Skip to Content


United States Section; Notice of Availability (NOA) of the Draft Supplemental Environmental Impact Statement (DSEIS) for Clean Water Act (CWA) Compliance at the South Bay International Wastewater Treatment Plant (SBIWTP), San Diego, California

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


United States Section, International Boundary and Water Commission (USIBWC).


Notice of Availability.


This announces the availability of the DSEIS that assesses the potential environmental impacts of the construction and operation of a range of treatment and disposal alternatives for the SBIWTP to achieve compliance with the CWA. Situated in the United States at the United States/Mexico border, the SBIWTP treats sewage flows originating from the City of Tijuana, Mexico and the surrounding region and discharges into the Pacific Ocean through an ocean outfall. The DSEIS considers existing and new alternatives that would enable the USIBWC to bring the SBIWTP into compliance with the CWA and the requirements contained in its National Pollutant Discharge Elimination System (NPDES) permit and to evaluate new information on the current discharges of advanced primary effluent from the SBIWTP through the South Bay Ocean Outfall (SBOO), as well as interim actions that would continue operations of the SBIWTP until the SBIWTP achieves CWA compliance. The United States Environmental Protection Agency (USEPA), Region 9, San Francisco, California, is a Cooperating Agency for this action.


Written comments are requested by February 28, 2005. The public comment period of the DSEIS will end 60 days after publication of the NOA in the Federal Register.

Public Hearing: A public hearing regarding the findings of the DSEIS and to take comments on the DSEIS will be held at 6:30 pm on Wednesday, February 2, 2005 at the San Ysidro Middle School (Auditorium), 4345 Otay Mesa Road, San Diego.


Written comments (no e-mails or faxes) must be addressed to: Mr. Daniel Borunda, Environmental Protection Specialist, Compliance Section, USIBWC, 4171 North Mesa Street, C-100, El Paso, Texas 79902. A copy of the DSEIS is available at and in local public libraries in the San Diego area. A Start Printed Page 78484limited number of copies will be available, if you wish to obtain a copy contact Mr. Daniel Borunda at the address above.

Start Further Info


Mr. Daniel Borunda, Environmental Protection Specialist, USIBWC, at (915) 832-4701, by fax at (915) 832-4167, or by mail at the above listed address.

End Further Info End Preamble Start Supplemental Information


Pursuant to Section 102(2)(c) of the National Environmental Policy Act of 1969, as amended, the USIBWC has analyzed the impacts of alternatives for SBIWTP to achieve compliance with the CWA and its NPDES permit. This action is needed because the SBIWTP currently operates and discharges only at the advanced primary level and cannot meet all the requirements of the CWA and its NPDES permit, including secondary treatment requirements.

This DSEIS also evaluates new information on the current discharges of advanced primary effluent from the SBIWTP through the SBOO, as well as treatment and disposal options in Mexico to achieve CWA compliance.

The No Action Alternative and six action alternatives are evaluated in the DSEIS. The alternatives were developed in a manner that would enable wastewater flows to be treated in compliance with the CWA and the SBIWTP NPDES permit. Alternatives formulation was the result of a public consultation process that included the public, regulatory agencies and environmental organizations.

This DSEIS evaluates the following seven alternatives:

1. Alternative 1: No Action (Continue operation of SBIWTP as Advanced Primary Facility).

  • Option A: With No Future Improvements to Mexico's Existing Conveyance Facilities
  • Option B: With Future Improvements to Mexico's Existing Conveyance Facilities

2. Alternative 2: Operate SBIWTP as Advanced Primary Facility With Treated Flows Conveyed to Mexico for Discharge.

3. Alternative 3: Operate SBIWTP With City of San Diego Connections (Interim Alternative Only).

4. Alternative 4: Implementation of Public Law 106B457, Secondary Treatment Facility in Mexico.

  • Treatment Option A: Operation of SBIWTP as Advanced Primary Facility, Secondary Treatment in Mexico
  • Treatment Option B: Cease Operation of SBIWTP, Secondary Treatment in Mexico
  • Treatment Option C: Bajagua LLC, Proposal—Operation of SBIWTP as Advanced Primary Facility, Secondary Treatment in Mexico
  • Discharge Option I: Treated Effluent Discharged in United States via SBOO
  • Discharge Option II: Treated Effluent Discharged in Mexico at Punta Bandera

