The team at Eagle Mountain does an exemplary job with a new extended aeration plant — and isn’t above reaching out to help neighboring facilities.
The four operators at the Eagle Mountain Water Reclamation Plant are used to doing a lot with a little. Their efficiency and excellent work ethic have served them well. In 2016, they won the 2015 Outstanding Wastewater Service to Customers Award from the Rural Water Association of Utah, recognizing long-term performance over 15 years or more.
“We do a good job with what we have,” says Matt Goodrich, wastewater supervisor. “We’ve never had a plant violation, and the collections system has been solid.”
The team does everything, including sampling, collections system operation, cleaning and repair, routine plant maintenance, and solids hauling. Says Goodrich, “We do it all, and we know a little about a lot of things related to the treatment and collection process. Operators at the bigger plants don’t get the variety that we do.”
The 1.2 mgd (design) Eagle Mountain plant started up in 2010, replacing a 0.3 mgd package plant from 1998. Population growth had pushed the old plant to capacity. City leaders looked at four options: aerated lagoons, extended aeration (oxidation ditches), membrane bioreactor, or pumping wastewater to the Timpanogos Special Service District (TSSD) water reclamation facility in American Fork.
They chose extended aeration and obtained a grant to help fund the project. Today, the plant serves about 8,300 people in the southern part of the city (south service area). The TSSD treats the wastewater from the north service area. The Eagle Mountain Sewer Department handles the collections for both areas, with help from the TSSD.
Raw wastewater enters the influent pump station and equalization basin, flows through a Parshall flume and enters the headworks with bar screening, PISTA Grit vortex grit collector (Smith & Loveless) and a grit clarifier. From there, the wastewater is sent to the oxidation ditch with Orbal disc aeration system (Evoqua Water Technologies) and on to two clarifiers. Clarified water is pumped to a storage pond, where it evaporates. When the pond becomes full, the effluent is sent to a rapid infiltration pond where it filters through the ground and into aquifers.
Twenty-five percent of the clarified water is pumped from the storage pond to a chlorine gas disinfection system with an Evoqua regulator and Grundfos booster pump. It then goes to a recycled-water land application field. “We use the recycled water to irrigate the sage brush, which serves as habitat and food for a variety of wildlife,” says Goodrich.
Activated sludge is sent to one of three places, depending on time of day — the oxidation ditch, a Cannibal solids reduction system (Evoqua) or a drying bed. The dried solids are hauled to the landfill.
“Some of our equipment differentiates us from many other plants,” says Goodrich. “For example, we have a rotary drum screen (Evoqua) that filters out hair, pocket lint, small wrappers and paper down to 250 microns. A cyclone separator system (Evoqua) filters out sand, talcum powder and small inorganic particles. And then there is the sidestream interchange bioreactor/solids separation module that is the heart of the Cannibal process.”
The plant staff chose the Cannibal solids reduction system after researching other plants’ experiences with it. “We liked what we saw,” says Goodrich. “Also, the solids reduction would reduce our operating costs.”
While there was no guarantee that Eagle Mountain would see the same reductions as other facilities, the plant is seeing improvement. “We hoped to waste a few times a month, but we are wasting four to five times a week, at around 1,600 pounds per day,” Goodrich says. “This isn’t bad, and we are seeing better-than-average solids reduction over a conventional plant that doesn’t have a drum screen or cyclone system.”
The process posed some training challenges. “Evoqua sent two engineers and a few equipment specialists to help us start up the plant and train us on the process and equipment,” says Goodrich. “Evoqua also provided instruction files on plant operation, including how to track solids, solids retention time, flows and other parameters. Project manager and consultant Rod Erickson of Rodeo Construction also taught the team how all the new equipment should operate.”
There were a few headaches during startup: overloaded headworks, clogged pumps, and more flow than the grinder pump could handle. “We had to open our bypass channel to keep the flow from overfilling it,” says Goodrich. “In the solids separation process, the auger for the drum screen would fail, causing the drum screen to shut down.
“Also, the bypass valve wouldn’t automatically open, causing the flow to go out the front of the screen and onto the building’s floor. These challenges helped us learn what to do if the problem ever happened after all the vendors’ employees left the plant to us. It took us about a year to get to the point where we didn’t have to call them or Rod with questions.”
The operators’ greatest challenges are cleaning rags and baby wipes out of the intake pumps and taking turns hauling biosolids away in a pump truck five days a week. “We spend a lot of time cleaning out the pumps to keep them running,” says Goodrich. “The flow backs up when the pumps stop, and then we have to go to the plant in the middle of the night to get them running again.
“Two to three times a week, we put solids on the drying bed, depending on how warm it is outside, but we only have one bed, so it’s hard to keep up with the amount of material that needs to be dried.” The team hauls the solids that are not put on the drying bed — about 4,000 pounds per week — to a manhole in the north service area. From that point the material flows to the TSSD.
