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(415) 457-9760 Mill Valley Refuse Service 112 Front Street San Rafael, CA 94901

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Compost FAQs

You can download a PDF version of our general FAQs here.

How do I avoid unpleasant odors and/or food scraps sticking to the bottom of my cart?

Both of these problems are pretty easily resolved simply by mixing your food waste together with yard waste in your cart. A layer of yard waste at the bottom of the cart keeps food waste from sticking, and adding yard waste over food helps contain odors. During those times of the year when you don’t have yard waste, putting a layer of newspaper—or shredded documents—at the bottom of the cart, and bagging the food waste in a paper shopping bag will work. Keeping the lid closed at all times holds odors in, even if the interior smells between pickups.

Another tip from one of our customers: collect compostable leftovers and scraps in a paper bag in the freezer until collection day when you can toss the whole thing in your green compost bin. It will save you daily trips to the green cart and avoids rotting or spoiled food in the kitchen. It's a win/win! (Thank you for the suggestion, Ariana!)

And don’t forget—our weekly pickup schedule will ensure the timely removal of food waste before it gets a chance to become overly ripe!

Why are we not allowed to use Biobags to hold our food waste?

(The following answer was supplied by Daniel North, district manager of Redwood Landfill and Recycling Center, the facility where we take our green waste and food scraps to be composted.)

BioBags are indeed a highly respected brand of compostable litter and food waste bags. The ASTM D6400 standard requires that a compostable plastic biodegrade 60% in 6 months in a compost operation. BioBags may biodegrade more quickly and more fully than this, but it's not required under the standard. The problem with composting BioBags at our facility is three-fold:

  1. BioBags still decompose over a longer time line than green waste and food scraps. We have about 150 tons per day of inbound material to compost. The compost process takes only about four-and-a-half months. We need to ship finished (mature, stable) compost out to our customers as soon as we can to make room for new compost. Because most of the BioBag would not decompose before the finished compost is screened, the bag would be screened out and would end up in the landfill.
  2. BioBags are difficult to distinguish from petroleum plastic bags, and we pull out plastic whenever we can before we grind the yard waste/food waste.
  3. Most importantly, our compost is certified for organic use. Federal regulations governing the production of compost used on organic farms prohibits the composting of all synthetic material except for paper. The compostable plastics industry is currently working with the National Organics Standards Board to come up with a few formulations of compostable plastic that would be acceptable in compost used on organic farms. To date, however, no compostable plastics have made the cut.

So unfortunately, until bioplastics (a) can be composted in the same amount of time as green/food waste and (b) achieve certification for organic farming use, we will continue to discourage their inclusion in the compost cart.

What substances must compost be free of to be certified as being organic?

(The answer that follows is also from Dan North.)

You can learn more about organic compost and other organic products at the Organic Materials Review Institute. Redwood Landfill sends compost to be laboratory tested before we sell it. The laboratory that we use is approved by the US Composting Council for participants of its Seal of Testing Assurance (STA) program. The compost is tested for pathogens, metals, nutrients, and other safety and quality markers. The lab even performs a cucumber germination test to ensure that there's nothing toxic in the compost that could harm plants.

Also, we are registered with California Department of Food and Agriculture (CDFA) as an Organic Input Material. They inspect our site at least annually. In 2012 they visited the site three times. When CDFA makes their annual visit, in addition to examining our processes and paperwork, they take their own samples of our compost and test them to ensure that their test results are consistent with our test results.

I live in an apartment/condo complex. Can I compost too?

Yes! Single-family residents have been composting their food waste for years now. Apartment and condo complex residents can participate too. Some that already use our compost service include the Cove Apartments in Tiburon, the Villa Tiburon apartments in Strawberry, Eucalyptus Knolls in Mill Valley, and Sandpiper Circle in Corte Madera, among others.

If you’re a tenant in an apartment building or a condo owner, and your complex is not yet participating in our food composting program, just ask your property manager to call our office to start compost service. We will supply green compost carts at no extra charge to the existing trash bill. We can provide these services only if requested by a person authorized to order service for your complex (usually a representative of the management company whose name is on the trash bill).

Tell the manager or property owner they may be able to reduce the cost of trash service by using Green Compost Carts and reducing the number of trash cans your complex is currently using.

Complex Managers: download our Food Scrap Flier, which can be posted on the wall of your trash area, so your residents will know which items can be put into the Green Compost Carts. The compost carts themselves will also have these instructions applied to the lids of the carts.

Back to the Compost Services page.