Total Maximum Daily Load (TMDL) and the 303(d)

This project was developed as a TMDL alternative as part of the Palo Verde Agricultural General Order and addresses DDT and toxaphene impairments in the Palo Verde Outfall Drain and Lagoon. The Palo Verde Agricultural Order was approved by the Regional Water Board on May 15, 2019 and the associated TMDL a alternative is currently under review by the USEPA.  Please email Francisco Costa or phone (760) 776-8937.

This TMDL is part of the Imperial Valley Agricultural General Order and will address PCBs, chlordane, chlorpyrifos, DDT, diazinon, dieldrin, and toxaphene impairments in Alamo River, Imperial Valley Drains, and New River. Please email Logan Raub or phone (760) 776-8966.

This TMDL will address Bifenthrin and Cypermethrin impairments in the New River. Please email Logan Raub or phone (760) 776-8966.

This TMDL will address chloride, indicator bacteria, and toxicity impairments in the Alamo River. Please email Emma McCorkle or phone (760) 340-4521.

This TMDL will address dissolved oxygen and nutrient impairments in the Salton Sea. Please email Emma McCorkle or phone (760) 340-4521.

The TMDL was adopted by the Regional Board June 27, 2001, approved by the State Board on February 19, 2002, approved by the Office of Administrative Law on May 3, 2002, and approved by U.S. EPA on June 28, 2002. The following documents are now available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. 01-100
• TMDL Staff Report
• Appendix A - Soil Association Descriptions
• Appendix B - SWRCB Toxic Substances Monitoring Program
• Appendix C - Source Analysis Data and Calculations
• Appendix D - Load Allocation Calculations
• Appendix E - Silt TMDL Technical Committee
• Appendix F - Silt TMDL TAC BMPs
• Appendix G - Recommendations of the UCCE
• CEQA Checklist and Determination
• Natural Environment Study

The TMDL was adopted by the Regional Board on October 10, 2001, approved by the State Board on March 21, 2002. It was also approved by the Office of Administrative Law on March 23, 2002, and approved by U.S. EPA on August 14, 2002. The following documents are now available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. 01-197
• TMDL Staff Report
• Appendix A: Historical Bacterial Concentrations for New River at International Boundary
• Appendix B: New River Fecal Coliform Results for 2000
• Appendix C: Infectious Agents Potentially Present in Raw Domestic Wastewater
• CEQA Checklist and Discussion

The TMDL was adopted by the Regional Board on June 26, 2002, approved by the State Board on November 19, 2002, approved by the Office of Administrative Law on January 13, 2003, and approved by U.S. EPA on March 31, 2003. The following documents are now available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. R7-2002-0097
• TMDL Staff Report
• Appendix A: Soil Association Descriptions
• Appendix B: SWRCB Toxic Substances Monitoring Program
• Appendix C: Source Analysis Data and Calculations
• Appendix D: Load Allocations
• Appendix E: Silt TMDL Technical Advisory Committee
• Appendix F: TAC Recommendations for On-Field Best Management Practices
• Appendix G: Recommendations of the UC Cooperative Extension
• CEQA Checklist and Discussion
• Natural Environment Study

The TMDL was adopted by the Regional Board on June 21, 2006, approved by the State Board on April 18, 2007, approved by the Office of Administrative Law on August 2, 2007, and approved by U.S. EPA on September 24, 2007. The following documents are now available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. R7-2006-0047
• TMDL Staff Report  |  Appendix A  |  Appendix B
• CEQA Checklist and Discussion
• Natural Environmental Study

The TMDL was adopted by the Regional Board on January 19, 2005, approved by the State Board on July 21, 2005, approved by the Office of Administrative Law on September 8, 2005, and approved by U.S. EPA on September 30, 2005. The following documents are now available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. R7-2005-0006
• TMDL Staff Report
• Appendix A - Silt TMDL TAC
• Appendix B - Source Analysis 
• Appendix C - Allocations
• Appendix D - Implementation Plan
• CEQA Checklist and Determination
• Natural Environment Study
• Economic Impact Assessment
• Responses to Public and Peer Review Comments
• Staff Supplemental Report (9/14/04)

The TMDL was adopted by the Regional Board on May 16, 2007, with revision later adopted by the Regional Board on June 17, 2010. The TMDL was subsequently approved by the State Board on July 19, 2011, approved by the Office of Administrative Law on February 2, 2012, and approved by U.S. EPA on April 27, 2012. The following documents are available:

