We call them street sweepers, but the same mechanical surface cleaners can be customized to pick up just about any kind of debris from almost any surface. Sweepers can range in size from full trucks to portable, towable machines. The largest trucks are big enough and can go fast enough to drive on and clean up highways. They do have to slow down to do the actual cleaning, however; trying to sweep the highway at 70 mph (113 kph) just isn't going to work.
Little three-wheeled sweepers are far more maneuverable for cleaning between shelving units in a warehouse, for example, or any place where tight turns and limited space are an issue. There are sweepers built specifically for dumping collected debris in tall containers or trucks and sweepers that can empty their hoppers into low-lying containers. Some sweepers, like the Elgin GRV, are made specifically to remove de-icing solution from airport runways before it can seep into the groundwater.
Street sweepers do much more than just keep things clean. They're used to pick up trash, dirt, chemicals, motor oil and more that can contaminate the environment. If these potentially harmful substances are removed from the street, the construction site, or the parking lot before they reach storm drains, they are less likely to end up in rivers and lakes.
The United States government has already taken steps to combat this type of pollution. In 1987, the Environmental Protection Agency (EPA) enacted the PM-10 standard, which regulates the number of particles in the air that are 10 microns (.001 centimeters, or .0004 inches) or smaller. These particles are small enough to affect our health because of their ability to reach the lower regions of our lungs. Most street sweeper manufacturers have several machines that meet PM-10 removal standards, keeping our streets cleaner and our lungs clearer. Street sweeper makers need to stay on their toes, though -- the EPA is considering lowering the standard to PM-2.5, or regulating particle matter measuring 2.5 microns (.0001 inches) or less.
Some areas have policies regarding the amount of pollution the street sweepers themselves emit. For example, The South Coast Air Quality Management District in California -- which covers the smoggiest section of the U.S., including Orange County and most of Los Angeles -- has instituted Rule 1186, which requires any new large, outdoor street sweepers to run on alternative fuels. Many companies have machines that comply with Rule 1186 for sale across the country. They usually run on compressed natural gas (CNG), liquefied petroleum gas (LPG) or liquid natural gas (LNG).
All this technology isn't cheap: A conventional, mechanical, brush-using street sweeper costs in the neighborhood of $100,000. A vacuum-assisted model will cost $150,000 or more, with alternative fuel engines and pollution compliance driving up the dollar amount to more than $200,000. But that's a small price to pay to keep lungs (and gills) free and clear of contaminants.
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More Great Links
- AbsoluteAstronomy.com. "Street Sweeper." (March 6, 2009)http://www.absoluteastronomy.com/topics/Street_sweeper
- BlackInventor.com. "C. B. Brooks." (March 11, 2009)http://www.blackinventor.com/pages/cbbrooks.html
- Dorenkamp, Jim, mechanical engineer. Personal interview, March 8, 2009.
- Santa Clara Valley Urban Runoff Pollution Prevention Program. "Enhanced Street Sweeping." (March 6, 2009)http://scvurppp-w2k.com/trash_bmp_toolbox_2007/Inst%20Ctrl%20-%20Street%20Sweeping.pdf
- South Coast Air Quality Management District. "Rule 1186.1 -- Less-Polluting Sweepers." (March 11, 2009)http://www.aqmd.gov/TAO/FleetRules/1186.1Sweepers/index.htm
- Tennant Company. "Tennant 810 Large Industrial Rider Sweeper Product Brochure." (March 11, 2009)http://www.tennantco.com/na-en/products/machines/810-rider-sweeper.aspx
- U.S. Environmental Protection Agency. "Particulate Matter (PM-10)" (March 11, 2009)http://www.epa.gov/air/airtrends/aqtrnd95/pm10.html