Page 130 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

The previous permit required monthly storm water visual observations. This
required Dischargers to conduct visual observations for QSEs that were not
being sampled since only two QSEs were required to be sampled in the previous
permit. As discussed below, the sampling requirement has been increased to
four QSEs within each reporting year with two QSEs required in each half of the
reporting year. We expect that this will result in more samples being collected
and analyzed, since most of California experiences, on average, at least two
QSEs per half year. This General Permit streamlines the storm water visual
observation requirement by linking the visual observations to the time of
sampling.

3. Sampling and Analysis

a. General

As part of the process for developing previous drafts of this General Permit, the
State Water Board considered comments from numerous stakeholders
concerning sampling and analysis. Sampling and analysis issues were the most
dominant of all issues raised in the comments.

The State Water Board received stakeholder comments that fall into three
primary categories concerning this General Permit’s sampling and analysis
approach:

i. Comments supporting an intensive water quality sampling and analysis
approach (with the goal of producing more accurate discharge-characterizing
and pollutant concentration data) as the primary method of determining
compliance with effluent limitations and receiving water limitations. Since this
approach requires large amounts of high quality data to accurately quantify the
characteristics of the discharges, it is referred to as the quantitative monitoring
approach. Stakeholders supporting the quantitative approach generally also
support the use of stringent NELs to evaluate compliance with this General
Permit;

ii. Comments supporting only visual observations as the primary method of
determining compliance: These stakeholders generally assert that storm water
sampling is an incomplete and not very cost effective means of determining
water quality impacts on the receiving waters; and,

iii. Comments supporting a combination of visual observations and cost-effective
water quality sampling and analysis approach (sampling and analysis that
would produce data indicating the presence of pollutants) to determine
compliance (similar to the previous permit’s approach). Since this approach
uses more qualitative information to describe the quality and characteristics of
the discharges, it is referred to as the qualitative monitoring approach.

Within each of the three categories, there are various recommendations and
rationales as to the exact monitoring frequencies, procedures and methods,
required to implement the approach. Stakeholders in favor of the quantitative
monitoring approach commented that it is the only reliable and meaningful

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