How to Find Your Industry's Section of Pennsylvania's PAG-03 Stormwater Permit by SIC Code, and What That Appendix Means for Your Sampling
If you've opened Pennsylvania's PAG-03 permit for the first time, you've probably noticed it isn't one set of rules so much as a stack of them. Parts A, B, and C apply to every covered facility, and then there are 21 lettered appendices, A through U, each written for a specific industrial sector. Your appendix is where your sampling parameters, benchmark values, and sector-specific practices live, so landing in the right one shapes most of what your stormwater program looks like day to day. The short answer to finding yours is to identify your facility's primary SIC code, look that code up in Table 1 of DEP's PAG-03 Notice of Intent instructions, and then read the appendix it points to.
In this article, we'll walk through each of those steps in more detail, including how DEP decides which of your activities counts as "primary," what to do when your SIC code isn't listed anywhere, and how DEP handles a site with activities that fall under more than one appendix. We've also included a table matching common Pennsylvania industries to their appendix under the current permit. If you'd rather have someone look at your site and tell you where it fits, feel free to reach out to RMA.
Table of Contents
TL;DR
PAG-03 puts its industry-specific requirements in 21 appendices, lettered A through U, and each one is tied to a group of SIC codes. To find yours, figure out your primary SIC code (DEP treats the activity that brings in the most revenue as primary), look it up in Table 1 of the PAG-03 NOI instructions, and read that appendix for your sampling parameters, benchmarks, and extra practices. If your site has more than one covered activity, more than one appendix can apply, and if your code isn't listed at all, you may not need coverage, or DEP may place you under Appendix J or require an individual permit. Appendix letters and contents can change whenever DEP reissues the permit, so always confirm against the current version.
How Are PAG-03 Requirements Split Between the Main Permit and the Sector Appendices?
PAG-03 is Pennsylvania DEP's general NPDES permit for stormwater associated with industrial activity. NPDES stands for the National Pollutant Discharge Elimination System, the federal program that controls pollutants going into streams and rivers, and DEP runs it in Pennsylvania under both the Clean Water Act and the state's Clean Streams Law. A "general" permit is one standard permit that many facilities sign onto by filing a Notice of Intent, or NOI, instead of each facility getting its own custom permit written from scratch. The current edition of PAG-03 took effect on March 24, 2023, and runs through March 23, 2028.
The permit works in two layers. The main body applies to everyone, and the appendices add sector-specific rules on top. Two plants across the street from each other can both hold PAG-03 coverage and still sample for different pollutants because they fall under different appendices. Here's roughly how the two layers divide the work:
| Main permit (Parts A, B, and C) |
Sector-specific appendix (A through U) |
| Narrative discharge limits that apply to everyone, such as no sheen, floating solids, or foam |
The specific pollutants your sector samples for |
| General best management practices (BMPs), routine inspections, and the PPC Plan |
Benchmark values your sample results get compared against |
| Standard conditions, recordkeeping, and how eDMR reporting works |
Extra BMPs written for your type of operation |
| The list of non-stormwater discharges allowed at any covered site |
Any sector-specific non-stormwater discharges that are allowed, and any discharges that are prohibited for your sector |
The PPC Plan mentioned above is Pennsylvania's Preparedness, Prevention, and Contingency Plan, the site-specific plan DEP expects you to keep for preventing and responding to pollution. It's built around the same activities that decide your appendix. If you're still figuring out how that plan compares to the SWPPPs used in other states, our article on SWPPPs vs. PPC Plans for PAG-03 covers the differences.
How Do You Find Your Facility's Primary SIC Code for PAG-03?
SIC stands for Standard Industrial Classification, a four-digit code system the federal government created decades ago to sort businesses by what they do. Most of the government has since moved to NAICS codes, but the federal stormwater rule at 40 CFR 122.26(b)(14) and Pennsylvania's PAG-03 still use the 1987 SIC codes. So the code on your tax return or business registration may not be the one that decides your stormwater obligations. If you only know your NAICS code, the U.S. Census Bureau publishes crosswalks between NAICS and 1987 SIC codes, and EPA includes one in Appendix N of its Multi-Sector General Permit. DEP also points facilities to OSHA's SIC search tool. If you already have coverage, compare the SIC code on your existing NOI against what the site does today, since businesses drift and a code a previous owner picked years ago may no longer fit.
Plenty of sites do more than one thing, so DEP needs a way to decide which activity counts. Its answer, from the industrial stormwater FAQ, is revenue. Add up what each activity on site brings in, and the one that generates the most revenue is your primary industrial activity. Its SIC code is your primary SIC code. A plant that mostly molds plastic parts but does some metal fabrication on the side is a plastics facility for PAG-03 purposes.
