Skip to main content Skip to navigation

Could Lewis County Be Home to the PNW’s First Commercial Poplar Biorefinery?

Noelle Hart | October 2018

AHB’s biorefinery siting models identify southwest Washington as a good location for a poplar-based bioproducts industry. But do the locals agree?

The AHB Extension Team set out to learn from stakeholders in Lewis County and surrounding counties to find out whether people involved with local agriculture and natural resources felt it was reasonable to expect enough land could be converted to poplar to support a biorefinery. We also wanted to know whether there were opportunities and challenges for poplar as an environmental services provider. In the region, one wastewater treatment facility already utilizes poplar, and poplar may be an appropriate crop in the region’s flood-prone agriculture lands.

Map of SW WA and Lewis County
Southwest Washington study region (orange circle), which is the area within 100 km of Centralia (star) in Lewis County (red).


We heard from roughly 33 stakeholders through 16 interviews and two group discussions. Stakeholders came from environmental consultant agencies, a county conservation district, WSU Extension, farming operations, non-profit conservation/landowner organizations, WA Department of Ecology, economic/land development interests, and wastewater treatment plants.

In complement to this stakeholder research project, Amira Chowyuk, a graduate student at the University of Washington, and Dr. Rick Gustafson are exploring the techno-economic feasibility of co-locating a biorefinery with the TransAlta Power Plant in Centralia, Lewis County, WA, that could be supplied by poplar grown within 100 km (62 mi) of the site.

TransAlta Power Plant
TransAlta Power Plant in Centralia, WA with Mount Rainier in the distance.

Co-locating a poplar biorefinery with a power plant would save costs by utilizing the plant’s excess boiler capacity or low pressure steam. The TransAlta Power Plant in Centralia could be a good location. The plant is the only coal-fired power plant in WA and has agreed to stop using coal by 2025. The techno-economic assessment model assumes that the plant will operate natural gas fired boilers.


Stakeholders’ Perspectives – Poplar and Agriculture

The first reaction we heard during our two group discussions was – we’ve done poplar before for the pulp and paper industry, and it didn’t work out:

“This isn’t news. [Poplar] was tried … and it didn’t prove profitable for the people, and now it’s back in farmland … What makes it viable now?”

Participants were concerned about where the initial investment in the new poplar bioeconomy would come from, given the substantial costs of building a biorefinery, acquiring harvest equipment, and establishing many poplar plantations. We agree that this is a major barrier and suggest that a developing industry may require grower contracts with a biorefinery, a growers’ cooperative, and government incentives.

Another consideration is the risk of wildlife damage. As one person put it, “Cottonwood is candy to deer, elk, and beavers.” Participants observed that, while fences are an option, they are expensive and may not work in areas that are frequently flooded. Without protection from wildlife, the damage can be extensive: “[The elk and deer] ate 30,000 [poplar] trees of 60,000 in the first year.” It is worth investigating whether densely-planted “poplar for biomass” plantations would experience the same level of damage and developing mitigation strategies (e.g. less tasty poplar varieties, flood-proof exclosures).

If a poplar market was established and wildlife damage risks addressed, poplar could present a real opportunity for the region. Participants shared with us that agriculture in Lewis and surrounding counties is struggling. In the past, families could support themselves on a farming lifestyle, but a loss of infrastructure among other struggles makes that hard to do today:

“That’s the funny thing about farmers:  farmers like to farm. If they can find a way to make a living, they’ll do it. I’d rather be farming than anything else, but I finally got out of it ‘cause it just wasn’t paying the bills.”

Profit is the bottom line, but, given a convincing business model, participants did not think it would be difficult to find suitable land and secure willing poplar growers.

A field of grass under a blue sky with green forestland in the background.
Agriculture and pasture land in Lewis and surrounding counties could one day be poplar farms, if a biorefinery created a market for poplar.

