TMDLs & Impaired Waters in California

What is a TMDL?

Generally, a TMDL is a written implementation plan or component thereof that designates a lesser water quality standard(s) for an impaired water body and must account for all point sources and non-point sources of water pollution.

What is an “impaired water body”?

An impaired water body is a water body that does not meet acceptable water quality benchmark standards despite best efforts to prevent or minimize water pollution from point sources by using technology-based approaches.

What does TMDL stand for?

TMDL stands for Total Maximum Daily Load.

Can the TMDL be more than a daily plan?

A TMDL can be either daily, monthly, annual, seasonal etc. Thus, the name TMDL can sometimes be a misnomer in cases where the plan is not daily (i.e. monthly, annual, seasonal).

Does a TMDL address a single pollutant or multiple pollutants?

A TMDL may address a single pollutant or may address multiple pollutants.

What is the background of the TMDL?

Despite best efforts to prevent or minimize water pollution from point sources by using technology-based approaches, some water bodies (impaired water bodies) in our nation still do not meet acceptable water quality benchmark standards.
The Clean Water Act (CWA) acknowledges that such situations occur and requires states to make a list of such impaired water bodies via Section 303(d).
Pursuant to the 1972 CWA Section 303(d), the states are required to create lesser water quality standards (TMDLs) for each of these water bodies on the list, which must be approved by the EPA.
Generally, a TMDL is a written implementation plan or component thereof that designates a lesser water quality standard(s) for an impaired water body and must account for all point sources and non-point sources of water pollution.

Who develops TMDLs in California?

In California, TMDLs are developed by the Regional Water Quality Control Boards or by the U.S. EPA. These TMDLs are amendments to a Basin Plan (water quality control plans).
TMDL status may be reviewed and updated from time to time by the Regional Water Quality Control Board. Currently the Regional Boards are developing more TMDLs.

How much does it cost to prepare a TMDL?

According to the CA Water Board, the cost to prepare a TMDL can reach over $1 million.

Who approves of the TMDL?

The EPA must approve the TMDL.

What are the steps to develop a TMDL?

  • Involve Stakeholders
  • Assess Water Body
  • Define the Total Load and Develop Allocations
  • Develop Implementation Plan
  • Amend the Basin Plan

What are the elements of a TMDL?

  • Problem Statement
  • Numeric Targets
  • Source Analysis
  • Allocations
  • Implementation Plan
  • Linkage Analysis
  • Monitoring/Re-evaluation
  • Margin of Safety

List of TMDLs in California (Table) for Industrial Stormwater Dischargers

San Francisco Bay Regional Water Quality Control Board

Napa River Sediment
Sonoma Creek Sediment

 

Los Angeles Regional Water Quality Control Board

Santa Clara River Reach 3 Chloride
Santa Clara River Nutrients
Los Angeles River Metals
Los Angeles River Nutrients
San Gabriel River Metals and Selenium
Santa Monica Bay Nearshore Debris
Machado Lake Nutrient
Harbor Beaches of Ventura Bacteria
Ballona Creek Metals
Ballona Creek Estuary Toxic Pollutants
Los Angeles Harbor Bacteria
Marina del Rey Back Basins Bacteria
Santa Clara River Bacteria
Walker Creek Mercury
Oxnard Drain No. 3 Pesticides, PCBs (Polychlorinated biphenyls) and Sediment Toxicity
Long Beach City Beaches and Los Angeles River Estuary Indicator Bacteria
Los Angeles and Long Beach Harbors Toxic and Metals
Los Angeles Area Lakes Nitrogen, Phosphorus, Mercury, Trash, Organochlorine Pesticides and PCBs
Santa Monica Bay DDTs and PCBs
Machado Lake Toxics
Colorado Lagoon Pesticides, Polycyclic aromatic hydrocarbons, PCBs, and Metals
Calleguas Creek Watershed Salts
Calleguas Creek Watershed Metals and Selenium
Ballona Creek, Ballona Estuary, and Sepulveda Channel Bacteria
Marina Del Rey Harbor-Back Basins Copper, Lead, Zinc, and Chlordane, and Total PCBs
Los Cerritos Channel Metals

 

Santa Ana Regional Water Quality Control Board

San Diego Creek and Newport Bay Toxic Pollutants

 

San Diego Regional Water Quality Control Board

Chollas Creek Diazinon
Chollas Creek Copper, Lead and Zinc
Los Penasquitos Lagoon Sediment
Rainbow Creek Total Nitrogen and Total Phosphorus
Shelter Island Yacht Basin Dissolved Copper
Baby Beach in Dana Point Harbor and Shelter Island Shoreline Park in SD Bay Indicator Bacteria
Twenty Beaches and Creeks Indicator Bacteria

Note: Tables listed here are according to California Permit Order 2014-0057-DWQ