Virginia Law

A. Discharges covered under this section. The requirements listed under this section apply to stormwater discharges associated with industrial activity from facilities generally classified under SIC Codes 3251-3259, 3261-3269, 3274, and 3275 that are engaged in either manufacturing the following products or performing the following activities: structural clay products including tile and brick; pottery and porcelain electrical supplies; and concrete, plaster, and gypsum products.

Concrete block and brick facilities (SIC Code 3271), concrete products facilities, except block and brick (SIC Code 3272), and ready-mixed concrete facilities (SIC Code 3273) are not covered by this permit.

B. Stormwater controls. In addition to the requirements of Part III, the SWPPP shall include, at a minimum, the following items:

1. Facilities shall prevent or minimize the discharge of spilled cement; aggregate (including sand or gravel); kiln dust; fly ash; settled dust; and other significant materials in stormwater from paved portions of the site that are exposed to stormwater. Measures used to minimize the presence of these materials may include regular sweeping, or other equivalent measures. The SWPPP shall indicate the frequency of sweeping or equivalent measures. The frequency shall be determined based on consideration of the amount of industrial activity occurring in the area and frequency of precipitation, but shall not be less than once per week if cement, aggregate, kiln dust, fly ash, or settled dust are being handled or processed.

2. Facilities shall prevent the exposure of fine granular solids ( e.g., cement, fly ash, and kiln dust) to stormwater. Where practicable, these materials shall be stored in enclosed silos or hoppers, buildings, or under other covering.

C. Numeric effluent limitations. The following numeric effluent limitations shall be met by facilities with cement manufacturing and material storage runoff. Any discharge composed of runoff from the storage of materials, including raw materials, intermediate products, finished products, and waste materials from the manufacture of cement, shall not exceed the limitations in Table 130-1. Runoff from the storage piles shall not be diluted with other stormwater runoff or flows to meet these limitations. Any untreated overflow from facilities designed, constructed, and operated to treat the volume of material storage pile runoff that is associated with a 10-year, 24-hour rainfall event shall not be subject to the TSS or pH limitations.

D. Benchmark monitoring and reporting requirements. Clay product manufacturers (SIC Codes 3251-3259, SIC Codes 3261-3269) and lime and gypsum product manufacturers (SIC Codes 3274, 3275) are required to monitor their stormwater discharges for the pollutants of concern listed in Table 130-2.