Guadalupe River Watershed Mercury TMDL

U.S. EPA gives final approval to TMDL and Water Quality Objectives for Mercury in the Guadalupe River Watershed
On June 1, 2010, the U.S. Environmental Protection Agency approved the Basin Plan amendment adopted by the Regional Water Board in October 2008. These actions establish New Water Quality Objectives and Total Maximum Daily Loads (TMDLs) and an Implementation Plan for mercury in waters of the Guadalupe River Watershed. The amendment is now part of the Water Quality Control Plan for the San Francisco Bay Basin (Basin Plan), the master planning document for water quality in the Bay Area.

Previously, the State Office of Administrative Law (OAL) approved the amendment on February 24, 2010, the State Water Board approved the amendment on November 17, 2009, and the Regional Water Board adopted the amendment on October 8, 2008.

U.S. EPA Approval of TMDL (pdf)
U.S. EPA Approval of Water Quality Objectives (pdf)
OAL Approval Action (pdf)
State Water Board Approval, see item no. 7: Resolution No. 2009-0082
Regional Water Board Adoption: Resolution R2-2008-0089
Adopted Basin Plan Amendment (pdf)
Final Staff Report (pdf, 7.5MB)
- Oversized Figures (tabloid size; also included in Staff Report (pdf, 1.3MB)

Materials from Sept. 11, 2008 meeting with Alamitos Creek property owners
Questions and Answers about the Guadalupe River Watershed Mercury TMDL
Slide presentation
Streambank Repair Guidance Manual for the Private Landowner (Santa Clara Valley Water District publication)

Reference documents
Final Conceptual Model Report, May 22, 2005 (Tetra Tech, Inc.)
Due to the size of the original PDF document (47.98 MB), we have made both the full document and each separate chapter available below for download. All these PDF files were created using Adobe Version 6. If you do not have this version (or higher), you will not be able to view the files.

Full Document (47.98 MB)

Individual Files (smaller-size documents):
Cover Page, Table of Contents, and Executive Summary (1.4 MB)
Chapter 1. Introduction (233 K)
Chapter 2. Watershed Characterization (15 MB)
Chapter 3. Data Summary (2.3 MB)
Chapter 4. Estimated Mercury Loads (4.3 MB)
Chapter 5. Conceptual Model of Mercury (5.9 MB)
Chapter 6. Summary (203 K)
Chapter 7. References (233 K)

Derivation of Numeric Wildlife Targets for Methylmercury in the Development of a Total Maximum Daily Load for the the Guadalupe River Watershed (USFWS 2005) (2.3 MB)

Reservoir Sediment Sampling, April 2005 (Tetra Tech, Inc., 203 KB)

Draft Project Plan, June 2004 (407 KB)

Preliminary Project Definition, August 2004 (45 KB)

Background:

The Guadalupe River Watershed supports many beneficial uses, such as drinking water supply, sport fishing, and habitat for wildlife and endangered species. Santa Clara County has issued a fish consumption advisory for mercury contamination. Mercury concentrations in fish tissue that exceed the U.S. EPA human health mercury fish criterion (0.3 mg/kg), have been measured at numerous creeks and reservoirs in the Guadalupe River Watershed. Elevated mercury concentrations in fish tissue may also pose a threat to wildlife, such as birds, amphibians, and mammals.

The Guadalupe River Watershed Mercury TMDL will examine this water quality problem and provide a watershed-wide mercury management strategy. The main source of mercury in the Watershed is the New Almaden Mining District, the largest-producing mercury mine in North America. Other sources include atmospheric deposition from global and local sources, soil erosion from areas not known to contain mines, urban stormwater runoff, seepage from landfills, and Central Valley Project water inputs to Calero Reservoir. In addition to being the primary regulatory means of achieving water quality goals in the watershed, the Guadalupe River Watershed Mercury TMDL will simultaneously reduce the amount of mercury in the Bay in accordance with the San Francisco Bay Mercury TMDL's proposed requirements.

Links:
Santa Clara Valley Water District (home page)
For extensive Guadalupe River Watershed information, go to "Shortcuts," (top right-hand side of the page), select "Your Watershed," then click on Guadalupe.

CalFed (Bay-Delta Authority) Mercury Project
See especially the document "Mercury Strategy for the Bay Delta Ecosystem"

San Francisco Bay Mercury TMDL

For more information contact:
Carrie Austin
Environmental Engineer
San Francisco Bay Regional Water Quality Control Board
1515 Clay Street, Suite 1400
Oakland, CA 94612
Phone: 510-622-1015
Fax: 510-622-2460
E-mail: CAustin@waterboards.ca.gov