Making Earth

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Back in January we told you about a remarkable deal offered by the City of Lakewood using the facilities of a company called Compost Colorado. The suggestion, you might recall, was to “Do the ROT thing.” ¹ Compost Colorado deals with the stuff we don’t like to smell. Food scraps. Household waste. Garbage. They use it to make soil. Dirt. Humus. Earth!

A group of us in Sustainable Southern Gables visited the Compost Colorado processing center in Denver this week, to see how they do it. We met with Executive Director Noah Kaplan and “Microbe Manager” Alex Thompson. 

First, a little review. A big reason for doing this at all is to reduce what goes into landfill. As we learned in January, in case you missed it…

The conditions of a landfill are not natural; without oxygen methane is released, harming the atmosphere. In a proper composting environment, the decomposition process enriches soil and sequesters carbon. Instead of making a problem worse, the right action (The ROT action) makes it better. According to Kaplan, “The material cooks itself with biology.” Temperatures in the pile at the heart of the composting process reach up to 180°. That breaks down toxic materials, allowing microbes to thrive and reproduce, happily eating up bad stuff, raising their microbe families and engaging in microbial society, living happy lives making ugly stuff neat and clean. The healthy conditions they make for themselves transfer easily back to gardens and lawns; with good use of compost and mulch you can water your garden or yard half as often, and all trees and plants love the stuff.

Executive Director of Compost Colorado, Noah Kaplan

With collection points all over the city, and pickup service as well for those who prefer that, Compost Colorado is handling a huge volume and making a big impact in a small facility, starting with their location in the Globeville-Elyria-Swansea neighborhood. Noah pointed out that surrounding the grounds where we stood there are three refineries, four meat processing plants, two tire manufacturers, the Purina pet food factory, rail yards and trucking depots, and a giant new data center. It is one of the most heavily polluted areas in the United States. True to its roots as a local force, Compost Colorado is leveraging its resources to clean up its own neighborhood by fostering increased gardening and plant culture right there in the GES community. Making life easier for plants – the green kind, not the brick & mortar kind – is at the heart of the compost business. It’s introducing biology back into soils that have been depleted. The other goal, as we all know, is more wide-ranging: reducing the load on landfills. Landfills make more pollution than the entire aviation industry.

The bins of collected food scraps. Raw materials for the onsite process.

We gathered at the bins containing the freshly-collected raw material, and got our bearings. There were flies. Noah and Al had hoped to show us some of the lizards that come to feast on the flies but apparently they were taking the day off. The fact that they are often seen there was a surprising improvement to the local ecology; lizards aren’t common in the area. Still, they found their way there and are thriving on the Compost Colorado grounds. As the lizard population grew, so did the numbers of birds. Not a bad improvement to the urban ecosystem.

Noah pointed out the arrangement of the bins, adjacent to several piles of wood mulch, and told us that both of those resources – organic matter and cellulose – get combined in the two 40-yard converted cargo containers where the process begins with “Stage 1” to make the product. They use a bin tipper and a skip loader to put the ingredients in the front end. Over a period of 7 to 10 days, a giant auger works the material as it is drawn back and forth by a sturdy chain drive. That’s where Al Thompson runs the process. Asked about the ratio in the mix, he said “We don’t do decimals” and that it is as much an art as a science. Experience counts.  Al monitors and controls the moisture content, rate of mixing, and aeration so as to make a pleasant environment for the microbes that are doing the work. At the other end of the container a product that comes out looks pretty much like compost, but it’s just getting started.

Don’t worry, it’s compostable and will get digested in the next 2 months. Just don’t use real plastic!

At this point Noah showed us some of the anomalies they deal with, such as compostable garbage bags, cups, and other single-use items such as straws. These items certified as “compostable” are made from carbon polymers instead of petrochemicals, and at this early stage we could see them still in the mix. We saw some shreds of compostable bags, and a food cup that looked like clear plastic, partially melted from the heat in the mix but not yet broken down. Noah said they will break down by the end of the final stage, so not to worry. They are way better than the plastics that are so harmful to the environment. 

Noah expressed the hope that we’re on our way to transitioning away from single-use items entirely, not just by replacing them with compostable throwaways. Using durable goods such as reusable bags is even better than these compostables, as he said, “We still have to use resources and facilities to manufacture them, and people use them for three minutes and then throw them away. We’ve got to use corn and soy to make this stuff out of and even then you need to transport it and then we need to process it.” He said that it’s not ideally sustainable but certainly better than plastic containers, cups, utensils and straws. “We want to move as quickly as we can, but this is an important middle step as we transition away from the most wasteful processes.”

At the end of Stage 1 the material is moved into a series of piles where the microbes really get to work. At the pile most recently out of Stage 1 we saw a temperature gauge showing 130°. Noah said it will get hotter and hotter. In this maturing stage, they pump air into the piles from the bottom to provide oxygen that is needed for the process, using the simple kind of air pumps like in kids’ bounce castles. They have three bays with these “aerated static piles” and one bay for mixing. This stage is about 2 1/2 months. It gets hot enough, Al said,  that the crew actually cooked filets in the middle of the pile in one of the parties that they had. Heat can be harvested by the use of water pipes to keep buildings warm. 

The tarps are for retaining moisture. We could see steam rising through some little gaps.

A big part of what Al does is managing thermometers. “That’s the biggest measuring tool that we use and it for sure tells us more than any other instrument.” The process, called PFRP for “process to further reduce pathogens” has specific time and temperature standards to destroy harmful bacteria, viruses, parasites, and weed seeds. Sometimes the pile can cool down when digestion process has slowed and all the easy stuff has been processed so now there’s more plant available so the oven turns itself off. Noah explained, “When the temperature goes down, you know you have less biological activity and there’s a couple reasons why that might be happening. Either they’re running out of food, which means that the process is kind of reaching completion or there’s something not quite right with the process such as not having enough water for the microbes. We may have too much nitrogen and not enough carbon. Or it’s too dense so the air isn’t making its way through.”

Al with screening machine. Separating the fine material from oversize pieces (“fines and overs”) for different markets

Our last stop was to another part of the yard where final screening is done and the finished product is stored for transport or pickup. A large sifting machine separates the fine mixture that home gardeners prefer – almost like potting soil – from the coarser pieces that go for application in larger places such as around trees and in parks. 

Noah and Al showed obvious pride in what they are doing. “Zero waste” has become a catch-phrase that is claimed more than it is earned, but at the facility we saw, it is really so. The process at Compost Colorado is truly a circular economy with, as Noah Kaplan told us, “absolutely zero waste. There’s not a product that comes out that’s not used.” 

Lakewood is offering a great deal. Five dollars a month for drop-off service. It normally costs $19 a month but Lakewood made a volume deal for $10 And THEN, committed to pay half of that with money collected from the ten-cent bag fees. All of the information you need, including how to sign up and get started, is here: Lakewood Food Scrap Drop Off Program. 

If you want to dig deeper (groan!) before committing $5 to Lakewood’s deal, here is the company’s website: Compost Colorado.

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