WorldWide Drilling Resource®

Notes from the Groundwater Guy by Thomas E. Ballard, P.G., C.H.G. Southeast Hydrogeology, PLLC Common Causes of Well Failure - Location I was once contracted by a winery operation to conduct a pumping test on a new well they were plan- ning to drill to support an expanded winery and tasting room. I asked if they needed any assistance in identifying a good well location, and they told me they already had a location picked out. Since there was an existing 300-gpm (gallons per minute) agricultural well on the property and they needed 50 gpm for their operation, it should have been a slam dunk, right? Not quite. When we showed up to do the pumping test, we found the well had conveniently been drilled next to a power source which, in and of itself, is a good thing. The only problem was the power source and the well were located substantially uphill from the high-producing agricultural well and where the productive alluvial aquifer pinched out for the most part. They ended up with a 25-gpm well - half of what they needed - all because they did not pay attention to the geology. More than anything else we have talked about with respect to causes of well failure, proper location of a well relies heavily on the geology. There are places in the country where you get nice sand aquifers and can put a well almost anywhere to get a good yield, but for most of the country, there needs to be some consideration of the location of a well site with respect to geology, hydrogeology, and environmental factors. In alluvial aquifers, yields are typically more predictable, but even in places like the Central Valley of California, a careful review of existing drilling logs is important in locating a new well. This is to take into account not only aquifer zones and potential yields, but also environmental and contamination issues. In some parts of the country, the presence of nitrates and arsenic can be important considerations in locating a well. Fractured bedrock aquifers in igneous and metamorphic rocks are often the most challenging when it comes to locating a successful well, since they have poor primary porosity and rely solely on the development of fractures in the bedrock to transmit and store groundwater. Locating productive fracture zones is critical to siting a good well in these geologic environments. Other geologic environments can have their own unique challenges, but in all cases, applying a bit of geology can go a long way to avoiding a poor well location. Tom Tom Ballard may be contacted via e-mail to michele@ Alberta Water Well Drilling Association Convention / Trade Show March 26-28 Cambridge Hotel & Conference Centre Red Deer, AB, Canada 403-346-2091 Thursday 26th Palermo Room 3 PM Public Forum 1st Session Alberta Environment & Parks 8 PM - Wine & Cheese Welcome Friday 27th 8:30 AM Continental Breakfast and Trade Show Opens Noon - 2:00 PM - Luncheon Guest Speaker Don Henderson, Geologist - Royal Tyrell Museum, followed by AWARDS and PRESENTATIONS Palermo Room 2:00 - 4:00 PM - Public Forum 2nd Session Alberta Environment & Parks 4:00 - 5:30 PM Annual Meeting 1st Session • 7:00 - 11:00 PM - TRADE SHOW OPEN NEW!! THEME - “Tribute to the Past” Entertainment 50’s and 60’s DRESS the PART! Friday evening - Saturday 1:30 PM - Silent Auction Saturday 28th 9:00 -10:30 AM Technical Sessions 10:30 AM - 2:30 PM TRADE SHOW OPEN (Lunch provided - tickets required) 2:30 - 4:30 PM - Annual Meeting 2nd Session Palermo Room 4:30 - 5:00 PM - Bylaws update. CONTACT Sheena Larson for more info 780-386-2335 or e-mail 8 MARCH 2020 WorldWide Drilling Resource ® N&N Drilling Supply offers sampling equipment for obtaining soil samples at or near the surface for environmental sampling and monitoring, as well as geotechnical testing applications. Samplers are 18-24 inches in length and the Lynac head has coarse threads which make assembly/disassembly much faster. All shoes for samplers are heat treated to withstand continued heavy use. A ball check feature prevents a washout of material when retrieving a finished sample. Split-spoon samplers are used in geotechnical analysis which don’t require undisturbed samples. Lynac standard and heavy-duty come in 2-inch and 4-inch diameters. N&N Drilling Supply is a Valued WWDR Advertiser. WTR