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Noise Issues in Parking Area Sweeping

The Honorable Brent Coles, Mayor
150 North Capitol Boulevard
Boise ID 83701

RE: Curtailment of power sweeping times of operation (copy of distributed letter, as agreed via phone).

Dear Mayor Coles:

A power sweeping contractor in your area recently contacted our office concerning your city's investigation into a possible noise or time of operation ordinance which would apply to power sweeping. With a clear look at all the ramifications, I believe you will find that a noise ordinance which applies to sweeping services will not provide a sensible or cost-effective solution. In fact, what might seem at first reading to be a 'quick fix' will, in all likelihood, create many more problems than it solves. A quick primer on sweeping will illustrate the reasons why this is true.

Sweeping contractors perform the invaluable service of cleaning up virtually all paved commercial surfaces. Through the use of powerful, sophisticated vacuum sweeping equipment, dirt, food, wrappers and other containers are professionally removed and disposed of correctly. For important reasons, which will be covered further along, most sweeping activity must take place at night. The result is that most citizens, and even city managers, are barely aware the activity of sweeping, let alone its many positive and necessary effects. Primarily due to this lack of awareness, in combination with the noise that sweepers make (though certainly minimal by any daytime standards), local sweeping efforts sometimes become the target of nighttime noise ordinances.

Noise complaints involving sweeper operation are actually extremely low. Unfortunately, however, commercial properties are being located more frequently in the midst of residential areas. As a result, noise-based complaints from homeowners are on the rise nationally. These complaints are typically the result of loud music from kids 'hanging out' in malls after hours, nighttime product deliveries, garbage disposal trucks and, more rarely, the operation of power sweepers. Fortunately, most incidences of individual noise problems with sweepers can be straightened out on a case-by-case basis through creative scheduling, operation without warning beacons flashing, powering down in certain areas, etc. Restriction of operation to daytime hours, however, creates a host of other problems.

Because of health and safety concerns, it is very important that all pavement surfaces are cleaned, and night is typically the only time when the absence of parked cars allows this to happen. Precisely because it takes place at night, city managers - and even the mall and business management customers of sweeping contractors - have little concept of the tremendous quantity of debris which is removed by sweeping. If sweeping is done during low traffic times (during the day), it tends to leave the same areas continually unswept, since shoppers and employees always park in the same spots, close to the entrance of the stores or their workplace.

Without regular sweeping, it doesn't take long before an unacceptable level of trash accumulates in these areas. If this were simply unsightly, the problem with this accumulation would be much less serious. More importantly, however, is that the discarded food in this debris attracts disease as it decays, becoming a feeding ground for rodents and other animals, as well as for microscopic bacteria. The uninitiated might suggest that employees or other personnel be assigned to 'handpick' the pavement of a mall or other business area.

Although that will make these surfaces look cleaner, the small particles of food and other debris remain behind in cracks in the pavement. Power washing, a formerly popular cleaning method, is today seldom feasible given the size of most parking areas. Even where it is not, cost of water and the environmental impacts of washing this debris into stormwater systems are prohibitive downsides. The expense associated with other methods of surface cleanup is also much higher than having a property cleaned via power sweeping. Without sweeping, there is also an accumulation of what are called PM10's, the very fine particles that include sand and other small grit.

Studies show that PM10's are where the hydrocarbons, heavy metals and other potentially toxic substances from automobiles and other sources tend to end up. If these are left on the pavement surface for the long term, there is an increased likelihood of toxicity developing for the area. Related ramifications include increased pollution in stormwater runoff from unswept shopping centers and other business paved surfaces, as the more highly polluted runoff water goes into the waste treatment system of the city.

As these PM10's accumulate, they also tend to fill all the small cracks that characterize virtually any paved surface. This reduces friction, and thus traction, especially in wet weather. This especially impacts walkers and bicyclists. The decrease in friction, combined with more litter which will accumulate heaviest near building entrances, will serve to dramatically increase the likelihood of slip-and-fall type accidents by shoppers, employees, etc. If the city has imposed an ordinance which disallows power sweeping along the professional guidelines needed to do the proper job of cleaning, the city will likely find itself named as defendant due to slip-and-fall injuries. I encourage you to discuss this factor in detail with your city attorney.

