Strong teamwork among a small do-it-all staff drives success for an award-winning 8.25 mgd activated sludge plant in Madison, Ala.
The Madison (Ala.) Wastewater Treatment Plant went through a major upgrade just six years after the original activated sludge plant was built. The upgrade solved the plant’s capacity needs, biosolids hauling problems and sporadic daily fecal coliform and TSS compliance issues.
But it’s a winning team of operators that has earned the plant recognition from the Alabama Water & Pollution Control Association (AWPCA) for the past three years. The plant’s five operators handle it all, from lab testing, maintenance, cleaning and grounds work to monitoring 25 lift stations in the collection system.
It wasn’t always that way. “From 2007 to 2009, we had seven full-time operators, but we’ve reduced staff through attrition and promotion,” says Mark Bland, chief wastewater operator. “So that means we’re jacks-of-all-trades here. We do all the maintenance, including minor electrical. It takes a really good team to do what has to be done in the time that they’re here, and I’m proud of that.”
Growing too fast
Completed in 2003, the original plant was designed for an average daily flow of 6 mgd and a peak daily flow of 18 mgd. It included headworks with a Parkson mechanical screen and Smith & Loveless PISTA grit chamber, Ovivo oxidation ditches and clarifiers, Gorman-Rupp return activated sludge (RAS) and waste activated sludge (WAS) pumps, and UV disinfection. The plant was on course to exceed capacity by 2008, as the city’s population averaged 4 percent growth per year.
Also, the state issued a consent order for fecal coliform and TSS violations, caused in part, by the plant’s solids handling protocol, and made worse by wet weather in 2005 and 2006. In addition, the disinfection system couldn’t keep up with the load.
“We were producing Class B biosolids that we were having a contractor haul away in liquid form, in four to six tractor trailer trucks per day,” recalls Bland. “It was 25 miles one way to some of the fields. It got to the point where it wasn’t profitable for the contractor, and he stopped doing it.”
The plant was also having problems with its vacuum prime pumps, and the staff had to repair them frequently. Also, the existing RAS pumping station had insufficient capacity for higher flows and needed to be upgraded.
Solution in upgrade
The upgraded plant design, by Krebs Architecture & Engineering, began in 2006, and construction started in 2007. During the design stage, the staff evaluated all process equipment for performance and energy efficiency and pre-selected the major new process equipment based on proposals that included purchase price, power usage and maintenance costs. The analysis of biological treatment (aeration and mixing) processes had to account for the cost of retrofitting the existing basins.
The new plant went online in phases beginning in 2008 and was completed in 2009. It consists of:
• A third Ovivo oxidation ditch for biological treatment.
• Low-horsepower submersible mixers and variable-speed drives on the aerators to reduce energy usage during periods when little or no aeration is needed.
• New self-priming Gorman-Rupp centrifugal pumps, which replaced the vacuum prime pumps in the grit chamber.
• Two JDV conveyors to eliminate the two rolling dump containers — the screenings and grit are now placed into a roll-off container.
• A new, larger RAS/WAS pumping station that consists of a dry pit enclosed by a building. All RAS/WAS pumps are now easily accessible. Piping restrictions were removed, larger piping was provided, and the new pumping station was designed to give operators flexibility to return or waste solids from individual clarifiers or waste at variable rates. This helps operators balance solids blanket levels in the clarifiers.
• A third clarifier (Siemens’ Tow-Bro).
• An Andritz biosolids centrifuge.
• A seepex progressive-cavity biosolids cake pump, chosen instead of a conveyor because it provides flexibility to pump biosolids cake to trucks, bins, or a temporary storage area. The cake pump can move 20 percent solids cake up to 250 feet and can be easily modified for future needs.
• New Ozonia UV disinfection system (Degremont Technologies) Aquaray 3x low pressure, high intensity, including a second UV channel for redundancy when maintenance or cleaning is required.
• SCADA modifications to incorporate new process equipment, and to allow operators to choose the equipment to be operated on standby power during power outages.
• A new 1,200-square-foot maintenance building to provide a place for equipment and vehicle maintenance, and for storing fuels, oils and parts.
The upgraded plant is permitted for an average daily flow of 8.25 mgd and can handle peak flows of 24 mgd. The new UV system consistently meets or exceeds fecal coliform limits, and the new solids handling facilities provide better control of solids inventory.
The plant now produces Class B cake biosolids, hauled away and applied to pasture and cropland. Recently, when a solids-hauling contractor was unable to keep up with production, the digesters filled and the plant had to recirculate a high volume of activated sludge.
