The effluent from SouthWest Water’s two main wastewater treatment plants in Alabama consistently meets permits that include a 0.2 mg/L phosphorus limit.

That’s in keeping with the character of the plants — the buildings kept spotless and the grounds manicured by a team of 14 operators and service specialists, led by Ryan Weldon, district manager.

“We’ve just set a standard, and we don’t fall below that,” Weldon says. “It’s something we’ve been doing for years. We have operators who really care about how the places look, and they go the extra mile. If we hear somebody is coming to visit, we don’t have to stop what we’re doing and work for a week to get the plants in shape. They stay that way year-round.”

Weldon believes the plants’ appearance helped them win three 2016 awards. The Riverview Water Resource Recovery Facility received a first place Excellence Award from Alabama’s Water Environment Association and a first place Best Operated Plant Award from the Alabama Water and Pollution Control Association. The North Shelby Water Resource Recovery Facility received a second place Award of Excellence from the Alabama Water and Pollution Control Association.

Responsible care

SouthWest Water, owner of the plants, dates back to 1925 and is based in Sugar Land, Texas. Its nearly 400 employees operate facilities in Alabama, California, Oklahoma, Oregon, South Carolina, and Texas, serving more than 1 million people. The company focuses on the entire water cycle, from its origin through transport, treatment, distribution, and recycling.

Besides owning and operating the Riverview and North Shelby facilities southeast of Birmingham, the company has a contract to operate the nearby Double Oak Water Resource Recovery Facility, a 1 mgd (design) sequencing batch reactor.

The Riverview and North Shelby facilities use extended aeration activated sludge processes and were upgraded in 2008-09 to meet tightened phosphorus limits and replace outdated equipment; the upgrades did not expand their 3 mgd design capacities.

A critical resource

Effluent from the two main treatment plants ultimately enters the Cahaba River, the longest free-flowing river in Alabama, home to a wide diversity of plants and fishes, and a popular recreational resource. It is also the source for about 75 percent of Birmingham’s drinking water. The plants’ strict permits reflect the river’s value.

The Riverview plant sits along a bend of the Cahaba on a heavily wooded 34-acre site; a 3-acre pond lies next to the office. “We’re about two blocks off Highway 280, which is the busiest corridor in Birmingham,” says Weldon, a Grade IV wastewater operator. “It’s nice that you can come here and you’re in nature where it’s nice and quiet.”

The plant process starts with two climber screens (SUEZ) and a PISTA Grit system (Smith & Loveless). Two aeration basins receive air from centrifugal blowers (Hoffman & Lamson, by Gardner Denver) by way of membrane disc diffusers (Sanitaire - a Xylem Brand). Three 60-foot-diameter clarifiers provide settling.

The flow then passes through a perforated panel screen (Andritz Separation) before entering a four-stage flocculation tank, followed by three AquaDisk cloth membrane disc filters (Aqua-Aerobic Systems). Two UV channels (TrojanUV) provide disinfection before release down a step cascade structure to the river. Excess solids are sent to three aerated digesters, where they are thickened and eventually run through one of two Envirex 1.5-meter belt presses (Evoqua Water Technologies).

The 2008-09 upgrade replaced aging sand filters with the cloth filter system. “During periods of high flow, the sand filters didn’t have the necessary capacity,” Weldon says. “In a two- or three-day rain, an operator would stand on the old filters, backwashing manually all day long. Each one of our cloth filters will handle 5 mgd, so we have excess filtration capacity in a small footprint. They do a great job, and the maintenance has been relatively low.” The old sand filter structure was converted to accommodate the new flocculators.

Simple and effective

The North Shelby plant has a residential neighborhood on one side and a commercial district on the other. Influent enters two oxidation ditches (Evoqua Water Technologies) with eight Passavant brush aerators (Evoqua Water Technologies). Solids settle in one 135-foot-diameter and two 85-foot-diameter clarifiers.

The effluent then passes through two traveling bridge sand filters (Aqua-Aerobic Systems) and a UV disinfection channel (TrojanUV) before being pumped 9 miles to Cahaba Valley Creek.

Biosolids are pumped from the digester to one of two belt presses (BDP Industries). Biosolids from both plants are landfilled, although beneficial use options are under study.

“North Shelby has no screening or grit removal, but it still manages to put out some of the nicest looking effluent I’ve ever seen,” Weldon says.

Controlling phosphorus

As the leader of the operations team, Weldon brings 15 years’ experience in the clean-water industry. He previously managed a Batteries Plus Bulbs store: “I had maxed out what I was doing there and saw little room for growth, so I decided to change gears and enter the water business.” In 2003, he went to work as a purification maintenance worker at the Riverview plant, then owned by the Birmingham Water Works Board. SouthWest Water bought the Riverview and North Shelby plants and their collections systems in 2008; Weldon became district manager in 2015.  

