Engineering and design plans on Chickasha’s new water treatment plant have been completed and “we’re looking at putting it out for bids in August,” City Manager Jim Crosby told the City Council on July 7.
Mayor Zach Grayson said representatives from Freese and Nichols (F&N) will be invited to attend the council’s next meeting, on July 21, to provide city officials and local residents with a status report on the project.
In a related matter, the City Council authorized another task for F&N, consulting engineers on the new water plant.
The city amended the “scope of services” agreement with F&N to have a geotechnical analysis performed on the site for the new treatment plant.
Terracon engineering consultants on Sept. 4, 2024, recommended using deep driven steel piles (“100 feet plus or minus”) to ensure that the building’s foundation won’t be damaged by post-construction settling.
A little over a month later city officials sought a second opinion from Arrowhead Engineering via subcontract with Chisholm Trail Consulting.
Arrowhead recommended using “shallow spread footings and ground improvement technology in lieu of the deep foundations, so that settlement potential would be within allowable design parameters.”
During a meeting held Jan. 15 that involved representatives of the City of Chickasha, Chisholm Trail Consulting, and Freese and Nichols, F&N related that the revised geotechnical report “included results from the rigid inclusions, which according to Arrowhead reduced potential settlement.”
Based upon the anticipated benefits of reduced construction costs and time, F&N “agrees to rely upon the Arrowhead geotechnical report” and its shallow foundation design.
The city “agrees to accept any risks, costs, or consequences that may arise in order to achieve the anticipated benefits…” The additional inherent risks include “reduced performance, increased potential for soil settlements and heave beyond those which are estimated to occur, increased need for maintenance, coordination impacts pertaining to other elements of the project, and unanticipated schedule and cost implications.”
The geotechnical analysis cost the city $275,000, which raised the amount Freese and Nichols has been paid to date to $4,192,505 – double the amount F&N initially expected to spend to provide multiple phases of engineering services during development of the new water plant.
Chickasha’s water treatment plant is at least 60-plus and perhaps 70 or more years old, and is lacking in modern technological advancements in water purification.
The facility was designed to process 6 million gallons of potable water daily. Now, though, its “functional capacity” is 4.2 million gallons per day to serve the 16,500 residents of Chickasha and the nearby community of Norge, F&N professional engineers Clay Herndon and Jason Cocklin told the city council on Jan. 16.
The new facility planned by the Chickasha Municipal Authority (CMA) will be capable of producing up to 6 million gallons of drinking water daily “with provisions to expand to 8 mgd.” Production of 6 mgd “should get you out to the horizon, to about 206070,” Cocklin told the council last year.
The new plant’s treatment process will include pre-treatment, clarification, filtration and disinfection, the CMA said. The plant “will have full back-up generation and redundancy,” Cocklin said.
The new water plant will be built on three parcels totaling 70 acres west of the city’s aged water plant off Genevieve Street, Crosby said. The new facility will be named “The Erwin Family Waterworks” after the local family that’s providing the land on which it will be constructed.
The CMA will lease the land for a maximum of 50 years or until the death of Evie Erwin, “whichever is earlier,” the lease agreement provides. After her passing the land will be gifted to the city, Crosby said.
That provision “honors Ms. Erwin’s promise to her father that she would never sell the land,” he explained.
During her lifetime the CMA will pay the Evie Jo Erwin 2012 Revocable Trust $2,500 per month for the land; payments started April 1. The CMA will pay all utility bills and taxes on the acreage for the duration of the lease.
The CMA also will spend up to $40,000 for a memorial in the lobby of the new water plant that will memorialize Erwin’s family, the lease agreement stipulates.
Local residents voted overwhelmingly Aug. 8, 2023, to finance construction of a new water treatment plant with a capital improvements sales tax.
Chickasha residents opted to renew and increase a sales tax that’s dedicated to capital improvements; that levy, three-quarters of 1%, was scheduled to expire at the end of 2023. The CMA asked residents to raise it by one-half penny, to 1.25%, and impose the levy permanently.
Approximately $74 million is the projected cost of the new water treatment plant, including engineering, construction, and acquiring the land, city officials reported.