Get Ready For Indiana’s New Industrial Stormwater General Permit
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On September 20, 2024, the Indiana Department of Environmental Management (IDEM) issued a draft Industrial Stormwater General Permit (ISGP), which is open for public comment until November 19, 2024. KERAMIDA was a member of IDEM’s Industrial Workgroup during the development of the draft permit. The new ISGP marks a significant update as IDEM has not revised its Industrial Stormwater General Permit program (“Rule 5”) since 2003.
The facilities affected by Indiana’s new ISGP will be the same as those regulated by the current rule. However, the requirements will be more stringent in terms of sampling frequency, pollutant benchmarks, inspections, and corrective actions, as shown in the table below.
Key Proposed Changes to Indiana’s ISGP Program
Notice of Intent
The new ISGP will require more information gathering before the submittal of the NOI. Namely, the facility’s sector and the classification of the receiving water. A facility’s sector is based on its SIC code and determines what pollutants must be analyzed. Some sectors will also need to implement mandated Best Management Practices (BMPs). Determine your sector by looking at Appendix A of the draft permit. A facility will also need to determine if their receiving water is an impaired water. Impaired waters are sections of streams on IDEM’s “303(d)” list. Some impaired water have Total Maximum Daily Loads (TMDLs). Both classifications could mean additional BMPs or monitoring will be required.
SWPPP
Indiana already requires facilities to implement a Stormwater Pollution Prevention Plan (SWPPP). The SWPPP outlines Best Management Practices, Training, and Inspections to reduce impacts to stormwater. These requirements remain largely the same for existing and new permittees. However, new permittees must have their SWPPP implemented when their NOI is submitted, unlike the current requirement to implement the SWPPP within 365 days after the NOI is submitted.
Monitoring Parameters
The majority of facilities currently monitor for 8 pollutants: pH, COD, CBOD5, TKN, Nitrate+Nitrite, Oil & Grease, TSS, and Phosphorus. In the proposed ISGP, many facilities will actually have less pollutants to monitor. At a minimum, all facilities will need to monitor for pH, COD, and TSS. Additional pollutants will be required based on the Appendix A Sector. Some facilities will need to monitor for metals for the first time.
All monitoring results will be compared to benchmark values set by IDEM, as shown in the table below.
Results above the benchmarks are not permit violations, but the facility must investigate the sources and make efforts to reduce the pollutant in its discharge. As discussed in more detail below, the average of several sampling events are compared to benchmarks to determine what actions must be taken.
Examples of other benchmarks that may apply to certain facilities, based on their sector, are below.
1 - Benchmark is determined by the hardness in the receiving stream. Higher hardness results in a higher benchmark value.
Monitoring Frequency
Samples for Laboratory Analysis
A total of 4 quarterly samples must be collected from each outfall over the first 8 quarters (i.e. 2 years) of the permit. The monitoring frequency is then dictated by the average of the first 4 samples. The flow chart below shows how the monitoring frequency is determined.
Some facilities may only be required to collect 4 samples during the 5 year permit term. Others may be required to sample quarterly. The outfalls and pollutants to monitor and the frequency are determined by the levels of each pollutant in each outfall. Monitoring must continue at any particular outfall for any pollutant average that is detected above the benchmark values. Therefore, a facility may have quite a management task at hand for tracking the status of each outfall and each pollutant over the course of the permit term.
Samples for Visual Inspection
Facilities are also required to inspect and document the following qualities in a sample of runoff collected from each outfall on a quarterly basis:
(A) Color
(B) Odor
(C) Clarity (diminished)
(D) Floating solids
(E) Foam
(F) Suspended solids
(G) Settled solids
(H) Oil sheen
(I) Other indicators of pollution
So, although, samples may not need to be analyzed in a lab each quarter for the entire permit term, facilities should plan on sampling each outfall every quarter during a storm event from now on.
BMPs and Inspections
Best Management Practices (BMPs)
Currently, permitted facilities have SWPPPs with customized BMPs in place that address the unique risks to stormwater at their facility. (e.g. Ensure the all drums are stored under cover). Some facilities, based on their sector, will have additional BMPs that are required by the permit. For example, facilities in the transportation and warehousing sector with vehicle maintenance and equipment cleaning must:
Minimize the potential for stormwater exposure to leaky or leak-prone vehicles or equipment awaiting maintenance.
