The California Water Boards' Annual Performance Report - Fiscal Year 2012-13
PLAN AND ASSESS: TOTAL MAXIMUM DAILY LOAD |
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MEASUREMENTS
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WHAT THE MEASURE IS SHOWING
In Fiscal Year (FY) 2012-13, the Regional Boards adopted 12 TMDL projects that addressed 13 water body-pollutant combinations, or listings, to help restore impaired water bodies in the state. Another 87 TMDL project commitments, which address 433 listings, were underway. Since the early 1990s, the Regional Boards have adopted approximately 197 TMDL projects that have addressed almost 1,256 listings. Over 2,233 water body-pollutant combinations, however, remain listed as impaired (FY) 2012-13.
WHY THIS MEASURE IS IMPORTANT
When it is determined that a water body is too polluted to meet its water quality standards, the water body is considered degraded and put on the list of impaired waters, called the Clean Water Act Section 303(d) list. A total maximum daily load (TMDL) is required for impaired waters to restore them to conditions that support their beneficial uses. The TMDL specifies the pollutant loading that a water body can receive and still meet water quality standards, and allocates the pollutant loading that may be attributed to each source of the pollutant(s). TMDLs, along with their implementation plans, are adopted by the Regional Boards and the State Board. Each project is subject to U.S. EPA approval. This lengthy process involves dischargers and many other stakeholders. Subsequently, those responsible for the pollutant sources that cause or contribute to the impairments take corrective actions to protect the water bodies. There is variance in the complexity of each TMDL developed by the Regional Boards; some TMDLs will require more resources than others to develop. |
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TECHNICAL CONSIDERATIONS
- Data Source: TMDL Planner/Tracker database. Period: July 1, 2012 to June 30, 2013. Extracted in August 2013.
- Unit of Measure: Number of TMDL projects adopted and TMDL listings addressed in FY 12-13.
- Data Definitions: TMDL Project: A TMDL project is a planned strategy to reduce pollution in an impaired water body so that its water quality standards are met. A TMDL project addresses one or more pollutants for a given waterbody or segment of waterbody (known as TMDL listings). TMDL Listing: A TMDL listing refers to a pairing of a waterbody and a pollutant that is responsible for the impairment (i.e., each water body-pollutant combination is called a listing). A given waterbody is impaired due to the presence of one or more pollutants (each called a listing) and a TMDL project may address more than one listing. The extent of each listing varies among Regional Boards. The current TMDL projects and listings are documented in the Water Boards' 2010 Clean Water Act Section 303(d) list. Listing Underway: Listings remaining to be addressed by TMDL projects underway.
- References: Information on the Water Boards' TMDL activities
GLOSSARY
- Impaired Water
- An impaired waterbody is one that does not meet the water quality objectives established to protect the beneficial uses of the water due to the presence of one or more pollutants. Such waters are identified on the Water Boards' Clean Water Act Section 303(d) list.
- Pollutant
- A pollutant is a waste or substance that, at certain levels, can cause waterbody impairment. The monitoring programs of the Water Boards and others provide information on the levels of pollutants in the State's waters.
- TMDL Projects Adopted in FY 12-13
- The number of TMDLs adopted in FY 12-13.
- Other TMDL Projects Being Addressed in FY 12-13
- The number of TMDL development projects that were worked on (phases 1-6) during the fiscal year, but were not adopted during the fiscal year. This does not include TMDL implementation work.
- Listings Addressed by TMDL Adoptions in FY 12-13
- The numbers of listings that were addressed through work on "TMDL Projects Adopted in FY 12-13."
- Other Listings Being Addressed in FY 12-13
- The number of listings that were addressed through work on "Other TMDL Projects Being Addressed in FY 12-13."