Poplar and Wastewater

Currently, the Chehalis Regional Water Reclamation Facility irrigates a 176-acre poplar tree plantation with reclaimed water during times when the Chehalis River has low-flow, typically April through November. Perhaps poplar farms could be an effective tool for other treatment plants in the region.

Left - A group of people listening to a presenter outside. Right - A group of people standing in a poplar plantation,
AHB co-hosted a field tour at the Chehalis Regional Water Reclamation Facility’s Poplar Tree Plantation on June 19, 2018. The tour brought together stakeholders and AHB researchers to learn about the plantation and discuss the potential of poplar-based industry centered in Lewis County. 

The idea of linking poplar to wastewater treatment appealed to people. In addition to using poplar to evaporate re-use water, participants saw potential biosolids benefits:

The stigma from the general public is they don’t want [biosolids] to go on crops because ‘I don’t want to be eating stuff that has touched that.’ Whereas with trees, nobody cares and there’s a good situation there.”

Farming equipment spraying liquid biosolids directly onto a poplar tree.
Some wastewater treatment plants elsewhere in the Pacific Northwest, like Eugene/Springfield, OR, are already applying biosolids to poplar plantations.

From a technical perspective, wastewater professionals need to know if poplar harvested on 3-year cycles can soak up enough water to meet the treatment plant’s needs. They also pointed out that the permitting process for irrigating the poplar tree plantations can be more burdensome than discharging to the river. Therefore, at this point, it is unlikely that treatment plants will use poplar unless they are restricted from discharging to rivers. Poplar farming could be an economical alternative, as it was for the City of Chehalis:

“It was either remove all of our water during the summertime from the Chehalis River, some point well north of Centralia, which would have cost way too much money, so the poplar tree plantation was the cheapest and the most beneficial option that we chose and it’s still a good decision today.”

In the future, there may be more incentives to use poplar, if a biomass market emerges or regulations become stricter about treating personal care products and similar contaminants.

Poplar and the Floodplain

Flooding is a serious problem in the Chehalis River Basin, which suffered its five largest floods in recorded history in the past 30 years. Flooding destroys businesses, damages homes, and forces closures of I-5. The Chehalis River Basin is also habitat for critical aquatic species like salmon. Poplar may be able to mitigate flood damage by providing an appropriate crop for flood-prone areas and by altering the flow of floodwaters.

Floodwaters cover the landscape around I-5 near the city of Chehalis.
The devastating 2007 Chehalis River flood crossed over I-5, the interstate connecting Seattle and Portland. Photo credit: Washington State Department of Transportation.

Participants worried about non-native species (like hybrid poplar) being planted adjacent to rivers and streams (i.e., riparian areas) but embraced the idea of poplar farming in the wet bottomlands that make for challenging agricultural conditions:

“There’s a difference between riparian and floodplain, especially in the lower stretch of the river. I wouldn’t market [hybrid poplar] so much as for a direct buffer river habitat benefit, but if you’re talking about ‘hey, here’s a crop of value’…It’s not like peas or wheat are sitting in there because of the environment it’s in.” 

One participant also saw potential for poplars to be a part of larger floodplain restoration efforts to reconnect the river and the landscape, while balancing the needs of private landowners:

“It seemed to me that this would be something that we could couple with restoring the floodplain forest and then in areas that are now used for pasture, we could use poplar plantations. We could, say, put a poplar plantation on someone’s farmland in area where water’s going to be coming out of the river channel and that would effectively slow it down.”

A narrow stream with grass on both banks and tall trees in the background.
Even relatively benign-looking creeks (like Lincoln Creek pictured here in June) can cause fields to go under inches of water during the wet parts of the year.


Overall, if initial economic barriers came be overcome, participants saw chances for win-win situations where landowners could profit on otherwise low-value agriculture/pasture land and achieve ecosystem services for wastewater or floodplain management. Next steps could include establishing local experimental poplar plantations, developing a detailed business prospectus, and exploring feasibility with a greater number and broader diversity of stakeholders.