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Performance Report

The California Water Boards' Annual Performance Report - Fiscal Year 2009-10

PLAN AND ASSESS: TOTAL MAXIMUM DAILY LOAD

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GROUP: TOTAL MAXIMUM DAILY LOADS
MEASURE: TMDL PROJECTS ADOPTED
TMDL LISTINGS ADDRESSED
TMDL PROJECTS UNDERWAY
TMDL LISTINGS BEING ADDRESSED
MESSAGE:   Thirty-six percent of the TMDL project commitments underway in FY 2009-10 were adopted by Regional Water Boards
KEY STATISTICS FOR FY 2009-10
Number of TMDL Projects Adopted 9
Number of Listings Addressed 61

MEASUREMENTS

 

 

WHAT THE MEASURE IS SHOWING

In Fiscal Year (FY) 2009-10, the Regional Boards adopted nine TMDL projects that addressed 61 water body-pollutant combinations, or listings, to help restore impaired water bodies in the state. Another 16 TMDL project commitments, which address 156 listings, were underway. Since the early 1990s, the Regional Boards have adopted numerous TMDL projects, addressing 787 listings, or 35 percent of the 2,237 listings on the Water Boards’ 2006 Clean Water Act Section 303(d) list of impaired waters. Eight percent of those listings were addressed in FY 2009-10. It is clear from the regional breakdown of listings addressed that most imparied water bodies occur in the regions with relativelyl higher population densities. Some notable TMDLs that were adopted in FY 2009-10 include: temperature, nutrients, and dissolved oxygen for the Klamath River in Region 1; methylmercury for the Sacramento-San Joaquin Delta in Region 5; and dissolved oxygen for the New River in Region 7.

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.

TECHNICAL CONSIDERATIONS

  • Data Source: TMDL Planner/Tracker database. Period: July 1, 2009 to June 30, 2010. Extracted in August 2010.
  • Unit of Measure: Number of TMDL projects adopted and TMDL listings addressed in FY 09-10.
  • 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’ 2006 Clean Water Act Section 303(d) list (https://www.waterboards.ca.gov/water_issues/programs/tmdl/docs/303dlists2006/epa/state_usepa_combined.pdf). Listing Underway: Listings remaining to be addressed by TMDL projects underway.
  • References:  More information on the Water Boards’ TMDL activities is available at:  https://www.waterboards.ca.gov/water_issues/programs/tmdl/

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.

( Updated 9/20/11 )

 
 

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