Regional Water Board

• Basin Plan Amendment
• Resolution No. R7-2007-0039
• Resolution No. R7-2010-0028
• TMDL Staff Report
• Appendix A: Mean Monthly Streamflows, USGS Gage 10259540
• Appendix B: Relationship between Bacteria Indicators and Flows
• Appendix C: Coachella Coliform DNA Analysis Source Report
• CEQA Checklist and Discussion
• Natural Environment Study

State Board Approval

• May 18, 2011 Notice of Opportunity to Comment
• Comments Received
• Response to Comment
• July 15, 2011 Division of Water Quality Request for Executive Officer Corrections
• July 18, 2011 Executive Officer Response to Division of Water Quality Request
• July 19, 2011 State Board Meeting Agenda
• Item Sheet and Draft Resolution
• State Board Resolution No. 2011-0030

Office of Administrative Law (OAL) Approval

• OAL Approval Letter
• Concise Summary of Regulatory Provisions

CEQA Filing with the CA Natural Resources Agency

• Notice of Decision

U.S. Environmental Protection Agency (USEPA) Approval

The TMDL was adopted by the Regional Board on May 20, 2010. The TMDL was subsequently approved by the State Board on December 6, 2011, approved by the Office of Administrative Law on March 21, 2012, and approved by U.S. EPA on November 16, 2012. The following documents are now available:

Regional Water Board

• Resolution No. R7-2010-0011
• Basin Plan Amendment
• TMDL Staff Report
• Appendix A: New River Water Quality Objectives and Beneficial Uses
• Appendix B: Water Quality Data for the New River
• Appendix C: Monthly or Quarterly DO Concentrations Data for Agricultural Drains in the New River Watershed
• Appendix D: NPDES Permittee Information and Data
• Appendix E: Regional Board DO Data at Four New River Sampling Locations
• Appendix F: New River DO QUAL2K Model
• Appendix G: New River Third Party Cooperating Agencies and Organizations
• Appendix H: TMDL Model Scenarios
• New River CEQA and Environmental Checklist
• New River Natural Environment Study
• Public Review Comment and Response

State Board Approval

• September 16, 2011 Notice of Opportunity to Comment
• Comments Received
• Response to Comments
• November 21, 2011 Executive Officer Request to make minor, non-substantive changes to Basin Plan Amendment
• December 6, 2011 State Board Meeting Agenda
• Item Sheet and Draft Resolution
• State Board Resolution No. 2011-0061

Office of Administrative Law (OAL) Approval

• OAL Approval Letter
• Concise Summary of Regulatory Provisions

CEQA Filing with the CA Natural Resources Agency

• Notice of Decision

U.S. Environmental Protection Agency (USEPA) Approval

• October 23, 2012 Executive Officer Letter to USEPA Regarding Clarification of New River Dissolved Oxygen TMDL

The Colorado River Region tries to foster public participation during all phases of TMDL development to address as many technical and social issues as possible early in the process. Each TMDL project will have a unique approach to public participation dependent on the size of the watershed, the nature of the problem, who and how many interested parties or stakeholders emerge, etc. Public participation will at times take on one or more of these forms: occasional public workshops, regularly scheduled steering committee meetings, Technical Advisory committee meetings, Regional Board staff presentations at other organization's meetings, or written solicitations or request for comments sent by mail.

The public has the opportunity and legal right to review and comment on TMDLs before they are made a part of the Basin Plan. Essentially this means that the public has the opportunity to comment on Draft TMDLs in writing prior to Regional Board Hearings or verbally at Regional Board Meetings before a TMDL is adopted and implemented.

Bodies of water are listed as impaired after several steps. One of the steps is the review of information and/or data by Regional Board staff pertaining to a body of water. Regional Board staff will notify the public when the review process will occur, and publicly solicit information or data that would lead to a listing of a body of water.

This section provides other opportunities for the public to be involved in the TMDL process. If the section below is empty, this implies that no specific event is on the agenda in the near future. However, remember that the waters of the state belong to its citizens, and you are encouraged to participate in the process designed to protect this resource. Simply call the Regional Water Quality Control Board office and make inquiries to the staff person working on the body of water near you.