Wastewater treatment plant improvements continue

MONTROSE — City improvements to expand the Montrose Wastewater Treatment Plant continue on schedule despite winter weather.  

“The weather has kept us from doing some of the stuff that we’ve needed to do,” city engineer Jason Ullmann said, motioning toward a layer of snow on the side of the secondary clarifier site.

The plant’s capacity is being expanded by 50 percent through the $3.8 million addition of a third oxidation ditch and secondary clarifier, as well as a pump house. The city acquired a $1.9 million grant from the Environmental Protection Agency in 2002; this is combined with capacity fees to finance the expansion.

Construction began early last November. Ullmann said the project is on schedule for completion by Sept. 30, though he hopes weather conditions improve.

Montrose City Council approved adding the $290,000 pump house to the project Nov. 1, following concerns regarding clogging problems.

“Once they got into the design process it became apparent that we were going to need a pump house to pump the return sludge back,” Ullmann said Wednesday.

“Our existing two clarifiers just run back by gravity, so there’s no pump there, but we have some problems with that process. It takes a lot of maintenance. They have to keep going in there and flushing it out.”

He said problems associated with clogging can lead to health violations.

“We’ve never had a violation here at this plant in all our years since 1983 and we’d like to keep it that way,” he said.

The Colorado Department of Health and Environment regulates the plants and administers the EPA permits. Ullmann said that when municipalities don’t manage to stay far enough ahead of their capital improvement programs, they can begin having problems keeping the waste in the system long enough for all necessary materials to be removed.

Ullmann said the new pump house will also accommodate a fourth oxidation ditch and secondary clarifier when they’re needed, which could be in the next nine to 10 years. He said the other facilities built in the early 1980s, such as the sludge digester, will be able to accommodate expansion in addition to that currently under way.

The oxidation ditches, which are 8 feet deep, function to create an environment ideal for bacteria to break down waste. They keep the waste flowing and aerate it with large brushes.

The secondary clarifier is a large, deep pool where bacteria sludge settles and is scraped off the bottom and skimmed off the top. Some sludge is sent back to the beginning of the treatment chain to ensure a proper amount of healthy bacteria to break down the waste.

As for the current project’s status, the secondary clarifier hole has been dug and the 12-inch sludge line that will lead to the pump house is to be installed by Friday.

The clarifier’s slab is to be poured March 4. The pump house and oxidation ditch will follow.

Contact Robert Allen via e-mail at roberta@montrosepress.com