Water tower fixes deemed urgent

A recent inspection of Maryville's main million-gallon water tower, which stands at the end of Edwards Street on the west side of town, revealed the need for a couple of "emergency" repairs that will make the tower safer and more stable in the event of high winds or other severe weather.

The Maryville City Council on Monday was to review a report submitted by Public Works Director C.E. Goodall summarizing maintenance issues related to the 38-year-old tower, which has stood empty since before the Nov. 7 inspection by Kentucky-based Pittsburg Tank & Tower Maintenance Co.

In his report, Goodall said that while Pittsburg recommended completion of a number of maintenance tasks, only two are deemed essential: adjusting a network of slender "windage rods" in a way that should allow the tower to withstand wind speeds of up to 100 mph, and adding additional strut-end welds in order to boost the tower's overall structural integrity.

Cost of the repairs, which Goodall said he considers vital, is estimated at just under $17,000. Since the work was not budgeted for in the current municipal budget, the money will be taken out of existing water fund reserves.

Of the two projects, Goodall said getting the windage rods adjusted is the most critical, but that it will be cheaper to do the welds while the Pittsburg Tank & Tower crew is on site.

The need to re-tension windage rods is "not uncommon" as large water towers age, Goodall said, "but it is obviously a pretty important process for the integrity of the tower."

He added that since the work is exterior, the city is planning to bring the tank back online while trying out a newly installed equilibrium valve that will allow two auxiliary towers on the north and south ends of town to be completely filled.

Following their completion last year, it was discovered that both the new towers, due to an engineering error, stand slightly higher that the main tank on Edwards Street. This meant the auxiliary towers could only be filled to about 70 percent of capacity.

Think of it like this: There are three glasses standing on a table. One is eight inches high and the other two are 12 inches high. All are connected to a single hose and filled at the same rate. When the eight-inch glass is full it will simply keep overflowing, keeping the other two glasses at the eight-inch level as well.

The main tower is the eight-inch glass. However, this fall, the city installed a new valve that allows it to be shut off while the two new towers are filled. In theory, the set-up should allow the city to achieve its full 2.5-million storage capacity, but no one will know for sure until the new valve is tested.

In addition to maintenance designed to boost the tower's ability to resist high winds and other stresses, Pittsburg Tank also recommended other tasks that Goodall said the city may implement next year. These include pressure-washing the exterior and repainting either the entire tank or the bottom portion, which has become discolored with nearly 40 years of wind-blown grime.

Also likely, Goodall said, is an interior inspection using a robotic camera, which means the tank could be kept in service unless problems were found.

Other proposed chores include resealing the tank's foundation, adding electrical grounding for lightning protection and upgrading access ladders with anti-skid rungs and standoffs.