Saturday, April 6, 2013
If you live in Walla Walla long enough, you are bound to see a city street sweeper going down Main Street or through a neighborhood.
I’ve always wondered why the city bothers. When I’ve seen the huge trucks with swirly brooms spraying water as they creep along pressed to the gutter, it didn’t look like a whole lotta cleaning was going on. All I’ve ever seen is swirling brushes leaving a trail of dust with swirly marks.
What’s up with that?
Well, when I hooked up with Jason Mings, the city’s Street Division lead, I was set straight — quickly. Mings showed me the mountain of debris — 10-feet high and about 8-feet-or-so wide — that has been swept from city streets since January. I was surprised and impressed.
Apparently the swirly marks are simply the dust that gets kicked up by the brushes. It’s literally gone with the wind or washed away with rain. Mings said the real work goes on under the truck, where more garbage than I had imagined is being cleaned up.
The way it works, as Mings explained, is that the brushes mounted on both sides of the truck spin, pushing dirt, rocks, paper cups, cigarette butts and many other grungy objects under the truck. This works because water is sprayed to loosen the grime and keep down most of the dust.
Then a giant vacuum sucks up the road gunk and it’s pumped into a bin, sometimes called a hopper, that holds more than three cubic yards.
The city’s second sweeper truck operates differently. It has the brushes that move the debris to the center, but it is essentially swept onto a conveyor belt that takes it into the large bin.
The vacuum truck is mostly used to clean downtown and the major arterial streets.
Downtown is cleaned every day starting at about 2:30 a.m. The sweeping ends around 6:30 a.m. when folks start coming to work.
From downtown the sweeper heads out to sweep main arterials, such as Isaacs Avenue, which are cleaned about once a week or the secondary arterials, such as Chestnut Street, which get a scrubbing every other week.
The conveyor-belt truck is on the prowl during the day, mostly working the residential areas. The goal is to clean every street once every eight to 10 weeks.
The sweepers go around parked cars but if someone rushes out to move the car, Mings said the drivers usually double back to gave the missed spot a scrubbing.
The city has five employees who keep the two sweeping trucks on the street night and day weekdays for most of the year.
But the sweeping crew is in overdrive in the fall during the annual leaf pickup (a service I can safely say is beloved by Walla Wallans).
A whole bunch of leaves are hauled away by city crews. The street sweeper follows, with the brush up against the gutter, pulling up what’s left.
During the leaf pickup season, when crews aim to hit every street in town twice, the sweepers haul in 12 to 20 three-cubic-yard loads a day.
The rest of the year, Mings said, the average is about three to four full loads a day.
I got a close-up look at the road gunk when Mings opened a small door on the side of one of the huge bins, revealing a thick layer of dark, damp debris with (as my wine-loving friends like to say) a hint of motor oil (although it was difficult to detect the viscosity).
The street gunk can’t be used for anything because of the amount of paper, rocks and vile substances.
The gunk is piled high in cement-wall containers, where it sits for months so the oil and other contaminants can flow to the bottom and safely be removed. What’s left is hauled to the landfill.
After hearing all this, I wondered what kind of crazy and interesting things street sweepers come across as they swirl their way around Walla Walla.
Not much, Mings said, adding the drivers are pretty much focused on keeping the broom up against the curb.
Really? No raccoons hissing at the drivers or opossums playing possum and being swept away?
Well, he said, an occasional dead squirrel gets sucked into the hopper.
Rick Eskil can be reached at email@example.com or 509-526-8309. If you, too, wonder what’s up with that, let Eskil know about it and maybe he can find out.