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Compost facility solves toxic problem, back in business

“Our number one objective is organic material management. Our number two objective is to market a product,” said Dan Caldwell, farm and compost operations manager at the WSU compost facility.

After a two-year struggle with an herbicide contaminant, gardeners can once again purchase WSU compost.

“I’ve already contacted our previous customers and they’re aware that we’ll be back in business,” Caldwell said. Clientele primarily includes garden stores and landscapers in Washington and Idaho.

“Clopyralid,” an herbicide used for broadleaf weed control, left a residue in plant material acquired by WSU for compost-ing and contaminated the facility’s site. It was discovered in 2000, and became a problem for consumers. As a result, the facility could not sell its compost for the next two years.

However, identifying the clopy-ralid has allowed researchers in the Crop and Soil Sciences Department to become world-class leaders in compost contaminants.

What happened?
According to Caldwell, in 1999, an herbicide called “picloram” was improperly applied to hay that was later fed to livestock. WSU acquired the manure from these animals for use as a compost input. Picloram is typically used in such low levels that it has no impact on animals or humans.

It remained undetected for more than a year, but then WSU compost began killing desirable broadleaf plants. WSU offered compensation for affected gardeners and determined that the picloram would break down, with time, and dissipate to safe levels in their product.

However, in 2001, when the picloram had reached trace levels and was no longer a threat to sensitive plants, a second herbicide, clopyralid (similar to picloram), was discovered in the same compost. Clopyralid has no known effect on mammalians and is EPA approved. The chemical is persistent and effective, requiring few applications. However, it is toxic to broadleaf plants such as beans, peas, tomatoes, potatoes and sunflowers at levels of 10 parts per billion or less.

“We didn’t find anything in either herbicide test in the beginning because our analytical methods were calibrated at the parts-per-million level. But we ultimately detected clopyralid at the parts-per-billion level,” Caldwell said. “One bale of hay in 500 can be contaminated and, in turn, spoil entire piles of compost.”

“Thinking only in terms of picloram, we thought we were finally reaching acceptable contamination levels last year. But the clopyralid proved that this was not the case,” said David Bezdicek, a professor in the Department of Crop and Soil Sciences. “It has been two years now, and we are at last getting down to the level where we can market the material. One of the consequences is that WSU is becoming known worldwide as a leader on this issue.”

What to do now
With the reintroduction of WSU compost to local markets, there is also a stronger emphasis on gardening education.

“The big issue is educating the public on how much compost to use,” Caldwell said. “It’s compost, not fertilizer — it’s a soil amendment.”

In 2001, the Washington State Department of Agriculture established a statewide advisory committee to investigate the clopyralid issue in Washington. Consequently, clopyralid is now restricted from home use but is still available for golf courses and agricultural applications.

Bezdicek commented that recent surveys in Washington and Oregon still show widespread contamination of clopyralid in feedstocks and compost, but he feels that WSU has solved its contamination problem by being careful to buy feed that is free from the herbicide.

“Sellers must verify they have never used any clopyralid herbicides and that they grow their own products,” Caldwell said.

Quality control is the purview of Mary Fauci, research technician in Crop and Soil Sciences. She has conducted numerous studies using plant growth assays and has analytically tested WSU feedstocks and compost over the past three years.

The precautions are working — the 2001 levels decreased in 2002.

“Clopyralid is a worldwide issue,” remarked Caldwell, noting that it has also been detected in Japan, Australia, New Zealand and Canada. WSU clopyralid research has allowed for research partnerships with WSU Puyallup, other universities and with the United States Composting Council.

University enterprise
The WSU composting facility was created to help the university cut costs, decrease waste, and manage outputs in an environmentally friendly manner. It provides opportunities for researchers to study bioremedia-tion and for students to conduct research projects. It is one of the most successful university composting operations in the country, with faculty regarded worldwide as experts on herbicide contaminants.

Last year, the facility saved the university more than $200,000 in tipping fees at landfills, Caldwell said. And he anticipates generating about $60,000 in sales.

“We can’t undersell. We have a great product and people are still demanding it,” he asserted.

It takes 12 – 14 weeks for inputs to become compost.

Examples of “input” include manure and bedding from the dairy, beef center, cattle-feeding lab and veterinary college; coal ash from the power plant; food from the dining halls and waste vegetation from the greenhouses.

“The compost is exposed to high temperatures which kill pathogens and weed seeds, so the compost comes out inert,” Caldwell said. “It has less bacterial activity than the dry shavings used for bedding at the dairy, so they use our material. It gives them fewer problems.”

The facility consists of four acres, and the machinery required is a straddle windrow turner and a ball-deck screen to maintain consistency of the final product.

Organics leader
WSU is the first university in the nation to do organic composting on a full-scale campus level, Caldwell said.

“Other universities have been doing a lot of research, but we’re the first to do the entire campus,” he commented. “It’s a wonderful way to convert a controversial issue into a beautiful product and put it back into the environment. We’re closing the loop.”

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