Hydrology

To determine whether the K2 site is a good site for drilling a well, the PSWID board commissioned Highland Water Resources Consulting (HWRC) to prepare a report on the potential of the K2 site. PWCo commissioned three independent peer reviews of the HWRC report. A summary of the conclusions for each report and links to the reports are provided below.

The HWRC report found that the K2 site is a good site for drilling a production well based upon the hydrology. Two of the peer reviews agreed with the HWRC conclusions on the K2 site. The other peer review felt that there was insufficient data provided with the HWRC report to determine whether the HWRC conclusions were supported.

The HWRC report did not specifically address an estimated yield. The three peer review reports agreed that determination of whether the yield would meet the goal of 150 gpm is not possible prior to drilling the well. Two of the peer reviews consider the deep aquifer potential between the Pine and Strawberry areas the same. One peer review thinks that the Pine area has more potential.

Hydrology is not an exact science. It consists of taking surface features, knowledge of an area’s geological structures, and other incomplete pieces of data and coming up with a forecast of the results that drilling at a location would have. Some are more successful at that than others. The report and peer reviews represent the best efforts of each organization. None should be considered more definitive than the others.

1. HWRC Report
2. Clear Creek Peer Review
3. Morrison Maierle Peer Review
4. Southwest Groundwater Consultants Peer Review
5. Hydrology Links

Highland Water Resources Consulting (HWRC) Report

This report was authored by Michael Ploughe, P.G. The report’s conclusions on the hydrology are:

• “Upon review of existing data and the completion of a lineament analysis of the site HWRC is confident that the location is quite adequate for the drilling of a deep test and/or production well.”
• Anticipated that the deep aquifer ground water elevation is 1260 ft. to 1100 ft., depth to water. Primary water producing geology below 1460 ft., depth to water. Drilling to 2000 ft. should be sufficient
• HWRC belief is that water will be encountered at 700 ft to 1000 ft in the lowest portion of the shallow aquifer. Potential yield is unknown.
• Expressed concern over the potential for litigation over environmental and water rights issues if a high capacity well (>200 gpm) impacts the output of Fossil Springs. “HWRC currently believes that the subject K2 area may not be within that portion of the deep regional groundwater flow system supporting Fossil Springs. However, the exact location of the springs “capture” area is not clearly defined and the complexities of fractured groundwater flow occurring in the deep regional system may never be completely understood.”
• “HWRC believes that sufficient data currently exists indicating that deep regional groundwater wells installed to the east, in Pine, would not produce groundwater that otherwise would have discharged at Fossil Springs.

The report also ventures outside of the topic of hydrology and provides HWRC's opinion on the steps to be taken prior to drilling the K2 well. Those recommendations were:

• Conduct a hydrological survey of Pine to identify drilling sites in Pine.
• Explore opportunities for partnerships with other local Domestic Water Improvement Districts and/or private entities which may currently be in possession of deep regional groundwater supplies
• Explore opportunities for partnerships with Federal and/or County governments

These recommendations are outside of the scope of the requested report. Determination of the steps to be taken is the responsibility of the PSWID board. The PSWID board evaluated the opportunities for partnerships prior to approving the K2 project.

The full report can be found here: HWRC Report

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Clear Creek Associates Peer Review

This peer review was authored by Marvin Glotfelty, R.G. A summary of the peer review conclusions are:

• Does not think that there were enough data references and field data provided with the HWRC report to determine whether HWRC’s conclusions are supported.
• Due to past work in the area, they consider Pine area deep aquifer resources more favorable than those in the Strawberry area.

The full peer review can be found here: CC Peer Review

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Morrison Maierle Peer Review

This peer review was authored by Michael Kaczmarek. This peer review is very extensive and detailed. This peer review provides a good overview of the basic concepts. A summary of the peer review conclusions are:

• “My conclusion is that the K2 site recommended by HWR is a reasonable site to drill a production well into the R-aquifer and deeper strata.”
• “There is no reliable way of predicting if a well at this site will yield 150 gpm of not. However, as discussed later in this report, yields at the Strawberry Hollow and Milk Ranch wells indicate that a 150 gpm yield from the R-aquifer and deeper strata may be possible.”
• “…baseline yields of 150 gpm may be available from the deep aquifer in all of this area, both Pine and Strawberry. Drilling depths to the R-aquifer will be less in Pine than in Strawberry …”

The full peer review can be found here: MM Peer Review

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Southwest Ground-water Consultants Peer Review

This peer review was authored by Stephen Noel, P.G. A summary of the peer review conclusions are:

• “The conclusions presented in the HWRC Report are based on the current understanding of the regional aquifer system. These conclusions are reasonable based on the data we have reviewed and the data presented by HWRC.”
• “Based on review of the hydrology of the targeted deep regional aquifer, a yield in the range of 100 to 200 gpm is possible. Therefore a well with a sustainable yield of 150 gpm is a realistic goal, but has little supporting documentation.”
• Deep aquifer yields are expected to be similar in the Pine and Strawberry areas.

The full peer review can be found here: SGC Peer Review

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Hydrology Links

PSWID Technology Page

Watershed Monitor

Arizona Department of Water Resources

USGS Arizona Water Science Center

Arizona Water Well Association

Arizona Hydrological Society

Arizona Geological Society

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