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Environment and Ecology
P.R.E.P. does composting on a commercial scale
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Don Taylor, right, assistant district manager for composting operations at Pierce County Recycling, Composting and Disposal, chats with operator Steve Wandke while visiting the Purdy composting facility.Gig Harbor and Key Peninsula gardeners who utilize yard debris collection services are not only keeping their yards in meticulous shape, they are also helping Kitsap gardeners. The organic waste collected from around Pierce County — everything from recycled Christmas trees to grass clippings and dead leaves — becomes organic compost that is currently sold exclusively through Vern’s Organic Topsoil in Poulsbo.

The compost is produced in Purdy, near Gig Harbor, under the brand of P.R.E.P. (Pierce Recycled Earth Products), at a facility owned by Pierce County and operated by Pierce County Recycling, Composting and Disposal, LLC (doing business as LRI). Owned by parent company Waste Connections, Inc., LRI (http://lriservices.com) also operates the county’s transfer stations, including those in Key Center and Purdy.

The Purdy compost facility is the first one the company began operating. Built as state-of-the-art for its day back in the late 1980s, it produces close to 40,000 cubic yards of compost per year. LRI’s business model is to sell the product wholesale a year in advance, so Vern’s trucks pick up multiple loads daily. Vern’s then both sells the compost at retail and blends it into other retail products, such as mulch, topsoil and garden mix.

“What makes our compost different is the quality, the fact that we’re stringent about what we take,” said Don Taylor, assistant district manager for composting operations.

The material that is delivered by commercial trucks as well as individuals to the Purdy facility is first loaded up for hauling to Puyallup, where it is ground. When it comes back to Purdy, it begins a 30- to 45-day process (the length depends on the time of year) to become weed-free, chemical-free compost. Although this facility is not certified organic, it uses the same methods as the company’s Puyallup location, which does have the certification. There are just two major differences between the two: The Puyallup facility, built in 1998, is completely enclosed since it’s located in a residential neighborhood. It is also entirely automated for temperature, moisture and oxygen control — Taylor can even monitor things remotely from his iPad.

The company acquired its newest composting facility, Silver Springs Organics in Thurston County, in November. The operations are modeled after Purdy but there’s one distinct physical difference — a 5-acre roof. (The compost from the other two locations is sold wholesale to Corliss Enterprises.)

“Each location needs different protection for odor and we’ve also tried to incorporate improvements and things we’ve learned from the other facilities,” Taylor said.

The composting mimics the natural process, except it’s accelerated four times or more. What takes Mother Nature four to six months takes LRI 30 days in the summer and about 45 days in the winter.

“The floors are aerated and we monitor the material to maximize temperature, moisture and oxygen to maximize speed,” Taylor said. “We just give the natural microbes all the conditions to do what they do.”

The material goes through three stages once it arrives at Purdy. First, it is added in rows to the active composting floor, where a 130- to 160-degree temperature is maintained. A row turner mixes and moves each row twice a week, while hydrating and monitoring the aeration. In the meantime, the bacteria do all the breakdown work — forming a tell-tale white, “snow-like” cover on the piles, which are constantly emanating steam.

Once the material makes its way through each row of the compost floor and reaches the far wall, it has met all regulations and can be moved to a curing area for a week to 10 days. There, the temperature is lower and the material cools off and stabilizes.

When that final row moves to curing from the active compost floor, a new row of freshly ground debris can be added to the front to start the process over.

“Everything is done in unison,” Taylor said.

The final stage is a three-phase screening. Pierce County recently invested in a new screening plant, which allows for the screening process to be completed in one day instead of two and a half. Taylor expects that after applying some efficiencies learned at the Puyallup operation, the Purdy process can become about 10 percent more efficient thanks to the new screeners.

While the county owns the facility and all the fixed equipment, LRI provides the heavy machines and the five employees who staff the site. The operation is open, rain or shine, all year long except for three major holidays.

“In the winter, the material turns differently. As soon as you fill the building with one material and you get used to it, it changes (because of the season),” Taylor said.

Taylor started with the company 20 years ago as a laborer (before it was acquired by Waste Connections). As the manager overseeing composting operations, he travels around constantly from one location to another, including the smaller facility in Tacoma — the only one that accepts food waste, and a very small amount at that. (Pierce County recently explored the idea of a residential food waste program but decided not to launch one, citing challenges associated with food waste processing.)

He said another thing that distinguishes his company besides quality is the employee training. Although it’s not required by the county, all key employees go through a 40-hour course in compost facility operating. “We want them to understand why they’re doing this and the importance of the microbes,” Taylor said.

In addition to being used in landscapes and gardens, P.R.E.P. is popular with the state Department of Transportation and other agencies for erosion control due to its water-retention qualities.

More than 200,000 tons of waste a year is accepted at the four LRI facilities. “We’ve grown every year,” Taylor said. “We’ve grown by leaps and bounds.”

 
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