2007 Ground Water Summit

Tuesday, May 1, 2007 : 2:30 p.m.

Maintaining Production, Dual-Use, and Artificial Recharge Wells in Las Vegas Valley, Nevada

Erin Cole, NGWA, CGWP, Las Vegas Valley Water District and Todd Howard, Layne Christensen Co.

In March 2005, the Las Vegas Valley Water District (LVVWD) took a new approach to well maintenance.  After years of careful monitoring and data collection, an excellent data set was available to evaluate well performance through time.  This evaluation indicated that most of the LVVWD wells were performing at or close to original testing conditions and no further work – other than continued monitoring – was required.  However, the study identified 15 pumping wells and 10 artificial recharge wells with declining performance or dramatic well clogging.  In many cases, the well clogging appears to be a result of artificial recharge operations in the well.  The study used a cost-benefit analysis to prioritize the work. 

After evaluating available techniques, meeting UIC permit requirements, and bidding a multi-year well maintenance contract; the well rehabilitation work began in late summer 2005.  From August 2005 until November 2006, six wells were rehabilitated and a seventh was undergoing work.  Wells are first video-surveyed to assess casing condition and to observe the severity of corrosion and encrustation with depth.  A basic pattern of chemical treatment followed by well development pumping has been applied to 6 of 7 wells, and the results have been positive.  In most cases, the chemical treatment is designed to address biofouling of the wells; however, additional treatment is applied in the case of additional mineralogical plugging observed in the perforations. 

Out of a total of seven wells, four wells have had dramatic improvements in specific capacity:  one of them tested even better then when it was originally drilled.  The results appear to be linked to the treatment used, as well as, other characteristics (e.g., drilling method, well use, previous maintenance, and degree of deterioration). What remains to be seen is the long-term effectiveness of these well rehabilitation procedures.

Erin Cole, NGWA, CGWP, Las Vegas Valley Water District Erin Cole obtained M.S. degree from the University of Nevada-Las Vegas. She has spent 17 years working on ground water and geology issues. After several years in consulting, Erin worked as a hydrologist for the Southern Nevada Water Authority until 2000. From 2000 to 2003, Erin spent time as a volunteer in the United States, South America and briefly in Africa on natural resource development issues. She is a hydrologist in the Operations Department of the Las Vegas Valley Water District. She addresses issues regarding well operations, well maintenance, well replacement, and aquifer issues affecting pumping and artificial recharge cycles.

Todd Howard, Layne Christensen Co. Howard has been in the water well industry for over 23 years, specializing in water well rehabilitation, pump engineering and application. Mr. Howard holds professional certifications in pump design, engineering and application, as well as chemical well rehabilitation. His background includes specialization in water well and water storage and distribution system engineering and design. Mr. Howard now oversees the High Desert branch of Layne Christensen Company, with a territory that spans from Fresno, Ca. to Kingman Az.


The 2007 Ground Water Summit