Stormwater Program for Industrial Activity: Steps to Compliance

Step 13: Sample/monitor again, send in results

What to do if you have an exceedance after the end of year 4

Step 13a: Sample in Year 4

If  your “Year 2” Industrial Stormwater benchmark monitoring sampling requirements have ended and either could not collect any samples in “Year 2” or have exceeded for one or more pollutant parameters, you are required to sample in “Year 4.”

“Year 2” outcomes:

1. No flow:  If you have submitted all your SWMRs on time with “no flow” explanations:  You are required to conduct benchmark sampling requirements within “Year 4” of the current General Permit cycle.
2. No SWMR:  If you did not submit any or all of the required SWMRs within year 2, you are still required to send them in and should do so immediately. Failing to mail in the required forms may result in enforcement action.
3. Exceedances:  the sample results you submitted exceeded the Permit Benchmark Values.  If you had exceedances, there are 3 types:  

a.    You exceeded your benchmark value(s)
b.    You exceed and you discharge to an impaired water or Outstanding Resource Value Water (ORVW).
c.    You had a high exceedance (typically 10 times over the benchmark value).

In any of these exceedance situations, permittees are required to modify their SWPPP, consider different BMPs, and sample again in Year There are no required “Year 3” benchmark sampling requirements.  Step 12 of the Industrial Stormwater Program’s Steps to Compliance, has sector and pollutant-specific BMP suggestions.

For permittees that discharge to either an impaired water or to an ORVW, upon discovery of your exceedances, you are required to:

1. Update your Stormwater Pollution Prevention Plan within 30 days.
2. Implement necessary non-structural Best Management Practices (BMPs) within 60 days.
3. Implement necessary structural BMPs within 180 days.

“Year 4” monitoring requirements begin three years after you received your permit coverage. Just like “Year 2,” sampling requirements are based on quarterly monitoring intervals for one year.  For “Year 4” you only have to sample for those parameters and locations where you had exceedances.  

Approximately seventy (70) days from the end of your “Year 2” reporting period, your updated SWMR forms will be available through our Industrial Stormwater Permit Information Access search tool.  Please see Pages 27-28 of the General Permit for more information on these requirements.

Additionally, we have created an online PowerPoint Presentation (wq-strm3-65a) with embedded voiceover on this topic.

Step 13b: Fill out a Benchmark Exceedance Report

If you’re a facility that did not pass your benchmark monitoring requirements in year 2 and also in year 4, you are required to submit a Benchmark Exceedance Report (BER). The BER will ask you to provide the following information:

• Describe the inability to meet the benchmark values.
• Describe in detail the technical basis and reasons why the benchmark values cannot be met.

The Benchmark Exceedance Report shall be submitted to the Agency no later than 30 days after the fourth sampling interval of the monitoring year.

The form is not yet available.

Step 13c: Conduct fifth year monitoring

If sampling conducted in accordance with fourth year monitoring resulted in a benchmark value exceedance, the Permittee shall conduct fifth year monitoring. The fifth year monitoring may be limited to only the benchmark parameter(s), and benchmark monitoring locations for which a benchmark value was exceeded during the fourth year monitoring.

Once the fifth year samples for each benchmark monitoring location(s) have been collected and analyzed, the Permittee shall compare the average of the fifth year monitoring results with the applicable benchmark value and refer to the following outcomes to determine what further action may be required.

Step 13d: Re-visit Step 10 to review information about how to sample

Also, this page will be updated to provide information on what specific sectors may be able to do to improve their benchmark monitoring results.

Go to Step 14