Minimize contamination of stormwater run-off from fueling areas.
Maintain all material storage vessels (e.g., for used oil/oil filters, spent solvents, paint wastes, hydraulic fluids) to prevent contamination of stormwater and plainly label them (e.g., “Used Oil,” “Spent Solvents,” etc.).
Minimize contamination of stormwater run-off from all areas used for vehicle or equipment cleaning or maintenance.
Minimize stormwater run-on and run-off or utilize appropriate sediment control measures to minimize the off-site transport of sanding material associated with locomotive sanding areas.
Inspect all areas/activities associated with storage areas for vehicles or equipment awaiting maintenance, fueling areas, indoor and outdoor vehicle and equipment maintenance areas, material storage areas, vehicle and equipment cleaning areas and loading/unloading areas.
One would expect these types of BMPs are already in place, but more detailed expectations and standards in the draft ISGP provide better guidance to both permittees and agency inspectors.
Inspections
Similarly, the draft ISGP is more specific regarding what must be inspected and the records that must be kept. The current rule and the draft ISGP both require quarterly inspections of BMPs, areas of industrial activity, structural controls, other control measures, etc. In addition, the draft ISGP requires at least one of the quarterly inspections be performed during a period when stormwater discharge is occurring. In addition, as outlined above in Samples for Visual Inspection, a sample of runoff must be collected from each outfall on a quarterly basis and visually inspected for quality.
Corrective Actions
There is a formal corrective action process that must be followed. Documentation of corrective actions must be kept on file at the facility and will likely be reviewed during any IDEM inspections. There are many instances that trigger the corrective action process. The two most likely triggers are quarterly inspection results and sampling results that exceed benchmarks. The draft ISGP requires the following process be followed when implementing corrective actions.
A corrective action report must be initiated within 24 hours of becoming aware of such a condition and must include thorough documentation of the dates and locations of conditions needing correction, the schedule for correction, actions completed when implementing the corrective action, and consideration of other areas where the corrections should be made to prevent similar occurrences.
This type of formal corrective action is likely familiar to facilities in their overall daily operations. However, the level of detail and IDEM’s expectations are very specific regarding documentation and timelines. The ISGP may require “tweaks” to a facility’s existing corrective action processes in order to comply.
Reporting
Annual reports are currently required and will continue to be required under the ISGP. The content of the annual report is very similar to what is currently required. However, data on inspections, monitoring, receiving streams, corrective actions, etc. will be different, based on all the changes in requirements described above.
How To Prepare For the New ISGP
The new permit is expected to go into effect in 2025. There are several things that current permittees can do now to be ready for the new ISGP.
New ISGP To-Do List:
Determine what Sector you are in.
Determine what benchmark parameters apply.
Sample, if no data. Compare results to benchmarks.
Set up sampling schedule with laboratory.
Look for sources of pollutants.
Update your SWPPP.
Are you discharging to an Impaired Water?
Participate in Public Forums.
Current permittees will be required to transition over to the new permit within 180 days of being notified by IDEM that it is time for their facility to transition. The following will likely be the biggest changes in managing your permit compliance tasks.
Important Changes in Your Permit Compliance Tasks:
Know your NOI deadline and Submit your NOI on time
Increased sampling frequency
Change in parameters
Change in SWPPP program?
Change inspection frequency?
Change corrective action program?
Implement impaired water requirements?
Public comments will be accepted until 11/19/24. There may also be public meetings regarding the draft permit if IDEM determines they are necessary based on the comments received. KERAMIDA is reviewing the draft permit and will be submitting comments. If you would like to discuss how the new permit might impact your facility, please contact us or call (800) 508-8034 to speak with one of our stormwater professionals.
Author
Kristen Belcredi, P.E., C.H.M.M., ISO Auditor
Senior Vice President, Air & Engineering Services
KERAMIDA Inc.
Contact Kristen at kgb@keramida.com.
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