Green Compost Bin

Curbside Composting

Public Works

ALERT: Curbside compost collection has been suspended due to limitations on the number of passengers in DPW trucks to comply with social distancing. Drop-off compost is OPEN and has been expanded for those residents wishing to continue composting. We will resume normal collection services as soon as we are able to do so safely. 

We are asking that residents continue to place food scraps in the lockable GREEN BIN to protect against rodents. We will resume normal collection services as soon as we are able to do so safely

About Cambridge Curbside Composting 

Curbside compost pickup is a great way to reduce trash and turn food scraps into clean energy and fertilizer. In our first year of citywide compost, we composted 1800 tons of food scraps and reduced trash by 8% citywide.

Expansion to Larger Buildings (13+ units)

The City of Cambridge is currently planning to expand curbside composting beginning September 2019 to residential buildings with:

  • 13 or more units AND
  • City trash collection
If your building is eligible for this current expansion, please fill out this Curbside Compost Interest Form. We will follow up with you to schedule a site visit to help ensure a smooth rollout for residents, property managers and maintenance staff.

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 Bags?

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



Tips and FAQs

How does composting work?

Collect food scraps, napkins and paper towels in a kitchen bin lined with a compostable bag and place tied bags into the green curbside cart. Curbside carts go out onto the curb each week on the same day as trash and recycling by 7am the day of collection or after 6pm the night before.

What goes in the bin?

All food scraps including:

  • Fruits & Vegetables
  • Meat, Bones & Shells
  • Dairy
  • Bread & Grains


  • Tea Bags
  • Coffee Grounds & Filters
  • Napkins & Paper Towels
  • Cut Flowers

What should be kept out of bin?

What should be kept out of the bin?

  • Pet waste
  • Diapers (even if they are ‘compostable’)
  • Yard Waste
  • Plastic Bags
  • Recycling
  • Trash

Are compostable plastics accepted? What about compostable paper?

Compostable plastics, other than compostable bags to line kitchen bins, are not accepted because they don’t breakdown well enough.

Compostable paper items, such as cups, bowls and plates are accepted if there’s a BPI-certified compostable logo. Many paper food service items may look compostable, but please check every item for the BPI-certified compostable logo.

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. 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. 

Should I be concerned about pests and odors?

Curbside carts have a locking or latching lid, which should always be kept locked or latched. They are made with thick plastic, which makes it a better pest deterrent than most trash barrels. Rinsing carts as needed and putting carts out on the curb for weekly collection (even if they are not full) should keep odors to a minimum.

My building already has a curbside cart. How do I start composting?

If you just need an indoor kitchen countertop bin, feel free to stop by DPW to get one. Inside the bin you will find 3 rolls of compost bags and instructions.

DPW is open Monday: 8:30am-8:00pm

Tuesday-Thursday: 8:30am-5:00pm

Friday: 8:30am-12 noon

My building does not have composting yet. When is it expanding to larger buildings?

Curbside compost pickup is expanding to buildings with 13 or more units and City trash collection starting September 2019 and continuing through April 2020. In future years, the service will expand to additional buildings. If your building is eligible for this current expansion, please fill out this Curbside Compost Interest Form.

To get you started, your building will receive one or more green curbside carts and a kitchen bin for each unit with compostable bags and simple instructions inside.

DPW is here to help you find the best system for your building, including figuring out the right number of carts and finding a place to store them, providing information for residents and maintenance staff, and working with you to schedule a date for materials delivery.

Can residents get finished compost back from the City?

Unfortunately, the City can no longer offer finished compost for gardens at the DPW Recycle Center. As an alternative, sign up for our monthly newsletter for updates on one-time giveaways of finished compost that the City may offer. Finished compost can be purchased from garden centers such as Pemberton Farmsand Bonny’s Garden Center or some hardware stores. 

I use an in-sink garbage disposer. Should I compost instead?

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 has private trash collection. How can I still compost?

I already compost in my yard.

That’s great! You may decide you want to use curbside composting as well, either to compost leftovers, eggshells, meat and dairy, or as backup in the winter. If your backyard compost bin does attract rodents, we suggest switching to the curbside compost program.

Why should I use compostable bags?

Compostable plastic bags keep kitchen bins and carts 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, or you may choose to line the curbside cart with a large compostable bag instead, but please avoid using regular plastic bags.

What do I do if my cart is missing or broken?

Fill out a form to request a new cart at CambridgeMA.Gov/RecycleSupplies

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. Leave the bin out for collection. 

Do you have any more tips for keeping things clean and pest-free?

Here are a few tips from Cambridge residents we would like to share:

Kitchen bin

  • Change out the bag every 3-4 days or when it starts to smell.
  • Rinse your kitchen bin with dish soap and let it dry out before using a new bag.
  • Put in paper towels, napkins and coffee grounds.
  • If your bag leaks, bring your whole kitchen bin down to the curbside cart to empty it.
  • In the summer, keep food scraps in the refrigerator or freezer until just before pickup, especially when you are away for a few days.
  • Wrap meat, fish and shellfish in newspaper or compostable paper.
  • Set a fruit fly trap by placing a container of cider vinegar and a bit of dish soap near your kitchen bin.

Curbside cart

  • After collection, dump remaining liquid in the curbside cart onto the grass, rinse it out, and leave it in the sun to dry out.

Page was posted on 1/30/2018 9:57 AM
Page was last modified on 1/29/2021 4:19 PM
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