Two months after a major pipe break at the Maryville water treatment plant, permanent repairs to get the facility back to normal operations should be completed this week, according to PeopleService Region Manager Steve Guthrie.
A crew from White Cloud Engineering & Construction spent much of Friday morning installing a new 4,000-gallon polyethylene "backpulse" tank, which stores treated water used to clean the plant's filtration membranes.
The three sets, or "trains," of membranes act as a high-tech sieve through which millions of gallons of water flow daily. Capable of removing solid particles as small as one-tenth of a micron — a micron is one-millionth of a meter — the $2.1 million membranes are the heart of Maryville's water purification system.
When an L-shaped six-inch fitting failed the morning of Sunday, Feb 24, flooding a portion of the plant, PeopleService technicians rapidly executed a series of emergency repairs that almost certainly prevented serious damage to the membrane system.
PeopleService is a private company contracted by the city to operate both the treatment plant and the municipal sewage facility.
Guthrie said that when the pipe failure occurred, plant operator Joe Finch was able to mobilize various suppliers who rushed equipment and replacement parts to Maryville so that emergency repairs could be made, no mean feat on a Sunday morning.
"They came through for us. It was an outstanding cooperative effort," Guthrie said.
However, the break did significantly drop water pressure in some parts of town, leading to fears that back-flow would pull sewage into the drinking water supply. As most Maryville residents will recall, that led to a boil advisory that was in effect for nearly three days.
Since then, the emergency repairs have kept the plant running at nearly full capacity, but fluctuating pressure from the initial pipe break caused the backpulse tank to rupture a few days later. The process of replacing it got complicated when PeopleService realized that the tank was too big to remove.
Guthrie speculated that when the facility was constructed, it was actually built around the tank. To make the swap with a new tank, manufactured by Hopkins-based Houston Polytank, White Cloud was hired to install a large overhead door on the south side of the building.
Other equipment damaged by the pipe failure included electric motors, pressure sensors, solenoids, computerized gauges and fuses.
In addition to repairing or replacing the ruined gear, Guthrie said a number of plant upgrades have been completed to ensure that a similar incident does not reoccur. Those improvements include installing new valves and about 120 feet of pipe near where the breakage occurred.