5. Alternative 5: Secondary Treatment in the United States at SBIWTP.

  • Treatment Option A: Completely Mixed Aeration (CMA) Ponds at SBIWTP
  • Treatment Options B-1 and B-2: Activated Sludge Secondary Treatment at SBIWTP

6. Alternative 6: Secondary Treatment in the U.S. and in Mexico.

7. Alternative 7: SBIWTP Closure/Shutdown.

The USIBWC has identified Alternative 4, Treatment Option C as the preferred alternative in the DSEIS. The USIBWC will consider comments on the DSEIS to make a final selection of the preferred alternative.


The original Draft EIS for the SBIWTP project (1991) proposed the construction of a secondary treatment facility in San Diego to achieve secondary treatment using an activated sludge technology. Based on a 1994 Final EIS and Record of Decision (ROD), the USIBWC and the USEPA approved the construction of the SBIWTP and the connecting SBOO. The SBIWTP is on a 75-acre site in south San Diego County, California, just west of San Ysidro near the intersection of Dairy Mart and Monument roads. Treated effluent is discharged to the Pacific Ocean through the SBOO, a 4.5-mile long piping system completed in January 1999. This outfall extends about 3.5 miles offshore.

Pursuant to the completion of an Interim Operations Supplemental EIS in 1996, the USIBWC and USEPA decided to operate the SBIWTP as an advanced primary treatment facility before completion of the necessary secondary facilities. This decision would expedite the treatment of up to 25 mgd of untreated sewage from Tijuana that would otherwise have continued to pollute the Tijuana River and Estuary, as well as coastal waters in the United States.

Before the SBOO was completed in January 1999, advanced primary treated effluent was discharged through an emergency connection to the City of San Diego Point Loma Wastewater Treatment Plant. The emergency connection was used daily in the late 1980s and 1990s, but it has not been used in this manner since the SBIWTP started discharging to the completed SBOO in January 1999.

After the release of the May 1994 Final EIS and ROD and the 1996 decision regarding interim operation, significant additional information became available and changed circumstances warranted reconsidering the best means to complete the SBIWTP secondary treatment facilities. The USIBWC and USEPA decided to prepare a Supplemental EIS to examine new information as a settlement to a lawsuit that challenged the 1994 Final EIS.

In January 1998, the USIBWC and the USEPA issued the Draft Long Term Treatment Options Supplemental EIS to re-evaluate the SBIWTP secondary treatment options. In October 1998, the agencies issued a supplement to the 1996 Interim Operation Supplemental EIS that addressed impacts of the advanced primary treatment. This supplement disclosed new information about the presence of dioxins and acute toxicity in the advanced primary discharge. This new information was incorporated into the Final Long Term Treatment Options Supplemental EIS released in March 1999.

In the 1999 ROD for the Long Term Treatment Options Supplemental EIS, the USEPA and the USIBWC selected the CMA pond system at the Hofer property as the long-term option for secondary treating 25 mgd of wastewater at the SBIWTP. However, Congress did not fund the construction of these secondary treatment facilities and the plant has continued to provide advanced primary treatment only.

The specific purpose of the current analysis is to determine the environmental impacts of the alternatives that could accomplish compliance with the CWA and the SBIWTP NPDES permit. A decision on which of the alternatives will be implemented in order to achieve compliance with the CWA will be made by the USIBWC through a process that will consider a wide range of factors. The factors include, but are not limited to, environmental considerations, laws and regulations, implications for compliance with the CWA, the SBIWTP NPDES permit, budget considerations, schedule and public concerns.

A copy of the DSEIS has been filed with the USEPA in accordance with 40 CFR parts 1500-1508 and USIBWC procedures. Written comments concerning the DSEIS will be accepted at the address above until February 28, 2005.

Start Signature

Dated: December 21, 2004.

Susan E. Daniel,

General Counsel.

End Signature End Supplemental Information

[FR Doc. 04-28378 Filed 12-29-04; 8:45 am]