Frequency of Street Sweeping and Its Effects on Water Quality – Fayat Cleantech

Perhaps the most fundamental factor in the positive environmental impact of powersweeping is how much sweeping you’re doing daily, weekly, monthly, yearly. To increase your degree of effectiveness, and your revenues, the question to ask is, “Should I, and how can I, increase the amount of sweeping I do in a given period?” 

Mike Nelson, GM, Fayat Environmental Solutions, Cleantech America, offers these general criteria, variables, and other key considerations in determining the optimum frequency of street sweeping. He further examines the effects of ideal rates of pavement sweeping on water quality. Here, Mike talks about the sweeping routines that are best for different kinds of job sites and surrounding environments:

Fayat Cleantech – Powersweeping Industry Experts

Fayat Cleantech, a part of the Fayat Road Equipment Division, is a global provider of both mechanical and vacuum powersweeping solutions for municipal, commercial, and industrial applications. The Fayat organization is dedicated to environmental and social responsibility, innovation, and excellence. 

Fayat is the parent corporation of three international sweeper brands. Though still relatively new to the US market, Fayat has risen to become the sixth largest provider in the country. On the worldwide scale, however, when you combine all Fayat’s factories, the company is substantially larger than any other US sweeper manufacturer. The three primary brands under the Fayat umbrella of companies include: 

Compare Urban Street Sweeping in US Vs. Europe

In many European cities, the idea is to sweep the main downtown streets daily, often in 2 to 3 shifts. It’s unclear whether any street gets swept daily in the US. Predominately, the sweepers are vacuum or vac assist sweepers for collecting fine dust on highways. It’s just the nature of the world. There’s brake dust, vegetation, micro plastics, etc. Europe leads from an environmental standpoint, pushing sweeping as a primary means of maintaining clean water.

I think the US is behind in the mentality around sweeping needs. Sometimes, it seems like we sweep because we have to, not because we want to. Cleantech has a presence on every continent. So, we get to see the differences on all the continents. Many European cities have hundreds of sweepers, whereas very few US cities have even a hundred. In Europe, you can set a clock by when a sweeper goes by. 

I think changing the mentality we have here to say not just that we want clean cities, but that we have to do what it takes to keep them clean. To get clean water, again, we have to say not only that we want it, but that we must do what it takes to get it. The first priority is to get the stuff that comes off trees, and from people, and cars cleaned up and keep it cleaned up. That’s the role of sweeping.

Water Quality Improvements from Increased Street Sweeping

Obviously, more frequent pavement sweeping will result in a cleaner local water shed, reduced fugitive dust on roadways, and the maintenance of permeable road surfaces for better water infiltration via structural Best Management Practices (BMP) for stormwater. Sweeping is the first path of prevention to stop brake dust, phosphates, nitrates, and other harmful agents off paved surfaces and keep that stuff out of our waterways.  

Sweeping can also pick up microplastics before they enter the water through storm drains. Both Ravo and Scarab perform in the high 90% range in picking up microplastics, but you’ve got to sweep constantly, more than you think you should have to do. Otherwise, it’s not really effective enough. See the wealth of web search results providing research findings from numerous recent studies of the effects of powersweeping roadways and other urban public spaces. Various researchers from academic institutions to powersweeping industry watchers have examined the efficiency of sweepers in capturing dust, microplastics, and other pollutants now found everywhere in tires, brake dust, on roads, and in water.  

Fayat Sweeping Solutions for Cleaner Water

I think in a perfect world we’d clean the streets all the time. We don’t want to see rotted vegetation, trash, other debris, and dust built up on streets and parking lots in our area, and we don’t want the wrong stuff in our water. We want our streets to be free of clutter and storm drains clean so we don’t get avoidable flooding during storms. Sweeping really is the way to beat that challenge. Vacuum cleaning is proven as the best solution for that. All our brands have pure vac or vac assist. With Dulevo D3 and D6, we can even run waterless.

The purpose of using water for sweeping is, of course, to knock down the dust. Our Dulevo system has self-cleaning filtration, like Gore^Ⓡ, which uses a mechanical process for filtration. We have rotating gutter brooms, a main broom underneath that flips debris onto the conveyor, and also has a vacuum assist that pulls air from the ground and picks up anything that gets in that airstream from the brooms and the fine debris on the surface. The vacuum assist is strong enough to be able to utilize a wanderhose to clean catch basins and litter, which sets it apart from most mechanical sweepers.

It’s a very advanced system. See Dulevo/Fayat 50th Anniversary for details of this technology. It can be used by any municipality regardless of ambient temperature. It can be used in cement plants and highly industrial environments where sweeper trucks can’t use water, and in places where operators want to reduce water use (for example, where there may be concerns about conservation of overuse of potable water every year.

