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Santa Ana Region - Total Maximum Daily Load

Santa Ana Region - Total Maximum Daily Loads (TMDLs)

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What are TMDLs?

The Federal Clean Water Act Section 303(d) requires that States identify waters that do not or are not expected to meet water quality standards (beneficial uses, water quality objectives and the antidegradation policy) with the implementation of technology-based controls. Once a waterbody has been placed on the 303(d) list of impaired waters, states are required to develop a Total Maximum Daily Load (TMDL) to address each pollutant causing impairment. A TMDL defines how much of a pollutant a waterbody can tolerate and still meet water quality standards. Each TMDL must account for all sources of the pollutant, including: discharges from wastewater treatment facilities; runoff from homes, forested lands, agriculture, and streets or highways; contaminated soils/sediments, legacy contaminants such as DDT and PCBs on-site disposal systems (septic systems) and deposits from the air. Federal regulations require that the TMDL, at a minimum, account for contributions from point sources (permitted discharges) and contributions from nonpoint sources, including natural background. In addition to accounting for past and current activities, TMDLs may consider projected growth that could increase pollutant levels. TMDLs allocate allowable pollutant loads for each source, and identify management measures that, when implemented, will assure that water quality standards are attained.

California state law (Porter-Cologne Water Quality Control Act, California Water Code Section 13000 et. seq.) requires the Regional Board to formulate and adopt water quality control plans, or Basin Plans, for all areas within its region. The Basin Plans must include an implementation plan that describes how the water quality standards established in the Basin Plan will be met. TMDLs, with their associated implementation plans, are adopted into the Basin Plans through the Basin Planning process.

How are TMDLs developed?

In general, when developing TMDLs, the Regional Board undertakes the following five steps:

  • Involve Stakeholders: Stakeholders can be the general public, business interests, local, state or federal government entities, environmental groups, or anyone concerned with a particular water body. The Regional Board involves stakeholders at the beginning of the process in order to provide ongoing input to the Regional Board on the development of TMDLs.

  • Assess water body: In this step, sources and amounts, or "loads" of the pollutant to the impaired water body, are identified. In addition to calculation of daily pollutant loads, this analysis may also consider seasonal pollutant loads as well as annual pollutant loads. Then the overall effect of these loads on the water body is determined.

  • Define the Total Load and Develop Allocations : The loading capacity is the maximum allowable pollutant load that may be discharged to a water body and still achieve water quality standards. The total allowable load is then allocated among all sources that have been previously identified. TMDLs can address single pollutants or combinations of pollutants. Federal regulations provide that TMDLs can be expressed as mass, thermal energy, toxicity or other appropriate measures.

  • Develop Implementation Plan: This step is a description of the approach and activities to be undertaken to ensure that the allocations are met. The parties responsible for carrying out the actions are identified. The implementation plan also specifies any additional studies or data that are needed to refine the TMDL, and the monitoring that is to be conducted to determine whether the implementation of the TMDL results in achieving water quality standards.

  • Amend the Basin Plan: State law requires that TMDLs be incorporated into the Basin Plan through the Basin Planning process. The Basin Plan amendment legally establishes a TMDL and provides the basis for regulatory requirements. Basin Plan amendments are adopted through a public process that requires approval by the Regional Board, the State Water Resources Control Board, the California Office of Administrative Law, and USEPA.

TMDL Elements

A complete TMDL must contain all of the following elements:

  • Problem Statement: Describes the water body, impaired beneficial uses, and pollutant(s) causing the impairment.

  • Numeric Targets: Expresses the desired condition of the water body to protect beneficial uses.   Defines indicators and associated target(s) necessary to meet numeric or narrative water quality objectives.

  • Source Analysis: Assesses the relative contributions of different pollutant sources or causes and the extent of necessary reductions/controls.

  • Linkage Analysis: Describes the relationship between numeric target(s) and sources and estimates the ability of the water body to assimilate the pollutant.

  • Allocations: Allocates responsibility for pollutant reduction. Allocations may be specific to agencies or persons (businesses), or general by source category or sector. The sum of individual allocations must equal the total allowable pollutant level.

