Water Well Journal
Issue link: http://read.dmtmag.com/i/451364
property owners from degradation or loss of their water sup- ply due to activities or water extraction by another individual or entity. This means if drilling activity on an installation site causes a neighboring well to go bad or lowers the water table such that the neighboring well runs dry, the owner and, depending on legal interpretations, the contractors involved could be responsible for the restoration of the affected water supply. Consequently, the majority of open loop installations should be limited to high-yield aquifer areas in your service area. As installing contractors, we must always be aware of the legal ramifications and apply prudent judgment. If a problem should result, does the property have available space to convert to a closed loop system and allow the aquifer to recover? Or will the consequences mean providing new wells for adjacent properties? Water quality Almost every geothermal system manufacturer will publish a water quality standard for open loop installations. Of prime importance are cautionary statements to avoid water sources that: • Contain heavy iron or iron bacteria • Are heavy scale producers • Have a rotten egg odor caused by hydrogen sulfide • Have high chlorides as might a salt or brine water condition. Heat exchangers constructed from cupronickel will provide some protection against aggressive waters, but these waters may present other issues for their discharge. The chart above details the standards most manufacturers prefer contractors know when selecting a water source for an open loop installation. If water quality and the preliminary information obtained from the well log for a given address proves the home is a good candidate for an open loop geothermal installation, col- lect the following information when making an onsite survey. 1. Well pump entry point into the home. 2. Pressure tank location (take a photo for future reference). 3. If well pump has an interior control box, record the motor horsepower and pump model if it is listed. 4. Is there a water softener? 5. Is there a filter canister before the water softener? 6. Are there any spent filters available for viewing? 7. How often do they need to be changed? 8. Collect a sample of the raw water (before the water sof- tener) and keep it for at least a week to observe if red sed- iment accumulates in the bottom of the water bottle or jar. If the sediment remains as a red powdery film, the sample is likely free of iron bacteria. If however the sediment wants to clump together in small masses, bacteria are likely present and the chain structure of their growth habit is likely the reason for clumping of the sediment. Iron bacteria doesn't pose a health problem, but their growth habitat and ability to plug well screens, the formation surrounding the well, pump impellers, piping, and geo- thermal lines can make them a nuisance. 9. Ask the customer if there have been any service problems with the well or pump. Deep pump settings with the pump suspended on polyethylene pipe can allow the pump to rotate with the starting torque. This continually flexes the electrical harness and can cause premature electrical wire fatigue and failure, resulting in replace- ment of the pump. The conscientious pump installer will recommend and install a torque arrestor above the pump to reduce this rotation and prolong pump life. 10. Who services the well and pump? 11. Does the water have a foul odor? A rotten egg odor is associated with hydrogen sulfide in the water. Hydrogen sulfide occurs in association with iron pyrite, bacteria, and organics that may exist naturally within an aquifer. OPEN LOOP from page 15 Courtesy of WaterFurnace International 16 February 2015 WWJ waterwelljournal.com