Q: When I drive around Tacoma, I see city street sweepers sweeping streets where there are absolutely no leaves, no trees along the roadway. Yet I live on a street lined with trees — North Yakima Avenue — and we are lucky if we get our street swept four times a year.
Pat Z., Tacoma
A: If Pat is really getting his street swept four times a year, that’s actually pretty lucky. According to Environmental Services maintenance supervisor Vincent Sali, the city gets around to most residential streets twice a year.
The city’s street sweepers also operate on a set schedule, Sali said. Tacoma has three street-sweeping machines and four total operators, including one who works a graveyard shift sweeping the city’s business districts and high-traffic areas (to avoid doing it when businesses are open and those streets are busy).
During nine months of the year, Sali said, the street-sweeping team gets around to each of the city’s residential streets about twice. During the other three months — starting about now — they’re focusing on removing leaves from storm drains, because Sali said, even a handful of leaves in a drain can cause it to clog and flood.
In that nine-month period of scheduled sweeping, there are a few reasons why the city might not be sweeping your whole street.
For starters, the department sends out a flier in advance of when they’re planning to sweep a neighborhood to let people know to move their cars. There’s no penalty if you don’t move your car — you won’t get a ticket, and the sweepers will simply go around it — but obviously less of the street gets swept if there are lots of cars parked on the curb.
Another problem: Unwieldy trees that hang over the street sometimes make it impossible for the machines to pass underneath. The street sweepers need a minimum clearance of 11 feet to get to the curb, Sali said.
“One of the biggest reasons why they miss people’s houses is they don’t trim their trees back,” he said. “They don’t know if the city owns the trees or if they do, and if the trees aren’t high enough we can’t get under there. We could knock a mirror off or damage the equipment, or damage the tree.”
Street sweeping is done to protect Puget Sound from junk that would otherwise end up in the stormwater drains and be swept out to the water, Sali said.
“The biggest impact it has is on the stormwater quality. It keeps contaminants out of the storm system,” he said. “So all the drains you see along the road that collect stormwater, it goes straight into Puget Sound. That water isn’t treated. So by sweeping, we get a lot of the contaminants out of that system.”
For the record, Pat Z. wrote back four days after his initial email to let me know his street had been swept.
“I don’t know if you had anything to do with it, but if so, I thank you,” he wrote.
I didn’t. But I’ll take props where I can get them.
By the way, in Seattle, you can get a ticket for not moving your car when there’s a posted warning about street sweeping. So we win.