  • Margin of Safety: Accounts for uncertainty associated with calculating pollutant loads and their impact on water quality. The margin of safety may be implicit (i.e., through use of conservative assumptions) or explicit (i.e., by assigning a specific allocation to the margin of safety).

  • Implementation Plan: Details pollution prevention, control, and restoration actions, responsible parties and schedules necessary to attain water quality standards. Identifies enforceable measures (e.g. prohibition) and triggers for Regional Board action (e.g., performance standards).

  • Monitoring/Re-evaluation: Describes the monitoring strategy that will be used to evaluate the effectiveness of the TMDL and a schedule for reviewing and, if necessary, revising the TMDL and associated implementation elements.

How long does it take to develop a TMDL?

The process might take two to six years from the beginning of a TMDL project to a Basin Plan amendment. The time required depends on the complexities of scientific and policy issues, the availability of scientific information, and whether additional research studies and data are needed.

How are TMDLs implemented?

Developing TMDLs is only the first step toward solving water quality problems. TMDLs must be implemented to ensure the restoration of water quality standards. TMDLs specify a set of actions to improve water quality that can include the following:

  • Enhancing pollution prevention programs for wastewater and urban runoff.

  • Cleaning up contaminated soils/sediments, legacy contaminants.

  • Reducing pollution from agriculture, animal feedlots, septic systems, and marinas.

  • Restoring habitat for fish, birds, and other wildlife.

  • Working with local governments to create or revise ordinances and other policies.

  • Ongoing monitoring to track water quality improvements.

How can I get involved?

Public participation is a vital part of the TMDL process. Those interested in TMDLs are often referred to as stakeholders. Each TMDL has its own stakeholder process, which can include attending meetings, submitting written comments on draft reports, and reviewing posted items on the Regional Board website. Sometimes, the Regional Board will seek public assistance with tasks, such as data gathering, data analysis, or public education efforts.

To receive notifications by e-mail, subscribe on-line to our TMDL Projects, electronic mailing list.

Additional TMDL Information

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TMDL Projects in the Santa Ana Region

Watershed Impaired Water Body Pollutant(s) TMDL Project Status
Big Bear Lake Big Bear Lake Metals Metals TMDLs for the Big Bear Lake Watershed
(Michael Perez)
Other Action
Noxious aquatic plants Nutrients Implementation Phase
Sedimentation/ Siltation Sediment TMDLs for Big Bear Lake and Rathbun Creek
(Michael Perez)
Other Action
Mercury Mecury TMDL for Big Bear Lake
(Michael Perez)
Under development
Grout Creek Metals Metals TMDLs for the Big Bear Lake Watershed
(Michael Perez)
Other Action
Nutrients Nutrient TMDLs for Big Bear Lake Tributaries
(Heather Boyd)
Under development
Knickerbocker
Creek
Metals Metals TMDLs for the Big Bear Lake Watershed
(Michael Perez)
Other Action
Pathogens Knickerbocker Creek Bacterial Indicators
(Michael Perez)
Implementation Phase
Rathbone (Rathbun) Creek Nutrients Nutrient TMDLs for Big Bear Lake Tributaries
(Heather Boyd)
Under development
Sedimentation/
siltation
Sediment TMDLs for Big Bear Lake and Rathbun Creek
(Heather Boyd)
Other Action
Summit Creek Nutrients Nutrient TMDLs for Big Bear Lake Tributaries
(Heather Boyd)
Under development
 
Middle Santa Ana River Chino Creek,
Reach 1
Pathogens

Bacterial Indicator TMDLs for the Middle Santa Ana River Watershed Waterbodies
(Bill Rice)

Implementation Phase

Chino Creek,
Reach 2
High coliform count
Cucamonga Creek, Valley Reach High coliform count
Mill Creek
(Prado Area)
Pathogens
Santa Ana River, Reach 3 Pathogens
Prado Park Lake Pathogens
Santa Ana River, Reach 3 Nitrate Santa Ana River, Reach 3 Nitrate TMDL
(Hope Smythe)
Implementation Phase
 
