On December 8, 1999, EPA adopted new regulations governing the discharge of storm water. The regulations will be effective on February 7, 2000. They expand the existing NPDES Storm Water Program to address storm water discharges from small municipal separate storm water systems and at construction sites that disturb one to five acres. Small municipal separate storm water systems are defined as those serving less than 100,000 people. The regulations also exclude from the NPDES Program storm water discharges from industrial facilities that have "no exposure" of industrial activities or materials to storm water. They also extend until March 10, 2003, the date by which certain industrial facilities owned by small municipal separate storm sewer systems must obtain NPDES permits. The small municipal storm sewer system must adopt six minimum control measures as follows: (1)public education and outreach on storm water impacts; (2)a public involvement/participation process; (3)illicit discharge detection and elimination; (4)construction sites storm water runoff control; (5)post construction storm water management in new development and redevelopment; and (6)pollution prevention/good housekeeping.
EPA decided to regulate construction sites below five acres because it believes that the water quality impact from small construction sites is as high or higher than the impact for larger sites on a per acre basis. Moreover, smaller construction sites are less likely to have an effective plan to control erosion and sedimentation, are less likely to properly implement and maintain their plans, and are less likely to be inspected. The new regulations will apply to all construction activities greater than one acre and less than five acres unless the operator certifies that it is eligible for a waiver. Waivers are applicable where little or no rainfall was expected during the period of construction or when a TMDL or equivalent analysis indicates the controls on construction site discharges are not needed to protect water quality. Unless it obtains a waiver, the operator of the construction site is responsible for obtaining coverage under an NPDES permit for its activity. EPA expects that the vast majority of discharges covered by these activities will be regulated through general permits.
In order to claim relief under the "no exposure" provision of the regulations, the discharger of an otherwise regulated facility must submit a no exposure certification to the permitting authority once every five years. Unlike the old regulations which applied only to light industry, this provision is now available for all categories of industrial activity, except construction activities. The term "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. Industrial materials or activities include material handling equipment or activities, industrial machinery, raw materials, intermediate products, by-products, final products, or waste products. Storm resistant shelter is not required for (1)drums, barrels, tanks, and similar containers that are tightly sealed, provided they are not deteriorated and do not leak; (2)adequately maintained vehicles used for material handling; and (3)final products, other than products that would be mobilized in storm water discharges.