Groundwater Monitoring

The Spokane Valley Rathdrum Prairie Aquifer (SVRP Aquifer) is the sole source of water for over 500,000 people in Spokane County, WA and Kootenai County ID, this underground water-bearing rock formation is one of the region's most important resources. The aquifer is unique both for it's fast flowing and generous water supply, and for it's high susceptibility to contamination.

Since 1977 Spokane County has been monitoring water quality conditions in the aquifer.  Currently Water Resources staff collect samples on a quarterly basis from 29 monitoring wells and 16 public supply wells.  Objectives of the groundwater monitoring program include:

• Establish the areal distribution of groundwater quality from a network of wells covering the SVRP Aquifer recharge area;
• Identify water quality impacts from activities on the land surface;
• Collect long term data from wells to establish water quality trends; and
• Evaluate the potential water quality impacts of aquifer discharge on river quality.

Monitoring Program Documents

• Monitoring Well Map
• List of Analytes
• Quality Assurance Program Plan

2007 Annual Groundwater Monitoring Report

• Report Text
• Figures
• Appendix A
• Appendix B
• Appendix C
• Appendix D
• Appendix E
• Appendix F

2008 Annual Groundwater Monitoring Report

• Report Text
• Figure 1 - Monitoring Locations
• Figure 2 - Arsenic Exceedances
• Figure 3 - Iron Exceedances
• Figure 4 - Nitrate Trend
• Appendix A - Monitoring Well Construction Details
• Appendix B - Quarterly Results
• Appendix C - Monthly Results
• Appendix D - Data Validation
• Appendix E - Arsenic Summary Statistics
• Appendix F - Iron Summary Statistics
• Appendix G - Nitrate Summary Statistics
• Appendix H - Nitrate Trend Analysis