I highly recommend the Compost Tour at Rumford Ave led by Elaine Gentile (and mentioned by Courtney Forrester on Jerry Reilly’s earlier post about International Compost Week). I went on Wednesday. There is another one on Saturday, so it’s not too late to sign up. I don’t know if the very cool heavy equipment will be operating on a Saturday, but if not, you can still get a look at it up close. (There’s also a nice view to the southwest from the top of the Rumford Ave hill, not normally accessible to the public.)
One piece of equipment is the “Allubucket” — there seem to be at least three of them, which are like bucket loaders except with rotating paddles that yard waste is run through to break it up so it will compost faster. It used to take compost 1-1/2 years to “cook” into compost, and now it is down to 8 or 9 months, although DPW would like to get it down to 5 months, so that they won’t run out of space for the volume of yard waste they’re processing.
I hadn’t realized that until just three years ago, only municipal yard waste, from public property, was composted on site, while residential yard waste was hauled to Norwood. As of three years ago, DPW got the okay from DEP to do residential yard waste on site at Rumford Ave. Now they are turning about 25, 000 cubic yards of yard waste per year into about 5-6,000 cubic yards of compost, which gets sold in 50 cubic yard truckloads to soil companies who mix it into their product. It saves on disposal costs because the trucks collecting yard waste can do three loads a day in busy season, because they only have to drive it to Rumford Ave.
The yard waste gets piled into 15 foot high “windrows” which are monitored for temperature weekly by a composting expert from Lion’s Head Organics, who determines when they should get turned. The target temperature is 150 degrees, for composting to occur and weed seeds to be killed. Once cooked, it goes through the very impressive Doppstadt trommel screener, which spits out good, ready-for-sale compost on one side, and “tailings” on the other side, which at this stage are mainly organic matter that doesn’t fit through the 3/4″ screen. Tailings from earlier stages could be anything from plastic or tennis balls to all the other junk that ends up in yard waste that shouldn’t, and which you may be more conscientious about keeping out of your yard waste, once you see that it doesn’t really go away!