Last week, the California State Water Resources Control Board (SWRCB) gave notice of public opportunity to comment on its proposed April adoption of the Water Quality Control Policy for Low-Threat Underground Storage Tank Case Closure (Low-Threat Closure Policy). This should come as welcome news for the thousands of underground storage tank (UST) sites in California because the Low-Threat Closure Policy will hopefully make it easier to obtain closure.
The Low-Threat Closure Policy recognizes that many petroleum release cases pose a low-threat to human health and the environment. The policy’s purpose is to establish consistent California statewide case closure criteria for low-threat petroleum UST sites. To potentially qualify for closure, the site must satisfy eight general criteria (applicable to all sites), as well as media-specific criteria as it pertains to groundwater, vapor intrusion to indoor air and direct contact, and outdoor air exposure. Below is a brief description of each of these criteria.
The general criteria are as follows:
- Site must be in a service area of a public water system: The policy recognizes that while new water supply wells are unlikely to be installed in the shallow groundwater near former UST release sites, it is difficult to predict whether this will always be the case, particularly in rural areas that are undergoing new development. Therefore, the policy is limited to areas with available public drinking water supplies. Continue reading