The City of Cambridge continues to collect compost, but is not separating it from the regular garbage, for worker safety during the coronavirus epidemic. It's still good to put your compost into the separate green bins, where it stays safe from rodents.
When Cambridge does collect material for "composting", it is processed, along with sewage, into fertilizer, by means of anaerobic digestion. The compost Cambridge provides for gardeners comes from a different source: a composting facility in Saugus, and I'm not sure where those raw materials come from.
However, there is one way to get garden compost from your own kitchen scraps in Cambridge: you can do it yourself! We have three worm bins in the basement, each made from two plastic bins. Dave drills holes in the bottom of one bin, and sits it inside the other one. There are a few inches between the bin bottoms; that is where "worm juice" accumulates; we harvest that liquid fertilizer periodically.
We use red wiggler worms; apparently regular earthworms are not ideal -- and we avoid letting the red wigglers get out into the larger ecosystem of our garden and chicken coop. You can get red wigglers from us. We compost vegetable waste, but not dairy, meat or oils. This is a good article about composting with worms. We use leaves collecting each autumn to mix with the kitchen waste, but after reading that article I think I might try composting some of our cardboard boxes as well.
Every so often Dave harvests the worm bins by opening up the bin and putting it under lights or outside on a sunny day. The worms burrow deep to avoid the light, allowing Dave to scrape off the worm-free layer of processed compost from the top. He'll harvest the worm juice at the same time.
At the end of each growing season, we pull all the vegetation from the growing containers and compost it in composting containers in the chicken run. We also compost the rich mixture of straw and chicken manure from the coop. Each bin sits for a year or so before we pull from it.
It feels great to compost all our plant-based kitchen scraps right in our house -- I hope you will try it too! If you'd like some red wrigglers, visit our store!