Tuesday, December 13, 2016

Hamline University Waste Audit: Our Findings

CGEE Student Voice
Campus Sustainability
by Jenni Abere

previously posted some initial observations from the three-day waste audit we conducted in Hamline's student center, the Anderson Center. Now that the numbers have been processed, I can back up some of these observations with data.

As we prepare to start organics composting on campus, the biggest finding is that compostable waste constituted a larger percentage of waste by weight than trash or recycling -- combined. Yes, that's right, compostable waste was over 50% of the waste in a building that already diverts the majority of its food waste (through a hog farm). This is a surprising finding, and proves that we need to introduce composting on campus as soon as possible.

The total weight for each category from Friday, Saturday, and Sunday combined:
Compostable: 180.06 lbs
Recycling: 57.41 lbs
Trash: 84.9 lbs
Liquid: 15.9 lbs

I wrote about why we want to avoid throwing away liquids in my first blog post. But liquids can be considered part of the compostable category.

The recycling rate may seem low, but let's remember that this is just what was in the trash. We did not sort recycling. In 2015, Hamline recycled 15% of its waste. 15% is an abysmally low recycling rate, and now we know that part of the reason for that is because so much recycling is being thrown away.

Throwing Money Away 

We pay for everything that we throw away. In Ramsey County, there is a County Environmental Charge, which is essentially a landfill tax. $65/ton. That doesn't seem too steep, but for a large institution like Hamline it adds up. In 2015, we paid over $18,000 in this tax.

With these numbers from the audit, how much could we save if we composted and recycled everything we could? Let's wildly extropolate some data, shall we?

Our baseline 2015 numbers have shown that Anderson produced 66.92 tons of trash in a year, accounting for $4,349.80 in charges. The proportion we found in the waste audit should be consistent enough to apply to a year's worth of data.

If we only threw away what cannot be composted or recycled, we would throw away 16.73 tons of waste in a year. This would cost us $1,087.45 in charges, so the savings could be as high as $3,200 per year.

What's the real proportion of waste?

The finding that 25% of Anderson waste is landfill-bound is actual an underestimate, since we're not accounting for recycling that ended up in the recycling bins. Using campus-wide numbers that we recycle 15% of our waste, we'll assume that if 66.92 tons of trash came from Anderson, 11.81 tons of recycling came from Anderson.

That 25% of waste drops to 21% when we factor in recycling. This lines up well with estimates that say 75% or more of all waste is recyclable or compostable.

Beyond Anderson 

The proportion of compostable waste may be a lot smaller in buildings that don't deal with as much food as Anderson does. However, we also assumed that Anderson's percentage of compostable waste would be much smaller. Once we introduce composting in the Anderson center, we should conduct waste audits of other buildings on campus to see where there is a need.

Klas is a good place to start since it has a Subway. All bathrooms on campus would benefit from compost bins for paper towels. The dorms and apartments might be good candidates for composting as well. 

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