Water Well Journal
Issue link: http://read.dmtmag.com/i/668983
Typically, Christensen Well & Irrigation uses a three-man crew when drilling in the Ogallala, and they average a dozen to 15 jobs a year for Beck's Well & Irrigation. Cody has re- duced manpower needed by streamlining the drilling process. To construct a well in the Ogallala, 50,000 to 100,000 gal- lons of water is needed. In the past, Cody pumped water from another well which required four men to lay pipe and pick it up at the end of the job. Today, they use a hose reel they pur- chased in 2012 to transport water to the well they're develop- ing, which now takes only one man to lay out the hose. The rig setup was also updated in 2012. Originally built on a trailer, the rig is now on a tandem axle truck with hydraulic outriggers on it. Where it used to take at least three men an hour to set up the rig now takes one man about 10 minutes. Timing is a factor when developing a well. Beck is pretty adamant once Cody drills a well and gravel packs it—no mat- ter what time of the day it is, a test pump is installed. "We feel it's very important to pump the drilling fluid out of those holes immediately after drilling," Cody says. "We've just had great results doing that. You might not think it'd be a great big deal to wait four or five hours until the next morn- ing, but we feel it's in our best interest and the customer's best interest to do it that way." Drilling in the Ogallala over the years has taught Cody to use a finer slotted well screen along with a high-quality gravel pack around the well casing. He found placing the gravel down the borehole using a hopper assembly lets the gravel flow even and consistent, resulting in a high success rate of pumping pure water with no sand or formation. "A lot of the wells that are made out there the sand can be fine," Cody says, "and if you don't use the right screen or the right gravel pack, you can end up with wells that pump sand and they'll do it their whole lives." Water Quality The Kansas Geological Survey says the quality of Ogallala water is particularly high because the sands and gravels of the formation have a low solubility and act as a filter to help purify the water. The No. 1 contaminant issue Cody and Beck are concerned with and treat is nitrates, a contaminant the sands and gravels do not help clean up. In north-central Nebraska and east of it, dryland farming (meaning without irrigation) dates back 80 to 90 years. The first 70 of those years farmers didn't pay attention to how they applied fertilizer, Beck says. Because of the soil types, leaching occurred and now nitrate issues exist in the shallow aquifers. Fortunately for most of Beck's area there are com- bining zones and better water quality in lower aquifers. But it's not uncommon for Beck to need to drill into the deep sand for quality water. He recalls drilling a 310-foot resi- dential well recently where at 70 feet the gravel formation had 25 parts per million nitrate. High nitrates are affecting the housing market in parts of Beck's area. Home sellers are unable to receive a loan from the U.S. Department of Agriculture Rural Development due to high nitrate levels; conversely, the new homeowner can't get a mortgage without a decent water quality test. Oftentimes cus- tomers prefer Beck to redrill the well for homes up for sale rather than install a treatment system. Beck estimates he does a handful of these type jobs each year. "People have high nitrate water in their gravel formation they're pumping out of," Beck says, "and when the well was drilled in the 1960s or 70s nobody was paying attention to that." In western Kansas, the Ogallala is up to several hundred feet thick in places; it is thickest in southwestern Kansas. In places, tens to hundreds of feet of the Ogallala are saturated with good quality water. However, the impact over overuse has caused significant concern. Take for example a small city in western Kansas which during recent evaluations identified a loss of 60 feet of saturated thickness in their wells, according to Ned Marks, PG, owner of Terrane Resources Co. in Stafford, Kansas. Michael Schnieders, PG, PH-GW, president of Water Sys- tems Engineering Inc. in Ottawa, Kansas, says recharge has occurred within the Ogallala, but it is limited and localized— not widespread or sustained. In some areas, a change in water quality has been identified as being attributable to the water level declines. These are localized changes due to interaction with saline waters or from poor well design and influences with either upper or lower aquifers. For example, according to Marks, there is evidence of intrusion by the Arkansas River alluvial aquifer directly attributed to poor well design and insufficient grouting. Water Level The condition of the Ogallala Aquifer varies significantly depending on the location and whether the aquifer is able to be recharged from precipitation. Water level declines in southwest Nebraska have led to aggressive management by the Natural Resources Districts OGALLALA from page 21 The Ogallala Aquifer. Image courtesy Kansas Geological Survey. waterwelljournal.com 22 May 2016 WWJ