The March 6, 2007 Technical Working Group Meeting with representatives from the State Engineer's Office, Colorado Ground Water Association and Colorado Water Well Contactors Association addressed important topics for water well professionals. These topics included preliminary scheduling of Fall continuing education classes during October 2007, coordination with the Colorado Oil and Gas Conservation Commission and detailed discussion of additives in cement grouts.

Joe Meigs, CWWCA Technical Director, provided a detailed review of costs per cubic yard for neat cement relative to cement with fly ash or sand additive. This comparison identified a potential 20-percent cost savings by using a fly ash or sand additive. In addition to cost savings, cement with fly ash or sand additive is easier to handle in many cases. Mr. Meigs’s focused on use of cement with additives for well abandonment, specifically in deep, Denver Basin applications.

Nolan Lloyd, Chief Well Inspector of the Colorado Division of Water Resources, directed the Technical Working Group to Policy 2000-5 of the Board of Examiners, which allows use of approved proportions of fly ash additive in cement grouts without need for a variance.

Dave McElhaney, Chief of Geotechnical Services of the Colorado Division of Water Resources, addressed use of cement with an additive for well abandonment. Mr. McElhaney stated that fly ash is a preferable additive relative to sand because sand may bridge on well screens and form an incomplete seal.

Variances to use sand additive or greater proportions of fly ash to cement than provided in Policy 2000-5 may be available on a case-by-case basis for well abandonment. For example, if the well was not properly grouted across confining layers, the casing may need to be ripped prior to cementing. Or, to ensure an adequate seal, the casing or screen may need to be ripped prior to cementing with a sand additive. Dave McElhaney recommended making a phone call to the State prior to submitting a variance request to discuss the site-specific conditions.

Variance requests are best sent by email, but fax and mailed requests are also acceptable. While there is no form for variance requests, they should include: (1) Well identification, including permit number(s), (2) Summary of well construction, (3) Well location, and (4) Proposal for abandonment program. Variance requests benefit from diagrams and any additional information, such as a well construction and test report. Good verbal and written communication with the State is crucial for this process.

Future topics for the Technical Working Group include well location and lithologic logs.