Water resource recovery facilities represent a major market for aeration blowers. Blower and Vacuum Best Practices Magazine interviewed Brent Herring, manager of the Wastewater Treatment Division at KC Water in Kansas City, Missouri, to get an owner’s perspective on the industry.
Brent Herring, Manager of the Wastewater Treatment Division KC Water, Kansas City, Missouri.
Good morning! Please describe KC Water.
We are a municipally owned water, wastewater, and stormwater utility with three separate rate bases. I oversee the systems that have to do with wastewater, while other divisions handle water treatment and distribution and stormwater management. Our 320-square-mile service area includes 2,800 miles of sewer lines and 2,800 miles of water lines.
KC Water encompasses six wastewater plants and 43 flood and sanitary stations. There are 15 flood stations along the Missouri River that keep Kansas City dry. Then we have 1,350 acres of land for biosolids application. Industrial pre-treatment is the responsibility of the Regulatory Compliance Division. We all work closely together.
What has been your attention lately, given the need to continuously upgrade a utility of this size?
We’ve spent a lot of money upgrading infrastructure. We spend a lot of money on pipes in the ground in terms of addressing combined sewer overflow. Our issue wasn’t so much capacity at plants as it is the way you move flow across 320 square miles, twenty four hours a day, seven days a week.
We’ve done many, many projects. At any one time in my division, we have 100-125 projects under way in construction or design. Our projects range from small to large both in terms of complexity and cost, ranging from pump station upgrades to a $150 million thermal hydrolysis biosolids facility design-build project.
How do you decide what’s best for all involved given so many projects?
We often use the Quadruple Bottom Line (QBL) approach, which is a takeoff of the Triple Bottom Line concept. We weigh investments decisions on four criteria: environmental, community, operations, and economic impacts.
We apply QBL when it looks like there is no super clear alternative to a particular solution, or when it looks like there might be diverging issues among these four areas. We don’t use it all the time because there are times when the most environmentally friendly project is also the most cost-effective. What I really like about QBL is the ability to maximize resources and minimize the burden on ratepayers and the environment.
It sounds as though QBL is a balanced approach to decision-making.
That’s exactly what it is. Our goal is to have a holistic decision-making framework that is responsive to the needs of ratepayers and our rate structure, while also giving us the ability to weigh the environmental benefits and take into account system and facility operability and short- and long-term costs. At the end of the day, we blend those together in a logical and consistent manner.
We’re also very committed to Envision (https://sustainableinfrastructure.org/envision/), which is a decision-making framework created by the Institute for Sustainable Infrastructure. Envision helps us to continue to create a sustainable and resilient utility.
Does KC Water rely heavily on aeration blowers to maintain treatment?
Three plants serving the north portion of our service area use aeration blowers. Two have turbo blowers and one has multistage blowers. The other three plants don’t use blowers since we use bio towers (trickling filters). The multistage blowers are in a plant that is fairly old. The turbos have been running for seven to 10 years. We don’t have any issues with those blowers in that application.
A turbo blower in use at the Fishing River Wastewater Treatment Plant in Kansas City, Missouri.
Aren’t blowers usually the biggest single energy use for most municipalities?
Not only that, but wastewater treatment and water treatment facilities are second only to schools in terms of capital investment. These operations are usually either the biggest or the second biggest capital investment for most municipalities. Our focus with blowers and most processing equipment is on reducing energy consumption while ensuring operability. We need to be looking for the renewable, the reuse portion, the green portion of wastewater treatment.
Do you use separate buildings for your aeration blowers?
We’ve always put blowers in buildings because a building was already there, not because that was the best place to put it relative to where you’re going to put the air. I’d much rather have blowers next to the aeration tank. We want to minimize that delivery system, subsequent losses, or any other issues, whether it’s accumulation or condensation or any other issue. Also, it takes a lot of energy to push that air. It’s only 10 feet away, but 10 feet is 10 feet over the lifetime of the facility.
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What is your approach to blower sizing?
