In 2017, Grimm鈥檚 Fuel鈥檚 outlook was just that – Grimm. With over a thousand odor complaints a year, the facility was faced with a choice; Either shutdown composting operations or get rid of the odor issue and rebuild community trust. As composting pioneers and committed members of the community, the choice was obvious, It was time to modernize their operation and win back the support of their now very proximal neighbors. 鈥淲e鈥檙e really proud that we鈥檝e been good neighbors with our composting facility over the past five years,鈥� said Jake Grimm, fourth generation owner of the business. 鈥淲e did have some issues back before our facility upgrade was made, but as a family business it鈥檚 very important to treat our neighbors like family.鈥�
As the company name implies, Grimm鈥檚 Fuel is not just a commercial composting facility. The company has been a leading provider of heating oil and firewood to the Portland Oregon region for decades. In the 1990鈥檚 the company began commercially composting yard waste and manure from the region, using a static pile composting method. They used heavy equipment to periodically tumble the material to provide oxygen for the aerobic microbes that convert organic waste into compost. 鈥�We tried experimenting with an air slab in the 90s,鈥� said Jake Grimm. 鈥� But with the technology of the time and the wet climate, large static piles proved to be more effective for our volume.鈥�
As the facility grew so did regional development, a bad combination for compost odors. They were also facing challenges with compost production efficiency and product consistency. In 2018 Grimm鈥檚 contracted with Seattle-based Green Mountain Technologies(GMT) to Design an aerated static pile (ASP) composting system, which uses an automatic aeration system connected to ductwork under the composting pad to automatically optimize the oxygen and temperature levels in the material, without the need for frequent mechanical tumbling. The first phase of ASP infrastructure was installed in 2019, and then expanded to Phase 2 in 2020.
GMT designed a 16-zone, WebMACS controlled, Covered Aerated Static Pile (cASP) composting system equipped with reversing aeration and biofiltration to optimize odor control. Current annual composting volumes are close to 50,000 tons per year, making this one of the largest commercial composting facilities in Oregon, although the facility鈥檚 could handle up to 100,000 tons per year. The ASP composting system keeps the composting microbes happy, which accelerates the composting process and eliminates the buildup of the 鈥渁naerobic鈥� microbes. 鈥淭o my knowledge in the last 6 years we鈥檝e only had one legitimate odor complaint. A few of the complaints were erroneous, like one from a woman 8 miles away, which couldn鈥檛 have been about us. Our only serious odor issue during this time was due to a stuck temperature probe, which made the zone get too hot. As soon as we fixed that probe the aeration system adjusted itself and the odors went away.鈥�
Anaerobic conditions are a primary cause of odor issues and methane emissions in general. The ASP composting system not only keeps the material in aerobic oxygen-rich conditions, it also speeds up the composting process while reducing material handling costs because there is less need to mechanically tumble the material. 鈥淥bviously somethin had to change,鈥� Grimm said. 鈥淚n 2018 Green Mountain Technologies came in and analyzed our system and helped us design an ASP system and a much better overall approach.鈥�
“Everyone I talk to is impressed with the changes we鈥檝e made over the years. My grandfather was kind of a pioneer in composting back in the late 80s and 90s,鈥� said Grimm. 鈥淗e played around with some air floors back then but ended up doing static pile composting with excavators for turning. At that time we were out in the middle of nowhere and it was a pretty good solution. It worked but it was stinky. Odors became a real problem with the volume that we grew to after 2010. We also had fire issues on a regular basis, we鈥檇 have to flip the whole pile to put the fires out. We got really good at dealing with fires”
Grimm鈥檚 installed their own aeration system in 2019 with design assistance from GMT, but the aeration floor had some operational challenges. In 2020 GMT installed their patented 鈥渟parger鈥� aeration floor system with advanced automated control systems, which brought dramatic improvements to the facility鈥檚 efficiency. 鈥淥ur first ASP design that we installed on our own was with aeration pipes set at grade and holes drilled into the exposed top side of the pipes,鈥� explained Grimm. 鈥淣ow that we have our GMT sparger aeration system the process works way better. The aeration holes never need to be cleaned out.”
Jake says the materials they receive on site have significant odors as they arrive, but the odors go away as soon as the material is put into an aeration process. “Our feedstocks coming in have way more odor issues than our in-process materials. The aeration system really solved our odor issues, even with neighbors directly across the street,鈥� said Grimm. 鈥淚t鈥檚 night and day compared to how things were before GMT鈥檚 aeration system. Our neighbors are surprised there鈥檚 no odors. Yeah it smells like dirt and wood chips and grass but not composting odors.鈥�
Grimm鈥檚 manages most of their own maintenance on the overall ASP composting system, with occasional support from GMT. The company also has 6 blower trucks for field application of compost, several semis for commercial delivery of compost, and a fleet of dump trucks for home delivery. They build their own dump truck boxes, blower boxes, trommel screens, and conveyors. “We鈥檙e a do-it-yourself type of operation in general, but I don鈥檛 think we鈥檇 be able to operate at the scale we do today without the support we get from GMT,鈥� said Grimm. 鈥淎s far as the aeration system goes, GMT鈥檚 technology and support has been great. My wife Haley takes care of the software and programming, Jasmine Kamdar at GMT has been a huge help for her. It鈥檚 been really awesome.”