The primary code matters because it decides whether you need coverage at all. DEP's FAQ lays out three scenarios:
| Your situation |
What DEP expects |
| Your primary SIC code is listed in the federal rule and Table 1 |
Apply for PAG-03 coverage (or an individual permit) or qualify for a No Exposure Certification |
| Only a secondary SIC code is listed, and no listed narrative activity happens on site |
No coverage required, unless DEP determines one is needed under the Clean Streams Law |
| A listed narrative activity happens on site, whatever your SIC codes are |
Apply for coverage or qualify for No Exposure |
"Narrative activities" are the categories the federal rule defines by what happens on site rather than by SIC code. They include hazardous waste treatment, storage, and disposal facilities, landfills that have taken industrial waste, and vehicle maintenance and equipment cleaning at transportation businesses. If you're not sure whether anything at your site is regulated to begin with, our article on stormwater associated with industrial activity is a good place to start.
Which PAG-03 Appendix Covers Common Pennsylvania Industries?
Once you have your primary SIC code, you look it up in Table 1 of the PAG-03 NOI instructions (DEP form 3800-PM-BCW0083a), which is repeated in the permit's fact sheet. The table below pulls from the 2023 PAG-03 and groups the SIC ranges into facility types we see often in Pennsylvania. Use it to get oriented, not as your final answer. Appendix letters and the SIC codes assigned to them can change when DEP reissues the permit, so confirm your code against the current Table 1 before you file anything or set up a sampling program.
| Pennsylvania facility type |
SIC codes in the 2023 Table 1 |
PAG-03 appendix |
| Ready-mix concrete, block, precast, and other concrete products |
3271-3275 |
N: Glass, Clay, Cement, Concrete and Gypsum Products |
| Cement plants, brick and tile makers, glass plants, cut stone shops |
3211-3269, 3281, 3291-3299 |
N: Glass, Clay, Cement, Concrete and Gypsum Products |
| Steel mills, iron and steel foundries, nonferrous smelting, rolling, and casting |
3312-3369, 3398-3399 |
B: Primary Metals |
| Metal fabrication, machine shops, and industrial machinery makers |
3411-3499, 3511-3599 |
U: Fabricated Metal Products |
| Plastics molding and extrusion, tire and rubber products |
3011-3069, 3081-3089 |
S: Rubber, Miscellaneous Plastic Products and Miscellaneous Manufacturing |
| Food processing, dairies, bakeries, meat packers, breweries, and beverage plants |
2011-2099, 2111-2141 |
I: Food and Kindred Products |
| Paper mills, paperboard mills, and corrugated box plants |
2611-2679 |
E: Paper and Allied Products |
| Chemical, paint, plastic resin, pharmaceutical, and cleaning product makers; petroleum refineries |
2812-2899, 2911, 3952 |
F: Chemicals and Allied Products |
| Sawmills, millwork, pallet makers, and wood preserving |
2411-2499 (listed codes) |
D: Timber Products |
| Commercial printing and publishing |
2711-2796 |
R: Printing and Publishing |
| Asphalt paving plants and roofing material makers |
2951-2952, 2992, 2999 |
M: Asphalt Paving, Roofing Materials and Lubricants |
| Trucking terminals, bus depots, and rail yards (vehicle maintenance, cleaning, and fueling areas only) |
4011, 4013, 4111-4173, 4212-4231 |
L: Land Transportation and Petroleum Stations and Terminals |
| Petroleum bulk plants and terminals |
5171 |
L: Land Transportation and Petroleum Stations and Terminals |
| Scrap metal and waste recycling yards |
5093 |
P: Scrap and Waste Recycling Facilities |
| Auto salvage yards |
5015 |
O: Automobile Salvage Yards |
| Textile mills, apparel makers, and leather goods |
2211-2399, 3131-3199 |
Q: Textile Mills, Apparel and Other Fabric Products |
| Leather tanning and finishing |
3111 |
T: Leather Tanning and Finishing |
| Airports (maintenance, cleaning, and deicing areas) |
4512-4581 |
G: Air Transportation Facilities |
| Steam electric power plants, including coal handling |
4911 |
H: Steam Electric Generating Facilities |
| Landfills and land application sites that have received industrial waste |
4953 and others |
C: Landfills and Land Application Sites |
| Hazardous waste treatment, storage, and disposal facilities |
4953 and others |
A: Hazardous Waste Treatment, Storage or Disposal Facilities |
| Existing salt storage and distribution sites |
Various |
K: Existing Salt Storage and Distribution Sites |
| Facilities DEP designates, or industrial activity no other appendix describes |
Various |
J: Additional Facilities |
A few notes on reading the table. Transportation businesses like trucking companies, bus operators, and rail yards are only regulated for their vehicle maintenance, equipment cleaning, and fueling areas, not the whole property, and public warehousing (SIC 4221 to 4225) is carved out of the federal transportation category. Some codes inside a listed range aren't covered, so the range in our table is shorthand, not a substitute for checking your exact four-digit code. Concrete producers can find more on their specific situation in our producer's guide to concrete plants and stormwater permits.
