Page 19 - California Stormwater Workshop Handouts

Industrial General Permit Order

61. This General Permit incorporates a multiple objective performance
measurement system that includes NALs, new comprehensive training
requirements, Level 1 ERA Reports, Level 2 ERA Technical Reports, and
Level 2 ERA Action Plans. Two objectives of the performance measurement
system are to inform Dischargers, the public and the Water Boards on: (1) the
overall pollutant control performance at any given facility, and (2) the overall
performance of the industrial statewide storm water program. Additionally,
the State Water Board expects that this information and assessment process
will provide information necessary to determine the feasibility of numeric
effluent limitations for industrial dischargers in the next reissuance of this
General Permit, consistent with the State Water Board Storm Water Panel of
Experts’ June 2006 Recommendations.3

62. This General Permit contains annual and instantaneous maximum NALs.
The annual NALs are established as the 2008 MSGP benchmark values, and
are applicable for all parameters listed in Table 2. The instantaneous
maximum NALs are calculated from a Water Board dataset, and are only
applicable for Total Suspended Solids (TSS), Oil and Grease (O&G), and pH.
An NAL exceedance is determined as follows:

a. For annual NALs, an exceedance occurs when the average of all
analytical results from all samples taken at a facility during a reporting
year for a given parameter exceeds an annual NAL value listed in Table 2
of this General Permit; or,

b. For the instantaneous maximum NALs, an exceedance occurs when two
or more analytical results from samples taken for any parameter within a
reporting year exceed the instantaneous maximum NAL value (for Total
Suspended Solids, and Oil and Grease), or are outside of the
instantaneous maximum NAL range (for pH) listed in Table 2 of this
General Permit. For the purposes of this General Permit, the reporting
year is July 1 through June 30.

63. The NALs are not intended to serve as technology-based or water quality-
based numeric effluent limitations. The NALs are not derived directly from
either BAT/BCT requirements or receiving water objectives. NAL
exceedances defined in this General Permit are not, in and of themselves,
violations of this General Permit. A Discharger that does not fully comply with
the Level 1 status and/or Level 2 status ERA requirements, when required by
the terms of this General Permit, is in violation of this General Permit.

64. ERAs are designed to assist Dischargers in complying with this General
Permit. Dischargers subject to ERAs must evaluate the effectiveness of their

3 State Water Board Storm Water Panel of Experts, The Feasibility of Numeric Effluent Limits Applicable to
Discharges of Storm Water Associated with Municipal, Industrial and Construction Activities (June 19, 2006)
<http://www.swrcb.ca.gov/water_issues/programs/stormwater/docs/numeric/swpanel_final_report.pdf>
[as of February 4, 2014].

Order 2014-0057-DWQ 11