STANWOOD — A Stanwood firm is looking to double the size of its composting operation off Highway 532, a move which would make it one of the largest commercial composting facilities in the state.
Lenz Enterprises is seeking permits to receive up to 150,000 tons of organic materials like yard trimmings and food waste each year, twice what it is now allowed to handle at the site.
As envisioned, processing would occur more hours each weekday and, for the first time, on Saturdays. Areas used for each stage of the composting process would be enlarged, as would the equipment used for capturing emissions and preventing odors.
But the number of trucks making deliveries is projected to be the same or fewer. That’s because Lenz says it will replace its smaller “packer-trucks,” which carry only a few tons of material, with trucks capable of delivering up to 30 tons, according to information submitted by the company to regulatory agencies.
A company official described the proposed expansion as a “pretty minor project” that should not negatively impact the community.
Though production will be on a larger scale, program director Ed Wheeler said, “We’re going to continue to do what we’ve been doing the past 10 years.”
The Lenz composting operation is located within the family-owned company’s sand and gravel mine at 5210 Highway 532.
Composting began there in 2008. Initially, the company was permitted to accept up to 30,000 tons of organics a year, including compostable containers, yard debris and food and wood waste. It can also take in items such as animal manure, shells and marijuana waste as defined in state law.
In 2014, Lenz received permission to expand and process up to 75,000 tons per year of organics which are primarily made into a consumer product for gardening and landscaping. A vast majority of that material comes from the City of Seattle, though some comes from sites in Snohomish, Island and Skagit counties.
The firm is now looking to double its annual intake again, to 150,000 tons. For perspective, that’s roughly the amount handled by Cedar Grove at its Everett compost facility in 2018, according to the state Department of Ecology.
In February, Lenz applied to the Puget Sound Clean Air Agency for a modification of its existing air permit and to the Snohomish Health District for a modification of its solid waste handling permit. Both agencies approved the previous expansion.
An engineering report filed by Lenz with its permit applications asserts that since the 2014 expansion — which followed technological upgrades to speed up the composting and curing process — “no significant regulatory infractions have been received.”
And it states there’s been only one odor complaint since the facility opened in 2008.
“The cause for this odor issue was ambiguous but Lenz assessed operations and made minor modifications anyway to mitigate potential odors,” the report states. “No additional odor complaints have occurred since.”
That same engineering report lays out changes envisioned for each step of the process to accommodate the desired expansion.
The first involves the facility’s operating hours, which would go from the current six hours a day, Monday through Friday, to 10.5 hours a day — 7 a.m. to 5:30 p.m. — Monday through Saturday. Overlapping shifts of workers would be deployed to deal with the increase in material needing to be moved into pretreatment.
In the first stage, the area where material is aerating would be more than doubled. And 177,000 square feet of paved area would be added for the second phase of composting in which piles of material are turned. With more space for aerating and pile turning, the time spent in the curing process should be shortened and the potential for odorous emissions decreased, the report contends.
Another change is to increase the capacity of the air processing system in the tipping building where arriving organic material is deposited. This, too, is intended to prevent the escape of any potential odors.
At this point, the company’s application is not complete.
Wheeler said additional information will be submitted dealing with traffic and odors.
Also, the firm must submit further environmental analysis under the State Environmental Policy Act to the Puget Sound Clean Air Agency, said Steve Van Slyke, the agency’s director of compliance.
With that information, the agency can determine if the project could have any significant impacts requiring mitigation. A draft air permit, containing any mitigations, would then be published, he said. At that point, the public would be invited to review all the documents and offer comment on the draft permit and proposed expansion, he said.
He confirmed there has been no history of problems at the site.
“That doubling (in 2014) went well,” Van Slyke said. “Our challenge is making certain that this doubling goes as well.”
Anne Alfred, environmental health specialist for the Snohomish Health District, said the company has a good track record.
“They do a really good job managing their business,” she said. “With a process as complicated as making compost, there are things we want to be sure they are able to manage.”