The quality of water in the Borrego Valley is a concern because of the basin's reliance on groundwater for agricultural, recreational, and municipal supply. Groundwater quality can be affected by land-use activities occurring at or near land surface. These activities include irrigation of vegetated landscapes and the use of septic systems to dispose of wastewater. Groundwater quality can also be affected by declining water levels, as there is the potential to change the distribution of flow from underlying aquifers to wells. Historic and current water-quality data was used to determine which constituents had relatively high concentrations compared to water-quality thresholds and if these constituent concentrations were changing in response to declining water levels. Age-dating isotopes (tritium and carbon-14) were analyzed to determine if modern groundwater recharge is occurring in the Borrego Valley. Major findings of groundwater-quality portion of this study are the following:
Site Cluster, and number of wells in the cluster
Water-quality data displayed in the site popups show only the most recent sample for the water quality constituent class selected. If there is not a value shown for a constituent that means that the constituent was not analyzed for in that sample. However, that constituent may have been analyzed for in earlier samples, so the user should check the downloadable Excel workbooks found on the "Datasets" page.
Water-quality data can be downloaded in an Excel format from this website. The Excel workbooks contain current and historical water-quality data for groundwater samples collected in the Borrego Valley and spring samples collected in pertinent watersheds. The workbooks are categorized by constituent class. These classes are:
There are three sources for the water-quality data presented on this website: Borrego Water District (BWD), State Water Resources Control Board Division of Drinking Water (DDW) and U.S. Geological Survey (USGS)
Data displayed in the dialogue boxes show only the most recent sample for the water quality class/constituent selected.
If there is not a value shown for a constituent that means that the constituent was not analyzed for in that sample. However, that constituent may have been analyzed for in earlier samples, so the user should check the downloadable Excel workbooks.
Well and spring sites in the study area that had water-quality data in a hard copy format were scanned and formatted as Adobe Portable Format Documents (PDFs). Scanned water-quality data can be reviewed and (or) downloaded by clicking the site of interest on the interactive map.