Testing and Rehabilitation of Wells K41 and K42A

Regional Municipality of Waterloo
George Schneider, P.Geo., Manager Environmental Sciences Division, Golder Associates Ltd. 905-567-4444, ext 1214
Well Rehabilitation and Lineshaft Pump Service


This project was won through a competitive bid process.  All work was completed under contract with the Regional Municipality of Waterloo (RMOW), as part of the Integrated Urban System Groundwater Supply and Optimization Project (IUS).  The IUS was undertaken by the RMOW to restore and increase capacity of regionally operated potable water supply system.  The work for this project consisted of testing, rehabilitating and servicing K41 and K42A, unused wells located in the Lancaster well field.  Work was conducted under the direction and supervision of Golder Associates Ltd. who were retained by the RMOW to complete and implement the IUS study.  Activities completed by Lotowater comprised well rehabilitations, pump and motor inspections, video inspections, and diagnostic testing to determine if K41 and K42A could be returned to the municipal water supply system.  
Lotowater performed pre-rehabilitation testing at both K41 and K42A consisting of step tests to evaluate current performance and video inspections of the well casings and screens.  These efforts were undertaken to confirm well construction details, help diagnose problems and to develop and implement rehabilitation programs specific to the conditions encountered.  
The wells were rehabilitated using double Ener-Jet® treatments (equivalent to the SonarJet process) across the screened intervals to loosen encrustations and agitate the gravel pack, followed by acid rehabilitation and airlift pumping and surging.  These efforts were successful in restoring the performance of the wells to original levels.    
The 30 L/s, 50 hp vertical lineshaft pumps present in each well were completely disassembled and inspected.  This included inspection of all column pipe, couplings and shafting.  A detailed report was prepared for each well documenting the condition of all equipment, including measurements of all critical wear points with respect to manufacturer specified tolerances, and recommendations for repairs.  
Stand alone reports were prepared for each well and provided to the client for their records.  These included a brief narrative of the testing process, a summary of the results including recommendations, well performance test records, as constructed drawings, and a DVD copy of the well videos.  Both the client and consultant were very happy with Lotowater’s performance on this project.