USGS

Chemical Data for Detailed Studies of Irrigation Drainage in the Salton Sea Area, California, 1995–2001

By Roy A. Schroeder

 

U.S. GEOLOGICAL SURVEY

Scientific Investigations Report 2004-5036

Sacramento, California 2004

Prepared in cooperation with the
U.S. BUREAU OF RECLAMATION for the
NATIONAL IRRIGATION WATER QUALITY PROGRAM




Complete accessible text of report (2.62 MB PDF)
Complete accessible text of report cover (76.5 KB PDF)

To view PDF documents, you must have the Adobe Acrobat Reader (free from Adobe Systems) installed on your computer.
(download free copy of Acrobat Reader).

Abstract

     The primary purpose of this report is to present all chemical data from the Salton Sea area collected by the U.S. Geological Survey between 1995 and 2001. The data were collected primarily for the Department of the Interior's National Irrigation Water Quality Program (NIWQP). The report also contains a brief summary and citation to investigations done for the NIWQP between 1992 and 1995. The NIWQP began studies in the Salton Sea area in 1986 to evaluate effects on the environment from potential toxins, especially selenium, in irrigation-induced drainage. This data report is a companion to several reports published from the earlier studies and to interpretive publications that make use of historical and recent data from this area.

    Data reported herein are from five collection studies. Water, bottom material, and suspended sediment collected in 1995-96 from the New River, the lower Colorado River, and the All-American Canal were analyzed for elements, semi-volatile (extractable) organic compounds, and organochlorine compounds. Sufficient suspended sediment for chemical analyses was obtained by tangential-flow filtration.

    A grab sample of surficial bottom sediment collected from near the deepest part of the Salton Sea in 1996 was analyzed for 44 elements and organic and inorganic carbon. High selenium concentration confirmed the effective transfer (sequestration) of selenium into the bottom sediment. Similar grab samples were collected 2 years later (1998) from 11 locations in the Salton Sea and analyzed for elements, as before, and also for nutrients, organochlorine compounds, and polycyclic aromatic hydrocarbons. Nutrients were measured in bottom water, and water-column profiles were obtained for pH, conductance, temperature, and dissolved oxygen. Element and nutrient concentrations were obtained in 1999 from cores at 2 of the above 11 sites, in the north subbasin of the Salton Sea. The most-recent study reported herein was done in 2001 and contains element data on suspended material isolated by continuous-flow centrifugation on samples collected in transects extending out from the Whitewater, the Alamo, and the New Rivers into the Salton Sea.

    Chemical data on suspended sediment and bottom material from tributory rivers and the Salton Sea itself show that many insoluble constituents, including selenium and DDE, are concentrated in the fine-grained, organic- and carbonate-rich bottom sediment from deep areas near the center of the Salton Sea. Data also show that selenium and arsenic are markedly enriched in seston (plankton, partially-degraded algal detritus, and mineral matter that compose suspended particulates in the lake) collected just below the water surface in the Salton Sea. This result indicates that bio-concentration in primary producers in the water column provides an important pathway whereby high selenium residues accumulate in fish and fish-eating birds at the Salton Sea.

CONTENTS

 

Abstract

Introduction

Reconnaissance and Detailed Phases

Topical Investigations

Purpose and Scope

Acknowledgments

Sampling, Processing, and Analytical Methods

1995-96 Bi-National Monitoring

1996 Grab Samples from the Salton Sea

1998 Samples from Eleven Sites in the Salton Sea

1999 Samples from Two Cores in the Salton Sea

2001 Samples from Nine Sites in and near the Salton Sea

Data and Discussion

1995-96 Bi-National Monitoring

1996 Grab Sample from the Salton Sea

1998 Samples from Eleven Sites in the Salton Sea

1999 Samples from Two Cores in the Salton Sea

2001 Samples from Nine Sites in and near the Salton Sea

Summary and Conclusions

References Cited

Tables


Document Accessibility: Adobe Systems Incorporated has information about PDFs and the visually impaired. This information provides tools to help make PDF files accessible. These tools convert Adobe PDF documents into HTML or ASCII text, which then can be read by a number of common screen-reading programs that synthesize text as audible speech. In addition, an accessible version of Acrobat Reader 5.0 for Windows (English only), which contains support for screen readers, is available. These tools and the accessible reader may be obtained free from Adobe at Adobe Access.

 



Water Resources of California



U.S. Department of the Interior, U.S. Geological Survey
Persistent URL:
Page Contact Information: Contact USGS
Last modified: Thursday, December 01 2016, 08:03:37 PM
FirstGov button  Take Pride in America button