What If Your SIC Code Isn't Listed in Any PAG-03 Appendix?
Start with the good news. If neither your primary SIC code nor any narrative activity on your site shows up in the federal rule, you generally don't need PAG-03 coverage or a No Exposure Certification. That's the case for a lot of businesses people assume are regulated, including most standalone warehouses, car dealerships, body shops, quick-lube shops, and contractors' yards. Steel service centers are another common one, since many are classified as wholesale distributors rather than manufacturers. DEP does keep the authority under the Clean Streams Law to require a permit from any site it finds is putting pollutants into stormwater, so "not listed" means "not automatically required," not "never." Our article on who needs an NPDES stormwater permit walks through the general rules.
If you do need coverage and your code doesn't match an appendix, DEP can require you in writing to follow the appendix closest to your activities. When nothing fits, Appendix J, "Additional Facilities," is the catch-all for designated sites and industrial activity no other appendix describes. If you meet every other PAG-03 eligibility condition, DEP may approve you under Appendix J. If not, you'll need an individual NPDES permit, which DEP issues through its Individual NPDES Permit Application for Industrial Stormwater (3800-PM-BCW0403).
Some sites don't belong in PAG-03 at all, no matter what appendix their code seems to match. PAG-03 doesn't cover stormwater from mineral extraction, so quarries and sand and gravel pits go through DEP's mining program and its GP-104 permit, handled by the district mining offices. Asphalt plants sitting inside a permitted mine site and draining entirely to it also go under GP-104. Construction stormwater and sewage treatment plants are excluded, too. And any site discharging to a stream classified as High Quality or Exceptional Value under 25 Pa. Code Chapter 93 can't use PAG-03 and needs an individual permit. For a side-by-side look at how those paths differ, see general, individual, and No Exposure permits explained.
Older cities add a wrinkle. If all of your site's stormwater flows into a sanitary or combined sewer that's part of a public treatment plant, DEP's FAQ says PAG-03 coverage isn't required, though pretreatment rules and the local sewer authority come into play instead. In places like Philadelphia and Pittsburgh, that depends on where your specific drains go, so confirm with your sewer authority and DEP rather than assuming.
What Happens When One Site Falls Under More Than One PAG-03 Appendix?
More than one appendix can apply to the same facility. DEP's FAQ says it plainly: if a site has multiple industrial activities that each require coverage, the requirements of each matching appendix apply at that site. We've seen DEP permit records for a container manufacturer classified under both a paperboard container code and a plastics code, with monitoring pulled from Appendix E and Appendix S at the same time. That means a longer parameter list on your eDMR and a PPC Plan that addresses both sets of sector practices.
Support operations on the same property get folded in, too. DEP treats on-site auxiliary operations, like a vehicle maintenance shop or a warehouse that serves the main business, as secondary activities. They don't trigger coverage on their own, but if your primary activity is covered, your permit and PPC Plan have to address those secondary areas along with the primary ones. Off-site support operations are evaluated separately. A manufacturer's off-site truck garage, for example, doesn't need its own permit under the transportation category, but the same garage on the manufacturing site would have to be included. Facilities often miss these areas when they set up sampling, and an inspector walking the site will notice an on-site truck shop or fueling island that drains to an outfall.
Industrial parks and multi-tenant buildings add another layer. Each tenant's activity gets its own SIC code, and DEP prefers that the whole complex operate under a single permit, either held by the owner or shared by the tenants as co-permittees. If that isn't workable, DEP will accept separate NOIs from each tenant. Where tenants fall under different appendices, DEP applies the appendices outfall by outfall, so each discharge point is monitored for the activities that drain to it.
Watch for changes over time. Under the 2023 permit, you have to file an NOI to amend your coverage when a new or changed activity would add or change an applicable appendix, and DEP's amendment fee is $500.
What Monitoring Does Your PAG-03 Appendix Require?
Every PAG-03 permittee samples semiannually, once in each January through June and July through December period, from a qualifying storm event. DEP defines that as a storm producing more than 0.1 inch of precipitation, causing a discharge, and coming at least 72 hours after the previous storm. There are narrow exceptions under Appendix K for small salt piles and Appendix G for small airports that can drop to annual sampling. Results are reported through DEP's eDMR system, which our guide to Pennsylvania eDMR reporting walks through.
