Process Wastewater Technologies (PWTech) is a small but rapidly growing company working on combined sewer overflow and sludge dewatering technologies. One of its leading products is a volute dewatering press that can be used by wastewater plants to dewater sludge, vastly simplifying the task of disposing of it. In this interview, we speak to Business Development Manager and Regional Sales Manager Chris Hubbard about PWTech’s solutions for the wastewater industry. 

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Municipal Water Leader: Please tell us about your background and how you came to be in your current position. 

Chris Hubbard: I was born and raised in New Jersey. I went to Fairleigh Dickinson University in Teaneck, New Jersey, and studied mechanical engineering. Shortly afterward, I ended up working for a company that made centrifuges for the municipal wastewater industry. I started with it as a field engineer, then became a project engineer, then a process engineer, and then moved into a sales role. For 25 years, I have been either a regional sales manager or a representative in the municipal wastewater industry. Starting about 10 years ago, I competed directly against PWTech and got to be competitively friendly with my counterpart at that company, Alex Davey. Last fall, I got a call from Alex. He had been promoted to president of PWTech and asked if I’d be interested in joining his team as business development manager/regional sales manager and helping him build and grow the company, and here I am. 

Municipal Water Leader: Please tell us about the history of PWTech. 

Chris Hubbard: PWTech was formed in 2006, when our parent company, CDS Technologies, was sold to CONTECH Construction Products. CONTECH took all the product lines that made sense for it and spun off the dewatering technologies and the combined sewer overflow (CSO) technologies. That’s how PWTech was started. PWTech originally focused primarily on CSO, as the dewatering technology really hadn’t come into its own in the United States yet. One group focused on CSO, while Alex and the small team focused on sludge dewatering. Then, the prominence of the two segments flipped. Because the CSO market was fragmented, it was hard to gain traction in it with any regularity, whereas in the sludge dewatering market, a couple of good installations led to a few more good installations and a good reputation. That line of business has really taken off for the company. 

Municipal Water Leader: How large is PWTech? 

Chris Hubbard: We have around 33–34 people right now. We have carried out over 200 installations in the United States so far and are growing rapidly. 

Municipal Water Leader: Would you explain the basic issue of sludge disposal faced by wastewater plants? 

Chris Hubbard: Wastewater plants produce sludge and need to get rid of it. Some goes to landfills, some is incinerated, and some is applied to land for fertilization and soil quality improvement. On the industrial side, there are all sorts of disposal and reuse options, depending on what’s in the sludge. A lot of sludge is disposed of or handled in liquid form, which requires paying to truck an awful lot of water. By using a dewatering technology such as ours, you can remove the vast majority of that water and make the handling of your biosolids and residuals much easier and much less expensive. It is becoming a bigger and bigger challenge to manage the biosolids and residuals coming out of wastewater plants. Therein lies the reason for our rapid growth and growing success. 

Municipal Water Leader: Would you give readers an idea of the average sludge output of a wastewater plant? 

Chris Hubbard: A small plant might produce the equivalent of a very small dumpster load once a week. Large plants can fill multiple big roll-off containers per day. 

Municipal Water Leader: Do the companies have to test that end product to know how they can ultimately dispose of it, or is it fairly consistent? 

Chris Hubbard: It varies between municipalities and industrial plants. Municipal plants have to test for a number of pathogens and contaminants on a monthly or an annual basis, depending on the municipality. If the waste doesn’t meet the standards of the landfill or the reuse application, it’s entirely possible that the plant may need to incinerate it. I’m not sure if you’ve seen what’s going on in Maine right now. It has put a moratorium in place on the land application of the biosolids coming out of local municipal wastewater plants because of contamination by per- and polyfluoroalkyl substances, or PFAS. All those plants are suddenly scrambling to figure out what to do with their biosolids. 

Municipal Water Leader: Please tell us about the technology your company uses. 

Chris Hubbard: The AMCON technology is patented. It involves a volute dewatering press, which is a type of screw press. We think of it as screw press 2.0. Screw press technology is tried and true, but we improve it in a number of ways. While similar technologies exist, ours is the original and the highest-quality version available in the industry. The change from centrifuges, belt filter presses, and other dewatering technologies to screw press technology has gone well in North America. 

Municipal Water Leader: Would you explain the basic idea of a screw press? 

Chris Hubbard: The screw press is a simple technology at its core. It is a perforated or screen cylinder with an auger running up through the middle. There are different ways to do it, but essentially, the pitch or the spacing of the auger changes as it gets closer to the discharge, so it literally squeezes the water out of the solids as it progresses up the dewatering drum. Every single screw press does exactly that. The difference is in the style of the drum itself. 

