California has passed a bill that will remove Ward Valley from consideration for use as a low-level waste (LLW) disposal site. The bill also requires any future site to have certain engineered and natural barriers.

The bill establishes the required containment standards for any future disposal site, including a prohibition against shallow land burial. The bill requires that the facility be designed and constructed with an engineered vault system with multiple barriers to contain the waste for 500 years.

The facility would have to provide visual or remote monitoring to detect potential or actual releases of LLW. It would also have to be sited in a location with soils and hydrology that would minimise the migration of radioactive material if the engineered barriers fail.