Originally published in Treatment Plant Operator. By L.K. Williams.
http://www.tpomag.com/editorial/2013/03/hands_on_know_how

Small tanks: Operators are familiar with them and know that large tanks often seem too costly in smaller towns. So, like Joe Underwood, they tap into their creative side and often make do with what is on hand.

After the Muscle Shoals Wastewater Treatment Plant’s polymer mixing system couldn’t keep up with demand, chief operator Underwood and his three-member crew got to work. “We obtained two one-way totes from a local chemical company and used schedule 80 PVC pipe and fittings from previous jobs to hook them up to our polymer pumps,” Underwood recalls.

It only took a short time each day to prepare enough polymer manually for a full shift of the Komline-Sanderson belt press run. “Our cost was exactly zero dollars, and this system served us very well for the last 10 years,” he says.

That’s just one of the projects undertaken over the last few years by Underwood and his team, which includes lead operator David Moore and operator Keith Woodley (Grade IV certifications), and operator trainee Brad Isbell (working toward Grade IV).

The plant used the 1-meter belt press and manual mix polymer system for dewatering since 1995. But by August 2012, the Utilities Board replaced it with an Andritz centrifuge and a Fluid Dynamics polymer system. A Clean Water Act State Revolving Fund grant, a 2008 bond issue and general funds enabled Muscle Shoals to upgrade the facility’s solids processing system and much more.

Treatment trouble

The original Muscle Shoals plant started up in 1964. In 1986, the city Utilities Board expanded the 0.5 mgd extended aeration activated sludge plant to 1.3 mgd design capacity, in the process adding a new aeration basin and converting the old aeration basins into clarifiers. In the mid-1990s, the board added diffusers and abandoned the old clarifiers for two new ones, increasing capacity to 2 mgd.

Underwood mentions the city’s “growing spurt,” which has been placed at 10 percent per year over the last decade, as a cause for concern. According to the U.S. Census Bureau, the 2010 population was more than 13,000.

“The city outran the plant,” Underwood says. “Our treatment fell off as far as capacity and efficiency. We saw this coming. I was trying to inform our previous board of managers that we needed to do something. I don’t think they realized how fast the consent order was coming. Finally after we had several violations, it came pretty fast.”

The Alabama Department of Environmental Management (ADEM) cited the plant for an ammonia nitrogen violation in the summer of 2007 and assessed administrative and judicial penalties of almost $12,000.

Quick turnaround

After changes in leadership, the facility was brought back into NPDES compliance. “The manager we have now [James Vance] and our five-member board were willing to do whatever it took to do things right,” Underwood says. A new engineering firm, Engineers of the South in Florence, Ala., had drawn plans for a new plant and put out bids within a year. By 2010, the new 4 mgd facility was up and running. “We went probably 2.5 years from the time we were under a consent order to the time we were back in compliance,” Underwood says.

The upgraded Muscle Shoals Wastewater Treatment Plant uses fine-bubble, fixed-grid aeration diffusers (Sanitaire – a Xylem Brand), centrifugal blowers (Gardner Denver), and a chemical feed system (Grundfos Alldos pumps) for disinfection with 12.5 percent bleach.

Milltronics (Siemens Water Technologies) and Rosemount (Emerson Process Management) flowmeters were installed in open channels and closed pipes. The return activated sludge and waste activated sludge pumping station uses automated valves and screw centrifugal pumps (WEMCO-Hidrostal). Operators now maintain motorized valves (DeZURIK) and use a SCADA system from Revere Control Systems.

The bleach disinfection system replaced UV disinfection which, while widely accepted, did not work well for the specific conditions at Muscle Shoals. “Our water has high dissolved calcium and dissolved iron content from the Tennessee River and minerals in the ground that basically caked the quartz on the bulbs,” says Moore. “A lot of other places that we talked to don’t have that problem.”

The bleach system has worked well: “Our E. coli count is usually very low,” Underwood says. Disinfected wastewater is dechlorinated using sodium bisulfite before discharge to Pond Creek.

The plant’s two circular clarifiers had also been problematic: “We had an awful time with algae buildup in the trough. We had to go out there every week, get on our boots, get in the trough with brushes and hoses and clean off the algae.” The clarifiers were upgraded with fiberglass covers (NEFCO Incorporated) over the troughs.

