Walkerton Interim Water Treatment Facility

Walkerton Interim Water Treatment Facility

ZENON Mobile Emergency Response

The public water supply in many communities across North America is increasingly threatened by harmful contaminants that are resistant to conventional disinfectents. In the spring of 2000, heavy rains washed bacteria-laden livestock manure into an insecure well in Walkerton, Ontario, introducing E.coli 0157:H7 to the Town's water supply. E.coli can cause severe gastrointestinal sickness, with stomach cramps, diarrhea, fever and vomiting, to the point where it can have long-term health effects or even cause death. At the time, the chlorination disinfection system was not able to cope, and tragically the resulting E.coli outbreak was the deadliest in Canadian history.

Led by the Ontario Clean Water Agency, an army of consulting engineers set out to undertake the largest water supply clean-up effort in the history of Ontario. One of the first objectives was to determine both short- and long-term ways of providing the Town with safe water once again.

As an immediate measure to help Walkerton, ZENON was selected to deliver a mobile containerized ZeeWeed ultrafiltration water treatment unit. The system is part of a multi-barrier approach to treating Walkerton's groundwater, including wellhead protection, membrane filtration, chlorine disinfection and residual maintenance prior to distribution.

ZeeWeed Emergency Response Advantages:

  • Proven and reliable barrier technology
  • Incorporated in many emergency response applications
  • Quick delivery and commissioning services
  • >6 log removal of Cryptosporidium Oocysts, Giardia Cysts, and other harmful bacteria
  • >2 log removal of viruses
  • Highly automated system resulting in simple operation and maintenance

The containerized membrane system treats raw well water to remove solids, parasites and bacteria, thereby making chlorine a more effective disinfectant. Raw water is pumped into the ZeeWeed membrane tank. Under a slight suction (-1 to -10 psi), water is filtered by passing through hollow-fiber ZeeWeed membranes, which are attached to the suction side of an ANSI centrifugal pump. With an absolute pore size of 0.1 microns, the membranes form a positive barrier to impurities and contaminants in the water, which remain in the process tank. The system will produce a maximum flow of 1.32 MGD (5,000 m3/day) of ultrafiltered water.

The transportable, pre-assembled ZeeWeed system, which comes complete in two halves, minimizes on-site construction time and cost. The equipment, including process pumps, valve instrumentation and control systems, is housed in a single container. The ZeeWeed membranes are immersed in a steel tank supplied by ZENON. A Programmable Logic Control system makes necessary adjustments to ensure the plant is operating optimally.