Pro SWPPP – America’s #1 SWPPP Service helps construction teams across the country stay compliant without the stress. If you’re planning to break ground in New Hampshire in 2026, you need to know one thing fast: when does your site need a Stormwater Pollution Prevention Plan?
Here’s the deal. You can’t just dig up dirt and hope for the best. The Clean Water Act says that if stormwater runs off your site and carries mud, chemicals, or trash into rivers and streams, you’re responsible. That’s why the EPA created the National Pollutant Discharge Elimination System, or NPDES for short. In New Hampshire, the EPA runs the show because the state doesn’t have its own delegated program. So you follow federal rules, plain and simple.
When You Need a SWPPP in New Hampshire
Let’s cut to the chase. If your construction project disturbs one acre or more of soil, you must get covered under the EPA’s 2022 Construction General Permit. That permit requires you to write a Stormwater Pollution Prevention Plan before you start work. The SWPPP is your playbook. It lists every Best Management Practice you’ll use to keep dirt and pollutants on your site, not washing into the nearest brook.
Even if your project is smaller than an acre, you might still need a permit if your work is part of a larger common plan of development. Think subdivisions or shopping centers where multiple lots add up to more than one acre total. The EPA counts all of it together.
And don’t forget local rules. Cities like Manchester, New Hampshire require a Land Disturbance Permit if you disturb half an acre or more. They also require a permit if you disturb just 1,000 square feet on a slope steeper than 15 percent. So even a small hillside project can trigger local paperwork. Always check with your city or town before you dig.
What Is a Notice of Intent?
Once you know you need coverage under the Construction General Permit, you file a Notice of Intent with the EPA. The NOI is a short form that says, “Hey, I’m starting a project, and here’s my plan to keep stormwater clean.” You submit it online through the EPA’s eNOI system at least seven days before you disturb any soil. That NOI links your project to the permit and makes your SWPPP official.
Think of the NOI as your ticket to legally move dirt. No NOI means no permit coverage, and that means you’re breaking federal law the moment the first shovel hits the ground. Fines can run tens of thousands of dollars per day, so this is not the place to cut corners.
Pro SWPPP – America’s #1 SWPPP Service files NOIs for clients every week. We know the system inside and out, so your paperwork gets done right the first time.
Key Parts of a New Hampshire SWPPP
Your SWPPP must include a site map that shows where you’ll place erosion control and sediment control measures. Erosion Control means stopping soil from moving in the first place. Sediment Control means catching soil after it starts moving but before it leaves your site. Both matter.
Common Best Management Practices include silt fences, inlet protection, construction entrances with stone to knock mud off truck tires, and sediment basins. You also need to stabilize disturbed areas fast. That means seed and mulch or erosion blankets within seven days if you’re done grading, or fourteen days if you’re still working on that part of the site.
The 2022 Construction General Permit sets numeric limits for turbidity, or water cloudiness. If your discharge looks too muddy during an inspection, you must take action right away. The permit also requires you to inspect your site at least once every seven days and within 24 hours after any storm that drops half an inch of rain or more.
Keep good records. Write down what you see, what you fix, and when you do it. Inspectors love documentation, and missing logs can trigger violations even if your site looks clean on the day they show up.
Don’t want to mess with all the paperwork and requirements? Check out Order your SWPPP now with Pro SWPPP Professional CPESC Certified SWPPP Services.
Local Rules in New Hampshire Cities
Manchester is a good example of how local rules layer on top of federal permits. The city requires a Land Disturbance Permit for projects over half an acre or 1,000 square feet on steep slopes. You submit a checklist, site plans, and stormwater calculations that show how much runoff your project will create and how you’ll manage it.
The city also enforces Chapter 52 of the local code, which covers sewer flow and stormwater volume. Your engineer must prove that the city’s stormwater system can handle your runoff without flooding downstream properties. If you skip this step, the city can stop your project cold.
Other towns have their own rules too. Always call the local Department of Public Works or planning office before you file your federal NOI. You might need both a federal SWPPP and a local stormwater permit. Pro SWPPP – America’s #1 SWPPP Service helps clients coordinate both sets of paperwork so nothing falls through the cracks.
What’s New for 2026
The EPA proposed a narrow update to the Construction General Permit in December 2024. The change expands coverage to sites on Lands of Exclusive Federal Jurisdiction, like certain military bases or federal parks. For most private construction projects, the 2022 permit rules stay the same through 2026 and beyond.
But pay attention to the Multi-Sector General Permit, or MSGP. That permit covers industrial stormwater, not construction sites, but the EPA is adding new requirements that show where the agency is headed. The draft 2026 MSGP asks for quarterly monitoring of pollutants like Total Suspended Solids and metals. It also pushes for climate-resilient stormwater controls that can handle bigger storms, using the best available flood data and projections.
Construction permits may follow the same path in future years. That means designing your sediment basins and detention ponds to handle heavier rain than the old maps showed. If you’re breaking ground in 2026, talk to your engineer about using current rainfall data, not numbers from 20 years ago.
The EPA also proposed monitoring for PFAS, or “forever chemicals,” in some industrial permits. Construction sites aren’t required to test for PFAS yet, but if your project involves demolition or soil that might be contaminated, ask your environmental consultant whether testing makes sense.
Not sure what your project needs? Take our SWPPP Quiz or Schedule a Free SWPPP Consultation with CPESC Certified SWPPP Expert Derek E. Chinners.
