Page 106 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

this General Permit emphasize effective “low-tech” controls, such as regular
cleaning of outdoor areas where industrial activities may take place, proper
maintenance of equipment, diversion of storm water around areas where pollutants
may be picked up, and effective advanced planning and training (e.g., for spill
prevention and response).

E. Receiving Water Limitations and Water Quality Standards

Pursuant to CWA section 301(b)(1)(C) and Water Code section 13377, this General
Permit requires compliance with receiving water limitations based on water quality
standards. The primary receiving water limitation requires that industrial storm water
discharges not cause or contribute to an exceedance of applicable water quality
standards. Implementation of the BMPs as required by the technology-based effluent
limitation in Section V of this General Permit will typically result in compliance with the
receiving water limitations. The discussion of BMPs in this General Permit generally
focuses on requiring implementation of BMPs to the extent necessary to achieve
compliance with the technology-based effluent limitations, because the technology-
based limitations apply similarly to all facilities. In addition, however, this General
Permit also makes it clear that, if any individual facility's storm water discharge causes
or contributes to an exceedance of a water quality standard, that Discharger must
implement additional BMPs or other control measures that are tailored to that facility in
order to attain compliance with the receiving water limitation. A Discharger that is
notified by a Regional Water Board or who determines the discharge is causing or
contributing to an exceedance of a water quality standard must comply with the Water
Quality Based Corrective Actions found in Section XX.B of this General Permit.

Water Quality Based Corrective Actions are different from the Level 1 and Level 2 ERAs
that result from effluent-based monitoring. It is possible for a Discharger to be engaged
in Level 1 or Level 2 ERAs for one or more pollutants and simultaneously be required to
perform Water Quality Based Corrective Actions for one or more other pollutants.

Failure to comply with these additional Water Quality Based Corrective Action
requirements is a violation of this General Permit. If additional operational source
control measures do not adequately reduce the pollutants, Dischargers must implement
additional measures such as the construction of treatment systems and/or overhead
coverage. Overhead coverage is any structure or temporary shelter that prevents the
vertical contact of precipitation with industrial materials or activities. If the Regional
Water Board determines that the Discharger’s selected BMPs are inadequate, the
Regional Water Board may require implementation of additional BMPs and/or may take
enforcement against Dischargers for failure to comply with this General Permit.

F. Total Maximum Daily Loads (TMDLs)

TMDLs are regulatory tools that provide the maximum amount of a pollutant from
potential source in the watershed that a water body can receive while attaining water
quality standards. A TMDL is defined as the sum of the allowable loads of a single
pollutant from all contributing point sources (the waste load allocations) and non-point
sources (load allocations), plus the contribution from background sources. (40 C.F.R. §
130.2, subd. (i).) Discharges covered by this General Permit are considered to be point

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