Water Quality Assessment Of The Principal Valley Fill Aquifers In The Southern Sanpete And Central Sevier Valleys Sanpete County Utah

"This study (132 p., 6 pl.) assesses water quality in the aquifers in the southern Sanpete and central Sevier Valleys to determine likely sources of nitrate pollution and determine the relative age of high-nitrate water"--Back label of container.

This CD contains a 125-page comprehensive study of the hydrogeology of Cedar Valley, Utah County, located in north-central Utah. The report includes 72 figures; two plates, one of which is a potentiometric map of the basin-fill, bedrock, and several perched aquifers; and seven appendices of data. Field investigations included groundwater chemistry sampling, regular water-level monitoring, and multiple-well aquifer testing. The field data were incorporated into a 3D digital groundwater flow model using MODFLOW2000. Seventy percent of the recharge to the Cedar Valley aquifer system is from precipitation in the Oquirrh Mountains. Groundwater generally flows from west to east and exits the aquifer system mostly as interbasin flow through bedrock to the northeast and southeast. The groundwater model showed a 39-year (1969-2007) average recharge to the Cedar Valley groundwater system of 25,600 acre-feet per year and discharge of 25,200 acre-feet per year. A significant volume of precipitation recharge (perhaps 4300 acre-feet per year) does not interact with the basin-fill aquifer but travels within bedrock to discharge to adjacent valleys or as bedrock well discharge. 125 pages + 2 plates

The U.S. Environmental Protection Agency is recommending that states develop Pesticide Management Plans for four agricultural chemicals – alachlor, atrazine, metolachlor, and simazine – herbicides used in Utah in the production of corn and sorghum. This report and accompanying maps are intended to be used as part of these Pesticide Management Plans to provide local, state, and federal government agencies and agricultural pesticide users with a base of information concerning sensitivity and vulnerability of ground water to agricultural pesticides in Utah. We used existing data to produce pesticide sensitivity and vulnerability maps by applying a combined process-based and index-based model specifically tailored to the Western United States using Geographic Information System analysis methods. This is a first cut at developing pesticide sensitivity and vulnerability maps; better data and tools may become available in the future so that better maps can be produced. 40 pages + 2 plates

This report characterizes the relationship of geology to groundwater occurrence and flow, with emphasis on determining the thickness of the valley-fill aquifer and water yielding properties of the fractured rock aquifers. Develops a water budget for the drainage basin and classifies the groundwater quality and identifies the likely sources of nitrate in groundwater.