Composting Information

Compost Material Drop-off Site

Resident Weekday Drop-off, 7:30 a.m. - 3:30 p.m.

Where: Thornton’s IMC 12450 Washington Street. Please call 720-977-6200 ahead of your arrival for instructions or head to the north gate entrance with access from 126th Avenue, east of Washington Street. Once at the gate, press the button for access into the yard and let the operator know you are there to drop off compost material. Be prepared to open all bags on site.   Only 3-gallon compostable kitchen bags are accepted. NO paper sacks or other compostable bags are allowed. No commercial or landscaping businesses.

Composting FAQs 

Acceptable materials to be placed in the compost bin

  • Food scraps such as produce, eggshells, bread

  • Coffee grounds

  • Small yard and plant trimmings such as twigs or flowers

  • Grass clippings

  • Leaves

  • 3 gallon, compostable kitchen bags

Which items are NO LONGER ACCEPTED in the compost bin

  • Paper products, including tissues, paper towels, napkins, tissue paper, brightly colored paper, paper scraps and shredded paper, tea bags, and coffee filters (please dump coffee grounds into the compost bin and trash the filter).

  • Food-soiled or greasy pizza boxes (please compost leftover crusts, throw away the greasy half of the box, and recycle the clean half).

  • All compostable packaging and products, even certified compostable ones, including cups, utensils, plates, and takeout containers.

  • Compostable bags larger than a 3-gallon size.

  • Paper yard bags.

Why aren’t these and other “certified compostable” items accepted anymore?

  • A1 Organics, which operates THE ONLY permitted large-scale compost manufacturing facility serving the Front Range community, has changed the materials they will accept for composting. Due to the high contamination levels in the compostables stream, they cannot sell their finished compost product made from community collection programs and are calling for a cleaner stream of organics.

  • For every certified compostable product (such as cutlery, tableware, cups, straws, and compostable bags) you might come across, there are several more “look-alikes” that mislead customers into thinking these items are compostable (using terms like “biodegradable,” or “plant-based”) when in truth they often contain non-compostable plastics.

  • Unfortunately, the volume of contamination A1 receives due to misleading labeling makes any packaging or service ware item too costly to accept because of the challenge of distinguishing and sorting certified compostables from “look-alike” products that are not compostable.

  • The same is true for paper. Many papers, like coffee cups and many “to go” paper containers, are coated in plastic, leaving microplastics in the compost.

  • Compostable bags often contain and conceal non-compostable contamination.

  • To simplify the stream and ensure there is NO contamination, A1 Organics does not want any packaging, service ware, or paper of ANY kind.

Sign for Compost Drop-off at the IMC