Lime Feed System Replacement & Miscellaneous Improvements

Water Treatment Plant Filters, Lime and Other Miscellaneous Improvements

Project Manager

Water Resources / Candy Staring, P.E.

SUA Project No. 16WG08

What We're Doing

The City of Stillwater and the Stillwater Utilities Authority will be upgrading different chemical feed and filtration systems at the Water Treatment Plant (WTP). One of these systems is the Lime feed, which is used to soften hard water. 

The existing lime feed system was installed in the 1980s and have 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, other facilities will be evaluated and either replaced or repaired in order to maintain proper operation and functionality of the treatment process. These additional areas include various handrails and walkways at the WTP and wastewater treatment plant (WWTP), the Solids Contact Unit No. 3 improvements, filtration system and various chemical feed systems.

Project Benefits

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 makers, water heaters and other appliances that use water.

How We're Paying For It

Funds for the construction of the project and associated services will come from the City's Water Capital Fund. 

Latest Project Update

March 12, 2018: After evaluating most of the process and chemical feed systems at the WTP, a priority has been assigned to each individual component. The Project Team is initializing design for the chlorine system upgrade which is the highest priority. Additionally, a Facilities Plan will be prepared to develop a conceptual and phasing plan for the remaining work with includes filters, lime, carbon dioxide, ammonia and many other improvements.

Project Timeline

February 7, 2017: Black and Veatch has been hired to provide conceptual design services.

September 6, 2017: The project continues to be in the design phase. In July, SUA approved multiple additions to the scope due to discoveries of various safety issues and equipment deficiencies. Evaluation of the filters has been added in order to optimize filtration and improve overall functionality. Many chemical systems are being considered for rehabilitation due to their age, poor condition and frequent malfunctions.

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


(Posted Feb. 7, 2017):

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

Aerial site plan of Water Treatment plant with call outs for Filters, Solids Contact Unit and Lime Feed Stystem

(Posted February 7, 2017):

Existing equipment of the lime feed system located in the Lime Silo.

Photo of existing equipment inside lime silo