CN produces wastewater at maintenance shops and other sites as part of operating a railroad. We comply with all environmental agency regulations governing the discharge of company storm and wastewater.

We have nine wastewater treatment plants and numerous oil/water separators and stormceptors located in our yards and have made some major investments over the years to ensure treatment processes are well controlled and operated. CN complies with all operations, maintenance and discharge regulations.

Continuous monitoring

CN is currently in the process of upgrading our treatment plants with Supervisory Control and Data Acquisition (SCADA) systems. These are computer programs that allow an operator to control the water treatment process onsite or from a remote location using the Internet. SCADA systems enable CN to verify at all times that the wastewater treatment plant is operating correctly, to reduce the volume of chemicals used and to ensure that we are in compliance with discharge regulations. We also conduct periodic inspections and monitoring of our plants to ensure compliance.

Reduction Initiatives

In addition to the responsible management of discharges from our wastewater systems, CN actively looks for ways to reduce our water consumption.

For example, water is reclaimed from wastewater treatment plants at some CN yards to wash locomotives. In addition, at CN's Diesel Shop in Memphis, since December 2008, engine coolants from locomotives are recovered and reused in the locomotive once they are repaired in the shop.