At a May 15 work session, the Pagosa Springs Town Council had an in-depth discussion about the future outlook — both short- and long-term — for the town’s current wastewater conveyance system.
The town-run Pagosa Springs Sanitation General Improvement District (PSSGID), through a series of pump and lift stations, currently conveys its wastewater about 7 miles uphill to the Vista wastewater treatment plant, which is owned and operated by Pagosa Area Water and Sanitation District (PAWSD).
Since coming online in 2015, this system has been plagued by failing pumps, electrical malfunctions, aging pipes and other problems.
The town has since hired Roaring Fork Engineering to consult with the town about the future outlook of the system, as well as weighing the costs and analyzing the possibility of switching to a different system, which would utilize a more traditional town-run treatment plant downtown.
The town also recently hired Interim Public Works Director Phil Bennet to analyze how to ensure this current system works until a new plant could be designed and built, a multiyear project.
Bennet was on hand at the work session to help the council take a deeper dive into the current system and the challenges it faces.
He explained that his main objective is to “keep the force main running” for another 10 years or so, because “we don’t have another way, right now, to keep the sewer running.”
“How can we make it last another decade?” he asked, indicating that would give the town time to explore options for a new treatment plant.
He noted that the town must “utilize the existing system” while minimizing disruptions to an “aging and poorly designed” system, and then “decommission it after 10 years.”
He added that, in analyzing the town’s uphill conveyance system, which sends wastewater a total of about 656 feet uphill, he was hard-pressed to find other systems in the world that do a similar thing.
His research discovered that Portland, Ore., is the only other place with this type of system.
He explained that one of the main problems is that Pagosa’s system was designed to actually pump a lot more sewage than the amount that actually flows through it.
“It was designed for 1 million gallons a day,” he said, and since the system is handling a much smaller amount of wastewater, “the pumps aren’t always pumping,” causing problems.
“We are only using about 15 percent of the system’s capacity,” and this causes waste to move through the system slower than it should, which causes hydrogen sulfide concentration in the system, he told the council.
Hydrogen sulfide causes electrical damage by attacking copper wiring and steel components, and it’s also explosive under certain circumstances and poses a potential health hazard, he explained.
Council member Leonard Martinez remarked, “It seems like they over engineered the system to avoid risk, but ended up creating another risk.”
Bennet agreed, adding that the hydrogen sulfide problem has reoccurred “about every three weeks since I’ve stepped into the role.”
It gets into circuit breakers, ruining copper wiring, and the town has been “paying too frequently for new control components” due to this problem, he explained.
It cost the town around $90,000 for one pump train replacement, he stated, but sounded optimistic that the new Flygt pumps that the town will likely order would be a much better fit for the system and should work for the town over the next 10 years.
He said that “the only other system like ours in the world,” near Portland, uses these Flygt pumps and they work well.
But, he added, Portland’s system is “much better designed than ours.”
He explained that Roaring Fork Engineering is working with the Flygt pump manufacturer to make sure its pumps can handle the system.
He also added that the town should “contract with the manufacturer to do annual maintenance on the pumps, so we don’t get behind.”
He explained that after the Flygt design review is completed by Roaring Fork, the town would be able to order the pumps by early June, and then it’s a six-month delivery time to receive the new pumps.
Another problem that Bennet identified with the system is corroding concrete within the wet wells throughout the system.
Here, “we have an acid situation,” he said, explaining that “sulfuric acid makes concrete feel like putty.”
He continued, “We will have to repair this wherever we see it,” explaining that the epoxy protecting the wet well wall surfaces at Pump Station 2 is “essentially gone” and “it’s not protecting the concrete anymore.”
He noted he is not sure if the wet well walls were not coated properly with epoxy, if the wrong type of epoxy was used or if this is just the natural corrosion of concrete over time, but, either way, “we need to get in there and recoat the well wells” with epoxy.
He also suggested that a field trip to Portland might be in order to go see what it is doing to protect concrete in wet wells.
As the town works to stabilize the current system and then moves toward getting away from uphill conveyance with a downtown treatment plant, Mayor Shari Pierce suggested that the town should develop a graph or some sort of “visual to show the public all the steps that it will take to get from here to a new plant.”
She added, “we’d basically be building two systems, fixing this one and a new plant,” she said.
Sanitation Projects Administrator Karl Johnson explained that town staff has initiated the application process for a “discharge permit” for a new plant, but that it would be about 12 to 18 months before the town could move to the next phases of design and construction.
Bennett noted that the time it would take to build a new plant “is really unfortunate,” requiring the current system to work properly.
He added that in his eight weeks on the job, he has witnessed the town’s Public Works staff doing a “heroic job” to keep this system running.
derek@pagosasun.com
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