Page 144 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

dataset does not provide a way of evaluating actual BMP implementation at each
facility when analyzing the data; therefore the monitoring information reported
during the previous permit term cannot be linked to compliance with technology-
based standards. The State Water Board intends to use data collected during
this General Permit term to evaluate the percentile approach, improve the quality
of collected data for other parameters, and further develop an understanding of
how reported data relates to implemented BMP-control technologies.

Under this General Permit, a Discharger enters Level 1 status and must fulfill the
Level 1 status ERA requirements following its first occurrence of any NAL
exceedance. Level 2 status ERA requirements follow the second occurrence of
an NAL exceedance for the same parameter in a subsequent reporting year.
This ERA process provides Dischargers with an adaptive management-based
process to develop and implement cost-effective BMPs that are protective of
water quality and compliant with this General Permit. This General Permit’s ERA
process is designed to have a well-defined compliance end-point. It is not a
violation of this General Permit to exceed the NAL values; it is a violation of the
permit, however, to fail to comply with the Level 1 status and Level 2 status ERA
requirements in the event of NAL exceedances.

The State Water Board acknowledges that storm water discharge concentrations
are often highly variable and dependent upon numerous circumstances such as
storm size, the time elapsed since the last storm, seasonal activities, and the
time of sample collection. Since there are potential enforcement consequences
for failure to comply with this General Permit’s ERA process, the State Water
Board’s intention is to use NAL exceedances to solely require Dischargers with
recurring annual NAL exceedances or drainage areas that produce recurring
instantaneous maximum NAL exceedances to be subject to the follow-up ERA
requirements.

If NALs exceedances do not occur, the State Water Board generally expects that
the Discharger has implemented sufficient BMPs to control storm water pollution.
When NAL exceedances do occur, however, the potential that the Discharger
may not have implemented appropriate and/or sufficient BMPs increases, and
the Discharger is required to implement escalating levels of ERAs. If NAL
exceedances occur, this General Permit requires Dischargers to evaluate and
potentially install additional BMPs, or re-evaluate and improve existing BMPs to
be in compliance with this General Permit.

3. Baseline Status

At the beginning of a Discharger’s NOI coverage under this General Permit, the
Discharger has Baseline status. A Discharger demonstrating compliance with all
NALs will remain at Baseline status and is not required to complete Level 1 status
and Level 2 status ERA requirements.

If a Discharger has returned to Baseline status (from Level 2 status) and additional
NAL exceedances occur, the Discharger goes into Level 1 status, then potentially

Order 2014-0057-DWQ 60