Municipal Water Leader: How does your device differ from conventional screw presses? 

Chris Hubbard: The screw press technology brought some great advantages to the dewatering market: The machines are slow moving, easy to maintain, compact, and energy efficient. Our volute dewatering drum has more dewatering surface area available than any of the other screw press technologies. Our footprint is quite a bit smaller for the same throughput. It requires less material, such as stainless steel, to construct. No brushes or wipers are required to keep the dewatering surface clean—it’s self-cleaning. The entire surface of the dewatering drum becomes an open area for pressing the water out of the sludge. 

Municipal Water Leader: Are the units typically always the same size, or do you build larger units for higher-volume water plants? 

Chris Hubbard: We have four different drum diameters, one of which is in the research and development stage. The other three are typical drum sizes for the industry; those are the three that we produce commercially. We use multiple drums to meet capacity requirements. 

Municipal Water Leader: How many units do most clients use? 

Chris Hubbard: It varies. Because it’s a robust, slow-moving, reliable technology, many customers use just one machine, sometimes even with just a single drum in it. A machine with multiple drums in it provides some backup redundancy, and a lot of customers prefer that. Then, quite a number of customers have multiple machines for complete redundancy.

Municipal Water Leader: Would you tell us about your project along the Connecticut River with Montague Water? 

Chris Hubbard: Montague was having issues with sludge and biosolids management. Over the years, the paper mills in town had gone out of business, so the sludge coming into the plant changed and became thinner over time, and the dewatering technology Montague Water had in place was not able to handle it. The utility had been forced to dispose of and truck liquid sludge for years at a cost of several hundred thousand dollars per year. Seeking to change this, it piloted a couple of different technologies. Based on the pilot testing, it selected the PWTech press as the technology that would satisfactorily dewater its incoming sludge. The whole project was great, but one really interesting aspect was that Montague actually purchased the dewatering machine directly, and plant employees installed it themselves. They did not use an outside contractor or an outside engineering firm. They poured the pad and did all the plumbing and electrical work. Within less than a year, Montague had processed all its backlog sludge, which was stored in tanks, and it was back within permit limitations. 

Municipal Water Leader: Does PWTech just manufacture the units, or do you do installation as well? 

Chris Hubbard: Our forte is the manufacturing end of things. Because the volute press is a simple, lightweight piece of equipment that is easy to install, we often just have somebody on site to supervise installation. We have on occasion acted as the general contractor and done the physical installation, but typically, we’re not the ones turning wrenches or hammering concrete. We leave that to the people who are really good at it. 

Municipal Water Leader: Where are your products manufactured? 

Chris Hubbard: All our products are manufactured in the United States with the exception of some of our rotating assemblies, but even these could be produced here if needed. I’m sure the new Build America, Buy America Act will help us. For most of the machines, we will meet the requirement using rotating assemblies imported from our licensee, but for the machines for which we don’t, we are shifting gears right now and manufacturing that technology here in the United States. 

Municipal Water Leader: What are some of the company’s top issues today? 

Chris Hubbard: Our biggest concern right now is managing our growth. We want to be able to continue to deliver solid solutions to all our customers on time and on budget. That’s easy to do when you only have one or two projects in house, but with our growth rate, our biggest challenge is finding qualified employees, or even people who aren’t yet qualified but are willing to work hard and learn with us. That has been far and away the hardest challenge for us. 

Municipal Water Leader: What areas of expertise are you looking for in prospective employees? 

Chris Hubbard: Project managers and field technicians—for example, people to run our pilot units and people to do startup and machine optimization—have been the hardest groups to find. We like to hire people who have just graduated or are just a couple of years out of school. These are travel-intensive positions, and we work at wastewater treatment plants, so you can’t be afraid to get your hands a little dirty. 

Municipal Water Leader: What is your company’s vision for the future? 

Chris Hubbard: Our vision is steady, manageable growth. We don’t want to be a huge wastewater conglomerate trying to do all things for all customers. We want to continue to deliver solid, profitable, responsible, and fair solutions to our customers. That model is serving us really well right now in the areas of sludge handling and biosolids dewatering. Those are our main areas of focus right now. We’ll bring other technologies and other solutions to challenges in those areas. After that, we will deliver high-value solutions to our customers for other challenges that they have at their plants.

Chris Hubbard is a business development manager and regional sales manager at Process Wastewater Technologies. He can be contacted at