Roxborough water district believes it has solved smelly problem

The Roxborough Water and Sanitation District believes it has solved an odiferous issue that plagued Columbine Hills residents after the completion of a new wastewater line.

That smell emanated from the district’s recently completed 14-mile pipeline, which is part of a wastewater regionalization project. But for those who live near — or simply drove by — Roxborough’s transfer station near C-470 and South Platte Canyon Road, that strong odor was too much to take throughout November.

“The rumors are true,” said Steve Howell, the Roxborough Water and Sanitation District’s director of operations. “There have been some odors in that area.”

The pipeline, which runs north from Roxborough to a Littleton and Englewood wastewater treatment facility, was completed in late August. One of the reasons for building the pipeline was to take wastewater from Roxborough and Lockheed Martin and to eliminate two discharge points in the South Platte River.

The pipeline starts near Waterton Canyon and extends to a connection point near South Santa Fe Boulevard and West Belleview Avenue.

“It now provides better quality and more cost-effective treatment of Roxborough’s water due to Littleton’s advanced treatment capability and economy of scale,” general manager Larry Moore said in a newsletter to district residents.

He noted, “The new pipeline reduces the district’s regulatory burden and compliance risks, avoids the need to expand the existing wastewater treatment plant, improves the wastewater treatment services to the community and stabilizes the cost of wastewater treatment for residents of the district.”

But the new system came with a couple of issues the water district had to resolve.

A “transition vault” installed near C-470 links a pressurized line from Roxborough to a gravity line that continues on to Englewood. Engineers originally designed the station with an odor-control bed to limit any smelly experiences for the people around it.

“But it got overwhelmed,” Howell said.

That brought a series of complaints from those affected the most by the unexpected smell: residents in Columbine Hills.

“It’s a whole community problem, and of course the smell depends on where you live in Columbine,” said Gary Helms, who lived close enough to smell the transfer station from his house.

Helms said the smell was most noticeable in the evenings after 8 p.m., and was worst between 9 and 10 p.m. There were other times of the day when the smell arose, but not as consistently as in the evening.

The calls and e-mails were enough to get the Roxborough Water and Sanitation District’s attention.

A first step to solving the problem was enlarging the odor control vault to about five times its original size. Howell said there is now a 600-square-foot odor-control medium made up of compost and wood chips.

“The design of this bed is that we actually grow a community of bacteria — or bugs — where they actually feed on these odors,” Howell said.

In addition, the district has injected additional hydrogen peroxide over the past two weeks, essentially adding oxygen and preventing release of gas. A further step has been to pump potable water into the pipeline, thus releasing tension that wastewater builds in the pipe.

“We have not had — since we enlarged the odor-control bed at the transition vault — we have not had any complaints here at the office,” Howell said.

As a final — and permanent — measure, Roxborough bought a Dynamox Unit to release compressed oxygen into the wastewater stream.

“We’re pretty confident, and our engineers are pretty confident, that we’ve got a handle on the odor problem,” Howell said.

When the district first started receiving calls, it established an e-mail list of those who were concerned about the smell. Howell said the district was active in communicating its steps to solve the smelly problem. Roxborough also began monitoring the hydrogen levels at various points in the pipeline.

“That information, along with the no calls, shows us that this has been reduced significantly,” Howell said.

He encouraged residents to contact the district at 303-979-7286 should they notice any more strong smells near the transition vault.

Contact Matt Gunn at matt@evergreenco.com.