Your appendix sets what goes into each sample. Under the 2023 permit, every appendix includes Total Nitrogen and Total Phosphorus, which DEP added to gather nutrient data for the Chesapeake Bay and other nutrient-impaired waters. Total Nitrogen is calculated by adding Total Kjeldahl Nitrogen to nitrite-nitrate nitrogen measured in the same sample. Beyond that, the list varies by sector. For example, the 2023 permit added oil and grease monitoring to Appendices B and U, added chemical oxygen demand (COD) to Appendices J, O, Q, R, and T, and added total aluminum to Appendix P. Your lab also has to meet DEP's Target Quantitation Limits for most parameters, and our article on how to pick a water testing lab covers what to ask.
Each parameter is compared against a benchmark value in your appendix. Benchmarks aren't permit limits. DEP uses them to judge whether your BMPs are working. Where an appendix lists them, the 2023 permit uses benchmarks of 100 mg/L for total suspended solids, 9.0 standard units for pH, 30 mg/L for five-day biochemical oxygen demand, and 120 mg/L for COD, plus 3.0 mg/L for nitrate-nitrite nitrogen in Appendices F, I, and U. If the same pollutant exceeds its benchmark at the same outfall for two consecutive monitoring periods, you owe DEP a corrective action plan within 90 days of the end of that period. At four consecutive exceedances, the plan has to come with DEP's Stormwater BMPs Checklist, and continued exceedances can lead DEP to require an individual permit. Our article on benchmark values vs. effluent limits explains the difference in more depth, and what to do when your stormwater results are high covers next steps.
Appendices also carry sector-specific prohibitions that can push a facility out of PAG-03 entirely. Runoff from material storage piles at cement manufacturing plants and runoff from asphalt emulsion facilities, for instance, are subject to federal effluent guidelines and need an individual permit. If your site qualifies for a No Exposure Certification, on the other hand, your appendix doesn't drive sampling at all. DEP only asks No Exposure applicants for the eight parameters listed in the certification instructions. For more on collecting the samples themselves, see our guide to Pennsylvania's PAG-03 permit and how to take stormwater samples.
Can PAG-03 Appendix Letters and Requirements Change When DEP Reissues the Permit?
Yes. DEP reissues PAG-03 on a five-year cycle, and each edition can change which SIC codes sit in which appendix, which pollutants get monitored, and what the benchmarks are. The 2023 edition kept the same 21 appendices as the 2016 permit but moved SIC codes 3511 to 3599, industrial machinery and equipment, into Appendix U, and it added nutrient monitoring across the board along with several sector-specific parameters. DEP has also said it will review DMR data three years after each reissuance to decide which pollutants each sector should monitor in the next term, so the sampling lists for 2028 and beyond may look different from today's.
The 2023 permit also changed how renewal works. Under the 2016 permit, the annual report generally kept your coverage going. Now, permittees have to submit a complete renewal NOI when DEP reissues the permit, and DEP publishes each reissuance in the Pennsylvania Bulletin. Since the current permit runs through March 23, 2028, expect to revisit your appendix, sampling parameters, and PPC Plan when the next edition comes out, and don't rely on an old binder copy of the permit in the meantime.
The safest habit is to treat any appendix table, including ours, as a starting point. Before you file an NOI, set up sampling, or change your operations, pull the current PAG-03 permit, NOI instructions, and fact sheet from DEP's industrial stormwater web page or eLibrary, and check your exact four-digit code against the current Table 1. If you'd like a second set of eyes, our article on getting a PAG-03 permit yourself vs. hiring a consultant lays out which parts most facilities handle on their own.
How RMA Helps Pennsylvania Facilities Sort Out PAG-03 Appendices
We're based in New Jersey and work with facilities across Pennsylvania on PAG-03 coverage, No Exposure Certifications, and individual NPDES permits. When a facility isn't sure where it fits, we start by looking at what the site does, where the revenue comes from, and where stormwater from each area ends up. From there we can help confirm your primary SIC code and appendix, flag any secondary areas or second appendix that should be in your coverage, and build your PPC Plan and sampling program around the requirements that apply. If it turns out you don't need coverage, or that a No Exposure Certification fits better, we'll tell you that, too.
There's no pressure and no obligation. Give us a call, send us an email, or fill out the form on our website, and tell us a little about your operation. If you have questions about which PAG-03 appendix covers your facility, or whether you need coverage at all, contact RMA and we'll help you figure out the right next step.