“We had four full digesters and very high clarifier blanket levels,” says Bland. “Now that we have a contractor that is doing a much better job, we have the blanket levels down and also one empty digester.”
While the upgrade helped the plant accommodate growth, four full-time operators and one part-timer make sure it stays in compliance. Lab tests for CBOD, TSS and pH are performed in-house three days a week, and all other testing is sent to an outside lab.
“It’s hard to accomplish everything with such a small staff,” says Bland. “The operators work seven days on and seven off, and we have one operator per shift, with two shifts.” Bland, considered a supervisor and not a working operator, is at the plant Monday through Friday from 7 a.m. to 4 p.m. and fills in as operator when needed.
He credits the operators’ can-do attitude for the plant’s success. “I probably have four of the best full-time operators in the state,” he says. “My guys are always busy, in the lab, doing maintenance, mowing the lawn, or cleaning floors and windows.
“For four guys, what they do is pretty amazing. Most of our equipment is outdoors. When it’s raining, they’re outside. When it’s cold, they’re outside. When it’s 105 degrees, they’re outside.”
In a recent example of teamwork, the operators stepped up when full-time operator Chris West was out for surgery, covering his shift without Bland having to assign someone. “I posted a schedule with the date and times that needed to be covered. The operators worked it out themselves, sharing the overtime for those that wanted it,” says Bland.
As another example, the construction contract and consent order required multiple milestones and completion dates for the new facilities. The operators went above and beyond to make sure the transition was smooth and that there were no permit violations. “We actually had to change the way we run the plant four different times to allow for takedown and startup of old and new equipment,” says Bland.
The new UV system was placed into service in October 2008, followed by the new solids dewatering facilities in January 2009, and the new aeration basin, clarifier, and RAS/WAS pumping station in September 2009. The existing aeration basins were returned to service in October 2009. Each startup required the operators to develop a detailed plan for maintaining treatment while the new facilities were placed into service, and long hours were required to closely monitor and adjust the new facilities.
Each shift does its share, and if one shift has a problem and doesn’t complete the scheduled work, the next shift makes sure it gets done. “Our operators take a lot of pride in the plant, and they keep it looking good all the time,” says Bland. “The Madison Utilities board members visited the plant and were impressed. As a result of the board’s visit, a newspaper article was written about us. The takeaway from this is that you can come through this plant anytime, and I will not be embarrassed by what you see.”
Managing for success
As chief operator with 18 years of service, nine of them at Madison, Bland believes in empowering his operators. “I encourage them to be part of the whole operation, and to make suggestions about how to improve things, including equipment upgrades,” he says. “I empower them as individuals to be part of the team.”
For instance, Bland held a contest to allow the operators to come up with the plant’s mission statement. He allowed each operator to take part in the new plant design process, from suggesting things that were needed, to reviewing the drawings and specification book. He encourages them through goal setting to make suggestions on how to make the plant run better, and then sits down with them to discuss whether those are viable options.
Operator Johann Caris has been at the plant from the start. Chris West was a meter reader supervisor before he went to work at the plant in 2007. Operators Tim Moody and Kevin Tipton have been there since 2007. Tipton moved over from lift station maintenance in 2009. Part-time operator Bryce McCreless started in 2010.
“Three of the four full-time operators have obtained their Grade 4 certification,” says Bland. “They attended limited training classes and also received one-on-one training here at the plant from me or other operators. Although several of the associations offer operator training, there is no college or trade school program in the state that offers a program that will enable a graduate to operate a plant effectively.”
Bland feels hands-on training is essential for operators to be effective. “They test you on what is in the manual, but not for real-life situations,” he says. “When a new guy comes in, I go through the plant process with him and say, ‘This is what you do when this happens, or that happens.’ Then, when it does happen, they know what to do.”
Meeting future needs
Bland hopes the plant can eventually hire more operators and return to the previous staffing level. In the immediate future, he is thinking of hiring high school or college students part-time to help with grounds work and cleaning.
The plant may need to upgrade again in less than 10 years to keep up with rapid growth. Madison is a bedroom community for Madison County, home to some of the nation’s large defense contractors. “Our town is one of the fastest growing in Alabama, and our wastewater plant is already averaging 5 mgd this year, so we may need to upgrade in as little as five years if the economy turns around,” says Bland.
In the meantime, Bland is optimistic that his operators will continue to excel and the plant will continue its success. “Overall, being a wastewater treatment operator is a good job,” he says. “I love my job, and I think everyone here does too.”