The DOE Office of Legacy Management (LM) is responsible for ensuring that the Grand Junction processing site selected groundwater compliance strategy remains protective of human health and the environment. LM conducted a limited annual groundwater monitoring program, as a best management practice, collecting samples from select monitoring wells through 2006. Samples are now collected once every five years. Sampling at five‑year intervals will continue until concentrations of all analytes are below their respective maximum concentration limits or within the range of background values, or until the monitoring program is modified.
LM manages the Grand Junction disposal site according to a site-specific Long-Term Surveillance Plan that ensures the disposal cell systems continue to prevent release of contaminants to the environment. Under plan provisions, LM conducts annual site inspections to evaluate surface feature conditions, performs necessary site maintenance, and monitors groundwater to verify the disposal cell’s integrity.
In accordance with 40 CFR 192.02(a), the disposal cell is designed to be effective for 1,000 years, to the extent reasonably achievable, and, in any case, for at least 200 years. However, the general license has no expiration date, and LM’s responsibility for the safety and integrity of the Grand Junction disposal site will last indefinitely.