I come from a time when you probably needed three blowers – two at maximum flow, and one as a spare for backup. Well, maybe we need to look at different options. Maybe we need to have them sized in sort of a Mama Bear/Papa Bear/Baby Bear arrangement. Blowers are mission critical, and they are a significant part of our operation due to energy costs and regulatory compliance. They are one component that can cause a problem with permit compliance.
In wastewater treatment plants today, we need to optimize our ability to treat flow more efficiently for objectives that were never envisioned in the original Clean Water Act, such as managing nutrients. The industry – the blower industry, the profession, the required treatment, water quality objectives, our understanding of treatment technologies in wastewater – has come a long way. We’re on a curve to optimize wastewater treatment, but it is not a simple equation.
Shown are the main blowers used at the Rocky Branch Wastewater Treatment Plant in Kansas City, Missouri.
Are newer technologies, such as remote monitoring, a big part of your efficiency efforts?
Years ago, we didn’t have the ability to monitor remotely like we do today. The cost of doing these large-scale SCADA systems has dropped exponentially over time. As a profession, we have not told the good story about technology investment benefits like we are able to with metrics and analytics today.
That’s important, because we don’t work in a profession that’s easy to explain. Sometimes, the story is not easily told in 10-second sound bites. Analytics enables us to quantify performance at a very high level, which we hope enables our internal stakeholders and ratepayers to be more comfortable with investing in technologies that improve efficiencies.
How do you use analytics with blowers, for example?
A good example is blower timing. Where you have demand charges for electricity, can we shift treatment operations to lower-cost, evening-time periods? It goes to wastewater diurnal variations. In a service area as large as Kansas City, the diurnal variation is not as significant as it might be elsewhere. But we can still optimize our strategy in terms of the incoming flow and organic loading.
The blower system doesn’t operate as a thing in and of itself. Everything else responds and relates to it. It needs to be an integrated system within all of the facility’s components. As it relates to blowers and any piece of instrumentation that has controls, one needs to really give some serious thought to how many signals you bring back to the SCADA system; and how to optimize the control strategy to enable more effective human interaction with operations and maintenance staff.
Anytime we can use technology like blowers and controls to optimize how treatment occurs is significant. I think the only way we get quickly to cleaner water is to optimize how we use the technology we are buying.
Are Inputs/Outputs (I/O) a major consideration for optimization?
Yes. If it costs $100,000 to have 500,000 I/O points, but you’ve got a number of additional systems, how much money can one invest? There might have as many as 15 points on a single blower that should be monitored, and maybe you’ve got four blowers in a system. Don’t forget the physical need to wire that stuff so you can troubleshoot it. This isn’t rocket science, but one needs to know and understand how all the pieces come together and how they relate to each other in their operation, troubleshooting, and maintenance.
Is it correct to say your operations staff remains a big part of optimization?
Right, and budget pressures continually cause us to consider how we deploy resources. They have over the years. No one wants to hear that. Yet technology enables our ability not only to staff appropriately but also to increase people’s skill sets and equip them to be critical thinkers and troubleshooters.
You know, years ago, if you had a problem with a pump, it was pretty simple to diagnose. Same with a blower. It worked or it didn’t. Nowadays, you can’t figure out if it’s the blower or the controls because everything is so integrated. Today’s workforce needs to be able to understand the sophistication of controls. It makes it even more important for operators to be comfortable with technology. Job security is not just about fixing things. Job security should be based on the fact that I can operate things.
Describe the changes you’ve seen in treatment plant operators in recent years.
A majority of the folks coming in are millennials. In my view, the old command-and-control management structures no longer work; in other words, doing something just because I tell you to go do it. One can do that, but that approach is not likely to get the needed collaboration and cooperation. Millennials are accustomed to constant feedback. So how do I meet the need they have for that? How do we integrate that with other generational needs and norms?
Today, we need to build an organization that is continually responsive to the human elements; incorporates thoughtful technology implementation; and meets the needs of our customers cost-effectively and enables our team members to be the best water professionals they can be.
Thank you for these insights.
All photos courtesy of KC Water.
To read similar wastewater treatment plant industry articles, please visit https://www.blowervacuumbestpractices.com/industries/wastewater.