5/23/2019 4:36 p.m. Expect significant traffic impacts in Harvard Square area due to Boston Calling music festival May 24-26, at Harvard’s Athletic Complex, 65 N. Harvard St., Allston. Many attendees will be taking Red Line to Harvard Square Station and walking to event. Please contact event organizers via the Community Hotline at 617-903-0157 or email with questions or concerns. More details »

Green Compost Bin

Curbside Composting

Public Works

In 2008, the City set a goal to reduce residential trash disposal by 30% by 2020, and by 80% by 2050. A key strategy to Cambridge's waste reduction goals, curbside compost collection began citywide in April 2018. To date, there's been an 8% reduction in the City's trash tonnage. 

Currently, only 1-12 unit buildings with City trash collection are eligible for the curbside compost program.

Why is the City doing this?  Removing food scraps reduces trash in landfills. By diverting our food scraps, we are helping protect the environment by:

  • Reducing our impact on climate change. Our food scraps become clean energy through anaerobic digestion.
  • Returning nutrients to the Earth in the form of fertilizer.

Need more compost bags? The City is offering a free roll of compost bags per household, while supplies last, at the following locations during regular business hours. 

  • City Hall 795 Massachusetts Avenue
  • City Hall Annex 344 Broadway
  • Cambridge Public Library 449 Broadway
  • DPW 147 Hampshire Street
  • Boudreau Branch Library 245 Concord Ave
  • Central Square Branch Library 45 Pearl Street
  • Collins Branch Library 64 Aberdeen Ave
  • O'Connell Branch Library 48 Sixth Street
  • O'Neill Branch Library 70 Rindge Ave

For a complete list of local stores selling compost bags, click here


Tips and FAQs

What if my curbside compost bin is missed on collection day?

It's the same protocol for if your trash or recycling is missed. 

Report a missed curbside compost pickup at CambridgeMA.Gov/311 between 4pm on collection day and 9am the day after your collection. 

How can I get more compostable bags?

Your kitchen kit includes a 6-month supply of EcoSafe 6400 compostable bags. Click here for Cambridge stores selling compost bags. You may also purchase more bags online. Bags should be 2.5-3 gallons in size and BPI-certified.

Why aren’t compostable plastics and paper containers accepted?

Compostable plastics, other than compostable bags to line kitchen bins, are not accepted because they don’t breakdown well enough. 
Paper food containers are not accepted because it is hard to tell whether the container is compostable or not since many paper containers have a plastic coating. In order to avoid confusion, and possible contamination, we ask residents to keep them out of the City’s curbside compost program. 

After DPW picks up the food scraps and compostables, where does it go?

DPW brings food scraps and other compostables to a facility in Charlestown where it is screened to remove contaminants and blended into a slurry that has a consistency similar to cooked oatmeal. The slurry then goes into an anaerobic digestion tank that uses microbes to eat the organic material, releasing methane. The methane is captured to make clean energy in the form of heat and electricity. Remaining solids are made into a nutrient-rich fertilizer. For a more detailed account on this process, please check out where do food scraps from Cambridge go for organics recycling. 

What are some tips for the Curbside Compost program?

To keep bins clean: Use compostable bags and drain liquids. Wash compost carts with warm water and dish soap. Drain soapy water from your compost cart onto grass or soil -- not on the sidewalk, driveway, or into storm drains. Never pour fats, oils or grease down the drain.

To keep odors down: Wrap meat, fish and shellfish in paper. Set the cart out on the curb every week -- even if it is not full. In the summer, keep food scraps in the refrigerator or freezer until just before pickup. Sprinkle baking soda on the bottom of your bins.

To manage fruit flies: Add food-soiled napkins or paper towels to food scraps. Store your kitchen bin in the refrigerator or freezer. Set a fruit fly trap by placing a container of cider vinegar and a bit of dish soap near your kitchen bin. 

How can I participate?

