No Odors, No Trash, No Violations for This Utah Water Reclamation Facility

The team at the South Valley Water Reclamation Facility never stops looking for ways to enhance efficiency and performance.

No Odors, No Trash, No Violations for This Utah Water Reclamation Facility

Spencer Parkinson, pretreatment director

If you had to pick one word to describe the South Valley Water Reclamation Facility, that word would be “excellence.”

This 50 mgd (design) facility treats about 20 mgd. It lies on the western slope of Utah’s Wasatch Range, 14 miles south of Salt Lake City International Airport, and serves 325,000 people from its contributing agencies: three special service districts and two cities.

Walking through the facility, you can feel the team members’ drive to excel. The evidence ranges from Water Environment Association of Utah plaques on the lobby wall to squeaky-clean, odor-free grounds.

Residential neighborhoods and commercial buildings come right up to the fence line, yet no odors intrude as you walk around the property. No stray trash litters the walkways and roads. The grass is neatly cut, and everything appears orderly.

No odor sources

“This is a strictly aerobic plant,” says Randy Wyness, director of facility operations and head of the 19-person Operations Department. “We don’t have primary clarifiers or anaerobic digesters, so we don’t have the odors associated with those processes.” Biofilters at the headworks building provide 10,000 cfm of air change to control odors. Six 900 hp Turblex blowers provide air for aeration and odor control.

A plaque discreetly displayed on the lobby wall recognizes the plant as the state’s 2017 Outstanding Water Reclamation Facility. Another plaque shows that South Valley won Water Environment Association of Utah’s Excellence Award for 2016. The facility is 33 years old and is about to undergo major phosphorus and grit removal upgrades. It’s one of four major wastewater treatment facilities serving the Salt Lake City area.

“We’ve been looking at the coming phosphorous regs and our readiness to meet them well into the future,” Wyness says. New phosphorus limits will take effect in 2020.

Targeting phosphorus

Wastewater enters the headworks and passes through three, 6 mm step screens (HUBER Technology) and two aerated grit chambers on the way to the headworks wet well. After screening, six 250 hp influent pumps move the water to splitter boxes that direct it to five 6 million-gallon bioreactors. Each 250 hp pump moves about 12,500 gpm.

Four of the bioreactor tanks are the plant’s original oxidation ditch structures; they were converted to modified Ludzack-Ettinger/anoxic-oxic bioreactors in 2006.

The fifth bioreactor tank, which can be further subdivided into two smaller tanks for finer control, runs as an anaerobic-anoxic-oxic (A2O) phosphorus removal process. It has anaerobic zones up front and is designed for phosphorus removal and denitrification. Flows from this bioreactor go to two dedicated, 1.5 million-gallon, 150-foot-diameter final clarifiers (WesTech Engineering).

Flows from the other four bioreactors go to four additional 1.5 million-gallon, 150-foot final clarifiers (also WesTech Engineering). These bioreactor tanks will be retrofitted to an A2O process for phosphorus removal in the near future.

Waste activated sludge goes to dissolved air flotation thickening and then to belt filter presses that produce material at 15 percent solids. About 60 percent of that material is thermally dried (Komline-Sanderson) to become Class A biosolids. The rest remains unclassified. Both the dried materials go by truck to a landfill.

Meanwhile, the clarifier discharge goes through a 72-inch line to a UV disinfection system (WEDECO - a Xylem Brand), then flows over a cascade aeration structure before discharge to the Jordan River.

Plant effluent passes through 10-micron filters (Aqua-Aerobic Systems) before disinfection with sodium hypochlorite for use as seal water and for grounds irrigation, equipment cleaning and other purposes.

Improvements in store

Enhanced grit removal is on the horizon for South Valley. Wyness notes that better grit removal will reduce costs and boost efficiency because grit is hard on pumps, takes up valuable space in treatment tanks and costs money to remove. “Grit accumulation has negative effects on oxygen transfer and causes greater power consumption,” Wyness says.

South Valley is also replacing some 50,000 ceramic diffusers in its bioreactors with EPDM diffusers (Aquarius Technologies). EPDM is a rubbery, elastic material with small slits that seal shut when the blower air is turned off. Wyness says the EPDM diffusers are as effective as ceramic diffusers without the fouling tendencies. EPDM tends to lose its elasticity over time, but that hasn’t been a problem based on current testing. “It’s like having backflow prevention” in the aeration chamber, Wyness says.

Overachievers

It’s not just equipment that makes South Valley excellent. Team members are always willing to go the extra mile. Recently, the engineering firm designing the grit and phosphorus removal upgrades needed mounds of data to help with modeling for the new facilities.

Sherry Sheffield, lab director, notes with pride that the four-person lab staff was able to supply 90 percent of the data the engineers needed the day they asked for it. “We catch grief from some of the other plants because they say we overdo it on data collection,” she says, “but we’re never caught short.”

Spencer Parkinson, pretreatment director, says his group monitors more than 500 businesses. Thirteen of these are significant industrial users and are tightly regulated. Education is Parkinson’s weapon of choice. “We do a lot of education,” he says. “I’ve seen our numbers go down as a result.”

One example is a local culinary arts teacher who requires her students to tour the water reclamation facility before they start classes with her. The school went from having clogged drains several times a month to maybe once a year because of what the students learned.

The pretreatment staff also handles most of the plant’s public education. The minimum age for plant tours is sixth grade. One operator is assigned per 10 students. For large groups and children younger than sixth grade, plant staffers go to schools.

Making it all work

With all the demands of around-the-clock operations facing them, how do the 50 South Valley team members remain ready to meet them? “We make our expectations known,” Wyness says. And expectations are high. All team members except administrative staff are required to be certified operators. That includes maintenance, pretreatment and the lab.

The six directors all work together. “Always, in the backs of our minds, we want to be the best plant in the state at any given time,” Sheffield says. The directors meet weekly to share information, solve problems and keep things running smoothly.

A positive outlook by the board of directors toward staff education and training helps enable excellence. Since he has been at South Valley, Parkinson has earned an associate degree in environmental science and a bachelor’s degree in business administration and is working on an MBA. Sheffield had a bachelor’s in zoology when she joined the team as an entry-level lab technician and has since earned a master’s in environmental science.

South Valley has very little staff turnover. “For my first 10 years here, I was the new guy,” Wyness says. After 24 years, he believes the staff is the plant’s greatest asset: “Our focus is on protecting public health and the environment. But we’re always asking ourselves: What can we do to make things better?”


Industry watchdogs

One of the least understood functions in wastewater treatment is the pretreatment program, a federal mandate for public treatment facilities to regulate nondomestic discharges.

Spencer Parkinson, who has been with the South Valley Water Reclamation Facility in Utah for 20 years, is director of pretreatment. He and five staff members regulate 13 significant industrial users. He also chairs the U.S. EPA Region 8 Pretreatment Association conference.

“We analyze the majority of our pretreatment samples in-house,” Parkinson says. “We don’t do metals or pesticides, but our lab does everything else. We run a user charge program on top of that. It entails charging users for BOD, TSS and fats, oils and grease.” The program is about 50 percent funded by user charges.

The facility also accepts hauled wastes from the area. “We’re right off the freeway,” Parkinson says. “We’re a convenient stop for the haulers. They just pull in, dump their load and work their way up and down along the Wasatch Front.”

The pretreatment group spends a lot of time educating customers: “We help the businesses we regulate by showing them how to avoid costs by changing certain processes.” Randy Wyness, director of facility operations, says South Valley has the most extensive pretreatment program in Utah.



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