Page 132 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

anywhere from thousands to hundreds of thousands of dollars per facility
depending on the size and nature of each industrial facility. At many facilities,
the construction of such conveyances may also violate local building codes,
create safety hazards, cause flooding, or increase erosion. In addition,
eliminating sheet flow at some facilities could result in increased pollutant
concentrations.

The State Water Board has considered the complexity and costs associated with
quantitative monitoring. Unlike continuous point source discharges (e.g., publicly
owned treatment works), storm water discharges are variable in intensity and
duration. The concentration of pollutants discharged at any one time is
dependent on many complex variables. The largest concentration of pollutants
would be expected to discharge earlier in the storm event and taper off as
discharges continue. Therefore, effective quantitative monitoring of storm water
discharges would require that storm water discharges be collected and sampled
until most or all of the pollutants have been discharged. Multiple samples would
need to be collected over many hours. To determine the pollutant mass loading,
the storm water discharge flow must also be measured each time a sample is
collected.

For a quantitative monitoring approach to yield useful pollutant loading
information, the installation of automatic sampling devices and flow meters at
each discharge location would usually be necessary. In addition, qualified
individuals would be needed to conduct the monitoring procedures, and to handle
and maintain flow meters and automatic samplers are needed. A significant
majority of storm water Dischargers under this General Permit do not possess
the skills to manage such an effort. Dischargers will bear the cost of employing
and/or training on-site staff to do this work, or the cost of contracting with
environmental consultants and acquiring the required flow meters and automatic
samplers. The cost to Dischargers to conduct quantitative monitoring varies
depending on the number of outfalls, the number of storms, the length of each
storm, the amount of staff training, and other variables.

To address these concerns, this General Permit includes a number of new items
that bridge the gap between the previous permit’s qualitative monitoring and the
quantitative approach recommended by many commenters. This General Permit
includes a requirement for all Dischargers to designate a QISP when they enter
Level 1 status due to NAL exceedances. The QISP is required to be trained to:
(1) more accurately identify discharge locations representative of the facility
storm water discharge (2) select and implement appropriate sampling procedures
(3) evaluate and develop additional BMPs to reduce or prevent pollutants in the
industrial storm water discharges.

Dischargers that fail to develop and implement an adequate Monitoring
Implementation Plan that includes both visual observations and sampling and
analysis, are in violation of this General Permit. Dischargers that fail to comply
with Level 1 status and Level 2 status ERA requirements, triggered by NAL
exceedances, are in violation of this General Permit.

Order 2014-0057-DWQ 48