Home / NPDES Permitting
PAG-01, PAG-02, individual permits and CAFO. We prepare the application, build the erosion control and post-construction stormwater behind it, submit it to the right conservation district, and answer every review comment until it's approved.
01 — The threshold
Under Pennsylvania's Chapter 102 rules, two numbers govern almost every project:
This is where projects go wrong. It's the total area you grade, strip, excavate, stockpile or otherwise disturb — the pad, the drive and its shoulders, the yard, the staging and stockpile areas, the utility trenching, the strip regraded for a swale.
A building that covers 3,200 square feet routinely disturbs well over an acre once the yard and access are counted. That one number decides whether you need a permit at all.
02 — Which permit
Which one applies depends on the size of the disturbance and on conditions at the site.
| Route | Typically applies to | Character |
|---|---|---|
| PAG-01 General permit, small construction |
One acre or more but less than five, where the project meets the permit's eligibility conditions | The lighter path. Offers simplified alternatives for satisfying post-construction stormwater that are not available under PAG-02. |
| PAG-02 General permit, construction |
Five acres or more, and smaller projects that don't qualify for PAG-01 | The standard general permit. Full post-construction stormwater design and analysis. |
| Individual NPDES | Projects ineligible for either general permit | Site-specific permit. Longest and most involved review. |
Eligibility isn't automatic at the right acreage. Discharges to exceptional value or high quality waters, threatened and endangered species considerations, and other site-specific conditions can push a project off the general permit track regardless of size. That determination belongs at the start of design, not after the drawings are finished.
Our guide to PAG-01 covers the eligibility conditions, the three post-construction stormwater alternatives and what a complete submission contains. We follow the draft permits as they're proposed and comment on them, so we know what's changing before it reaches your project.
03 — What we handle
We file these constantly, which is the whole argument for using us on one.
Notice of Intent, fees, the E&S plan, the post-construction stormwater narrative and calculations, site characterization, mapping, the supporting modules, and the municipal and county notifications the package requires. Incomplete applications aren't accepted — which means the review clock never starts — so compiling it properly the first time is the single biggest schedule saving available.
Usually the most expensive requirement on a small site — it's what turns a corner of the property into a basin. Which alternative your site can use is worth establishing before the layout is fixed, because the layout determines whether they stay available.
A first-round comment letter is normal, not a problem. We answer every comment in writing and carry the application to approval rather than handing you a letter and a drawing set.
Permits expire, properties change hands, and coverage has to be terminated properly once a site is stabilized. All of it has deadlines, and none of it announces itself.
A different animal from construction stormwater — a discharge permit for concentrated animal feeding operations, with its own renewal cycle and annual reporting. More on agricultural compliance →
04 — Before you commit
The most useful call we get is the one before the money is spent — before the ground is bought, before the contractor is booked, before the materials are ordered.
On that call we’ll tell you which permitting framework the project falls under and what work of that kind generally runs. Scoping proper is the first phase of the job: how much you’ll actually disturb, whether that clears an acre, which permit route applies, whether the site is eligible for a general permit at all, and what the municipality adds on top.
Occasionally scoping ends with us saying the project isn't worth pursuing as conceived. That's a good outcome — a great deal cheaper than finding out after the ground is bought.
05 — Questions
Generally no. Phasing to avoid permit coverage on what is really one project doesn't work, and reviewers look for it. There are legitimate reasons to phase a build — staying under a threshold by splitting a single development isn't one of them.
Two different questions. Placing gravel almost always involves disturbing the ground beneath it, so it counts toward earth disturbance. Whether it's treated as impervious for stormwater purposes depends on the standard applied and how the surface is built — compacted gravel under traffic frequently behaves as impervious in practice.
Stop and call somebody. Unpermitted earth disturbance is an enforcement matter, and the response is far less painful when you get ahead of it than when an inspector arrives. These are resolvable — they're simply better resolved early.
Yes, and it happens regularly. Send us the latest comment letter and the current submission. We'll tell you honestly whether the faster route is answering the comments as drawn or fixing the thing that keeps generating them.
Send us the site and roughly what you're putting on it. We'll tell you.