Those are the primary factors involved in the sweeping activity, per se. However, as a graduate economist, I think it is important to outline the business economics related to this ordinance: In a city the size of Boise, I estimate that over 100 jobs are tied to power sweeping, with an associated payroll in excess of a million dollars per year. Even without considering the multiplier effect on your economy of this level of payroll dollars, the impact of abolishing sweeping would be very substantial. It doesn't stop there, however. Let's add to that the alternative: handpicking all the places where parked cars prohibit sweeping during the day. Also, the following would occur in addition to the previously discussed potential health hazards and increased likelihood of slip-and-fall accidents and related liability for these by the city:

1. An increase in the cost of maintenance of the interior floor surfaces throughout the city's businesses, as more grit is tracked from the parking areas into stores, etc. This added upkeep, which can be substantial, is eventually passed along to all consumers.

2. Less longevity for paint striping and other pavement marking in parking lots due to the higher level of grit tracked onto them by tires. This cost is eventually passed along to all consumers.

3. Reduction in the level of business conducted. The largest factor determining where people shop is their perception of the cleanliness and overall attractiveness of a given store. Because the outer appearance of parking areas around the stores will degrade, as well as interior floor surfaces, a percentage of shoppers (especially those in outlying areas of the city) will choose to go to adjacent towns where there has been no impact on cleanliness by the noise ordinance. This will be felt by the city of Boise as a decrease in its tax revenue base.

4. Because it won't take long for the general appearance of the business districts of Boise to look shoddy, compared to cities where normal sweeping operations are allowed, there will probably be an impact upon the number of conventions that Boise can attract. The convention industry is well connected, and word travels fast when something occurs in a city to reduce its beauty.

5. There will likely be an increase in the cost of stormwater treatment, due to increased particulate levels in the water which arrives for treatment. This will include a higher level of hydrocarbon deposits and heavy metals.

6. Finally, in terms of overall appearance and quality, Boise will soon become bereft of the beauty which has been one of its hallmarks to date. Without effective power sweeping taking place throughout the business community, there is simply no way for it to maintain a clean look or, more importantly, to actually be clean.

Now, for some good news: Fortunately, modern power sweepers operate at a decibel output which is well under OSHA requirements for noise, and at one which most nearby residents don't find objectionable even when the sweeping is being done at night. Usually it is only during hot summer months, when residents have open bedroom windows, that complaints are registered. By and large, the benefits of conducting regularly scheduled sweeping far outweigh this slight inconvenience to a very small minority of residents.

Power sweeper manufacturers are currently doing everything they can to reduce the noise of their equipment. This includes making available noise shields which dampen the sound output of sweepers. Due to the nature of the job being performed, however, a certain amount of noise is inevitable. It takes a powerful column of air to pull debris up from the pavement: If you take a look/listen for yourself, you will find that simply the air movement created by this action makes up a surprisingly high percentage of the sound of a modern sweeper.

The intention of our office in furnishing this letter is to enable the decision-makers of the city of Boise to become better able to understand the role of power sweeping in their community and in its economy. As a person in that position, I urge you to now go one step further and take a firsthand look. Schedule an appointment with a local sweeping contractor to see for yourself how a modern sweeper operates. Ask them any questions that might help you in your decision-making.

Also feel free to contact my office, at 360-724-7355, with any questions. You may also contact me directly via email. If you have Internet access, you will also find that our American Sweeper website ( will provide a host of additional information about the sweeping industry which may prove helpful.

On behalf of the power sweeping community, as well as your own business community which relies so heavily on the many benefits of regular sweeping, I urge you to consider all of the factors before deciding upon your course of action. A nighttime noise ordinance which would restrict the efforts of sweeping contractors to keep the paved areas of the city clean is something which would have far-reaching negative implications for the beauty and competitiveness of Boise. Weigh carefully the factors, and you will surely discover the truth in that statement. There are many other ways to address individual instances of noise disturbance by a sweeper. Your local sweeping contractors are no doubt aware of these and, again, you may feel free to call on our office as well.

Ranger Kidwell-Ross, M.A.

Editor, American Sweeper Magazine (Today, Ranger is editor of

cc: City Attorney, City Council Members, Central District Health Department

This article is reprinted from American Sweeper magazine, v5n1.

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