THE DIRT ON THE STREET - THE FUTILITY OF STREET SWEEPING IN PORTLAND, OREGON

The City's street cleaning program removes dirt and debris from City streets to provide a healthy, safe, and attractive environment for the citizens of Portland. Regular removal of leaves and debris is necessary to prevent stormwater drains from clogging, which can result in street flooding. Street cleaning protects water quality and minimizes the burden on the sewer system from surface debris. 

The above introduction is on the City of Portland Bureau of Transportation street cleaning web page.  I agree that clean streets are a good thing, and that the City should regularly clean them for the benefits listed. The only problem is that the City of Portland street cleaning program doesn't do any of the above. 

The method used to clean the streets is street sweeping machines; you've seen the vehicles with the large rotating brushes going down the street. The street sweeper recently went through our neighborhood; this is done 1 or 2 times per year.  


Here's a photo I took near my house soon after the sweeper went through.

Look closely and you will see the track made by the sweeper; it went around the parked cars.
 
Further into the web page cited above, the City states that 97% of the dirt and debris on the street is within 40 inches (3.3. ft) of the curb. A car typically takes up the area about 6 ft from the curb. So in other words, except when it can get to within 3 ft of the curb, the sweeper only gets about 3% of the dirt. On our block, there are typically no empty parking spaces, so the sweeper misses most of the street dirt. 


I wondered how much dirt and debris the sweeper leaves behind, and on the 4th of July, I had an opportunity to figure it out. On that morning, there were only 2 cars parked on our side of the street for the entire block. So I went our with a square-end shovel and push broom and did the street sweeping myself (I actually try to do this at least once a year). 

What I found was a layer of dirt against the curb, a lot of which had weeds growing in it. There was also debris: cigarette butts, scraps of paper and plastic, bits of metal; you get the idea. And also, a lot of oil and grease stains on the pavement - I couldn't sweep those. 

I shoveled and swept the area within about 3 ft of the curb on one side of the entire block - you remember that this 3 ft is where 97% of the street dirt is found. I piled all of it into a yellow plastic recycling bin. 

I then measured the size of the bin and did some calculations; I had 1.78 cubic feet, or 0.07 cubic yards, of dirt and debris.  The length of the one side of the street I cleaned was 250 ft, or 0.05 mile. 


A standard dump truck holds about 5 cubic yards (cy) of dirt; that is about 75 of my yellow bins full of dirt. One dump truck at 5 cy would hold about 72 of my bins full of street debris. Or, if we consider both sides of the street, a dump truck would hold about 36 blocks worth of street dirt. The City of Portland has 4,700 miles of paved streets. Using the length of my block, 36 blocks would be 1.7 miles. Do the math, and you get a total of 2,765 dump truck loads.


2,765. That is the number of dump trucks full of street dirt that the City street cleaning program leaves behind every time they clean the streets, based on the assumptions of my small exercise and calculations. 

But wait - what about posting "no parking" signs so that the streets can be properly cleaned? In many cities, street sweeping is scheduled for specific days and people know not to park on those streets. Can't we do that in Portland? Apparently not. The second half of the City web site cited above lists numerous reasons (excuses) why the City of Portland can't do that.  And of course, as the City web site states: "Any attempt to provide a schedule online or through the mail would almost certainly result in a frustrated public because too many factors beyond our control always result in delays to our street sweeping schedule." We certainly don't want a frustrated public! 

Read the opening statement of this post again (go ahead, scroll up, I'll wait). Based on my small study, the statement is not true; the City does not really remove dirt and debris from the streets, they leave 97% of it. For me, this begs the question of "why bother?" Why continue a program that does nothing? Either do it correctly, or don't do it at all. 

We are very green in the City of Portland. We strive mightily to protect the water quality in our rivers and streams, to save the salmon, to improve our quality of life and the environment. We all pay stormwater fees, including the off-site stormwater fee that "pays for the construction, operation and maintenance of facilities that manage stormwater runoff from city streets." Part of the above is to deal with the water quality of stormwater runoff from streets. Effective street cleaning is one of the easiest and best ways to deal with water quality from street runoff - remove the contaminants before they go down the drain! 

Now, some of you might be wondering "what did he do with the yellow bin full of street sweepings?" I phoned the street cleaning department at the City of Portland and explained to a very helpful person what I had done. I said that I didn't want to put the sweepings into my green can (non-Portlanders; that's the can we put yard debris and food waste into that is picked up weekly for composting), and he said that was correct because "you don't know what's in it." "Oh, I do know what's in it," I replied. He asked for my address, I left the yellow bin out by the curb, and the next morning it was empty - a city crew picked it up for proper (hopefully) disposal. 

Should the City of Portland sell their street sweepers, re-assign most of the staff, and instead distribute shovels and brooms to every property owner? I think not. I think that the City needs to evaluate their street cleaning program and change to a program that actually meets the intended goals.