Dean D Stoughton

About the Book

Small mountain valleys are wonderful places to live or recreate; yet few consider the source of their drinking water. The Greater Pole Creek Basin is typical of many of these mountain gems. An hour and a half west of Denver, Colorado, and a world away, Pole Creek has recently experienced increased population and tourism. Virtually all water for new residences and commercial interests is supplied by groundwater pumped from the Troublesome Aquifer, which has not been studied in detail. This report reviews and interprets available data to provide a summary of the hydrogeological setting, explains how much water is generally available and why it is often difficult to extract, presents information about groundwater wells and how they are commonly constructed, and provides information about water quality of this sole-source resource. Forecasts of future water use and water availability are presented along with recommendations for further study.
Buy Now

Table of Contents

Figures………………………………………………………………………………………………………………………………………………. 1

Tables ………………………………………………………………………………………………………………………………………………. 5

Appendix – Figures …………………………………………………………………………………………………………………………….. 6

Appendix – Tables ………………………………………………………………………………………………………………………………. 7

Acknowledgements …………………………………………………………………………………………………………………………….. 8

About the Authors ………………………………………………………………………………………………………………………………. 9

Abstract ……………………………………………………………………………………………………………………………………………10

1 – Introduction …………………………………………………………………………………………………………………………………..11

1.1 – Purpose and Scope ………………………………………………………………………………………………………………………..11

1.2 – Location and Geological Setting ……………………………………………………………………………………………………..13

1.3 – Available Well-Log Data ………………………………………………………………………………………………………………..17

1.4 – Troublesome Formation Aquifer System – Hydrogeological Parameters and Estimated Water Volumes ……22

1.4.1 Determination of Aquifer Sand Intervals and Associated Specific Yield ……………………………………………….22

1.4.2 Method for Determining Aquifer Extractable Water Volume ……………………………………………………………..26

1.4.3 Estimated Available Water Stored in the Troublesome Aquifer ………………………………………………………….28

2 – Troublesome Aquifer Water-Table Dynamics ……………………………………………………………………………………..31

2.1 Potentiometric Map ……………………………………………………………………………………………………………………….31

2.2 Aquifer Segmentation – Effect of Water Flow to Wells ………………………………………………………………………..36

2.3 Time Variant Water-Table Changes …………………………………………………………………………………………………40

2.4 Aquifer Water-Table Monitoring – Proposed Additional Wells …………………………………………………………….42

3 – Pole Creek Water Budget and Troublesome Aquifer Viability ……………………………………………………………….44

3.1 – Watershed Precipitation ………………………………………………………………………………………………………………44

3.2 – Aquifer Recharge ………………………………………………………………………………………………………………………..48

3.3 – Aquifer Hydraulic Properties ………………………………………………………………………………………………………..49

3.4 – Water Consumption …………………………………………………………………………………………………………………….56

3.5 – Surface-Water Volume Estimates ………………………………………………………………………………………………….59

3.6 – Water-Volume Accounting and Future Projections ………………………………………………………………………….59

3.7 – Upper Troublesome Aquifer Viability – Supply Versus Demand Projections …………………………………………64

4 – Water-Well Construction and Deliverability ………………………………………………………………………………………67

4.1 – Water-Well Construction Options …………………………………………………………………………………………………67

4.2 – Water-Well Production Considerations and Best Practices ……………………………………………………………….72

5 – Troublesome Aquifer Water Quality ………………………………………………………………………………………………….74

5.1 – Water-Quality Purpose and Scope …………………………………………………………………………………………………74

5.2 – Factors that Influence Groundwater Geochemistry ………………………………………………………………………….74

5.3 – Previous Groundwater Studies, Well Database and Annual Testing …………………………………………………….77

5.4 – Key Deep Troublesome Well ………………………………………………………………………………………………………….79

5.4.1 – Review of Water Quality Testing – Initial Well Construction Versus Recompletion ……………………………..79

5.4.2 – Key Deep Troublesome Well – Review of Water Quality using Geophysical Logs ………………………………..80

5.5 – Deep Troublesome Wells – Initial Review of Groundwater Water Quality Issues ………………………………….82

5.5.1 – Well Geochemical Sample Comparisons ……………………………………………………………………………………….82

5.5.2 – Deep Troublesome Wells – Water-Quality Issues………………………………………………………………………….. 84

5.6 – Implications for Homeowners ………………………………………………………………………………………………………94

6 – Conclusions ………………………………………………………………………………………………………………………………….95

6.1 Considerations for Future Work ……………………………………………………………………………………………………..96

6.1.1 Water-table Monitoring Wells ………………………………………………………………………………………………………96

6.1.2 Additional Mapping …………………………………………………………………………………………………………………….96

6.1.3 Additional Well Pump Test Data ……………………………………………………………………………………………………96

6.1.4 Groundwater Flow Modeling ………………………………………………………………………………………………………..96

6.1.5 Develop a Comprehensive Water Budget. ……………………………………………………………………………………….96

6.1.6 Additional Water-Quality Assessments …………………………………………………………………………………………..97

6.1.7 Other Fraser Valley Aquifer Assessments ……………………………………………………………………………………….97

References (with internet links) …………………………………………………………………………………………………………..98

Appendix – Figures …………………………………………………………………………………………………………………………..101

Appendix – Tables ……………………………………………………………………………………………………………………………106

Conversion Factors ……………………………………………………………………………………………………………………………113