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o�� California Groundwater Association An NGWA Affiliate State 700 R Street ` TERI Suite 200 Sacramento, CA 95811 cga@groundh2o.org 916-231-2134 CGA STANDARD PRACTICE SERIES ARTICLE 299 ESTRUCTION OF WATER WELLS BACKGROUND GENERAL With increasing concern over trace quantities of contaminants affecting the quality of ground water, the potential for inactive or "abandoned" wells to act as pathways for contaminants into groundwater becomes more critical. Although Bulletins 7 -81 and 74-90 contain general guidelines as to materials and procedures to be followed in the destruction of wells, there have been advances in technology and sealing materials since Bulletin 74-90 was issued. Further, in considering destruction procedures we.now need to eliminate potential contamination from organic contaminants such as MTBF that were not even identified as such when the bulletins were prepared. Therefore,;the purpose of this standard is to,provide guidance, based on current industry practice, on the type and application of sealing materials, and techniques used in the physical;, process of well destruction that are not covered, or depart from, those specified in Bulletin 74. As with Article 580 of the CGA Standard Practice Series on the Destruction of Test or Exploration Holes, another purpose of this standard is to provide guidance where local jurisdictional agencies may,rely on Bulletin 74 as a reference for their requirements for well destruction. The definition of an "abandoned" well, and the time limits after which a well should be destroyed are contained in Section l 15700(d)the California Health and Safety Code,which states: "A -permanently inactive well is a well that has not been used fir a period of one year, unless the person owning land in fee simple or in possession thereof under lease or contract of sale demonstrates an intent for future use,for water supply, groundwater recharge, drainage, or groundwater level control, heating or cooling, cathodic protection,grouniwater monitoring or related uses." Requirements for "demonstrating an intent.fir future use"are included in the Code. DISCJSSION BASIC CONCEPTS If destruction is properly accomplished, the well is no longer a conduit for surface water contamination, cross-contamination of water of differing quality into multiple aquifers, and the pressure head in the aquifer(s) is preserved. If vertical movement of water within the well bore, including the annular space, is prevented, then the objective for destruction of the well is achieved. An open well (particularly the large diameter "hand dug" variety) that presents a safety hazard is mitigated by the destruction process. Applicable destruction methods and materials as discussed in this Standard will depend on the specific reason for destroying the well and on its condition and construction details. For effective destruction procedures, the hydrogeologic setting of the well should be considered. For example, in water-table conditions, the main consideration is sealing the well with impermeable ARTICLE 299—DESTRUCTION OF WATER WELLS —Page 1 of 8(Revised 4/27/2013)