Plan before Notice of Intent
Develop the plan before submitting your Notice of Intent for coverage.
You must develop a SWPPP consistent with Part 7 before submitting your NOI for coverage under this permit.
The engine
A determination you can hand to an inspector
Most stormwater tools give you a number. This one gives you the number, the permit section it came from, and the reasoning that got there, so the answer survives being questioned.
How it works
Six steps, in order, every time
- 1
Decide whether coverage is triggered
One acre of disturbance, or less than an acre inside a larger common plan of development or sale. The second is the trigger people miss, and it is why a small lot in a subdivision is covered.
- 2
Resolve the permitting authority
EPA or the state. Indian country stays with EPA even inside a delegated state, and some federal facilities do too. Where the governing permit is one we have not read, the engine says so instead of substituting the federal permit.
- 3
Run that permit's eligibility screens
Endangered species, historic properties, receiving water sensitivity and prohibited discharges. Two of them are screenings you complete and document, and the output says so rather than marking them passed.
- 4
Attach the requirements
Inspection frequency, stabilisation deadlines, corrective action windows, buffers, retention and the filing path. Each carries its permit section and a line explaining why it attached to this site.
- 5
Answer the credential question
Whether a credentialed preparer must prepare the plan, which credentials qualify, and whether a state course sits on top. In a gated state the generated document is a draft for that person to sign.
- 6
Show the derivation
Every conclusion is reachable from a numbered step carrying the section that decided it, so the output can be handed to an inspector rather than merely trusted.
Worked example
A 6.5 acre site in New Mexico
New Mexico is not NPDES authorised, so EPA's permit governs directly. Six and a half acres is above the five acre break, so the shorter stabilisation deadline applies. Below is the real engine output, generated when this page was built.
Filing
Notice of Intent deadline
14At least 14 calendar days before commencing construction activities
Why this applies here: This is the deadline for a new site. A transfer to a new operator or an emergency related project has a different deadline.
must submit to EPA a complete and accurate NOI in accordance with the deadlines in Table 1 prior to commencement of construction activities
Notice of Termination deadline
30Submit the Notice of Termination within 30 calendar days of meeting a termination condition.
You must submit an NOT within 30 calendar days after any one of the conditions in Part 8.2 occurs.
Inspections
Inspection frequency, option 1
7At least once every seven (7) calendar days
Why this applies here: The site does not discharge to an impaired or high quality water, so you may choose either standard option.
At least once every seven (7) calendar days; or
Inspection frequency, option 2
14Once every 14 calendar days AND within 24 hours of a storm event producing 0.25 inches or more of rain in a 24-hour period, or of a discharge caused by snowmelt from a storm event producing 3.25 inches or more of snow in a 24-hour period.
Why this applies here: The site does not discharge to an impaired or high quality water, so you may choose either standard option.
Once every 14 calendar days and within 24 hours 67 of the occurrence of: A storm event that produces 0.25 inches or more of rain within a 24-hour period. If a storm event produces 0.25 inches or more of rain within a 24-hour period
Who may inspect
The person inspecting the site may be a member of your staff or a third party you hire. You are responsible for ensuring that any person conducting inspections is a "qualified person", meaning someone who has completed the training required by Part 6.3.
Why this applies here: This is why Basinwise cannot perform your inspections. The permit requires a trained person physically on the site.
You are responsible for ensuring that any person conducting inspections pursuant to this Part is a “qualified person.” A qualified person is someone who has completed the training required by Part 6.3.
Stabilisation
Initiate stabilisation
"Immediately" means as soon as practicable, but no later than the end of the next business day, following the day when the construction activities have temporarily or permanently ceased.
Why this applies here: This applies at both land disturbance amounts.
In the context of this provision, “immediately” means as soon as practicable, but no later than the end of the next business day, following the day when the construction activities have temporarily or permanently ceased.
Complete stabilisation
7Complete the installation of stabilization measures as soon as practicable, but no later than seven (7) calendar days after stabilization has been initiated.
