cambridge started single-stream recycling last october. that's funny, because i've always thought recycling was single-stream so i never once separated my recyclables, nor did the weekly collection crew refuse my donations. still, i've always been curious about how exactly they sort through the recyclables at the recycle plant, and when i learned the city was offering a free tour, i jumped on the opportunity to go see for myself.

i arrived at the cambridge department of public works before 1:30. others were showing up and our contact person randi (an enthusiastic young brunette) gathered everyone together. i actually recognized one of the people, nancy, whom i bought that purple 3-speed ross bike for $40 (i didn't tell her it cost me an additional $30 to get the thing fixed).

the casella recycling center is actually in charlestown so we needed to carpool to get there. i rode with randi along with nancy and one other guy (a freelance lawyer). casella not only services cambridge, but pretty much all towns in eastern massachusetts.

we arrived at the plant and gathered in a conference room overlooking trucks arriving and dumping out piles of recyclable materials. mike was our tour guide. after giving us a talk about the recycling plant, how showed us the various stages with live joystick-controlled security cameras mounted inside the facility. next we took an actual tour of the center which involved following multi-leveled catwalks above and through the inner workings of the recycle factory. everyone was issued safety vests and given safety glasses if we wanted them.

the place didn't smell too bad. there still was a slight foul odor because of trace amounts of food residue, but for the most part, since the material isn't organic, it doesn't smell as much.

single-stream recycling has been rebranded to zero-sort recycling to differentiate the old system from the new system. single-stream in the past had a bad reputation for impurities, like ground glass in the cardboards. zero-sort produces a more refined product thanks to automated optical scanners that are programmed to sort through a conveyor-belt stream of recyclables much faster than a human. people are still part of the equation though, and the plant actually hires more people than before when they were just manually sorting by hand, but now the hires are part of the quality control team, removing the occasional stray misidentified recyclable that slipped through the scanners.

a recycle plant is all about sorting. how do you organize the plastics from the papers from the glass to the metals? some metals like steel can be removed magnetically. glass can be grounded to small bits and passed through a filter. papers can be rolled through drums of various diameters and sized that way. various plastics pass through the scanners, which are programmed to recognize the difference between a gallon milk container versus a 2 liter bottle. when the desired item is identified, air jets blow the container into a catch basket that goes to another conveyor for sorting.

a lot of the people who work there were latinos. they make about $7-12/hour, which isn't too much. they wore vests and goggles and gloves, but i didn't see any earplugs even though the place was pretty loud from the sounds of the machines.

our tour guide kept talking about "balers" but i didn't understand what he was saying. i kept thinking about "baelor" the blessed, the 9th targaryen king to sit on the iron throne of westeros. turns out a baler is the machine that compacts the collected sorted recyclables and turns them into bales. a bale of cans weigh a ton, where it will then be shipped to china, one of the biggest customers of recycled raw materials.

recyclables getting wet can be a big issue, especially for paper and cardboard, which then become too heavy to be easily sorted. now that cambridge has wheeled bins with covers, it's become less of a concern. plastic bags are also a real problem because they clog up the drums; the equipment have to be cleaned every day because of this, and the paper sorters need to be cleaned every 4 hours. another no-no: VHS tapes. they unspool and make a mess of the conveyor belts.

the bales don't have to be 100% of the given material, because once they arrive at their destinations, the customers will continue to sort and refine the raw materials into their pure form.

once the tour was done, i got a ride back to the DPW with randi. next thursday they're doing a trash survey and they need volunteers; i'm tempted to go, get a chance to sift through 2 tons of cambridge trash and manually sort everything out. also next month i'm going on another tour, this time to the trash processing plant, which i hear is very smelly. can't wait! i biked back home.

marco came home after 10:00. he left me a note this morning, apologizing for getting home so late last night (2:00) and didn't let me know beforehand. when he got back tonight, he told me his brand new asus laptop stopped working. the lights turn on, but the computer just wouldn't startup and didn't make any sounds. it wouldn't even eject the cd-rom drive. he's going to try and get it fixed but he bought the laptop in italy and don't know if the warranty applies in the US. if not, he's going to send home the computer and buy a new one here in the states. i feel bad because he needs a laptop to do his work. i don't have a spare laptop for him to borrow but told him maybe his lab might have a few (it's MIT after all).

he ate some of my leftover chicken noodle soup for dinner, still hot on the stove.

julia, my neighbor from across the street, is moving. she just got her house painted recently, and last week i saw two ladies that looked like real estate agents going into her place. this morning more than 2 dozen people showed up to look at her house in a private showing. later in the afternoon, i saw a coldwell banker sign hanging from her porch. i hope some cool people move into that place, to offset the mean lesbians who live downstairs (actually only 1/2 is mean).