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Since the first powered street sweepers hit the streets 90 years ago, water has been used to wet the roadway to control dust. For about a dozen years, a waterless alternative to this practice has been sitting on the fringes of the sweeper world, and environmental demands and water restrictions are bringing it into the mainstream.

The water factor
In the past, people didn't place that much value in water and used it freely. This has changed. Hardly a day goes by that the media doesn't have an article about droughts and general water shortages. It's not uncommon to have lawn-watering bans as well as restrictions on car washing and other non-critical activities. To really understand the magnitude of the problem facing us, one only has to look at the amount of money spent on water resources. The U.S. market for water resources management, equipment, and services reached $102 billion during 2004.

Most people don't realize the quantity of water that a properly operated sweeper can use. A typical broom sweeper that has a PM10 rating can consume 1,500 gallons of water a day. It's not uncommon for a large city to use over 1 million gallons of water per day for sweeper dust suppression.

In addition to the fact that fresh water is becoming a more precious commodity, contractors that use water for sweeping don't have the easy access to it that the cities do. They must either install water meters on each sweeper or have a central hydrant and meter the water used from it. They must then pay for the water on a per-gallon basis. The bookkeeping involved to monitor this process is another form of overhead that steals profits from contractors.

Every time the sweeper is stopped to fill up with water, at least 20 minutes is wasted. This can easily consume an hour or more per working shift. Every contractor knows that, in order to make money with a sweeper, the brooms must be turning. Locating a hydrant and filling up with water is not productive.