Autumn Sweeps

Year-round sweeping programs are important, and not only improve the appearance of the area, but are also a recognized Best Management Practice for any stormwater runoff program and are beneficial for the environment. While the spring cleanup removes tons of stone, salt, sand and cinders, the autumn’s primary concern are the leaves. These leaves, if not swept up, will flow to streams, rivers and lakes causing an excessive increase in nutrients that promotes bad aquatic plant life and algae that can be detrimental to the fish and other wildlife. The unswept leaves can also plug storm drains and catch basins, possibly causing flooding, which, in turn is a safety hazard for both pedestrians and vehicles.
We were told the City of Denver communicates their sweeping program to the residents and encourages them to “Show Your Pride and Move Your Ride.” Parking restriction signs are posted on the streets being swept, and they note the street sweeping schedule. They also note that there is a $50.00 fine for obstructing the route. This increases the efficiency and effectiveness of the sweeping while reducing liability. Similar type signage can be used on private parking areas where vehicles may be left for extended periods without authorization. Some cities have even set up smartphone apps that notify the residents when the street sweepers are coming to their neighborhood. Many cities and contractors have web pages that explain their sweeping programs, list FAQ’s and includes contact information, should anyone have a question or a request for sweeping. Most also list what the residents can do to help make the sweeping program more efficient. Such as:
• Keep the right-of-way in front of your house clear for access to the curb line.
• Remove vehicles and trailers from the area.
• Keep trees trimmed back at least 12 feet above curb line.
• Keep large branches and debris off the street.
• Keep basketball goals out of the right-of-way.

Setting the sweeper up for leaves is simple. With regenerative sweepers, it’s a matter of making sure that all the air pathways are clean and free of obstructions, especially the hopper intake screen. When sweeping leaves with a regenerative sweeper, it’s important not to let the leaves build up in front of the sweeping head or “bulldoze.” By opening the air bleed valve just enough to suck the front flap back, the leaves will be drawn into the sweeping head before they touch the flap. This keeps the leaves from bunching up. Using hopper water or a hopper spray bar also helps keep the leaves from floating to the screen. It also helps compact the leaves in the hopper, increasing the capacity.
Mechanical sweepers are not usually known for being the best leaf sweeping machines, but they can be set up to pick up leaves quite well. Pre-wetting the leaves with the front and main broom spray bar helps add weight to the leaves and makes it easier for the main broom to pitch them to the conveyor. As with the regenerative sweeper, you do not want the leaves to build up. If the leaves build up between the conveyor and main broom, there is no clear line of pitch to get the leaves into the conveyor. If this happens, your best course of action is usually to lift the main broom, spread the leaves and start over. When using a mechanical sweeper for large amounts of leaves, it is best to put the conveyor into the leaf lift, raising it off the pavement and allowing the leaves to travel unobstructed under the conveyor to the main broom. The use of a strip- type broom also seems to help with leaves. Some people have even reported removing every other strip to help sweep large amounts of leaves. It’s also important that the main broom down pressure be set to a 1” to 3” strike pattern. The broom doesn’t need a lot of down pressure, but you do want a flick as the broom bristles leave the pavement. Proper broom speed is also essential; too slow and the leaves won’t make it to the conveyor and too fast (the mistake that most people make) and the leaves get carried over the top of the broom.
Another thing to remember this time of year, and one of the most important, is dry leaves can be a fire hazard. If the sweeper is coming into contact with a lot of low hanging branches, the dried foliage could get drawn into the engine compartments, creating a potential for a fire. Be sure to keep the engine and exhaust areas free and clear of debris. This should not only be done before and after the shift, but also at each break or dump cycle. Today’s engines and exhausts can run hotter than ever before, due to EPA regulations on engine exhaust emissions. The combination of dried leaves and a cigarette butt can also be a fire hazard. This is especially true with air sweepers that can stoke a dying ember. This is yet another reason to use water to keep the debris wet.
Lastly, don’t be caught with that first surprise morning freeze. Be sure to drain water systems and purge pumps before putting the equipment away for the night. I hope that this helps make your sweeping more productive and enjoyable.

For over forty-two years in the street sweeping business, Schwarze Industries has been committed to providing an exceptional level of customer support. Schwarze offers one of the most comprehensive sweeper lines in the sweeping business. For additional information visit the Schwarze® website at

Story by Jim Adair, Director of Product Management at Schwarze Industries