Rogers Water Utilities To Expand Sewage Plant

Officials Work To Keep Up With Rising Costs

Last updated Monday, March 28, 2005 10:43 PM CST in News

By John L. Moore
The Morning News

Editor's note: This is the second of two stories dealing with the Rogers Water Utilities and its effort to keep pace with the city's growth. Today's story deals with the sewage collection system and wastewater treatment plant.

Total project costs were estimated at $33 million to expand to 12 mgd and an additional $17 million to expand to 16 mgd.

Rates won't cover those costs, McAlister said during Water and Sewer Commission meetings this year.

The city added sewer connection fees this year to defray some of those costs. Increases in both rates and the connection fees are likely in the coming years, said Commission Chairman Donnie Moore.

Capital expenses are not the only things for which customers pay.

Operating cost includes the staff and equipment to operate a system that grew from 8,500 customers in 1984 to 21,536 in 2004.

Maintenance of the city's water and sewer lines is another expense.

The city has 350 miles of sewer lines. In some cases, lift stations are needed to pump the sewage into gravity-fed main lines, which carry wastewater to the treatment plant.

The oldest sewer lines -- in the downtown area -- were built in the 1930s. Those lines need tender loving care to keep them in shape, said William Evans, the supervisor of field operations.

Maintaining sewer lines and lift stations can be more expensive than people realize, Evans said.

The utility spent approximately $27 million in 1997 and 1998 for a sewer rehabilitation program. The program included miles of new sewer lines that parallel existing lines to handle the wastewater when stormwater infiltrates the sanitary sewer system.

The project also added 14.5 million gallons of temporary storage at the treatment plant.

As much as 45 million gallons of water was going to the plant daily during rain storms, McAlister said.

Infiltration and inflow are the enemies of Evans' crews. Infiltration is water that seeps into the lines through cracks or breaks. Inflow is water that enters through other means, such as when a sewer cleanout cap is left off.

Constant monitoring and repair efforts are part of the routine to help keep as much stormwater out of the lines and the treatment plant as possible, Evans said.

The utility spent $450,000 last year to replace 11,000 feet of sewer lines to help keep that groundwater out. Digging up an old sewer line and replacing it with new line can cost more than $60 per foot, McAlister said.

Rogers Water Utilities contracted with Insituform of Jacksonville, Fla., which used a flexible thermo-plastic liner, which was run inside the older pipes.

When the liner is heated to 180 degrees with hot water, it hardens into a plastic pipe.

"It's like getting a brand new artery," Evans said.

Regular maintenance is performed year-round on lines, Evans said.

The Rogers plant treated an average of 7.14 million gallons of sewage per day in the past 12 months, said Mike Lawrence, plant manager. The system was designed to handle 6.7 mgd.

The plant was designed to operate 20 years without expansion. That time is ending, Lawrence said.

The capacity of the plant can be expanded to 8 mgd relatively inexpensively, but that will only delay an inevitable expansion, he said.

Lawrence credited pretreatment programs and conservation efforts for delaying the need for expansion.

People may not realize that conservation efforts don't just save water. Conservation also controls the amount of wastewater the treatment plant has to deal with, Lawrence said.

The less water coming down sewer pipes, the less water to be treated.

Industrial pretreatment programs reduce the amount of pollutants sent into the sewer, thereby extending the life of the plant, Lawrence said. The programs also help the utility satisfy state permit requirements.

The permit specifies the amount of substances that can be in treated water when it leaves the plant and enters Osage Creek.

Two changes to the state permit will likely mean more expense to the utility, McAlister said.

The plant already exceeds a requirement to limit phosphorus in the plant's effluent to 1 milligram per liter or less. Last year, the plant averaged 0.43 milligrams per liter of phosphorus in its effluent.

The state will likely stop the utility's practice of applying sludge to fields in 2006. Sludge is the solid material left after the wastewater is treated.

McAlister said it could cost about $800,000 a year to operate a sludge drying facility and to transport the sludge out of the region. It could also mean about $6 million to $7 million in capital costs.

A regional sludge handling facility, proposed to be owned and operated by the Northwest Arkansas Conservation Authority, may help control some of those costs for Rogers and other cities.

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