Beaver Lake Middle School Cafeteria Waste Audit By Chris Bruno, Resource Conservation Manager With help from John Dunn, Lane Helgeson And students Annika Kumar, Shen Zhao, Nicholas Montgomery, Khushi Shashidhar Chris conducted an audit of the Beaver Lake Middle School cafeteria on January 6, 2016, for commingled recycling, compost recycling, liquids, and trash. John and Lane collected all waste from both lunches and the students weighed the four categories at 27, 42, 30, and 75 lb respectively. Based on this sample Beaver Lake has a current cafeteria recycling rate of about 60%. Chris then sorted through the trash bags and found 5 lb of commingled material, 46 lb of compostable material, and 12 lb of liquids. Therefore, about 84% of the trash could have been recycled. All recycling bags were also checked for contamination. The commingled bags had a small amount of contamination but for the compost bags the amount was negligible. Thus from this sample size, Beaver Lake has a potential cafeteria recycling rate of about 90%, assuming all materials and liquids are placed in the proper receptacles.

Sample Size: 179 lb commingled recycling compost recycling trash 18 bags of solid waste from three stations covering both lunches. Liquids buckets were emptied right after lunch and hence are not included in this picture.

Solid Waste Current Composition by Weight With a small sample of just one day, the recycling rates should be estimated to one significant figure only. The left pie chart shows the data from simply weighing the trash/recycle bags, and the right one is a more in-depth look at what was found in the bags. Over half the trash by weight could have been composted. The liquids buckets are well utilized, and there is very little contamination for both recycling categories.

Solid Waste Potential Composition by Weight The best opportunity for improvement comes from diverting compost out of the trash. This audit found about half of all compostable material being discarded into trash bins.

Solid Waste Composition by Weight Category Weight (lb) Commingled recycling 27.4 Commingled recycling (found in trash bags) 4.6 Compost Recycling 41.8 Compost recycling (found in trash bags) 45.8 Liquids 30 Liquids (found in trash/recycle bags) 12.6 Actual trash 13.2 Total 179

Commingled Recycling All six bags of commingled recycling with contamination separated at the bottom of the picture. Mostly cans, water bottles, and milk cartons. Only a few paper bags and plastic containers are visible. Any type of rigid plastic is recyclable as long as it is (at least mostly) free of food contamination.

Commingled Recycling An alternate view of the “good” recyclable items. A plastic cap is recyclable if it is attached to the bottle.

Commingled Recycling Contamination This material weighed 4.2 lb, giving a contamination rate of about 15%. Most of that weight, however, came from a few fruits and sandwiches. Plastic film, foil wrappers, and plastic utensils must be discarded as garbage. Food, paper wrappers, and plates can go in the yellow compost bins.

Compost Recycling All six bags of compost recycling with contamination separated at the bottom of the picture. Most food was at least partially eaten but there were some untouched fruits and sandwiches.

Compost Recycling An alternate view of the “good” compostable items. Paper plates, boats, wrappers, and bags all can be composted. Food scraps, of course, are also acceptable.

Compost Recycling Contamination This material weighed 1.2 lb, giving a contamination rate of about 3%. Mostly half empty chip bags or plastic bags that were partially full of food. Styrofoam must always be discarded as trash.

Trash Bags Sorted commingled recycling in trash: 4.6 lb compost recycling in trash: 45.8 lb actual trash: 12 lb The trash bags were sorted to determine how much “actual” trash they contained.

Commingled Recycling in Trash: Close Examination All the bags were stuffed with empty bottles, leftover food, etc. Many milk cartons but few water bottles or cans.

Compost Recycling in Trash: Close Examination

Actual Trash: Close Examination Most chip bags, sandwich bags, and saran wrap. Only a few unopened yogurt containers and granola bars (not pictured).

extra pictures available on connect.issaquah.wednet.edu To find more pictures, a pdf report, and a PowerPoint slide show, go to Connect: Intranet Operations Department Resource Conservation Waste Audits