WorldWide Drilling Resource

29 WorldWide Drilling Resource ® MAY 2018 Saving Arizona’s Sonoran Pronghorn with Flexible Drop Pipe Adapted from Information by Hose Solutions, Inc. At a remote site in Southern Arizona, the Bureau of Land Management (BLM) designed a program to save the endangered Sonoran Pronghorn, which is similar to an antelope. These majestic animals had almost disap- peared completely, due to drought conditions. The BLM knew it had to bring water to the area so the animals would come back and thrive. Six sites with windmills relied heavily on the inconsistent supply of wind. In addition to requiring wind, the windmills also needed a lot of attention and regular maintenance to ensure their continued operation. With the abundant supply of sun in the Southwest, solar pumps offered more consistent pumping. Replacing the windmills with solar pumps on flexible drop pipe reduced the number of moving parts, leading to lower maintenance costs. Plus, with a 50-year warranty and no corrosion or internal scaling to worry about, Boreline’s flexible drop pipe was an obvious choice. In this installation, the pump, power cable, and flex- ible drop pipe were all prepared the day before. The con- tractor drove out to the site and simply installed the pump at the push of a button. Boreline Flexible Drop Pipe Simplify your life. Replace your rigid pipes. BORELINE Flexible Drop Pipe Hose Solutions, Inc. Scottsdale AZ 480-607-1507 Sales@HoseSolutions.com www.HoseSolutions.com Simple installation and retrieval. Total corrosion resistance. Safer working environment. 50-year warranty. 900 psi burst; 40,000 lbs. tensile. WTR Environmental Monitoring by Thomas Kwader, Ph.D., P.G. Reducing Bacterial Growth in Your Well Screen During my earlier years in the environmental phase of my career, I was responsible for designing groundwater recovery wells to either dewater and/or capture chemically contaminated groundwater plumes. This is actually a very difficult task because it involves containing or capturing a body of contam- inated water so it does not migrate any farther off-site, and “shrink” it in size. To accomplish this task, it involves pumping an amount of water greater than or equal to the volume flowing into the plume (from rainfall, seepage, etc.). Determining the optimum water balance is often difficult to obtain since it changes naturally over time. Anytime we overpump an aquifer and lower the natural water levels we risk exposing the well screen, or worse, lowering the water level to the pump intake level and air enters the discharge. Lowering the water level below the screen will greatly in- crease the probability of bacterial growth (algae and other “slimes”) which will plug the screen, sand pack, and pump impellers - all of which result in greater drawdowns in the well, which exacerbates the problem even more. Once a bacterial growth occurs in a well, it can be very difficult to kill all the bacteria and restore the well capacity back to “original” capacity. Harmful bacteria can be difficult to treat away from the well screen and in the adjacent formation. Untreated bacteria can begin growing in minutes. Injecting chemicals and antibacterial agents usually only push the bacteria farther out into the formation. Design Recommendations - I have found the following practices helped to keep bacteria out of pumping wells: Never pump the water level below the top of the screen. Bacteria thrive in “air” or an aerobic environment, and will rapidly grow in wells with water levels below the top of a screen. To prevent this from occurring, it is recommended to build the screen/sand pack as efficiently as possible to minimize drawdown. Wells should have a properly designed sand pack and be fully developed. Pumping levels should be adjusted to maintain 5-10 feet above the top of the screen. A short 5- or 10-foot screen at the bottom of the well is recommended over a long screen. The pump should be on the bottom of the well and pumped at low volumes. Multiple low-volume wells are preferred over a few high-capacity wells to meet pumping objectives. Tom Tom Kwader may be contacted via e-mail to michele@worldwidedrillingresource.com ENV