Various well maintenance and rehabilitation projects

Client: 
Regional Municipality of Peel
Contact: 
Dallas Stinson, C.E.T., Supervisor - Water Treatment Regional Municipality of Peel Phone: 905-791-9400
Brief: 
Well Rehabilitation and Service
Year: 
2004/2005
Project: 

Caledon Landfill Injection Wells
Lotowater Technical Services Inc. performed chemical rehabilitation of six landfill leachate injection wells at the Caledon Landfill.  The initial investigation revealed that a significant amount of sediment had accumulated in the wells.  The rehabilitation process involved purging each well followed by the injection of a hydrochloric acid/acid-enhancing polymer solution.  The system was subsequently treated with chlorine to help control nuisance iron buildup in the wells.  Testing confirmed these rehabilitation activities were successful at returning the wellfield to its original as-built capacity. 

Alton Well # 3

Lotowater carried out a rehabilitation of this overburden well in 2004.  Baseline conditions of the well were established prior to the rehabilitation by the completion of a pumping video, a flow distribution profile, sand content testing and a variable rate pumping test.  The well rehabilitation comprised the injection of acid followed by airlift development to remove the loosened biological and mineral buildup from the well.  A new wellhead, designed and fabricated by Lotowater in accordance with Regulation 903, was installed after all rehabilitation activities were completed.  

Alton Well # 4

Flow profile and in-well video testing of this well by Lotowater showed that the upper 2 m of the well screen was almost completely clogged with mineral and biological buildup and that most of the well’s flow originated from the lower 3 m of screen.  Extensive rehabilitation of this well by Lotowater was successful at removing the clogging and eliminating a serious sediment production problem.  A newly designed wellhead was installed at the time the well was put back into service. 

Bolton Well Abandonment 

Lotowater Technical Services was awarded the contract to abandon four production wells in Bolton.  This work involved removing the existing pumping equipment and completing a video log followed by purging, disinfecting and abandoning each well in accordance with Regulation 903.