Water Well Journal
Issue link: http://read.dmtmag.com/i/440561
the under-treatment of wells in an effort to target one specific zone, thereby discounting the influence of an entire column of water on the selected products. Mechanical cleaning efforts are generally used as a means of both pre-treatment to remove bulk material, and agitation during treatment to disperse chemical solutions throughout the well column and into the borehole. Chemical cleaning should be conducted in a safe manner with careful attention placed on the handling and administra- tion of the chemicals into and out of the well. The investiga- tion efforts conducted prior to treatment should help and act to focus the treatment into areas needing more aggressive efforts or longer contact times. Proper prior planning with regard to materials handling, neutralization procedures, containment equipment, and safety precautions will help assure a safe work site during treatment. During chemical cleaning efforts, pH, conductivity, and visible turbidity should be monitored and recorded. Testing should begin at the wellhead prior to the introduction of any chemicals, and continue throughout the entire treatment process. Testing during treatment procedures allows for moni- toring reactions occurring downhole. Upon evacuation, moni- toring these parameters will assist in tracking the removal of both the chemical solution as well as the disrupted material. Once cleaning efforts are completed, the chemical solution and disrupted material should be fully evacuated from the well system. The well should be purged of debris, with the materials collected above ground for monitoring, neutraliza- tion, and disposal. During the evacuation process, monitor pH, visual turbid- ity, and conductivity of the discharged solution to ensure all chemicals and disrupted material have been evacuated from the well. Never neutralize downhole. Disposal of the spent cleaning solution is dependent on local, state, and federal regulations and should be mapped out prior to beginning the cleaning process. The use of acids as part of well maintenance can be effec- tive at reducing fouling mechanisms that impact well opera- tion and produced water quality. However, the selection and employment of any chemical should be undertaken with care and consideration. Although numerous chemical products are available on the market, the choice of which product to use should be based on an understanding of the problem. The proper use and applica- tion of any chemical is essential to a safe and successful cleaning project. Twitter @WaterWellJournl Michael Schnieders, PG, PH-GW, is a hydrogeologist and senior consultant for Water Systems Engineering in Ottawa, Kansas. He has an extensive background in groundwater geochemistry, geomicrobiology, and water resource investigation and management. He can be reached at mschnieders@h2osystems.com. WWJ January 2015 21 WWJ Quality, Service & Solutions Phone: 800-356-5130 monitor@baker-mfg.com www.bakerwatersystems.com Water Well Products Well caps Well seals Pressure switches Pitless adapters Pitless units Yard hydrants Tank tees Point-of-use filtration Water well accessories Stainless steel and lead free brass Insert fittings - Gauges - Valves - Pitless adapters - Tank tees High-Capacity Groundwater Wells and Groundwater Well Accessories Environmental Products PVC water well screen Flush thread PVC screen and casing Flush thread HDPE well screen Open end PVC well screen Belled end PVC screen Perforated well screen Custom slotted well screen PVC submersible pump screen Centralizers Sparge point Complete line of PVC fittings and well accessories