When the flow of visitors in Steamboat Springs rises during heavy tourism times, so too does the waste, making management of the Steamboat Springs Wastewater Treatment Plant a challenging and often smelly job.

“It’s significantly harder to run a wastewater treatment plant in a resort town that sees a big influx of visitors than in a city where your population is static,” said Jon Snyder, the public works director for Steamboat Springs. “Consistent population makes a biological process easier to manage.”

“More people in town could create an upset in the biological process,” Snyder said. “It’s when that process gets upset is when it smells worse.”

The plant’s operational status averages 60% capacity, but utilization can range from 26% during “mud season” when Steamboat sees fewer people in town to a record high of 72% in January 2022, explained Gilbert Anderson, plant superintendent.

The maximum 24-hour flow into the plant can fluctuate widely during the year; for example, the flow in 2024 peaked at 7.14 million gallons per day on April 5 and was the lowest at 1.87 million gallons per day on Oct. 16, Anderson reported.

During specific atmospheric conditions such as on cold mornings with temperature inversions — especially during the busy holiday times of Christmas, New Year’s and Presidents’ Day — the waste smells may be most noticeable to nearby homeowners, Snyder said.

The vintage 1980 plant maintains a six-step process inside buildings to try to contain as much odor as possible, Snyder said. Yet, residents say the wastewater smells can be noticed at homes downwind and in nearby neighborhoods such as Riverbend Cabins, Heritage Park and Steamboat II.

Routt County resident Julie Green, a former member of Steamboat Springs City Council in the late 1980s, posted in late January on social media: “Is anyone else experiencing strong odor from the Steamboat Springs Wastewater Treatment Plant? Is it particularly bad on the weekends? This year has been particularly bad at my house.”

Other nearby residents responded to the post with comments such as, “I notice it when it’s super cold out,” and “I was smelling it a lot around Christmas.”

Snyder said the wastewater treatment plant does not create odors but rather receives the odiferous waste materials from the public that flow down pipes to the plant. Snyder said odors have recently improved following repair of two aeration blowers that had been down.

“The biggest thing we do to try to suppress these odors is to enclose all the processes, put them indoors,” Snyder said. “A lot of treatment plants are outdoors.”

During a tour of the plant last week, the first stop was at the preliminary treatment building.

“I’m going to stay out here because my clothes will stink for the rest of the day,” Snyder said.

At preliminary treatment, debris ranging from plastics to rags is removed by two mechanical bar screens and drops out of a chute into a dumpster. This first step illustrates the city’s strongest educational message for residents and visitors.

“Flushable wipes are not flushable, even if the package says so,” Snyder said.

Anderson, who has worked at the plant for 42 years, knows by the incoming smells when paint or paint thinners have been wrongly flushed down a toilet or poured down a sink or drain.

“We are aerating whatever comes in, so it’s aerosolized,” Anderson said. “So that means you are going to smell it. It goes into the atmosphere.”

It’s a biological system, so anything that hurts biology is not good for the system — medicines, chemicals, paints, solvents, gasoline, diesel,” Anderson explained of the plant located about 3 miles west of Steamboat Springs on the south side of the Yampa River.

Before walking into the secondary treatment complex that houses huge aeration basins and clarifier tanks, a fan pushes smelly air outside the building to ensure the health of employees and prevent any risk of explosion from built-up gases, Snyder said.

Fifth-grade classes on field trips visit regularly at the plant, and employees say the youngsters are fascinated by how “the bugs eat the poop.” In other words, bacteria already present in the wastewater break down and consume the organics when the wastewater is in the plant’s aeration basins.

The plant is currently fully staffed with seven full-time workers, and some employees pull evening shifts when tourism levels — and therefore, waste — are higher. The plant also requires two-hour shifts on weekends.

Although city staff say the smells at the plant are not directly connected to the discharge permit they are operating under from the Colorado Department of Public Health and Environment, the city has been waiting more than three years for an updated permit.

The state permit for the effluent that flows into the Yampa River was issued in 2016 and was “administratively continued” on Dec. 31, 2021, according to the CDPHE. So, the city continues to operate under the previous permit with the same extended requirements and conditions, according to John Michael, CDPHE water quality control division spokesperson.

Snyder emphasized that the city is not complaining about the lag time for the updated state permit, and he expects a new permit to be issued within two years.

The state delay is “delaying our master plan for our wastewater treatment plant,” Snyder said. “As soon as they issue us the permit, we will get started on a master plan.”

Complicating state permitting is the number of issues now tracked from wastewater treatment plants. Anderson said when the indoor plant opened in 1980, the state regulated for four items: biochemical oxygen demand, suspended solids, ammonia and E. coli. In 2025, that regulatory list has added 10 more issues: nitrates, phosphorous, 25 PFAS synthetic-chemical compounds, bioassay, sulfate, boron, 13 metals, temperature, pharmaceuticals and microplastics.

“Now they have a permit where they have to assess the impacts on every one of those issues on the environment,” Anderson said.

Snyder noted that state permitting engineers’ “job has gotten much tougher.”

According to Michael, roughly half of all permits CDPHE manages are administratively continued.

“The division oversees a substantial portfolio of approximately 7,000 permittees. We strive to manage these permits efficiently and effectively, ensuring the protection of the environment and public health, and we are actively working to reduce the number of permits that are administratively extended,” Michael said.

Snyder said that as the city grows, 80% capacity use at the plant would trigger an expansion design, and 95% capacity would trigger plant expansion construction.