In Phase II rules for the National Pollutant Discharge Elimination System, aimed primarily at small municipal storm water systems and construction sites, the U.S. Environmental Protection Agency introduced a “no exposure” exclusion available to any industrial category (except construction) included in existing storm water regulations.
To qualify, a company must complete and submit a form every five years certifying that none of the following activities or materials are exposed to precipitation:
1. Using, storing, or cleaning industrial machinery or equipment. This includes areas where residuals from those activities remain and are exposed to storm water.
2. Materials or residuals on the ground or in storm water inlets from spills/leaks.
3. Materials or products from past industrial activity.
4. Materials handling equipment (except adequately maintained vehicles, see below).
5. Materials or products during loading/unloading or transporting activities.
6. Materials or products stored outdoors (except final products intended for outside use where exposure to storm water does not result in the discharge of pollutants.)
7. Materials contained in open, deteriorated or leaking storage drums, barrels, tanks and similar containers.
8. Materials or products handled/stored on roads or railways owned or maintained by the discharger.
9. Waste material (except waste in covered, non-leaking containers such as dumpsters).
10. Application or disposal of process wastewater unless otherwise permitted.
11. Particulate matter or visible deposits of residuals from roof stacks and/or vents not otherwise regulated (such as under an air quality control permit) and evident in storm water outflow.
“No exposure” means that all industrial materials or activities are protected by a storm-resistant shelter to prevent exposure to rain, snow, snowmelt and/or runoff. Some temporary shelters, such as tarps, may be permitted, but that and other non-specified conditions will be evaluated by local NPDES authorities on a case-by-case basis.
The agency did note that “adequately maintained vehicles such as trucks, automobiles, forklifts or other such general purpose vehicles at the industrial site that are not industrial machinery, and that are not leaking contaminants or are not otherwise a source of industrial pollutants, could be exposed to precipitation or runoff. Such activities alone does not prevent a discharge from being able to certify no exposure under this provision.
"Similarly, trucks or other vehicle awaiting maintenance at vehicle maintenance facilities, ...that are not leaking contaminants are or are not otherwise a source of industrial pollutants, are not considered exposed.”
More information, including a copy of the certification form, can be found at www.epa.gov/owm/sw/phase2.