San Jacinto Canyon Lake
(Railroad Canyon Reservoir)
Nutrients Nutrient TMDLs for Lake Elsinore and
Canyon Lake

(Hope Smythe)
Implementation Phase
Pathogens Bacterial Indicator TMDLs for Canyon Lake
(Bill Rice)
Other Action
Lake Elsinore Nutrients

Organic Enrichment/Low Dissolved Oxygen
Nutrient TMDLs for Lake Elsinore and
Canyon Lake

(Hope Smythe)
Implementation Phase
 
Newport Bay/San Diego Creek Newport Bay,
Lower
Metals Organochlorine Compounds and Metals TMDL, Lower Newport Bay: Rhine Channel
(Wanda Cross)

San Diego Creek and Newport Bay Metals TMDLs
(Linda Candelaria)

Newport Bay/ San Diego Creek Selenium TMDLs
(Terri Reeder)
Technical TMDLs
Nutrients Nutrient TMDL for the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
Pathogens TMDL for Fecal
Coliform Bacteria in
Newport Bay

(Linda Candelaria)
Implementation Phase
Pesticides/
Priority Organics
San Diego Creek/Newport Bay Organochlorine Compounds TMDLs
(Terri Reeder)

Organochlorine Compounds and Metals TMDL, Lower Newport Bay: Rhine Channel
(Wanda Cross)
Technical TMDLs
Siltation TMDL for Sediment in the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
Newport Bay, Upper
(Ecological Reserve)
Metals San Diego Creek and Newport Bay Metals TMDLs
(Linda Candelaria)

Newport Bay/ San Diego Creek Selenium TMDL
(Terri Reeder)

Technical TMDLs

Nutrients Nutrient TMDL for the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
Pathogens TMDL for Fecal Coliform Bacteria in Newport Bay
(Linda Candelaria)
Implementation Phase
Pesticides Diazinon and Chlorpyrifos TMDL for San Diego Creek and Upper Newport Bay
(Doug Shibberu)

San Diego Creek/Newport Bay Organochlorine Compounds TMDLs
(Terri Reeder)
Implementation Phase



Technical TMDLs
Siltation TMDL for Sediment in the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
 

San Diego Creek,
Reach 1

Metals San Diego Creek and Newport Bay Metals TMDLs
(Linda Candelaria)
Technical TMDLs
Nutrients Nutrient TMDL for the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
Pesticides San Diego Creek/Newport Bay Organochlorine Compounds TMDLs>
(Terri Reeder)

Diazinon and Chlorpyrifos TMDL for San Diego Creek and Upper Newport Bay
(Doug Shibberu)
Technical TMDLs


Implementation Phase
Siltation Sediment TMDL for the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
San Diego Creek,
Reach 2
Metals San Diego Creek/Newport Bay Metals TMDL
(Linda Candelaria)
Technical TMDLs
Nutrients Nutrient TMDL for the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)
Implementation Phase
Siltation TMDL for Sediment in the Newport Bay/San Diego Creek Watershed
(Doug Shibberu)

Implementation Phase

Unknown toxicity Addressed by metals and organochlorine TMDLs  

Status column:

  • Under Development The technical report in support of the TMDL is being developed. Obtain the current status through the staff contact.

  • Regional Board adopted TMDL has been adopted by Regional Board; other requisite approvals are pending.

  • Technical TMDL USEPA established technical TMDLs (without implementation plans) for toxic pollutants in San Diego Creek and Newport Bay on June 14, 2002. Regional Board staff are developing the State required Basin Plan amendments, including implementation plans.

  • Implementation Phase Adoption process by the Regional Board, the State Water Resources Control Board, the Office of Administrative Law, and the US Environmental Protection Agency completed and TMDL being implemented.

  • Other Action A process other than a TMDL is being pursued or considered for the impaired waterbody/pollutant combination. 'Other Action' includes a pending 303(d) delisting, a recommended delisting, or implementation through permits or other regulatory actions.