Attention to detail is a way of life at the plants, and that applies to basic housekeeping. “We do all of our own painting and all of our own landscaping,” Weldon says. “It’s a full-time job. We paint year-round. We cut every day in the summer to keep the grass, trees, bushes and hedges trimmed.”

Phosphorus removal has been a continuous challenge. The 0.2 mg/L limit was imposed in 2010 by the Alabama Department of Environmental Management; it is scheduled to decrease to 0.043 mg/L in 2027. Phosphorus is controlled mainly through addition of polyaluminum chloride. “The majority of it goes into the aeration basin effluent,” Weldon says. “In addition, at Riverview, we introduce PAC in the flocculators. At North Shelby, another dose goes into the clarifier effluent.”

Cohesive team

Weldon, stationed at the Riverview facility, benefits from a team on which the majority of members have at least five years of experience. The Riverview team includes Grade IV operators Mark Globetti and Terry Johnson; C.J. Knight, operator-in-training; and service technicians Branden Coomer, Loren Gilliland, Ronnie Howard, and Nelson Sharit (who is also a Grade II operator).

At North Shelby are Grade IV operators Barry Givens, Dave McCombs, and Scott Elrod; Justin Tripp, operator-in-training; and service technicians Richard Burnett and Tom Johnson.

Weldon works to instill consistent teamwork: “We try to get everybody together frequently to have some time together that’s not necessarily work-related, where everybody can just hang out and talk to each other. We’ll have a barbecue or go to breakfast at the Cracker Barrel. A lot of the guys have been here so long that they’re friends outside of work. It’s more like a family than a work atmosphere here.”

On the job, there are weekly staff meetings to review service maintenance needs and organize tasks for the week. Safety topics are covered in an online Safety Skills service. “Every month we get three to five safety topics to train on,” Weldon says. “We can sit down as a group and go through them on a big screen in our break room. Or, if we have a lot going on, and most of the time we do, the guys can log on and review the topics at their own pace.”

For continuing education, team members attend Alabama Water and Pollution Control Association and Alabama’s Water Environment Association conferences and short courses. Operator McCombs teaches a variety of in-house classes. Operator Johnson, retired from another area facility, uses his experience to support colleagues studying for exams.

Givens, lead operator at North Shelby, sets an example with his no-nonsense dedication. “He’s got that old-school mentality,” Weldon says. “He works an honest eight hours for eight hours’ pay. His work ethic really shows in the way the plant looks.”

Stepping up

The team’s dedication comes in handy when big jobs need doing. Late last year, the team at Riverview replaced 1,689 old ceramic diffusers in each of two aeration basins with membrane diffusers. “That was one of the more challenging projects we’ve done in the past few years,” Weldon says. “We did one whole basin in four days, pulling the old ones out, putting the new ones in, making repairs here and there, and filling the basin up again.”

Weldon’s basic advice to operators is to pay attention to their senses: “If you get out into the plant and make regular rounds, you get to know your plant. You know what it’s supposed to look like, sound like and smell like. If you pay attention to your senses when the plant is running tiptop, then you’re going to notice when it’s not. Before the lab results or anything else, the operators’ senses are the first line of defense.”

All in all, he’s glad he made the switch to the water business. “I’ve got great backing from the leadership of SouthWest Water and a great team of guys around me. I really can’t say enough about them. I appreciate the work they do every day.”

All hands in ditch

If Ryan Weldon ever needed proof that his team would come through when it counted, he got it the day a 14-inch force main broke along Highway 119.

“Our plant operators routinely work with the service technicians on the collections system,” Weldon says. “We had a bad section of force main on Highway 119 that blew out, and we had to call on some of our operators and operators-in-training. We had a party on the side of the highway fixing that force main. Everybody stepped up and did what had to be done.”

The problem was complicated because multiple public and private pump stations fed the line. The team arranged for vacuum trucks to pump out the excavation site. “Then we just had to go in and fix it hot,” Weldon recalls.

The force main had been badly degraded because hydrogen sulfide gas had eroded the top of the pipe. “There were places where you could stick a probe rod through; it was probably an eighth to a sixteenth of an inch thick,” Weldon says. “We kept having to dig back to find places where the pipe was in good enough shape so we could cut and make a repair. We found a section that we thought could handle a repair sleeve. We made two cuts, pulled the bad piece out, measured twice and cut once, and put the new piece in.” The work took about eight hours.

“We’ve always done our own force main and pump station rehab work, so we have the tools and the capability,” Weldon says. “We really had to come together as a team.”