LAWTON – The Oklahoma Water Resources Board approved a $5 million low-interest loan that will enable the Lawton Water Authority to replace its antiquated computerized system that operates the municipal water treatment and distribution systems.
The computer operating system that runs the city’s water system is a Windows XP operating platform “that was built in the early 2000s,” said Rusty Whisenhunt, Lawton’s public utilities director. “We cannot upgrade the system” because Microsoft “doesn’t support that anymore.”
Total replacement of the control system is the only solution, he said.
The OWRB loan will pay for buying and installing a supervisory control and data acquisition (SCADA) system for Lawton’s Medicine Park and Southeast water treatment plants plus the water distribution system, Whisenhunt said.
SCADA is a control system architecture comprised of computers, networked data communications and graphical user interfaces for high-level supervision of machines and processes. It also covers sensors and other devices, such as programmable logic controllers, which interface with process plant or machinery.
Lawton’s SCADA system will control operations of both water treatment plants, their computer servers and programmable logic controllers which will manage the turbidity of the water, the chemical feed facilities, and water quality, Whisenhunt said. The computerized system will generate reports for the system operators.
The SCADA system also will regulate the levels of Lawton’s five elevated tanks that each store a million gallons of water, and its seven-million-gallon ground-level water storage tank on the west side of town, Whisenhunt said. The system also will control the turnover of water in those tanks to maintain the water quality, he said.
The new system also will control water pressure throughout the community. Lawton has five pressure zones, he said.
Although the state Department of Environmental Quality recommends a minimum of 25 pounds-per-square-inch (psi) in a municipal water system, “We try to maintain our pressure between 45 and 80 psi,” Whisenhunt said.
Of the proceeds from the OWRB loan, $4,910,500 will finance the SCADA project and the balance will pay for the bond counsel, a financial advisor and a trustee bank, OWRB records reflect.
The loan from the Drinking Water State Revolving Fund will be retired over a maximum 10 years, Water Board records show. The loan will bear an interest rate of 2.67% plus an administrative fee of 0.5% annually on the outstanding principal balance, said Tonya White, marketing and outreach manager in the OWRB’s Financial Assistance Division.
Security for the loan will be a lien on the revenues of the city’s water, sewer and sanitation systems, the OWRB reported.
Lawton has five other outstanding loans with the OWRB totaling $19,439,128, ledgers reflect.
The City of Lawton has a debt coverage ratio of 3.35 times, Joe Freeman, chief of the Financial Assistance Division, told the Water Board. That means the city has more than three times the resources needed to repay the OWRB loan.
Water consumption in Lawton averages about 17-18 million gallons per day (mgd), he said, but ranges from 11 mgd “at the low end” and approximately 35 mgd during a blistering summer day such as those Oklahoma has experienced lately.
Lawton draws water from three lakes: Ellsworth, Lawtonka and Waurika. The city relies heavily on the latter “from the end of May until September,” Whisenhunt said.