WorldWide Drilling Resource

Environmental Monitoring by Thomas Kwader, Ph.D., P.G. Should all Water Supply Wells be Grouted or Sealed? An argument can be made that all water supply wells should be grouted from their producing zone to land surface. An example of an exception might be where a new house is being built in the country away from human sources of contamination and there appears to be little or no risk of contamination. However, this would be a rare occurrence. Most all wells have a small annular space between the sediments drilled and the well casing. Even the smallest of annular spaces (the 1/8-inch from a coupling) can provide a pathway for fluids to travel vertically down to the screen or open hole of a supply well. It can be argued, the concern of vertical movement of fluids is less of a problem with cable tool constructed wells (driven casing) versus rotary drilled wells where a casing (steel, PVC, etc.) is set in a larger open borehole having a one- to two-inch annular space. The cost and labor of grouting a rotary drilled well is more, but the probability of seepage of percolating water from above is much greater than a driven steel casing. I have seen many wells which experience significant turbidity (cloudy or unclear) problems due to water falling tens of feet along the annular space from above. Mother Nature often provides a unique natural filtration system which helps provide crystal clear, bacteria-free water to be withdrawn from wells. Layers of sediment (sands) can filter fine particles and remove any turbidity. Percolating groundwater from the unsaturated zone (where oxygen is available) through the anaerobic (low-oxygen) zone below the water table is ef- fective in killing most types of bacteria and viruses. Clays also help absorb metal ions and organic plant matter by absorbing many types of unwanted metals and particles. An unsealed well allows “dirty” water to travel deep to the producing area of a well which can eventually be pumped to our drinking water supply. Over time, even the most “pristine area” will experience growth and devel- opment which may be impacted by new source pollution. Unsealed wells can be a conduit for many sources of contami- nation, including septic tanks, animal waste, fertilizers, pesticides, leakage from fuel tanks, etc. A properly sealed well is not only a good investment, but a healthy choice as well. Tom Tom Kwader may be contacted via e-mail to michele@ worldwidedrillingresource.com 12 JANUARY 2019 WorldWide Drilling Resource ® New Check Valve Now Available Adapted from Information by Flomatic ® Corporation For more than 85 years, Flomatic ® Corporation has been changing the industry and lead- ing the market, manufacturing a full line of check valves for water and wastewater applica- tions. Now they have another one! The company has brought their new Model 508S6 Ball Check Valve to market. This simple, yet reliable 316 stainless steel check valve features a full-ported valve seat uniquely designed to allow a strong phenolic ball to seat on a Nitrile (Buna-N) seat. For vacuum or antiflooding valve applications, an optional “floating” rather than “sinking” ball is used. Due to its simple, flow-efficient design, the valve is virtually main- tenance free. The valve is commonly used in submersible wastewater lift station applications. Bo Andersson, Flomatic’s president is particularly proud with this new valve. “It was our goal to deliver a longer service life ball check valve; the Model 508S6 does just that. This new valve can be installed both vertically and horizontally, and the optional Flomatic ® Auto-Vac Model 77 vacuum breaker makes this a one-of-a-kind valve. I am very proud of the work the team has done with this new valve.” Rated at 150 PSI and a MAX 180°F (82ºC), Model 508S6 is available for immediate ordering on 1¼-, 1½-, and 2-inch sizes. The optional vacuum breaker mounted on the access port reduces hydraulic shocks (water hammer). WTR ENV