SUD: Unaccounted Water Loss, Long Range Planning

by Leslie Lytle, Messenger Staff Writer

“Unaccounted for water loss is extremely high,” Sewanee Utility District manager Ben Beavers told the board of commissioners at the April 20 meeting. “We’re working hard trying to find out where that water’s going.” Unaccounted for water loss is the difference between the amount of water treated at the plant and amount registered as sold on customer meters, meaning water SUD is not paid for. Discussing the two primary causes of unaccounted for loss, faulty meters and leaks, Beavers said the loss decreased when everyone was gone due to the pandemic. “That makes me think it’s the metering. If it was leakage, it would be more or less the same.”

Beavers explained aging customer meters slowed down, failing to record the full amount of water passing through them. Reports showed unaccounted for water loss at 34 percent for February and 36 percent year to date, compared to the low 20 percent late last spring and during the summer when there was very little for many in-town meters to record. SUD has zone master meters tracking the water going to the remote locations of Jump Off, Midway, Deep Woods and Sewanee Summit. “The master meters are quiet,” Beavers said, showing no significant variance between water delivered to the four regions and water registering on customer meters as sold. The conclusion followed the water loss was occurring in town. Beavers said tracking in-town changes in water flow was especially difficult to monitor because the service lines looped around rather than running in a straight line.

Speaking to solutions for finding the water loss source, Beavers said isolating segments of in-town flow with zone meters would be expensive, requiring eight to 10 large zone meters, cost $8,000-$10,000 each. He plans to begin with testing for slow down of large meters serving places like the Sewanee Inn and McClurg Dining Hall, and spot-checking residential meters.

“SUD also has an ultrasonic device capable of identifying changes in flow as an indicator of leaks,” Beavers said, “but using the device requires digging up the line.” Beavers suggested locating permanent manholes at strategic points throughout campus where the device could be strapped to the line for periodic spot checking. He expressed concern, however, the University would not welcome a four-foot manhole in locations like the Quad.

Looking to the future, the board met with Don Mills from the MG Group to discuss designing a metrics platform to aid SUD in long range planning. Mills proposed using historic data going back 10 years to project future revenue and capital needs. He posed the question, “At what point will we have to expand operations?...Engineering costs are not going to go down. Repair costs are not going to go down.”

Board President Charlie Smith recommended projecting at least 10 years out, noting Beavers already budgeted five years into the future.

Commissioner Doug Cameron stressed the importance of planning for drought and argued for a permanent supply line to Lake Dimmick as an alternate water source. Cameron also cited the need for identifying the lifetime of big-ticket items like the water plant and wastewater treatment plant.

“On down the road there will be some major water line replacement,” said Commissioner Randall Henley.

Smith pointed out the trend to move from urban to rural areas could increase water demand.

Regarding people moving to the area, Beavers observed fiber optic internet service in the Jump Off community “is already making a big difference…A lot of people are realizing they can work remotely.”

The board will identify critical metrics by the May 18 meeting. Mills will present the 2020 audit at this meeting.