The team uses ingenuity to solve problems. For example, when the old lift station pumps repeatedly clogged, the operators developed a system to bypass the station without renting expensive equipment.
“We used to have to rent an additional trash pump and about 200 feet of pipe to get the sewage up the street to a gravity-fed manhole,” says Goodrich. “So we installed a valve in the lift station force mainline to prevent back-feeding through the pump when we had our trash pump connected while bypassing the lift station.” The team then installed a cam lock system in the line so they could quickly attach the trash pump and get the flow out of the lift station. They used this system three more times to prevent backups when the lift station pumps went down.
The plant operators are a diverse group. “We all have different talents and ideas, and we use what works best in a particular situation,” says Goodrich. The plant is staffed seven days a week for 10 hours a day, and the operators rotate weekends and holidays.
“We usually have one person hauling solids and the rest of us are taking care of the plant or the collections system, or a combination,” Goodrich says. A SCADA system remotely monitors the plant after-hours and dials the on-call operator if there is a problem.
Goodrich, who reports to Mack Straw, public utilities manager, holds Grade 4 (highest) wastewater treatment and collections certification. He has been at the plant for 15 years. Reporting to him are operators Brody Kinder (Grade 2, five years), Daxton Woods (one year) and Dalton Harris (new hire).
The team’s exceptional service earned the recognition from Rural Water. One example was assistance to the neighboring community of White Hills in solving a problem with its lagoon system.
“White Hills isn’t tied into our system, but is on a lagoon system, and they don’t have a full-time operator,” says Goodrich. “The inlet to the ponds was blocked by sagebrush, cattails, other debris and rags. We didn’t know where the inlet came into the ponds, so we got a mini-excavator and began digging in the general area where we thought it might be from looking down the influent flowmeter channel.”
They dug for about an hour, but found nothing. Then, one operator found a splitter box downstream of the influent flowmeter channel that diverts the flow to another pond. They dug down to the sewer line and followed it to where it flowed into the pond.
“From the box, the sewer line came out a few feet and then made a turn to the north from where it looked like it went from the influent flowmeter channel,” says Goodrich. “We followed the line to the bottom of the pond and found a soft spot. We used a blade on the mini-excavator to clear away the brush and started digging.”
Once they cleared away all the debris, the backed-up wastewater started rushing into the pond. “I don’t think I have ever seen guys move so fast, and it’s a good thing the mini-excavator has tracks to get it out of messy situations,” Goodrich recalls. The entire job took about four hours.
Goodrich says there are no plans to expand the plant, since it has enough capacity for five to eight years. Improving solids dewatering is on the wish list; the staff hopes to get a screw press in the near future.
The team is also working on an industrial pretreatment program. “Right now, the wastewater we treat is almost 100 percent residential,” Goodrich says. “We are a small city in terms of population, but we have the potential to be one of the biggest in the state once industrial and business growth starts picking up. We are trying to be proactive and get a pretreatment program going before it’s a problem.”
The staff members want to continue taking part in community events. “A while back, we did a video to educate the public about what they should and should not flush,” says Goodrich. “We recently hosted a community event at the Silver Lake Amphitheater in Eagle Mountain. All city departments were there to educate residents about what we do. We had a good turnout.”
In the more distant future, Goodrich envisions serving the entire valley. “White Hills will be first, and then other places can connect to that line,” he says. “The plant will be huge someday with the residential growth. I see it being a big contributor on the wastewater side.”
Operators at the Eagle Mountain Water Reclamation Plant deal with extreme weather, from high winds that blow tumbleweeds into the equipment to cold temperatures that freeze
“We’ve had to fish tumbleweeds out of the clarifiers and the oxidation ditch, especially in summer,” says Matt Goodrich, wastewater supervisor. “Our biggest hurdle in winter is ice removal. If ice gets on the clarifiers, we have to break it up so it doesn’t cause issues with the skimmer system.”
He recalls the time the interchange bioreactor level sensor froze: “The level sensor sits in the corner of the tank, along with pH and ORP probes. The sensor doesn’t see a lot of sun, and when it freezes, the ice attaches to the two sides of the tank and around the probes and stays suspended.
“When the tank decants, the level sensor reads the ice level and not the actual tank level. So, the tank will continue to decant until it is drained or someone notices the problem.” An operator did notice the problem, and the team installed a mixing pump in that corner of the tank so the sensor wouldn’t freeze again.
A blizzard in 2015 dumped 10 inches of snow. “Winter is the most stressful time for us, with frozen waterlines and icing on the equipment,” Goodrich says. “Summers are usually hot and windy in the afternoons, but the mornings are nice and cool with excellent sunrises over the mountains. I especially love spring, with all the new growth and new life, like baby pronghorn antelope, and baby ducks and geese on our ponds.”