Enforcing dust control

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    Credit: California Stormwater Quality Association

    The California Stormwater Quality Association's construction, industrial, municipal, and/or new development handbooks build on knowledge gained since the early 1990s about the effectiveness of best management practices in controlling particulates. Buy and download any of the four here.

Ever since the Dust Bowl of the 1930s, the federal government has been looking for dust-control solutions. EPA is considering aggressive changes to the Clean Air Act to address dust that becomes considerably worse in windy, arid, and semiarid regions.

Under the authority of the Clean Air Act, the California Air Resources Board has begun addressing inhalable particulate matter of less than 10 microns (PM-10), roughly 90% of which is considered dust.

At the same time, many local agencies require dust control to comply with nuisance and opacity (i.e., visibility impairment) ordinances.

Phoenix-area jurisdictions consistently violate both annual and 24-hour national PM-10 standards from vehicles kicking up dust on unpaved roads, earth-moving operations, unpaved parking lots, disturbed vacant lots, and agricultural fields. To alleviate the problem, Arizona Department of Environmental Quality (ADEQ) and Maricopa County permitting requirements include implementing BMPs, conducting observations and inspections, and monitoring/reporting.

Some states, such as Minnesota, have fairly stringent requirements preventing particulate matter from becoming airborne at construction sites.

For the time being, except for those involving soil impacted with hazardous waste or chemicals, most construction projects across the country aren't required to have comprehensive dust-control plans other than addressing dust control as part of the SWPPP. But given the federal government's continuing war on pollution, the Clean Air Act might one day be amended to require dust-control plans more stringent than the Clean Water Act's stormwater pollution framework for a wide range of construction activities.

That would be the logical next step: Dust control should be integral to mitigating stormwater pollution because preventing wind and water erosion on construction sites is one of the primary goals of SWPPP implementation.

Tip: Using just water to suppress dust is, in some cases, no longer sufficient. Fortunately, control techniques are continually refined and new technologies emerge every year. Here are a few low-cost ways to minimize erosion:

Water additives. Emulsions and additive products with colorful names like Dirtglue, Gorilla-Snot by Soilworks LLC, and Roadkill from Dustkill Inc. suppress dust much more effectively than just water. One of our favorites is M-Binder by Granite Seed Co.

Soil treatments. Products like hydrocrete, chemical binders, vegetation, etc., hold the top layer of soil in place by creating a barrier that keeps dust particles from moving.

Polymer-enhanced geotextile fabrics. These re made by combining geotextiles like jute mat with a polymer to provide double protection against erosion.

Modeling software. Available here, the U.S. Department of Agriculture's free Wind Erosion Prediction System (WEPS) identifies potential airborne contaminant issues and provides site-specific solutions by enabling users to insert BMPs, run “what if” scenarios, and see the effect of various preventive options.

For streets and roadsides:
  • Reduced and enforced speed limits
  • High-efficiency street sweepers with particulate filters
  • Hydro-seeding or wetting-agent applications
  • Track-out grates that knock dirt from tires before trucks leave sites
  • Tire wash stations
  • Construction activities scheduled to coincide with periods of minimum wind velocity.

Tip: To learn more about these and other new developments, tap into industry groups such as the International Erosion Control Association.

— Long (llong@scsengineers.com) is vice president of SCS Engineers' field services construction division, and Porter (sporter@scsengineers.com) is the national partner for stormwater and water quality services.