Evaluation of Selenium Remediation Plans
| Type |
- Feasibility Studies
- Site Characterization
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| Location |
California Central Valley and San Francisco Bay, CA |
| Partners |
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| Technology |
- Computer Simulations
- Load Allocations
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| Contaminants |
Selenium |
| Description |
Understanding the fate and effects of selenium is critical to evaluating
remediation options. USGS scientists developed a computer model
and applied it to evaluate one of the most complex and controversial
agricultural drainage problems in the Nation—irrigation of
western San Joaquin Valley agricultural fields and disposal of agricultural-drainage
water containing selenium via a proposed extension of the San Luis
Drain into the San Francisco Bay. The model can forecast environmental
selenium concentrations, bioaccumulation of selenium, and selenium
effects on resource fish and aquatic birds living in waters receiving
drainage from agricultural activities. Accurate forecasting of the
environmental fate of selenium is crucial because of selenium's
effect on reproduction in aquatic birds and fish. Water resource
managers in the San Joaquin Valley and San Francisco Bay area have
proposed several plans, some dating back to 1955, to remediate drainage
from irrigated lands and the associated salt buildup in soils. Some
of the plans include extending the San Luis Drain, which has been
closed since 1986, so that agricultural drainage water can be discharged
to the San Francisco Bay. When the San Luis Drain was active and
discharging drainage water into a national wildlife refuge in the
San Joaquin Valley in the past, the selenium in the water caused
fish mortality and deformities in aquatic birds, such as ducks.
USGS scientists evaluated several realistic options (ones that meet
current water needs) using the model, and predicted that selenium
concentrations in water, sediment, clams, ducks, and fish in the
Bay would exceed proposed criteria during the low-flow season for
all options that were evaluated.
The U.S. Fish and Wildlife Service, the San Francisco Estuary Project,
and other state and federal agencies have held workshops on agricultural
(irrigation) drainage that featured the results and application
of the model. The results of the modeling study and additional model
applications are being used to further evaluate and help design
options to remediate selenium contamination and to help with the
overall restoration efforts for the San Francisco Bay under the
auspices of the CALFED Bay-Delta
Program.
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| More Information |
|
| Contact |
- Samuel N. Luoma, USGS, National Research Program, Menlo Park,
CA,
- Theresa S. Presser, USGS, National Research Program, Menlo Park,
CA,
|
| Publications |
- Luoma, S.N., and Presser, T.S., 2000,
- Forecasting
selenium discharges to the San Francisco Bay-Delta Estuary--Ecological
effects of a proposed San Luis Drain extension: U.S. Geological
Survey Open-File Report 00-416, 387 p.
|
| Links |
San Francisco Bay Information
Selenium Information
|
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