Missouri Risk-Based Corrective Action (MRBCA)

The department works with hazardous waste facilities to investigate and clean up any release of hazardous waste into the soil, ground water, surface water and air. In some cases, it is not possible or practical to remove all traces of contamination, due to technological, physical or financial limitations. The department uses a risk-based corrective action process, where the site cleanup is based on the risks the contamination poses to human health and environmental as it relates to how the site is used, both now and in the future. 

The department adopted a risk-based corrective action process, also known as RBCA (pronounced "Rebecca"), that provides a framework for remediation, or cleanup, decisions at contaminated sites. This process is similar to other risk-based remediation systems used by other states. A risk-based framework can simplify the site cleanup and closure process, speed up the decision-making process, clearly define the endpoints and focus limited resources (both private and public) on sites with the highest actual or potential risks. Risk-based corrective action protects human health and the environment while allowing constructive current and future site use.

Establishing acceptable cleanup levels is based on planned land use (residential or non-residential) and the path the contamination could take (exposure pathway) from the source to humans, animals or the environment (receptors). An exposure pathway could be direct exposure to surface soil, using groundwater or vapor intrusion into buildings. A warehouse that is being redeveloped as residential apartments would require different cleanup levels and controls put in place than if it were to continue to be used in some sort of industrial use, where families do not live and play and workers can protect themselves from exposure. If determined to be safe, based on evaluating the exposure pathways and receptors, contamination may be left in place with appropriate tools and controls put in place to ensure long-term protection.

The department, with the assistance of stakeholders, developed two separate technical guidance documents for Missouri's risk-based corrective action process. One guidance covers petroleum storage tanks only and the second applies to all other departmental risk-based cleanups. In 2009, the department, with the assistance of stakeholders, developed a risk-based corrective action rule to codify the process and its key elements and methodologies. The Risk-Based Corrective Action Process rule, found in Code of State Regulations 10 CSR 25-18.018, became effective on Oct. 31, 2009. Both the rule and the guidance are used to guide the investigation, risk assessment and cleanup of contaminated sites.