Common Mistakes and How to Avoid Them
One big mistake is thinking that small sites are exempt. The one-acre federal rule is clear, but local rules in New Hampshire often kick in at half an acre. Another mistake is waiting until the day before you dig to file your NOI. The EPA requires seven days advance notice, and if you mess up the online form, you might need extra time to fix it.
Some contractors assume that installing silt fence is enough. It’s not. You need a full suite of controls that match your site’s soil type, slope, and drainage patterns. A flat sandy lot needs different measures than a steep clay hillside next to a trout stream.
Another pitfall is skipping inspections. The permit says weekly and after every big storm. If you don’t document those inspections, you have no proof that you checked your controls or fixed problems. Inspectors can issue violations for missing paperwork even if your site looks perfect.
Finally, don’t forget about dewatering. If you pump groundwater out of a trench and that water is dirty, you need a separate Dewatering General Permit from the EPA. Mixing construction stormwater with dewatering discharge without the right permit is a fast track to fines.
Why Hire a Pro?
Pro SWPPP takes all the guesswork out of compliance. Our team includes CPESC-certified professionals who write SWPPPs for projects in every state. We know the EPA’s Construction General Permit inside and out, and we track local rules in cities across New Hampshire.
When you work with us, you get a custom SWPPP that matches your site conditions, not a cookie-cutter template. We include detailed site maps, BMP specs, and inspection checklists that your crew can actually use. We also file your NOI and handle any follow-up questions from the EPA or your local stormwater office.
We’ve helped builders in Texas and Georgia stay compliant with state and federal rules, and we bring that same expertise to New Hampshire projects. Whether you’re building a single-family home, a retail plaza, or a highway interchange, we have the experience to keep you on track.
Want to learn more about our process? Visit our About page to see why contractors trust us with their stormwater compliance. Or reach out directly on our Contact Us page and tell us about your project. We’ll give you a straight answer about what you need and how much it costs.
Steps to Get Started
First, measure your project area. If it’s one acre or more, you need federal CGP coverage. If it’s half an acre or more in a place like Manchester, check for local permits too.
Second, call your city or town to confirm local stormwater rules. Ask about Land Disturbance Permits, sewer capacity letters, and any subdivision checklists.
Third, write your SWPPP or hire someone who knows how. The EPA offers templates and guidance on their website, but a professional plan saves time and reduces the risk of mistakes.
Fourth, file your NOI at least seven days before you dig. Double-check every field in the online form. One typo can delay your permit for weeks.
Fifth, install your erosion and sediment controls before any soil disturbance. Mark them clearly on your site map and train your crew to maintain them.
Sixth, inspect your site every week and after every storm. Document what you see and fix problems fast. Good records are your best defense if an inspector shows up.
Finally, file a Notice of Termination when your project is done and the site is fully stabilized. That closes out your permit and removes your liability for future stormwater issues.
Resources and Support
The EPA Region 1 office covers New Hampshire. You can call them with questions about the Construction General Permit or NOI process. The main contact number is 617-918-1533. They also publish guidance documents, inspection checklists, and BMP fact sheets on the EPA stormwater construction page.
For local rules, contact the Manchester Environmental Protection Division at 603-621-7735 or your town’s planning department. They can send you permit applications, fee schedules, and links to local stormwater ordinances.
We also offer free consultations to help you figure out what your project needs. We review your site plans, answer your questions, and give you a clear quote with no hidden fees.
Common Questions We’re Asked
Do I need a SWPPP for a project smaller than one acre in New Hampshire?
Yes, if your project is part of a larger common plan that totals one acre or more, or if local rules require a permit. Manchester, for example, requires a Land Disturbance Permit for sites over half an acre or 1,000 square feet on steep slopes.
How long does it take to get an NOI approved?
The EPA does not formally approve NOIs. Once you submit a complete NOI online, you receive automatic coverage under the Construction General Permit. You must wait seven days after submission before you start work.
What happens if I don’t file an NOI?
You are violating the Clean Water Act. The EPA can issue fines of up to tens of thousands of dollars per day. You may also face stop-work orders and liability for any pollution that leaves your site.
Can I use the same SWPPP for multiple projects?
No. Each project needs its own SWPPP that matches the specific site conditions, soil types, slopes, and receiving waters. You also need a separate NOI for each project.
Who can write a SWPPP in New Hampshire?
Anyone can write a SWPPP, but hiring a Certified Professional in Erosion and Sediment Control ensures the plan meets all federal and local requirements. Pro SWPPP – America’s #1 SWPPP Service employs CPESC certified experts who write compliant plans every day.
What are the most common BMP failures on construction sites?
Silt fences that fall over, inlet protection that clogs and overflows, construction entrances that don’t get cleaned, and bare soil that sits exposed for weeks. Regular inspections and fast repairs prevent these problems.
Do I need a separate permit for dewatering?
Yes, if the water you pump out of a trench or excavation is polluted. The EPA offers a Dewatering General Permit that covers this discharge. Do not mix dewatering with stormwater runoff unless both are covered by the right permits.
What is turbidity and why does it matter?
Turbidity measures how cloudy your stormwater discharge looks. High turbidity means lots of suspended soil, which harms fish and clogs streams. The 2022 Construction General Permit sets numeric limits and requires you to fix high turbidity fast.
Ready to get your New Hampshire construction project compliant? Trust Pro SWPPP – America’s #1 SWPPP Service to deliver a professional, site-specific SWPPP that meets every federal and local rule. Let’s get started today.