Eligible Cambridge residents will receive a kitchen compost bin and a lockable curbside bin.
  • Collect compostable items in the kitchen compost bin and empty into the curbside bin.
  • Put curbside bin out on your regular trash/recycling day.

Who is eligible to participate?

Cambridge residents with city trash/recycling pickup in buildings with up to 12 units.

If you’re not eligible, simply bring your food scraps to:
  • Cambridge Community Center 5 Callender St. (Howard St. side)
  • Danehy Park New St. Parking Lot
  • Recycling Center 147 Hampshire St. (Tues/Thurs 4-7:30pm, Sat 9am-4pm)

Is composting mandatory?

Composting is voluntary, but we hope everyone will participate. Start with something simple, like apple cores and banana peels, and put them in your kitchen bin instead of the trash.

When is my curbside compost picked up?

Just as you do with your trash, recycling, and yard waste, place your curbside compost cart on the curb weekly by 7am the day of collection or after 6pm the night before on your regular collection day.

Can residents get finished compost back from the City?

Yes! Finished compost is available to Cambridge residents mid-April through mid-October on Tuesday's and Thursday's 4pm-7:30pm & Saturday's 9am-4pm at the DPW Recycling Center, 147 Hampshire Street.  Residents are allowed 10 gallons per season. Bring your own bucket or receptacle to fill. The Finished Compost is from Rocky Hill Farm in Saugus, an aerobic composting site.

I use an in-sink garbage disposer. Should I discontinue that?

Yes, to reduce the risk of costly sewer backups, we strongly recommend using the curbside compost program rather than using in-sink disposals. 

My building isn't eligible. How can I still compost?

Cambridge residents may still compost by:

Also, 13+ unit buildings with City trash collection will eligible for the curbside compost program in the next 1-2 years. Stay tuned!

I already compost in my backyard. Should I discontinue that?

Not necessarily. Feel free to continue composting in your yard. Residents may use the curbside compost program to compost whatever you can’t put in your backyard compost. You may also use curbside composting as backup in the winter. Also, if your backyard compost bin is attracting rodents, we suggest switching to the curbside compost program. 

Why should residents use compostable bags?

Compostable plastic bags keep bins clean and keep odors to a minimum. They also make it easier to bring food scraps from your kitchen out to your compost cart on your way out. You may line your kitchen bin with paper bags instead, but please no regular plastic bags; they aren't accepted.

I live in a building with more than 12 units, will my building be eligible to participate eventually?

We hope to expand curbside compost collection to 13+ unit-buildings with City trash collection in the near future.

Will composting smell in my home?

If you use compostable bags and keep liquids out, you should be able to keep bins nearly odor free. Bring food scraps out to the curbside compost bin every 3-4 days to minimize odors.

Will the curbside compost bin attract rodents?

The curbside compost bins are more secure than trash bins for disposal. By moving your food from your trash bin into thicker-walled carts equipped with rodent-proof latching lids, you should be able to reduce rodent activity. To keep critters out, keep your curbside compost bin locked at all times. 

Do you have suggestions for managing fruit flies?

During the warm months, place a small glass filled with apple cider vinegar on the kitchen counter and add a drop or two of liquid dish soap. Fruit flies are attracted to the vinegar and the soap traps them in the liquid. Some folks advise covering the glass with plastic and poking holes in it, creating a trap.

Are any other cities doing this?

Composting has deep roots in Cambridge. Many Cambridge residents remember placing food scraps in in-ground buckets which were then collected to feed to pigs. The City has assisted with backyard composting, offered worm composting workshops, and helped businesses set up composting operations. In addition to piloting curbside collection, Cambridge now composts in every school, and also maintains 3 food scrap drop-off locations.

Residents in cities like San Francisco and New York City have been composting at the curb for years. Massachusetts is home to many pilot curbside compost collection programs. As the first municipality in the state to offer citywide collection free of charge, Cambridge is leading the way in waste reduction. 

Page was posted on 1/30/2018 9:57 AM
Page was last modified on 5/21/2019 12:35 PM
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