“In over two years, we have only had to clean the weirs and troughs once,” says Underwood. “That was probably some of the best money spent on the whole project. The covers weren’t cheap, but they were well worth the money.” The lesson, he says, is that product discussions among operators and managers should key in on the potential problems of using any particular system: It’s valuable to know up front what can go wrong and figure out how to resolve it.

Right place, right people

If the Muscle Shoals plant has come a long way, so has Underwood, a native of Tuscumbia, Ala., who worked in several industries before staking his future in wastewater treatment. “I worked in construction. I was an ironworker and I worked in mechanical. I’ve done drafting, worked on engines. I’ve done pretty much everything in my life,” Underwood says.

All this experience, including time in nuclear, coal-fired and hydroelectric power plants along the Tennessee River, prepared him for work at a wastewater treatment plant. Underwood notes that today, most new hires have taken water and wastewater management courses and some have completed degree programs. “I learned the ‘hand’ work first, and then I learned the paperwork and got my certification,” he says. “It worked out.”

He recalls that in the 1960s when he was a kid, his uncle had a job at the Tuscumbia wastewater treatment plant: “We would ride our bicycles down there. I didn’t really know what was happening or how it worked, but I remember knowing what it was. I never had any idea in the world that I would end up doing this.

“I have always enjoyed a challenge. The water and wastewater treatment field is not a job that everyone can do. You are learning new things and having to meet and solve problems on a daily basis. It takes a lot of training and dedication to become certified as an operator, and the pleasure of knowing I have met these challenges is my reward.”

Underwood hired Moore, his second in command, about 20 years ago, and Woodley came on board 12 years ago. Isbell has been with the team for two years. “I really don’t have to tell the operators their job because they know what they’re supposed to do,” Underwood says.

The crew of four did all plant maintenance until the Utilities Board hired dedicated employees to maintain equipment at both the water and wastewater treatment facilities in 2009. This staff expansion freed Underwood’s team to work on process control.

Recognizing progress

When issues arise, the team brainstorms possible solutions. “I listen to everybody’s ideas and we try to choose the best one,” says Underwood. “I’m not hard-headed and saying that we have to do it my way. I enjoy working with my operators. I’ve been around them for many years and we get along well.”

But the Muscle Shoals team is bigger than its operators. Underwood credits Vance, the Utilities Board and the engineering firm for contributing to the plant’s success. “That is why I believe we have a well-run plant: they listen to us and have given us everything they could to make it really easy to stay in compliance.” In addition, the facility’s distribution and maintenance departments keep the lines and pumping stations in order. “Without any of these people, we would be in trouble,” he adds.

The Alabama Water Environment Association, of which Underwood is a member, in 2011 presented the Muscle Shoals plant with a Wastewater Excellence Award. Members of the AWEA awards committee actually visit and inspect nominated facilities. What they saw at Muscle Shoals obviously made an impression.

“All of the basins are not new, but if you came to look at the plant, you’d think they were new,” Underwood says. He also regards the plant’s quick recovery from non-compliance as an important achievement. The inspectors noted that, observed the homemade polymer system, noted how long the team had operated the plant by hand, and appreciated the written standard operating procedures (SOPs) and detailed paperwork. “We just made things work because we had to,” Underwood explains.

Public impressions

One highlight the Muscle Shoals team shared with inspectors was the plant’s public tour program. The presentation changes depending on the audience, which often includes school classes and church groups. “We stress how to keep the water clean,” Underwood says. “That’s all we have, that’s what God gave us.

“Ninety percent of them, regardless of age, say the water just goes down that little hole. And then we say, ‘Well, if we don’t clean it, it goes into the river and the next town down there picks it up and puts it in their pipes.’ And then they’re sitting there looking at you thinking, ‘Well, I live in that next town.’ After the tour, they think about that a little bit.”

For Underwood’s part, he thinks often about the future of his plant and community. “I want to see the wastewater treatment plant and the water treatment plant stay ahead of city growth,” he says. “The people are in place. We just need to keep up with all the new treatment technology. That is the key to having a great operation that will always be an asset to the residents of Muscle Shoals.”