Title
Consideration of Change Order No. 6 to Services Agreement AGR17-30 for the Otowi Well #2 Design, Drilling and Development Project
Recommended Action
I move that Council approve Change Order No. 6 to AGR 17-30 for the Otowi Well #2 Design, Drilling and Development Project in the amount of $399,587.64.
Utilities Manager Recommendation
The Utilities Manager recommends that Council approve the motion as presented.
Board, Commission or Committee Recommendation
The Board of Public Utilities recommends that Council approve the motion as presented.
Body
The drilling of Otowi Well #2 began on January 16, 2018. The drilling operation was originally scheduled to take 60 days to complete the drilling and install the screen and casing. The original construction schedule is provided as Attachment A. The driller was using the reverse rotary mud drilling method and encountered a fissured basalt geological formation at about 50 feet below ground level. The fissures in the basalt caused the drilling mud to be lost into the formation and drilling was stopped since the cuttings could not be removed from the bore hole due to the loss of circulation. Through February and March 2018 the contractor and the DPU negotiated the project's first change order that modified the drilling equipment to change the drilling technique to a dual pipe rotary air drilling methodology. This was a high cost change due to the need to custom fabricate some equipment, re-tool the drilling rig and increase the number of air compressors to drive the air circulation process. Beginning on April 1, 2018 work continued using a combination of the dual pipe rotary air and reverse rotary mud methodologies. Drilling fluid and recirculated air continued to be lost to the formation. The contractor proceeded to use a number of additives to the drilling fluids to attempt to re-establish circulation, but the only effective solution was to install cement into the bore hole to attempt to seal up the ...
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