An initial study of groundwater resources in El Paso County, Colorado. 139 pages. Digital PDF download. WAT-2005-01D
From the Executive Summary
This report documents the work, findings, analysis, and recommendations of the CGS in executing the scope of work commissioned by El Paso County, through the Groundwater Study Committee, established in reference to Resolution No. 09‐202. The subject of this report is the groundwater quality of the alluvial aquifer within the Upper Black Squirrel Creek (UBSC) basin. The Phase 1 study objectives are to characterize the current groundwater quality in the alluvial aquifer and determine whether there is a correlation between existing and future land uses and groundwater quality. The scope of work for Phase 1 was finalized in January 2010, and the County contracted with CGS to perform the work.
The current study is limited to evaluation of existing water quality data for groundwater in the alluvial aquifer system of the Upper Black Squirrel Creek Designated Groundwater basin (UBSC basin) of east‐central El Paso County, Colorado. As part of the study a literature review identified 34 relevant publications and an annotated bibliography was prepared. Previous published studies indicated that the groundwater was of good quality, but identified nitrate as a contaminant of concern. Water quality data was acquired from a variety of public sources (county, state, and federal) and study cooperators. The data represent 150 samples collected from 72 different wells between 1954 and 2009. Samples collected for water quality analysis within the study area have a limited spatial and temporal distribution. Approximately 80% of the data were collected in the 1980s and 1990s, and the great majority of wells are within three miles of the Ellicott Highway. One of the most important characteristics of this data is the lack of multiple samples from individual locations. The northern and western portions of the UBSC basin where rapid development has occurred and is expected to continue are not represented in the data.