Walla Walla friends provide glass recycling update
December 26, 2019
Walla Walla’s struggle to retain its curbside recycling program has rightfully overshadowed our efforts to resuscitate glass recycling in our community. In many ways, this new struggle is repeating the one that resulted in the abandonment of glass recycling in 2012. In both cases, the problem is lack of cost-effective markets for the waste product.
While wholeheartedly supporting the efforts of the Sustainability Advisory Committee to retain the curbside recycling program, Ted and I and friend Philippe Michel are persisting in our glass recycling efforts. Because the demise of the glass recycling program hinged on the cost of transporting heavy glass hundreds of miles to reusers in large urban centers, we are focused on finding local ways to reuse our waste glass. With the help of Philippe, Ted and I bought our small glass crusher from a distributor in San Francisco, not because we saw it as a final solution but because we wanted to know exactly what kind of product we needed to find a home for.
In the crusher, a one-pound glass bottle is reduced in volume by 80 percent to one pound of crushed glass sand. The sand varies in color from white (clear glass) to shades of lime green (green glass) to light brown (brown glass, mostly beer bottles). With this small crusher, we have no choice about the grain size of the glass sand produced. (Large machines that can produce and sort varying sizes are in prototype.) Thanks to Chris Lueck and his contacts at WWU, we know that 0.02 percent of a random sample of our glass sand is large paper scraps from labels (+1/4” screen); 0.3 percent is above the size of normal quartz sand and is angular and sharp (+#4 screen); 71.7 percent is the size of quartz sand (+#60 screen); 12.9 percent is smaller than quartz sand (+#60 screen); and 15.1 percent is smaller still and might have been produced by the sifting process rather than the crusher itself. The sand is safe to handle because it is amorphous silica, not the crystalline silica that the glass was originally made from, and it does not cause the respiratory problems that can lead to silicosis. Having said that, you wouldn’t want to breath much of it, any more than you would want to breath a lot of woodfire smoke or farm dust.
Since September, we have conducted more than 20 demonstrations of the crusher to over 100 people. We have crushed about 1,000 bottles and jars and distributed many glass sand samples to officials, companies, and individuals. The crusher lives in an unheated garage, so demonstrations are on hold for the winter. However, our work continues, because this hiatus is a good time to catch up on much needed research. Some of the uses we are investigating are:
Soil amendment/replacement: I am testing glass sand as a hydroponic medium for seed sprouting. I also incorporated glass sand into one of our raised vegetable beds to increase soil friability and will amend berry beds in the spring. Does anyone else want to test the use of glass sand in a bed or two?
Greens management: While researching the effect of glass sand on worms, I found articles from greenskeepers who were testing glass sand on golf, lawn bowling, and cricket greens as a non-chemical way of controlling worm castings. Multiple applications showed no effect on worm casting levels and no degradation of the greens themselves. Philippe found a resort in California (The Ranch at Laguna Beach) that uses a crusher like ours to recycle all its waste glass in its golf course bunkers and pool filtration system, and to do pavement repairs (see Glassphalt below). Brad Rice offered to take a bucket of sand to the Country Club to share this information and explore potential uses there. Does anyone else want to help research this use further?
Viticulture: Other than one study from Lincoln University in New Zealand, no research in this area has been reported. Inquiries to WSU viticulture department have produced some suggestions but no interest in even modest studies. We naively expected grants to be available for plot trials into glass sand as a row mulch/weed control, as a deterrent to root eating critters, as a soil heat retainer, etc. Are there any adventurous vignerons in the Valley who are willing to run informal tests on a small block, especially if that block was left with unusable hanging fruit after October’s early frost?
Landscaping: A local hotel is testing glass sand in its new xeriscaped landscaping. At our house, Whitman students, who came to crush the glass they had accumulated in Environment House’s basement, created a large abstract design with glass sand on our Petanque terrain. Together with glass sand spread around an ornamental fountain, these touches brighten the yard while our plants hibernate for the winter. Would anyone else like to try sand painting a small area of their yard?
Foundation/additive for gravel driveways, parking areas, etc.: Valdemar Estates has ordered a crusher to produce glass sand for preparing an expansion parking lot. We would like to know whether glass sand is reflective enough at night to provide fog lines along the sides of gravel driveways, thereby increasing safety in dark or foggy conditions. Is anyone interested in experimenting for us?
Concrete additive: Philippe is talking with Koncrete Industries about the potential of mixing glass sand instead of or in combination with normal quartz sand in concrete. This conversation has been on hold during the construction season but will resume soon. We do not have the expertise to evaluate the engineering reports available about this use of glass sand, so we hope Koncrete will be able to help. In the meantime, Jodi Handley wants to experiment with glass sand in concrete planters she plans to build. Does anyone else have any small non-structural concrete projects that are test candidates?
Glassphalt: Using crushed glass as an asphalt additive works in major urban centers, principally New York. Realistically, Walla Walla can’t produce enough waste glass to make this use viable. However, a new use being tested in New Zealand involves tumbling glass sand and water with an “emulsion” product in a small concrete mixer to produce a slurry to fix potholes. The slurry can reportedly be driven across almost immediately and can be held in airtight buckets for up to a year. This product is worth checking out when it becomes available.
Anti-slip surfaces: New city council member Ted Kohler is interested in testing glass sand as a paint additive on steps in BMAC-managed properties. Fred Miller, Whitman College’s Environmental Health and Safety Manager, is interested in testing glass sand to prevent slipping on pathways around campus. We will test this use around our house this winter, but we don’t want anyone else to run tests until we have an idea of its effectiveness.
Sand blasting: A couple of companies elsewhere are using glass sand for sand blasting. Philippe has asked Key Technology for their opinion about this potential use and given them a bucket of glass sand for analysis. Is anyone in this line of business willing to test a sample?
Sandbags: Columbia County commissioner Check Amerien has taken a bucket of glass sand to his county engineer to assess possible use in sandbags for flood control. (Last year, two high-schoolers in Chelan used a GoFundMe account to raise the money to buy a crusher like ours, and current high schoolers are crushing wine bottles and filling sandbags for county use – go kids!) Patty Gardner and Jean Trenary offered to test sandbags on their property if we find an inexpensive source of bags. Any other offers or ideas?
Glass casting: One of our best attended demonstrations was for artists and art enthusiasts, with lively discussions about the potential of glass sand as an art medium. Unfortunately, although tests with fused glass and ceramic applications have shown some success, this use would consume only small amounts of glass sand. So, in response to a suggestion from Marilyn Hawkins, we bought a paperweight mold and plan to do test casts in our kiln. The idea is that cast glass objects could be sold as souvenirs in tasting rooms and home goods stores - “Made In Walla Walla From Recycled Walla Walla Wine Bottles!”. If tests are successful, we will approach new Port commissioner Kip Kelley, who has attended a crusher demonstration, about attracting a cast-glass manufacturer to Walla Walla to produce these items. We have already talked to Ron Williams of Visit Walla Walla about possibly incorporating such products into “The Walla Walla Story” that he presents to national and international travel organizations.
During our demonstrations, we had the opportunity to talk with a few people who were involved in past attempts to solve Walla Walla’s glass recycling problem. We know that we need to build on their hard work and knowledge, not ignore it or duplicate it. But things have changed in the past decade. Like recycling in general, glass recycling is every community’s problem, large and small, nationally and globally. And the ingenuity and technology to deal with the problem in our community is evolving faster than our team of three people can keep up with on our own. We invite those of you who are as concerned as we are to help us in any way you can.