• Home
  • Mine Tailing Drainage: A Bottoms Up Approach Using HDD Drilling and Installation Methods

Mine Tailing Drainage: A Bottoms Up Approach Using HDD Drilling and Installation Methods

  • 13 Jan 2016
  • 6:30 PM - 9:00 PM
  • Sheraton Tucson, 5151 E. Grant on the northeast corner of Grant & Rosemont


  • Member of SME Tucson that reserves by the deadline.
  • Not a member to SME Tucson Section
  • Must be a current UA mining student and member of UA SME.

Program:  David Bardsley, P.G. will present a case study of dewatering a tailings pond with unique challenges and conditions that could lead to a catastrophic toxic release. In this case, the Maine Department of Environmental Protection looked to horizontal wells to address their challenges.

Sponsor:  Available!

Currently, efforts are being taken to remediate historic mine tailing sites. At some sites the first step in remediation is to dewater the impoundment. Recently the Maine Department of Environmental Protection looked to horizontal wells to dewater a tailings pond. A horizontal well provides a dewatering option that could be placed under, not through the boulder/rubble tailings dam. Long distances to nearby utilities also restricted the de-watering operations to a gravity-fed design.

The Maine mine tailing site provided several challenges. One, the remote location and rugged terrain limited equipment access. Two, the impoundment’s embankments were constructed of mine waste including boulder and cobble materials. Three, little field data was available as to composition and water content of the sludge at the bottom of the pond.

To treat the tailings drainage a gravity-fed bio-reactor was to be constructed down gradient of the impoundment. The future site of the bio-reactor and the improved roads leading to it provided a logical location for drilling activities. By setting up in this location and drilling under the clay and rock embankments the first two challenges could be overcome.

The third challenge required a unique solution. By drilling under the embankment and then up through the floor of the pond a potentially uncontrollable drain may develop. Depending on the water content or slurry composition this could lead to a catastrophic toxic release. During the design phase of this project this became poignantly clear with the Gold King Mine release into the Animas River, Colorado.

To avoid a similar release several controls were implemented at the Maine site. Notably casing was driven under the embankment with the drilling going through the length of casing. The casing provided support to the overlying embankment and also focused any potential discharge through this one control point. A plug at the exit of the casing controlled flow out of the tailings pond.

A gravity-fed dewatering drain was successfully installed via horizontal directional drilling. Drilling operations worked down gradient of the impoundment toe, drill under the clay embankment and up into the lower levels of the impoundment. When taking this approach thorough planning and preparations are necessary to avoid an uncontrollable release of tailings liquids. Takeaway lesson from this project is that with proper planning mine tailings can effectively be drained using horizontal wells.

Speaker Bio:
David Bardsley has over 32 years of environmental drilling experience working in a variety of settings across the U.S. He started his career as a drill rig helper advancing through various technical and managerial positions in both small and large companies.  He is familiar with all of the drilling techniques utilized in the industry including; auger, air/mud rotary, casing advance, sonic, dual tube, direct push and wireline coring.  He was an early leader in the use of horizontal drilling to solve environmental challenges and has authored/co-authored over twenty papers on horizontal environmental drilling methodology.  David has been directly involved in the design and installation oversight of over 100,000’ of horizontal environmental wells including seventy-six blind well completions.  Mr. Bardsley has a Bachelor of Science degree in Geology & Geophysics along with a Communications Minor (1984) from the University of Missouri-Rolla. 

Registration Deadline is 12PM on Friday before dinner:

Include for EACH Person (badge will be printed as provided):

  1. First Name Spelled Out
  2. Last Name Spelled Out
  3. Company / Organization Spelled Out
Location: Sheraton Tucson at 5151 E. Grant -- northeast corner of Grant & Rosemont. Use Conference Center Entrance on west side of the hotel.


$27 SME Tucson members who reserve by deadline.

$35 non-members who reserve by deadline.

Add $3 to above ($30/$38) for late RSVPs if space allows.
Free for current UA mining students who are UA SME members.
Payable at the door by cash or check payable to SME Tucson
Cost does not include bar drinks. Cash bar is available.

Cancellations and No Shows: Please call or email by the registration deadline to cancel.  If you do not cancel your reservation by the deadline, SME is still required to pay for your dinner and you will in turn be billed. Thank you.

SME Tucson Section
PO Box 65931
Tucson, Arizona 85728
(520) 314-5066
Powered by Wild Apricot Membership Software