Groundwater Monitoring Plan for the Nonradioactive Dangerous Waste Landfill

The Nonradioactive Dangerous Waste Landfill (NRDWL), which received nonradioactive hazardous waste between 1975 and 1985, is located in the central Hanford Site (Figure 1.1) in southeastern Washington State. The Solid Waste Landfill, which is regulated and monitored separately, is adjacent to the NRDWL. The NRDWL is regulated under the Resource Conservation and Recovery Act of 1976 (RCRA) and monitored by Pacific Northwest National Laboratory. Monitoring is done under interim-status, indicator-evaluation requirements (WAC 173-303 and by reference, 40 CFR 265.92). The well network includes three upgradient wells (one shared with the Solid Waste Landfill) and six downgradient wells. The wells are sampled semiannually for contaminant indicator parameters and site-specific parameters and annually for groundwater quality parameters.