Dust mitigation on jobsites is nothing new – but compliance with new OSHA regulations may impact broom/sweeper selection.
The Occupational Safety and Health Administration (OSHA) has issued new rules related to exposure to silica dust on construction sites – those rules went into effect on June 23, 2016, and compliance for construction sites is required by June 23, 2017. These rules apply to any site that will “drill, cut, crush, or grind silica-containing materials such as concrete and stone”.
Other cities, sites and developers have their own rules about airborne particulate on the jobsite – rules that may disqualify contractors from participating if they don’t engage in approved dust mitigation practices.
This doesn’t apply to every construction site, but it does add significant weight to the selection process for broom and sweeper attachments for skid steers, compact track loaders, compact wheel loaders and backhoes. While relatively basic attachments, there are considerations to keep in mind when making your selection. And with new rules and regulations in place to protect workers and the community, erring on the side of greater containment/prevention may be your best bet.
There are generally two styles of brooms – angle and collector (or pick-up). An angle broom does exactly what its name sounds like: it operates at an angle to the left or the right, and pushes material off the surface and away from the machine. This style is common in snow removal, and with municipalities simply looking to sweep off shoulders or roadways. There are also select turf applications where these brooms may be used. This style of broom does not offer any capture ability, and therefore may not be advantageous in applications where dust mitigation is a priority. These would also generally not be appropriate for indoor applications, or for use in residential neighborhoods where it could result in material being pushed into yards and driveways.
A collector is likely more appropriate for most construction sites where the goal is the collection and pickup of debris from the site. This includes sites where airborne particulate and debris cannot be swept to the side, or where environmental laws and regulations require the suppression of dust and debris. They are also more suitable for use with heavier, clunky debris that cannot be easily removed by an angled sweeper.
As it relates to rules and regulations – and the types of sites a contractor will be able to work on – a general rule of thumb is that a collector/pick-up broom will be suitable for working on a broader range of jobsites than an angle sweeper.
There are additional options and components to consider with collector sweepers. Water systems emit a fine mist that helps knock down dust, making the collected material heavier and stickier. These systems are effective, but add a little extra time and cost to the equation: they require water storage somewhere on the machine (often on the roof or somewhere on the back of the machine), and the appropriate plumbing to pump the water into the broom. An additional factor important in some sensitive areas is the introduction of a fine slurry coat to the pavement through the process that could have storm water run-off implications. Water kits are also available for angle sweepers but are not as common
Waterless systems attempt to capture the dust and material within the structure of the sweeper, but can still be quite dusty. Waterless systems have evolved over the years to further improve collection and keep dust levels down. The most common of these older technology systems features high-volume suction that pulls the material into the unit and filters it through a particulate filter. These are effective, but when a system takes in high volumes of air, that air needs to escape somewhere – and with these systems, you still get dust that escapes into the surrounding environment. Newer waterless systems feature a high-pressure, low-volume fan that is used to merely create a negative air pressure within the body of the broom that effectively eliminates the airborne particulate from escaping the container. That lower air volume maintains air circulation at levels where it’s not pushing more air through than it can handle – ultimately keeping more of the particulate within the unit and making it easier to fall within jobsite/local standards and regulations.
Hydraulic and Electrical Capabilities
All sweepers operated by compact construction equipment can be operated off the standard auxiliary hydraulics made available with the machine. A 14-pin electrical connection may also be required. Many sweepers come completely contained with the pickup and disconnect hoses routed, and the electrical kit already installed. These are not particularly complicated attachments to implement.
The major sizing consideration with brooms is width. A good rule of thumb is to select a broom that is as close to the width of the tires and tracks as possible. Anything wider than the tires or tracks may limit accessibility to certain areas. Anything smaller than the tire/track width results in less surface area coverage – especially if it’s an angle broom which, when angled up to 30 degrees, actually covers even less area as the machine moves forward, and may even be offset to the left or right on some machines.
There are generally three types of brush media available on today’s construction brooms: polypropylene (poly), a poly and wire brush combo, and an all-wire brush. The all poly brush media swiftly moves material from the surface and is the least aggressive brush composition – ideal for snow, turf applications, and any surface that a contractor doesn’t want to scratch, such as sealed concrete, cement floors, etc.
A combo poly/wire is more aggressive and is better for dirt and debris on hard pavement and surfaces that can withstand a more aggressive brush – but is not so aggressive that it can damage the surface.
All-wire brushes are available but are not as common as they can be too aggressive to surfaces.
The way that filters work in collector brooms is that the airborne material is sucked through the filter media, and that material then falls down into the collection chamber either during normal operation or with the use of an optional “shaker” feature that can be triggered by the operator in the cab. Newer technology filters are easily removed, easily washable, cleaned and replaced, and come in a variety of micron sizes to control the amount of particulate that escapes out into the jobsite. The smaller the micron rating, the more material it will filter out and the less dust/particulate it will emit into the atmosphere.
Many current collector and pickup brooms do not give the operator a clear perspective of the broom and how it engages the ground. Collector brooms are now available that will provide a gauge or meter facing the operator that informs them when the broom is in its optimal operating position. This will provide the most efficient use of the broom, reduce rework and ultimately minimize the wear and tear on the brush media and the entire unit itself.
Once all of the material is collected in the bucket, it needs to be dumped out. Contractors should look for a solution that allows for high dump heights and a dumping mechanism/movement that minimizes the amount of material that can blow back at the operator.
A drape system around the base of a collector sweeper will further help keep dust and particulate within the confines of the sweeper.
Collector brooms purchased for street sweeping applications are best complemented with a gutter broom for optimal collection of materials up against curbs.
With the increased attention being paid to jobsite dust and airborne particulate, a contractor’s ability to contain and mitigate these materials will not only become more important, but it may also make them more competitive and increase their likelihood of being asked to bid on the next project. Choose wisely.
By Perry Girard, product marketing manager – construction components, CASE Construction Equipment