Water Treatment Plant Upgrades

Water Treatment Plant Upgrades

Project Manager: Candy Staring, P.E. | Water Resources

What We're Doing

The City of Stillwater and the Stillwater Utilities Authority will be upgrading and improving the various processes at the Water Treatment Plant (WTP). Nearly every treatment process will be improved or modified to provide a higher quality, more stable water for our customers. The processes included in the project are: clarification, softening, recarbonation, filtration, disinfection and chemical feed systems. One of the larger chemical feed systems is Lime which is used to soften hard water. The existing lime feed system was installed in the 1980s and has long been showing signs of poor operation and recurring breakdowns. Due to the deterioration of the system and lack of ability to get replacement parts, the softening process must be replaced. In addition to the softening process improvements, replacement filters will be provided, various chemical feed systems will be upgraded to current standards, a new WTP generator will be installed and many other improvements will be made.

The work will be conducted in multiple phases in order to prioritize the efforts will keeping the WTP in operation.

Project Benefits

Lime Softening - The Kaw Lake water flowing into the WTP has an average hardness that classifies it as moderate to hard water. A lime softening process is used to remove this hardness and reduce the potential for scaling inside the City's water lines and also inside our customer's plumbing. Customers may notice the benefits of a softer water because it reduces the amount of soap needed for washing laundry and bathing, leaves dishes shinier and cleaner and preserves the life of coffee makes, water heaters and other appliances that use water.

New Filters - The current filters are arranged in a configuration that prevents adequate cleaning. The new filters planned for the WTP will provide deeper beds for superior filtration, improved backwashing and better cleaning of the filter media for an overall quality of treated water.

New Generator - A new generator for providing back-up power during an electrical outage will provide an increase to the reliability of the WTP.

Chlorine System Replacement - Similar to lime, the chlorine system is aging and deteriorating. WTP staff currently rely on outdated instruments for measurement and control. The chlorine system replacement will include a new chlorine scrubber, cylinder regulators, chlorine feeders and fine-turned measurements and controls.

Miscellaneous - Additional improvements are being made to various chemical feed system and processes.

Actions authorized by Stillwater Utilities Authority (SUA):

  • 1.9.17 | SUA-17-01 | Professional Services Agreement

  • 7.17.17 | SUA-17-22 | Amendment to Professional Services Agreement

  • 9.10.18 | SUA-18-34 | Request for Additional Expenditures and to Execute Contract Amendments to the Professional Services Agreement


Site plan of the WTP and locations of where work will take place.

site plan of the water treatment plant and location of where work will take place