Pavement  August/September 1999
Street sweeping to reduce pollution

Montana buys 35 sweepers to combat PM 10 problems
By Allan Heydorn

To comply with a federal Environmental Protection Agency mandate, the state of Montana has adopted street-cleaning strategies that rely heavily on sweeping to combat PM 10 air pollution.

And to further their efforts, the Montana Dept. of Transportation (MDT), through the Montana Air and Congestion Initiative (MACI), recently helped localities throughout the state acquire a total of 35 new sweeping machines that will be used in the areas where PM 10 concentration is highest.

“Without exception the main pollution control strategies — on the transportation side — are sweeping and flushing,” said Dick Turner, chief of the multi-modal planning bureau for MDT.

PM10 (particulate matter smaller than 10 microns in diameter) is composed of small particles of solid or semi-solid material suspended in the atmosphere.

In large cities PM10 is most often caused by car and diesel truck emissions, but in less-populated areas, such as Montana, PM 10 results from traffic on unpaved or sanded roads. PM 10 levels are monitored at sites throughout the United States by the EPA and monitored in the state by the Montana Dept. of Environmental Quality.

According to the MDT, the EPA in the 1980s identified 18 Montana communities where residents were threatened by PM10 pollutants. Tom Steyaert, planner with the MDT, says that through the Montana Air and Congestion Initiative (MACI), the state had classified ten of those areas as “non-attainment” by the EPA with the remaining areas considered “‘at risk” for experiencing high PM10 levels in the future.

“In Montana, PM 10 levels tend to be seasonal,” Steyaert says. “We notice higher levels in the winter and spring, when sand is used on icy roadways. Vehicle traffic breaks down the sand, and the ultra-fine particles that result are kicked-up into the air. Visually the result is the plume of dust you see behind a car.”

It is the “plume of dust” Steyaert refers to that is considered a health hazard. Research in the United States has documented associations between exposure to fine particles and death from respiratory and cardiac disease, while in England PM 10 is considered by some to be that country’s greatest health problem.

EPA requires cleanup

Turner says federal mandates developed as a result of the Clean Air Act and the air-quality testing in the 1980s required Montana to develop a state implementation plan that, once in place, would begin cleaning up the air.

He says officials developing the program recognized the importance of sweeping and flushing to control pollution, so the state used those approaches as the backbone of the pollution control effort.

He says the federal mandate also required Montana’s affected communities to actually pass local ordinances requiring their local governments and departments of public works to improve the air quality by reducing PM 10 air pollution.

“The EPA required that the control strategies be legally enforceable, so the local communities were required to pass ordinances that set up a regular schedule for sweeping and  flushing,” Turner says.

He says the communities passed the ordinances as required, and then went to work implementing the pollution control program.

The problem, Turner says, is that most of the communities were working to comply with the air quality mandate using older, less efficient, and much less reliable sweeping equipment.

“Let’s face it, sweeping equipment is very high maintenance,” Turner says. “In many cases it’s been a real burden for those communities to comply with those ordinances.”

But difficult does not mean impossible.

Turner says the monitoring data from throughout the state indicates that the sweeping-heavy PM10 pollution control strategy has been working.

“The monitoring data has indicated that air quality has improved in all but one of the 18 areas,” he says. “That’s really a tribute to the dedication and the effort of the local crews and local public works departments to get this done — despite the fact they had older and less-effective sweeping equipment.”

Feds, state help locals

When MDT realized it could help upgrade the localities’ pollution control efforts, they jumped at the chance.

“Through the MACI program we’re able to pro-actively address PM10 concerns by allowing the ‘at-risk’ areas to purchase the equipment necessary to reduce this air pollutant.”

Steyaert says that through the MACI program the MDT initiated a project to buy 35 sweepers, 15 flush trucks, 32 liquid de-icer applicators (for use instead of sand), and 11 storage tanks. Total cost of the equipment was more than $6 million, with federal funding paying for almost 87% of the cost and local governments picking up the difference.

Cheryl Richman, MDT fiscal officer, says the following machines were purchased through the MACI program: 16 Tennant Model 830-II, 6 Elgin Broom Bear, 1 Elgin GeoVac, 1 Elgin Eagle, 1 Elgin Vac-All, 6 Athey M-9D, 1 Athey M-8A, and 3 Johnston Model 305.

“Right now in Montana the issue is one of air quality and congestion,” Steyaert says. “Fortunately removing fine particles from roadways significantly lowers PM10 levels.”

Frustrated with the “here today, gone tomorrow” firms that operate on the fringes of the sweeping industry, Contract Sweepers Institute (CSI) has taken steps to develop a certification of sorts for its members.

Carl Austin, Schwarze Industries, Huntsville, AL, will head a task force to develop a set of “best management practices” for sweeping contractors. The task force is charged with “providing CSI members with a set of business practices against which they can measure their own practices and procedures.”

The “best management practices” will be adapted from practices already a part of the American Public Works Association's Public Works Agency Accreditation and Self-Assessment programs.

CSI says that members who follow the best management practices and perform the necessary self-assessment and document the results will be able to note compliance on their company letterhead and other marketing materials.

CSI to develop “best practices” for sweepers

CSI says many of these “fringe” sweeping contractors are undercapitalized, charge unrealistically low rates, operate poorly maintained equipment, and perform low-quality work.

“In short, they are the ‘bad actors’ who give the sweeping industry a bad reputation while at the same time driving the local market for sweeping services to uneconomically low levels,” according to CSI.