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Recycled Crushed Glass


Crushed Glass is used for pipe and trench backfill,

used to backfill foundations and garages before pouring concrete,

used in replacement of sand or peagravel for construction applications.

Recycled crushed glass is a WADOT specification materials.





Two years ago The Olympian interviewed

John and Diana Specht,

the owners of Concrete Recyclers:


Recycling: Local company crushes for reuse - for now.   

By John Dodge


Business co-owners John and Diana Specht estimate they have about 8,000 tons of crushed glass on their hands, arriving at the rate of about 800 tons a month from solid-waste companies in Thurston County and surrounding counties that collect it separately from other recycled materials.


The Spechts crush the glass into a uniform size that’s waiting to be used as a substitute for sand and gravel in backfill and foundation construction projects.


But the economic recession, combined with a reluctance on the part of some engineers, contractors and government officials to use the material on private and public works projects, means the pile just keeps growing. 


The towering piles of crushed glass are symptomatic of a glass-recycling program that’s broken, solid-waste officials say.

“Glass is one of the only commodities that costs to collect and recycle without a decent return,” said Thurston County solid-waste education and outreach specialist Terri Thomas. “So since it is an added expense to collect separately, some jurisdictions have to seriously consider if they will collect it at all – if not in the commingled (recycled materials).”

When it’s commingled with other recycled materials, which happens in Olympia, it can break and contaminate paper that goes to mills for reuse. “It really eats up the mills’ equipment at a large expense,” Thomas said.

The 2009 state Department of Ecology solid-waste report estimated that 5 percent to 20 percent of the materials captured in a commingled recycling program are not recycled into new products. A July state Department of Ecology report on recycling in Southwest Washington called “Beyond the Curb” noted that glass is a contaminant in the commingled waste stream, and very little of it is going back to glass or insulation manufacturers for reuse.

The report recommended keeping glass separate from other recyclables. At the same time, Olympia city officials like the commingled recycling approach because it makes recycling easier and more readily used by city residents, city Public Works Director Michael Mucha said. “There’s a lot of big trade-offs with glass,” Mucha said. “And there’s no one right answer.” But simply separating glass is no guarantee of reuse of glass, noted Shannon McClelland of Ecology’s Waste 2 Resources Program. It has to be sorted again back into the different colors, which is next to impossible if the glass is broken.


Most recycled glass that makes it back to the regional manufacturers is recovered from Oregon and Canada, which have bottle bills, McClelland said. So for now, crushed recycled glass used as a substitute for sand and gravel is about the only recycling option around. Recycled glass is approved by the state Department of Transportation for nearly 20 construction uses, including backfill for drains, trenches, foundations and drainage layers.


“It’s absolutely a dream material to work with; it drains well and compacts wonderfully,” said Lorenz Schock of Schock Brothers, a South Sound excavation and utility construction firm. Since 2001, Schock Brothers has used it on a variety of projects, including 5,000 tons as a drainage layer on the South Puget Sound Community College soccer field and 1,500 tons at St. Michael’s Church in Olympia.  Once its crushed, there are no shards or sharp edges in the material, which sells at less than half the price of sand and gravel, said Diana Specht of Concrete Recyclers.  “It’s a very friendly product,” she said. “Project engineers just need to get comfortable with it as an acceptable substitute for sand and gravel.”

The growing glass pile at Concrete Recyclers also is a product of the downturn in the economy.  “When construction was booming, we couldn’t keep up with demand,” John Specht said. “We’re about to stop accepting it,” Diana Specht said. “And if it’s not coming here, it will end up at the dump.”

[An update to this story is that Concrete Recyclers is still accepting glass at a rate of about 800 tons per month and the amount being used is about 200 tons per month].




Glass Bottles before and after crushing

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