Research Areas > Contaminants > Sediment Quality Assessment > Background: Application of Sediment Quality Assessment

Background: Application of Sediment Quality Assessment

Background

The Porter-Cologne Water Quality Control Act (part of the California Water Code) is the principal law governing water quality regulation in California. It states that any activity or factor that affects water quality is subject to regulation. The Act established the State Water Resources Control Board (SWRCB), and nine Regional Water Quality Control Boards, to implement its provisions beginning in 1969. In 1989, amendments to the Porter-Cologne Act required the SWRCB to develop Sediment Quality Objectives (SQOs) to contribute to the protection of existing and future beneficial uses within enclosed bays and estuaries. To meet this requirement, the SWRCB developed a workplan in 1991to create SQOs, but did not complete the work. The current SQO program is the result of the settlement of a 1999 lawsuit, in which the SWRCB agreed to prepare a revised workplan and complete the SQOs.

To assist the SWRCB, SCCWRP researchers have developed tools and data interpretation methods that can be used to determine whether sediment quality at a specific location meets the goals, or SQOs, set by the State of California for enclosed bays and estuaries.

Key Elements

The State's SQO policy must accomplish several objectives. It should provide scientifically defensible SQOs that are protective of current and probable future beneficial uses in water bodies, including the support of healthy marine and estuarine ecosystems, fishing activities, and human health. In addition, the SQOs should be feasible for diverse regulatory agency staff having differing levels of technical expertise to implement in a consistent and transparent manner. To apply the SQO, three types of information are needed:

• Narrative SQOs for the protection of aquatic life, wildlife, and human health

• Specific indicators, tools, and implementation provisions to determine if the sediment quality at a station meets the narrative objectives

• Guidance for monitoring, stressor identification, and corrective action

Significance

Historically, sediment quality assessment has been an important feature of many monitoring programs throughout the nation, but no state has developed SQOs for statewide regulatory use. SQO adoption by the SWRCB represents a national milestone in environmental policy, making California the first state to have a standardized statewide protocol for the evaluation of sediment quality.