Page 139 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

e. Sampling Frequency Reduction

Facilities that do not have NAL exceedances for four (4) consecutive QSEs are
unlikely to pose a significant threat to water quality. If the storm water from these
facilities is also in full compliance with this General Permit, the Discharger is
eligible for a reduction in sampling frequency. The Sampling Frequency
Reduction allows a Discharger to decrease its monitoring from four (4) samples
within each reporting year to one (1) QSE within the first half of each reporting
year (July 1 to December 31) and one (1) QSE within the second half of each
reporting year (January 1 to June 30). If a Discharger has a subsequent NAL
exceedance after the Sampling Frequency Reduction, it must comply with the
original sampling requirements of this General Permit. Only Dischargers that
have baseline status or that have satisfied the Level 1 requirements are eligible
for this sampling and analysis reduction.

A Discharger requesting to reduce its sampling frequency shall certify and submit
a Sampling Frequency Reduction certification via SMARTS. The Sampling
Frequency Reduction certification shall include documentation that the General
Permit conditions for the Sampling Frequency Reduction have been satisfied.

Dischargers participating in a Compliance Group and certifying a Sampling
Frequency Reduction are only required to collect and analyze storm water
samples from one (1) QSE within each reporting year. These Dischargers must
receive year-round compliance assistance from their Compliance Group Leader
and must comply with all requirements of this General Permit.

5. Facilities Subject to Federal Storm Water Effluent Limitation Guidelines (ELGs)

Federal regulations at Subchapter N establish ELGs for industrial storm water
discharges from facilities in eleven industrial sectors. For these facilities,
compliance with the ELGs constitutes compliance with the technology standard of
BPT, BAT, BCT, or New Source Performance Standards provided in the ELG for the
specified pollutants, and compliance with the technology-based requirements in this
General Permit for the specified pollutant.

K. Exceedance Response Actions (ERAs)

1. General

The previous permit did not incorporate the benchmarks from any of the MSGPs or
NALs for Dischargers to evaluate sampling results. Unlike the requirements for
industrial storm water discharges that cause or contribute to an exceedance of a
water quality standards, the previous permit did not provide definitions, procedures
or guidelines to assess sampling results. Many Regional Water Boards have
formally or informally notified Dischargers that exceedances of the MSGP
benchmarks should be used to determine whether additional BMPs are necessary.
However, there was considerable confusion as to the extent to which a Discharger
would be expected to implement actions in response to exceedances of these
values, and the timelines that had to be met to prevent an enforcement action. The
lack of specificity with regards to what constituted an exceedance, and what actions

Order 2014-0057-DWQ 55