Page 61 - California Stormwater Workshop Handouts

Industrial General Permit Order

ii. A statement that the Discharger has identified and evaluated all
potential pollutant sources that may have commingled with storm
water associated with the Discharger’s industrial activity and may be
contributing to the NAL exceedance;

iii. A description of any on-site industrial pollutant sources and
corresponding industrial pollutants that are contributing to the NAL
exceedance;

iv. An assessment of the relative contributions of the pollutant from (1)
storm water run-on to the facility from adjacent properties or non-
industrial portions of the Discharger’s property or from aerial
deposition and (2) the storm water associated with the Discharger’s
industrial activity;

v. A summary of all existing BMPs for that parameter; and,

vi. An evaluation of all on-site/off-site analytical monitoring data
demonstrating that the NAL exceedances are caused by pollutants in
storm water run-on to the facility from adjacent properties or non-
industrial portions of the Discharger’s property or from aerial
deposition.

c. Natural Background Pollutant Source Demonstration

This shall include:

i. A statement that the Discharger has determined that the NAL
exceedance is attributable solely to the presence of the pollutant in
the natural background that has not been disturbed by industrial
activities. (The pollutant may also be present due to industrial
activities, in which case the Discharger must demonstrate that the
pollutant contribution from the industrial activities by itself does not
result in an NAL exceedance);

ii. A summary of all data previously collected by the Discharger, or
other identified data collectors, that describes the levels of natural
background pollutants in the storm water discharge;

iii. A summary of any research and published literature that relates the
pollutants evaluated at the facility as part of the Natural Background
Source Demonstration;

iv. Map showing the reference site location in relation to facility along
with available land cover information;

v. Reference site and test site elevation;

Order 2014-0057-DWQ 53