San Francisco is experiencing its fourth driest winter on record, and to fill the region's water needs, there's talk of diverting more precious flow from the Tuolumne River, threatening fish and wildlife (see "Draining the River").
The DPW's "street flushers" can each hold 3,200 gallons of water and use about 15,000 gallons of freshwater every business day to cover an average of 25 routes.
In comparison, three average San Francisco households would have to cease using water for an entire month to equal the amount of water used to clean local streets each day. The DPW's Bureau of Street Environmental Services used 5.6 million gallons of water last year, according to figures provided by water officials. The agency used 90.8 million for landscape maintenance, mostly irrigation for street medians, which during droughts in the late '80s was temporarily outlawed to conserve water, according to SFPUC spokesperson Tony Winnicker. San Francisco is not there yet, but "for now we would just like everybody to cut back," Winnicker said, "and certainly the city has room to do that as well."
There are costs involved in not cleaning the streets. The Maryland-based Stormwater Center, funded in part by the Environmental Protection Agency, argues that it's not clear how much street cleaners help remove surface pollution before it runs directly into the oceans. The center says, however, the runoff could be reduced by 5 to 30 percent with the right modern trucks and aggressive maintenance.
Street sweeping as a municipal function historically began as a matter of aesthetics. Unmanageable layers of trash and slime on the street are unsightly and generally not considered to be a part of good public policy, to say the least.
More recently, though, cities have looked at how street cleaning can also help green their locales. "They still want to pick up trash and litter, which was the original idea," said Jim Scanlon, a program director for the Alameda Countywide Clean Water Program. "But it's moving a little bit more toward wanting to pick up the finer particles because of the pollutant-reduction capabilities."
To its credit, the DPW has planted several thousand trees in the city over the past three years at the direction of the mayor, helping to contain burgeoning stormwater during heavy rains that would otherwise overflow into the ocean. It's a strategy lauded by groups such as San Francisco Planning and Urban Research. And elsewhere at the César Chávez maintenance yard, auditors noted the DPW's good housekeeping, including its storage of toxic materials.
But scooping up noxious sludge in one place and pouring it out somewhere else isn't exactly the sort of green behavior that Mayor Gavin Newsom likes to talk about. *