Inside the plan for a massive WA insulation plant to spin molten rock like cotton candy

A proposed manufacturing plant southeast of the Tri-Cities will make building insulation by crushing stone, melting it and spinning the lava-like material in an industrial-strength cotton candy maker.

Roxul USA Inc., aka Rockwool, plans to build a 2.7 million-square-foot plant at Wallula Gap Business Park, near Wallula Junction.

It’s buying 250 acres about 10 miles from Pasco from the Port of Walla Walla for $8.75 million.

In March, the company announced it would build ts fifth North American manufacturing facility in Eastern Washington to serve as a launch pad for its West Coast expansion. The others are in Canada and the U.S.

The first of three phases is a $175 million plant with 125 employees and an annual payroll of $8.5 million.

When all phases are complete, Rockwool will boast one of the larger manufacturing and warehouse facilities in the state. The Boeing Co.’s 4.3 million-square-foot airplane plant in Everett is the largest.

Rockwool’s 2.7 million square feet will be big enough to contain both warehouses Amazon recently built in east Pasco plus enough room left over for Sageview High School, the new school being built in north Pasco.

The company is a $4 billion manufacturer with a U.S. base in Kearneyville, W.Va. It is an arm of Rockwool Group, based in Denmark.

The proposed plant is a significant win for western Walla Walla County both for jobs and for its ability to recruit a manufacturer to the region.

More than two dozen documents totaling more than 2,240 pages released under the Washington State Environmental Policy Act in July offer a clearer picture of the plan beyond the details announced in the spring.

Rock insulation

Rockwool is being celebrated as an important addition to the green economy. Rock-based insulation fire- and water-resistant, sound proof and durable.

At the end of its 65+ year lifespan, the old insulation can be reused to produce new with no loss of value.

Stone-based insulation offsets 100 times the carbon released during the manufacturing process, Rockwool claims.

A nine-minute video tour of Rockwool’s Ranson, W.Va. plant with YouTube personality Matt Risinger shows how the company transforms crushed rock into the woolly insulation contractors embed in walls, attics, under floors and anywhere insulation is needed in commercial and residential structures.

It sells its products of varying insulation values under the Rockwool name.

It all starts with the same recipe: Gravel, high heat, spinning molten material in a giant candy cotton machine.

Rockwool plants receive truckloads of gravel from area quarries.

It screens the material and magnets remove metal debris. It is crushed to a consistent size.

A giant melter heats the material to a lava-like consistency. Industrial spinners fling the molten material into a web of thin strands. If the process is shut down for some reason, the molten material flows into a waste chamber, where it cools into glassy bits and is returned to the start of the process and reused.

Layers upon layers of glassy material form into thick batts. High-pressure water jets cut them them into commercial sizes.

The insulation is packaged and stacked on pallets before being shipped on to distributors.

U.S. Bank Stadium in Minneapolis, the Empire State Building in New York and Climate Pledge Arena in Seattle all incorporate Rockwool insulation, according to the company.

Heavy industry, heavy development

The Rockwool plans for Wallula Gap involved intense development, according to the SEPA documents, which identify the plant by its code name, “Project Sequoia.”

The extensive review is part of the process leading up to project approval. The plant is expected to begin operations in either 2027 or 2028, according to differing reports.

The Rockwool documents detail the expected traffic impacts, hazardous air emissions, power requirements and even the steps it will take to protect sensitive archaeology from excavators.

While it produces a sustainable product, Rockwool’s impact on traffic will be significant, though it’s not clear exactly how significant.

WSP USA, a Portland engineering firm, completed a 435-page analysis that said Rockwool would contribute 2,900 daily vehicle trips in the first phase, growing to nearly 7,700 by the time the second and third phases are complete in 20 years.

Port and state officials say the numbers are incorrect and are being revised.

Patrick Reay, the port’s executive director, said the port is working with the developer and the state Department of Transportation on revisions.

Meagan Lott, spokeswoman for WashDOT, confirmed the state views the 7,700 figure as inaccurate.

Regardless of the final number, Rockwool will be served by Highway 12, a road the state has spent the past 20-plus years working to expand from two lanes to four from Burbank, at the confluence of the Snake and Columbia rivers, all the way to Walla Walla. The Walla Walla side is largely complete, but the western section is still mostly confined to two lanes.

The eight phase of the “four laning” effort will cover 10 miles between the Wallula Gap industrial area and Nine Mile Hill to the east . The Burbank-to-Wallula Gap stretch comes after that.

Lott said the state is working with the port and Rockwool to ensure plant construction doesn’t affect work in the eighth phase, which is which is supposed to start in 2027.

She added that additional traffic along the four-lane section won’t create congestion, but officials are focused on the intersections that cross the highway.

Phased approach

If the project is approved as expected, Phase 1 would begin next year with grading of 112 acres. Physical construction would begin in fall 2025, with the plant beginning operations in 2027 according to one checklist or 2028 according the traffic study.

Phase 2 would begin in 2033 and would follow a similar path, with construction lasting about two years. Phase three would begin in 2041.

The project has one wild card: A possible rail line. If built, it will be constructed from 2032-34 and would allow raw materials — gravel— to arrive by train.

At maximum capacity, Rockwool could operate 24 hours a day, seven days a week and consume 168,000 tons of raw materials per year for each of the three anticipated phases.

Sourcing energy

Rockwool will power the plant with both electricity and natural gas.

The company has an agreement with Pacific Power to provide approximately 221,000 megawatt hours of electricity per year, enough to power a smallish city.

Paul Espinosa, spokesman, said its power supply will be 80% renewable by 2030 and 100% so by 2040, as required under Washington’s Clean Energy Act. Portland-based Pacific Power serves customers across the Northwest and generates electricity with a mix of coal, wind, dam, solar and natural gas.

Cascade Natural Gas will supply its gas needs.

Rockwool will use energy efficient equipment such as LED lights and motion sensors where feasible, he added.

Recruiting manufacturers

The Washington state Department of Commerce supported creation of the Wallula Gap Business Park last year when it named it one of six sites to split a $2.5 million grant to attract and expand manufacturing.

Rockwool is one of two manufacturers considering locating facilities there.

The second is SkyNRG, a Seattle aviation fuel company , which aims to build a produce sustainable fuel on a 130 acre site starting in 2029. It would employ 100.

Current neighbors include Packaging Corporation of America, Tyson Fresh Meats and Tri-Cities Intermodal.

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