Engineers outlined a plan for the city’s South Waste Water Plant last night that includes some needed attention before the project can move forward.
Professional Engineer Jeff Thorn, of Ollson Associates, told council members that the plant’s southern oxidation ditch system needs to be stabilized before a full renovation of the plant can happen.
The full plan includes replacing the plant’s northern system all together. In order for that to happen it must be taken off line, which leaves only the southern ditch’s system active while a new ditch is constructed to replace the northern system.
Thorn said the southern system of the plant is a good piece that can be used, but the northern system has reached its end.
“It’s older and it’s pretty well shot,” Thorn said about the northern system. “The technology has even gone by the set up. There’s much more efficient ways to do that.”
City Administrator Rick Childers agreed with Thorn, and said the Department of Natural Resources will most certainly have new regulations in place. The city’s North Waste Water Plant has already been notified by DNR that it has three years to upgrade to an ultra violet disinfection system. Estimates have that upgrade any where from a few hundred thousand dollars to more than a million.
“Trying to get five more years out of it is a crap shoot,” Childers said about the north ditch at the South Plant. “It really is.”
“We know some of the pipes are pulled apart,” Thorn added about the situation. “We just don’t know which ones.”
Thorn said the problem with the south ditch is erosion around the area. He said the erosion has caused some pipes to become disconnected. He said one pipe that connect a clarifier with the ditch is connected with a funnel.
Thorn said the erosion is caused by stormwater that saturates the side of the hill and causes the dirt to mound up at the bottom of the hill. Run off ditches and sinkholes are also starting to develop. He said the issue has to be addressed to move forward. He said his firm would work under two different contracts for design that both lead to the end result of a renovated South Plant. He said going this route would not add extra cost to the project because the stabilization has to take place anyway.
“We can’t do anything with that north train until we get that south train stabilized,” Thorn said. “It’s not wasted effort. It’s something we have to do.”
Thorn gave a rough estimate of construction costs between $200,000 and $220,000 for the stabilization project. Earlier estimates have the entire project costing around $6 million.
Thorn said his firm could have plans designed and ready to build along with an overall facility plan by August.
City Finance Director Melanie Allwood said at the beginning of this year the sewer fund had $280,000 in reserves. She said $75,000 of it has been committed to manhole replacement this year.
Childers said he believes there is enough money in the fund to pay for the stabilization design, but that doesn’t include construction.
Allwood warned that the city must keep some money back in case of an emergency. She said with a tight budget, the city only has about $1,500 going into reserve funds this year.
“ I don’t think it’s in our best interest to use all of that money, but obviously there is a little bit,” Allwood said. “We don’t want to use every last penny we have, but at same time we need to move forward.”
The six council members present instructed city staff to proceed.