Readers Note: This webpage provides information about ongoing remediation activities at the Reid Gardner Station, a former coal-fired electric generating facility in Southern Nevada. As of July 2020, the Reid Gardner Station is no longer actively producing electricity and all power-generating facilities have been decommissioned and demolished.
Administrative Order on Consent:
NV Energy and the Nevada Division of Environmental Protection (NDEP) entered into an Administrative Order on Consent (AOC) for the Reid Gardner Station (Station) on February 22, 2008. The AOC calls for NV Energy to continue with environmental contaminant characterization activities, including identification of clean-up measures for the soil and groundwater at the site and implementation of these clean-up measures. The AOC also calls for long-term operation and maintenance of NDEP-approved clean-up measures.
Potential environmental contaminants identified at the site include, but are not limited to, total dissolved solids (TDS), sulfate, chloride, metals, volatile organic compounds (VOCs), and petroleum hydrocarbons. [FACT SHEET] [MAP] [SCHEDULE]
Decommissioning and Demolition:
Permanent shut down of Units 1, 2 and 3 occurred on December 31, 2014 and March 11, 2017 for Unit 4. Decommissioning and demolition of the Station was completed in July 2020.
Decommissioning and demolition activities included the removal of coal stockpiles, buildings, stacks, rolling stock, utilities, scrap materials, subsurface structures, and structural foundations to a depth of at least 6 feet below ground surface. This work included identification, removal, and offsite disposal (in accordance with State and Federal regulations) of Universal Wastes, PCB containing materials, and asbestos containing materials (ACM). Other materials such as rolling stock, transformers, steel, and aluminum were either sold for reuse or recycled by the demolition contractor. Concrete foundations were broken up, rebar removed for recycling, crushed and used to backfill excavations in the center of the site. General construction and demolition debris was disposed in the existing Mesa Landfill in accordance with the current Class III industrial waste permit. In total, greater than 95% of the demolished materials were recycled or reused. The plant’s electrical substation was preserved for use in NV Energy’s transmission system. One warehouse, with office space, was also preserved for continuing use by NV Energy staff for onsite operations and site remediation purposes.
Characterization and Remediation Activities:
Operations at the former Station generated waste products including fly ash, bottom ash, and process water effluent. Ash management approaches used over the years of plant operation included placement in ash settling ponds, use of ash as structural fill in select locations, and disposal in the onsite landfill. The great majority of the ash generated by the Station was disposed of dry in the Mesa Landfill.
Process water effluent, including scrubber effluent, was routed to evaporation ponds. Historically, some of these evaporation ponds did not include engineered bottom liners, which resulted in impact to groundwater at the site. Extensive site investigation and evaluation of collected data has been completed by NV Energy since 2014. This work has included the development of a three-dimensional computer model to visualize and evaluate site hydrogeologic and groundwater data. This model is updated by NV Energy as new information becomes available and is being used to better understand the nature and extent of groundwater impacts resulting from pond use and to evaluate the need for corrective action.
Concurrent with site investigations, between 2010 and 2017, all evaporation ponds located within the Muddy River floodplain (Ponds 4A, 4B-1, 4B-2, 4B-3, 4C-1, 4C-2, D, E-1, E-2, F, and G) were taken out of service. Standing water in each pond was allowed to evaporate following which pond solids, bottom liners, and underlying soil were excavated. The exterior berms were retained to protect the areas from possible flooding by the Muddy River. Over 2,100,000 cubic yards of pond solids and underlying soils were removed from these former evaporation pond areas. All excavated materials were disposed of in HDPE-lined cells at the Mesa Landfill in accordance with all permit requirements.
Diesel fuel, which was discovered floating on groundwater in the late 1980s at the petroleum source area of the site, likely resulted from leaks in former underground diesel-fuel piping. A diesel recovery system, which recovered free product and contaminated groundwater, began operation in 1988, was upgraded in 2003 and 2013 before being decommissioned in 2015. An investigation, which began that same year, is currently underway to delineate the remaining extent of petroleum impacts to soil and groundwater. Additionally, as requested by the NDEP, a supplemental oil recovery test project was initiated by NV Energy in June 2022 to determine if residual free product remaining on groundwater in the area can be recovered using currently available technologies. This project is underway with evaluation of test results expected in 2023.
Between 2015 and 2022, NV Energy excavated petroleum impacted soil from five locations within the petroleum source area. Soil samples were collected to define the nature and extent of petroleum contamination and work plans were prepared for excavation and offsite disposal of impacted soil. In total, over 13,000 cubic yards of soil were removed from the former Units 1-3 Lube Oil Rack, Gasoline UST and Warehouse 1, Diesel Fuel Unloading Area, Free Product Recovery System Area, and the former Vehicle Maintenance Area. All excavated soil was disposed off-site at a facility licensed to receive petroleum-contaminated soil.
In the station area, ash/soil fill was used historically to level the ground surface in the Units 1-3 and Unit 4 coal pile areas prior to stockpiling coal for combustion in the generating units. Site investigations in this area were completed by NV Energy between 2016 and 2020 to estimate the quantities of ash/soil fill placed in the area and the nature and extent of impacts to soil and groundwater. Based on this work, remedial excavation of this fill material was initiated in December 2021. Approximately 451,000 cubic yards of this material has been excavated, transported, and placed in the Mesa Landfill. Additionally, about 11,000 tons of petroleum impacted ash/soil fill was excavated and disposed offsite at a facility licensed to receive petroleum-contaminated soil.
In addition to areas of the site associated with evaporation ponds, petroleum hydrocarbons, and ash management, various other potential areas of soil and groundwater contamination have been identified. These areas will also be addressed through implementation of the AOC. These efforts may include sampling soil and groundwater to characterize potential site contamination and then, as appropriate, implementing NDEP-approved clean-up activities.
Reid Gardner Generating Station AOC Meeting Minutes
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Reid Gardner Generating Station NDEP Correspondence
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Reid Gardner Generating Station Reports and Work Plans
