Origami is already complicated, but what if instead of 4-inch-square pieces of paper, you were folding multi-ton metal tubes through a 12- by 12-foot hole, then building 26 feet below ground?
That’s basically what happened in Edmonds after the Edmonds City Council three years ago approved funding for the city’s new carbon recovery project. The project was designed to replace Edmonds’ aging incinerator, which disposed of sludge from the city’s wastewater treatment plant.
The project is now operating almost a year after it was originally scheduled to go online. Part of the delay was due to the challenge of installing the new system into the small wastewater treatment plant, located on a 3.94-acre piece of land in downtown Edmonds, next to the ferry terminal holding lanes. Approximately a quarter of this space is across 2nd Avenue South and there are multiple buildings in addition. The building that houses the plant is only 53 feet by 39 feet by 39 feet.
The goal of wastewater treatment is to remove as much of the suspended solids as possible – these are known as sludge or biosolids – before the remaining water, called effluent, is discharged to the environment. In Edmonds’ case, that effluent ends up in Puget Sound.
Dedicated in 1991, the Edmonds wastewater treatment plant has served Edmonds for more than 30 years. It also treats and disposes of sewage from nearby partner jurisdictions including the City of Mountlake Terrace, the Olympic View Water and Sewer District, and the Ronald Sewer District. But the sludge incinerator became increasingly expensive to operate and maintain.
The new treatment system went online in mid-September, and so far has processed over 100 tons of sludge, according to Dave Mooney, CEO of EcoRemedy, the company that pioneered the carbon recovery system known as pyrolysis. Testing is still in progress and for now, EcoRemedy staff are running all the systems.
As soon as the new process reaches 24-hour capacity, training for the plant’s local operators will begin and they will take over the operations. This is expected to happen in October.
Pyrolysis is a way to process sludge without emitting carbon or adding to landfill waste. The pyrolysis system dries waste products at an extremely high temperature, without oxygen. Drying instead of burning makes the carbon stay in the waste rather than releasing it, where it would add to the carbon-causing climate change in the atmosphere.
Pyrolysis even produces a product that EcoRemedy has termed “FlexChar,” which can be used in a variety of practical applications. Typical sludge treatment using incinerators produces ash, which goes straight to the landfill.
Edmonds leads the way
The entire pyrolysis system that has been installed in the Edmonds facility is so unique that it just received a U.S. patent and has patents pending in 34 other countries, Mooney said.
Edmonds will join only three other locations in the U.S. and only a few in the world to use this process, according to a paper published by Wiley Water Environment Research titled Pyrolysis and gasification at water resource recovery facilities: Status of the industry. One of the other three – in Morrisville, Pennsylvania – was where EcoRemedy first applied its pyrolysis technology on municipal biosolids. The company’s previous use of pyrolysis was to process waste in the agricultural and forestry sectors.
As previously reported by My Edmonds News, the new pyrolysis system promises to cut CO2 emissions to near zero, reduce the plant’s electrical consumption by a third, and eliminate the need for fossil fuels necessary for the old incineration process. It is even self-sustaining, meaning that it produces more energy than it uses, turning what was once a sewage sludge incineration plant into a city-owned renewable energy producer.
Electrical savings will also be no less than 71,737 kWh per year, Fuel oil is expected to be reduced by 12,875 gallons per year, according to the City of Edmonds website.
The system was chosen with the future in mind in more ways than one. Edmonds Public Works and Utilities Director Oscar Antillon said in an interview that the system is designed to support current trends for population growth for at least the next 10 years.
The entire project has required a lot of collaboration between the city public works department, companies EcoRemedy and Ameresco, and other small contractors. EcoRemedy provided the gasification equipment, technology, training, engineering and controls. Ameresco brought its project management experience to manage mechanical and electrical contracting. Ameresco was also responsible for site demolition, including removing the old equipment and then installing new equipment in the facility.
“Really, they did a masterful job,” Mooney said of Ameresco.
The project features several improvements that highlight lessons learned from EcoRemedy’s last pyrolysis installation. These included problem solving to reduce the visible gas emitted from the plant and the need to work within the wastewater treatment plant’s small footprint.
Reducing the visible gas exhaust was a priority that emerged for the Edmonds community toward the end of the construction. “Nobody wants a great big white cloud obstructing their view,” Mooney said. He described the cloud as similar to the cloud of steam that exits from a typical clothes dryer. To address this problem, the company found a way to dry the exhaust before it reaches the outside air.
“That should move that cloud much, much higher in the sky and everybody will have a clear view of the beautiful Puget Sound,” Mooney said, adding that EcoRemedy is “trying to remain not only stewards of the environment, but stewards of our neighborhood.”
