coal ash, generated from nearby power generating facilities. Geosyntec was retained by the client to evaluate the as-built conditions of the CCB storage facilities, as well as to evaluate the nature and extent of potential impacts to groundwater and surface water from the stored coal combustion byproducts.
Geosyntec’s Scope of Services
To assess the as-built conditions and the nature and extent of potential impacts to groundwater and surface water from CCBs managed at the two storage facilities, Geosyntec performed site characterization activities at both sites.
First, Geosyntec gathered information on characteristics of CCB source materials through boring activities, sampling and analyzing both soils and the CCB materials in the storage cells. To assess the as-built conditions of the CCB management areas, Geosyntec evaluated the construction characteristics for both the stormwater and leachate collection and conveyance systems. Moreover, Geosyntec assessed the potential for off-site contributions from historic or current activities.
Geosyntec also evaluated the geological and hydrogeological conditions at the sites to develop an understanding of the potential for metals impacts to surficial aquifers and bedrock groundwater. As part of that evaluation, Geosyntec looked for potential interactions between groundwater and surface water and the sites. Furthermore, Geosyntec planned and performed sampling events for both surface water and groundwater, monitoring for target metals and other constituents. Finally, to better understand the potential impacts on the area, Geosyntec performed an evaluation of potential surface water and groundwater receptors.
At one of the locations, storm-related damage to a containment berm resulted in a release of CCBs from the site into an adjacent waterway. Geosyntec responded quickly on behalf of the client, performing a delineation of the affected area and a wetlands impact assessment. Geosyntec also assisted the client with contracting and completing recovery activities to restore the wetlands area. Work was done promptly and to the satisfaction of state regulatory agencies.