Page 156 - California Stormwater Workshop Handouts

Industrial General Permit Fact Sheet

and guidance for entities to determine whether they are eligible to indicate “No
Discharge” on the NONA as a reason for not obtaining General Permit coverage.

This General Permit addresses and resolves the issues discussed above by
establishing consistent, statewide eligibility requirements in Section XX.C for entities
submitting NONAs indicating “No Discharge.” When requested by the Water Boards
to obtain General Permit coverage, entities must meet these “No Discharge”
eligibility requirements or obtain General Permit coverage. The Water Boards retain
enforcement authority if a facility subsequently discharges.

2. “No Discharge” Eligibility Requirements

The entity must certify submit in SMARTS a NONA Technical Report signed (wet
signature and license number) by a California licensed professional engineer that
contains the analysis and details of the containment design supporting the “No
Discharge” eligibility determination. Because containment design will require
hydraulic calculations, soil permeability analysis, soil stability calculations,
appropriate safety factor consideration, and the application of other general
engineering principles, state law requires the technical report to be signed (wet
signature and license number) by a California licensed professional engineer.

The State Water Board has selected a containment design target that, as properly
applied will result in few, if any, discharges. The facility must either be:

a. Engineered and constructed to contain all storm water associated with industrial
activities from discharging to waters of the United States. (The determination of
what is a water of the United States can be complicated, and in certain
circumstances, a discharge to groundwater that has a direct hydrologic
connection to waters of the United States may constitute a discharge to a water
of the United States.) Dischargers must base their information upon maximum
historic precipitation event data (or series of events) from the nearest rain gauges
as provided by the National Oceanic and Atmospheric Administration’s (NOAA)
website, or other nearby precipitation data available from other government
agencies. At a minimum, Dischargers must ensure that the containment design
addresses maximum 1-hour, 24-hour, weekly, monthly, and annual precipitation
data for the duration of the exclusion.

Design storm events are generally specified as a one-time expected hydraulic

failure over a reoccurrence of years for a specified storm event. For example, if

a design storm standard is a 100 year 24-hour event, then a facility’s

containment system designed to contain the maximum volume of water would be

expected to fall in 24 hours once every 100 years. Design standards vary

dependent upon the regulatory program and the level of protection needed.

Since California has considerable variations in climate/topography/soil conditions

across the state, the “No Discharge” NONA eligibility requirements have been

created so that each facility’s containment design can incorporate unique site

specific circumstances to meet the requirement that discharges will not occur

based upon past historical precipitation data. Facilities that are not designed to

not meet the “No Discharge” eligibility requirements must obtain General Permit

coverage.

Order 2014-0057-DWQ 72