Water Well Journal
Issue link: http://read.dmtmag.com/i/592194
• Place powder on watch plate. • Apply several drops (three to four) of barium chloride solution (BaCl 2 ) to the crushed sample. • Apply several drops (three to four) of diluted hydrochloric acid (10% HCl) to the crushed sample. • Heat watch plate and view under microscope. • If the sulfate ion is present, a white precipitant powder of barium sulfate will form along with barium sulfate crystals. (SciOptic 2015) In working in the West Texas area, I have found this method useful in aquifer determinations when working in areas were the Ogallala aquifer overlies the Edwards/Trinity aquifer. The Ogallala tends to have a calcium carbonate residue, while the Edwards/Trinity sand- stone tends to have a potentially gypsif- erous cement residue. Parting Thoughts For most shallow drilling projects, it is not necessary to determine cutting samples to the degree as has been de- scribed. However, the potential exists in some areas for drilling into horizons or formations that contain components that are not easy to recognize. For example, one can drill through a recent age formation and unintentionally penetrate a Permian-age formation that may contain injurious water that is just below the shallow aquifer. Having the tools and knowledge to identify different rock types in the field can potentially make the difference be- tween a successfully completed project or a potential comingling offense. The right tools at the right time can make all the difference. References Bates, Robert L., and Julia A Jackson. 1984. Dictionary of Geological Terms, Third Edition. New York: Anchor Books. Compton, Robert R. 1985. Geology in the Field. New York: John Wiley & Sons Inc. Dickson, J.A.D. 1966. Carbonate Identi- fication and Genesis as Revealed by Staining. Journal of Sedimentary Petrology 36, no. 2: 491-505. SciOptic. 2015. SciOptic USA/Canada Geological Supplies. Website ac- cessed September 20, 2015. WWJ Raymond L. Straub Jr., PG, is the president of Straub Corp. in Stanton, Texas, a Texas-registered geoscience firm and specialized ground- water services firm. He is a Texas-licensed professional geo- scientist and holds master driller licenses in Texas and New Mexico and a master pump installer license in Texas. He can be reached at raymond@straubcorporation.com. 32 November 2015 WWJ waterwelljournal.com DACUM Codes To help meet your professional needs, this article covers skills and competen- cies found in DACUM charts for drillers and pump installers. DO refers to the drilling chart. The letter and number immediately following is the skill on the chart covered by the article. This article covers: DOE-5, DOE-6 More information on DACUM and the charts are available at www.NGWA.org. m I aisi undr F t t or Supp es e live v o mpr tion. uc ing A the NGWREF . ldwide or s wo . . ou r 2015 G e , Dec y, hursda T o er Exp t a ndw .m. er 17, 12-1 p emb o . er t a oundw r G ou r 2015 G , , tion uc om/A .c o Exp o er Exp t a ndw o FIELD NOTES from page 31