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Utah Water Science Center

Ground-Water Movement and Nitrate in Ground Water, East Erda Area, Tooele County, Utah, 1997-2000

U.S. Geological Survey Scientific Investigation Report 2005-5096—ONLINE ONLY

By D.D. Susong

This report is available as a pdf.


Nitrate was discovered in ground water in the east Erda area of Tooele County, Utah, in 1994. The U.S. Geological Survey, in cooperation with Tooele County, investigated the ground-water flow system and water quality in the eastern part of Tooele Valley to determine (1) the vertical and horizontal distribution of nitrate, (2) the direction of movement of the nitrate contamination, and (3) the source of the nitrate. The potentiometric surface of the upper part of the basin-fill aquifer indicates that the general direction of ground-water flow is to the northwest, the flow system is complex, and there is a ground-water mound probably associated with springs. The spatial distribution of nitrate reflects the flow system with the nitrate contamination split into a north and south part by the ground-water mound. The distribution of dissolved solids and sulfate in ground water varies spatially. Vertical profiles of nitrate in water from selected wells indicate that nitrate contamination generally is in the upper part of the saturated zone and in some wells has moved downward. Septic systems, mining and smelting, agriculture, and natural sources were considered to be possible sources of nitrate contamination in the east Erda area. Septic systems are not the source of nitrate because water from wells drilled upgradient of all septic systems in the area had elevated nitrate concentrations. Mining and smelting activity are a possible source of nitrate contamination but few data are available to link nitrate contamination with mining sites. Natural and agricultural sources of nitrate are present east of the Erda area but few data are available about these sources. The source(s) of nitrate in the east Erda area could not be clearly delineated in spite of considerable effort and expenditure of resources.

This report is contained in the following four files:

SIR2005_5096_sheet1.pdf (3.5 mb) This sheet contains text through"Water-quality change over time" section of the report and figures 1 to 5.

SIR2005_5096_sheet2.pdf (2.4 mb) This sheet contains text from "Covariance of nitrate and sulfate" section of the report and figures 6 to 12.

SIR2005_5096_sheet3.pdf (2.6 mb) This sheet contains the first page of table 1 and all of table 2.

SIR2005_5096_sheet4.pdf (1.5 mb) This sheet contains the second page of table 1.

The files are readable with Adobe Acrobat Reader. The reader is available for free download from Adobe Systems Incorporated. acrobat logo




Purpose and Scope

Previous Investigations

Methods of Investigation

Ground-Water Movement

Nitrate in Ground Water

Vertical Profiles of Nitrate Concentration

Water-Quality Change Over Time

Covariance of Nitrate and Sulfate

Other Water-Quality Constituents

Ground-Water Flow Simulations with Particle Tracking

Sources of Nitrate in the East Erda area

Septic Systems

Mining and Smelting in Pine Canyon

Nitrate from Natural Sources and Fertilizers

Future Movement of Nitrate Plume



Send questions or comments about this report to the author, D.D. Susong at, 801.908.5062.

For more information about USGS activities in Utah, visit the USGS Utah Water Science home page.

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Last modified: Thursday, December 01 2016, 06:43:38 PM
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