Sufficient frequency of pavement sweeping is essential for preventing debris from polluting water to extreme levels. Without consistent sweeping. As a society, we’ll never get rid of it once it’s in the groundwater. In suburban areas, many property owners will keep the roads clean in front of their houses, but downtown, where there’s so much more litter and so much more human activity, there really should be much more sweeping, but in many cases, there’s less attention to it, instead of more. 

In that perfect world, I’d like to see the European model of sweeping diligence more broadly adopted in US urban locations where there is a lot of movement of goods and humans. It would mean sweeping every day and every night. I know that seems expensive to do, but if we really care about clean cities, which requires clean streets, we know that’s what it takes.

Decarbonization By Electric Sweeper with Diesel-Level Power 

Electric sweeper trucks, of course, bring operators big energy savings and significantly reduce air pollutants as well as groundwater contaminants. Fayat is a world leader in electric sweeper manufacturing. We started building fully electric sweepers in 2016 and have had them on the market since 2018. We brought them to the US in 2021. Worldwide, we have over 400 electric sweepers running every day, the majority of which are in Europe. We currently offer 3 fully electric models, the Dulevo D.Zero², Ravo R5e and Ravo E2. 

Through this time, we’ve been able to really dial in our electric architecture. Because of our understanding through real-world experience, we’re able to size the e-motors and powertrain to use the power when and where needed; delivering uncompromised autonomy without sacrificing performance. 

The Ravo E2 electric powersweeper achieves decarbonization with no compromise in sweeping performance. The sweeper’s systems are optimized or replaced by greener technologies in electric, aeraulic, hydraulic, and/or mechanical components.

Among the Ravo series design integrations, the factories have essentially removed the diesel equivalent engines and replaced them with an e-powertrain and battery system that fits into the original space claim of the Cummins or Kubota diesel engine, for the R5 and R2 respectively.

On the E2, instead of using a hydraulic gear pump, which is only 75% efficient, we elected to implement e-motors immersed in a hydraulic out bath. This saves on energy consumption to cool the motors. Since we use 4 motors in total — for the brooms and fans in parallel — the system only runs motors for sweeper functions that are active. This significantly improves efficiency.  

Additionally, we use a total of 4 hydraulic accumulators, similar to the full-size Ravo, and store the hydraulic fluid power. So, instead of running a gear pump continuously and sending oil everywhere and then back to the tank, the e-motors run only when the broom or brooms are active. They charge their accumulators, and when they reach full capacity, they shut off. This architecture substantially increases the overall efficiency of the whole system. 

The Ravo E2 has implemented the broom and water system “start/stop” technology. For example, when the vehicle stops at a stop light, after about 5 seconds, the brooms and water system pause. When the sweeper begins rolling forward again, they resume functioning. This increases the autonomy of the Ravo, reduces noise levels during idle time, helps minimize water usage, and extends broom life.

Regenerative braking technology further improves efficiency by taking advantage of “free” potential energy,” such as from coasting down a hill or decelerating. It captures that now kinetic energy and converts it back to stored energy in the high-voltage battery for later use. 

Our battery suppliers keep improving their overall technology and battery density. The kW rating of the EV battery is increasing. For the E2, we’re actually using a low voltage architecture, a 96 VDC battery, which allows us to implement our novel battery swap system.  

Dulevo, RAVO, and Scarab Sweeper Selections from Fayat

Because of the comprehensive range of global standard-setting sweeper truck types manufactured by Fayat companies, Dulevo, RAVO, and Scarab, we’re able to offer mechanical broom or pure vacuum air sweepers for municipal, contractor or industrial customer applications. Our Dulevo D3 or D6 sweepers use a vacuum assist system with filtration to allow the mechanical broom platform to sweep dry, i.e. not using water where it would be reactive to lime, coke, cement, etc.

Our dealers can size our state-of-the-art sweepers for customers based on job type, overall size, transport speed, purpose-built, truck-mounted, volumetric capacity, CDL requirements, and other specifications. 

The market feedback we’ve received is that there are newer regulatory requirements for municipalities to sweep more often, which we believe is going to drive more sales in the US. Whether the municipality has an in-house sweeping program or contracts out, under the Clean Water Act, the EPA now mandates street sweeping as a part of storm water management. 

Fayat Pavement Sweeping Management

Ultimately, in determining the frequency of street sweeping to recommend to a customer, a municipality, for example, the predominant driver is the EPA’s Municipal Separate Storm Sewer System (MS4) mandate. The EPA recognizes that street sweeping is inherent in BMP and is, therefore, required in all municipal MS4 programs.  

Fayat equipment is utilized worldwide for street sweeping as a means of minimizing pollutants in storm water drains. Further, the “Water Fayat” group provides solutions for sustainable water management and implements water quality preservation measures, including plans for reduced consumption, and usage optimization. 

The Fayat company, more broadly, integrates technological innovations for wastewater treatment, water recycling, and other approaches that contribute to preservation of water resources and protection of waterways.

For information about Fayat Cleantech, you can call the US headquarters, Charlotte, NC at 732-874-2857, email info@fayat.com, or visit cleantech.fayat.com.