Due to the treatment plant building’s small size, Mooney said that those working on the project “folded this plant up and utilized every nook and corner of that facility’s available space.”
Mooney said this challenge actually pushed the company to improve its processes in ways that could radically reduce its installation time and make systems even more efficient. EcoRemedy has now developed a fully modular system, which Mooney says could turn an 18-month install into a two-month one in future projects.
Another improvement includes enhanced security and safety through new sensors within the plant, which allow EcoRemedy to program the system from afar. Mooney likened it to the type of smart technology that is everywhere in modern life, including TVs. In this case, he said that it will be vital in monitoring and trending performance.
“We as a Pennsylvania company can be monitoring and logging in and observing everything that’s happening in Edmonds, Washington,” Mooney said, adding that “It’s also a safety improvement because every single motor, every single sensor and device that is a part of our process can be reset, restarted and reprogrammed without ever entering the electrical cabinets that house them.”
Overcoming delays
When the City of Edmonds finalized plans to install the pyrolysis system for waste management in place of the old incinerator, the original goal was to have it up and running by summer 2022. The system is now operational a little over one year later than planned.
After the incinerator was removed in 2021 and construction continued on the inside, the sludge still had to go somewhere. The most cost-effective and efficient option ended up being to ship the sludge in open train cars — to Oregon.
Public Works and Utilities Director Antillon said that other options included “sending it for treatment to another plant or another industrial treatment place, which means putting higher liquid concentration biosolids into tankers and moving it to a treatment place.” All of this would have been more expensive than moving the sludge via open-top rail. Regarding the reason for choosing to ship the sludge out of state, Antillon said that “there are no landfills here in the area that are able to take this kind of waste.”
An overview of the Edmonds project on Ecoremedy’s website states that “reduced electricity consumption will save ratepayers an estimated $341,000 per year.” To pay for the project, “the sewer rate for the average single-family residential Edmonds homeowner increased by 88 cents per month — from $45.84 to $46.72.” The project is also being financed through revenue bonds approved by the Edmonds City Council in 2020.
Part of the project delay was also due to removal of the incinerator, which had to be taken apart and moved out in pieces
Other delays were caused by supply-chain issues during the pandemic, frequent staffing and leadership changes and learning curves for each organization involved. While personnel changes are not inherently negative, onboarding someone takes time and often new leaders will bring new ideas that then need to be vetted and responded to, Mooney said.
“With that turnover, you get new ideas and new creativity. But it also takes time to bring the new folks up to speed,” he added.
Personnel changes can also create communication challenges, as can the involvement of many different parties that are collaborating to implement a system that no one has done before in quite this way. To address this, Antillon said he facilitated more frequent and more direct communication between the various parties.
Antillon said that a breakthrough came when he started to include the voices of the people who will actually be working with the new equipment. He said it was important to get them on board. “One of the things I encourage is to be honest,” Antillon said. “The other part is, I brought all of the operators.”
The public works director said this step was vital to the process because “the reality is that my operators at the wastewater treatment plan need to be part of the project team. They’re gonna have to deal with this for, you know, the next 30 years.” He added that it was important to be asking the operators, “Does it make sense?”
Antillon said his new wastewater treatment manager, Ross Hahn, has been a key player in this effort. He was a supervisor at the time the pyrolysis system was being installed and was “consulting with the operator teams and making sure that they knew what we were getting into.”
Problem solving improves process
Reflecting on the project’s impact, Antillon pointed to two main improvements: Reducing the city’s environmental impact and the “very new and sort of a noble approach in how we deal with biosolids.”
“We are gonna stop sending all those biosolids out of state, so all the impacts that that has on the environment, including the hauling and moving all the stuff out of it out of here, out of the city,” Antillon said.
In addition,“it is a process that is gonna be a lot cleaner and it’s going to meet the air requirements,” he said.
In general, Mooney said this project reinforced Ecoremedy’s experiences about the efficacy of its system that were learned during the earlier Morrisville project. “We confirmed some things that we did very well. From the onset, the gasification process essentially is unchanged from the 20 years that we’ve been doing it at the agricultural sector. That worked wonderfully well. Our control logic worked really, really well. So the sequence, the automation, that type of stuff really worked very nicely.”
Once the Edmonds facility is up and running, the EcoRemedy team will start working on their next project – a larger facility in Hershey, Pennsylvania.
“I think that the people there in Edmonds appreciate the beauty that they have,” Mooney said. “They want to make sure that they do what they need to do and do their part to maintain that.”
— By Keelin Everly-Lang