Why this applies here: You have not told us how much land will be open at any one time, so we have assumed the whole 6.5 acres are, which takes the 7 day deadline. The permit measures this on land disturbed at any one time, not the project total: if you phase the work so no more than five acres are open at once, stabilising finished ground before opening more, the deadline is 14 days instead. Tell us your concurrent acreage to get the answer that applies to your site.
Complete the installation of stabilization measures as soon as practicable, but no later than seven (7) calendar days after stabilization has been initiated.
Corrective action
Corrective action, minor fix
By the close of the next business day after discovering the condition.
When the problem does not require a new or replacement control or significant repair, the corrective action must be completed by the close of the next business day; or
Corrective action, major fix
7Within 7 calendar days of discovery.
When the problem requires a new or replacement control or significant repair, install the new or modified control and make it operational, or complete the repair, by no later than seven (7) calendar days from the time of discovery.
Buffers
Natural buffer
50Provide and maintain a natural buffer or equivalent erosion and sediment controls where a surface water lies within 50 feet of the disturbance.
Provide and maintain natural buffers and/or equivalent erosion and sediment controls for discharges to any receiving waters that is located within 50 feet of the site’s earth disturbances.
Records you must keep
Inspection report deadline
24Complete the inspection report within 24 hours of completing the site inspection.
You must complete an inspection report within 24 hours of completing any site inspection.
Corrective action log entries
Record the condition within 24 hours of identifying it, and record completion within 24 hours of completing the work.
Within 24 hours of identifying the corrective action condition, document the specific condition and the date and time it was identified.
Record retention
3Retain inspection reports and the corrective action log for at least 3 years from the date permit coverage expires or is terminated.
Why this applies here: The clock runs from permit expiry or termination, not from when the record was written, so on a multi year project every record stays live for the whole project plus three years.
You must retain all inspection reports completed for this Part for at least three (3) years from the date that your permit coverage expires or is terminated.
How this answer was reached, step by step
- 1
Coverage threshold
The project disturbs 6.5 acres, at or above the 1 acre threshold, so it needs permit coverage.
- 2
Permitting authority
EPA. NM is not an NPDES authorized state, so EPA's Construction General Permit governs directly.
- 3
Preparer credential
New Mexico requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Mechanism
Why the answer is different from a lookup table
Branching, not lookup
A bigger site gets the SHORTER stabilisation deadline, and discharging to a sensitive water overrides the acreage table entirely. The engine applies the override first, then the table, and tells you which one decided your answer.
Unknown is a real answer
If you have not confirmed the receiving water, the engine does not quietly pick the convenient branch. It returns an explicit unknown, says what changes if the answer turns out to be yes, and leaves the screen unresolved.
Every fact carries its section
Requirements are assembled from a dataset where each entry holds the permit section, a verbatim quote and a confidence flag. A fact with no section cannot be verified no matter what the file claims, and the engine downgrades it at runtime.
Pure, so it runs anywhere
Zero dependencies, no clock, no randomness, no input or output. The same module runs in your browser tab, on our server, in the REST API and in the MCP server, so the free tool and the paid product cannot drift apart.
The boundary
What this product is not
Stated on the product page, not only in the terms, because these are the gaps that cost money when they are discovered late.
We do not perform site inspections
The permit requires a physical inspection by a qualified person on a schedule, and that person has to be standing on the site. We generate the plan and maintain the inspection record. We are a compliance documentation engine, not compliance.
In credential gated states our document is a draft
Where a state requires a credentialed preparer, what we generate is a complete draft for that person to review, amend and sign. It is not by itself a filed plan, and it says so on the document. We would rather lose the sale than have you file something that is not valid in your state.
An unread jurisdiction reads as unread
Where we have not read a state's permit we do not print a plausible number. The page says not verified, names the agency and links it. We never infer a requirement we did not read in a permit, and an honest gap always beats a confident guess.
Basinwise reports publicly published permit requirements and cites the permit section behind each one. It is not legal or engineering advice and it is not a permit. We do not perform the physical site inspections the permit requires; we generate the plan and keep the record. Where a jurisdiction requires a credentialed preparer, the document we generate is a draft for that person to review and sign. Always confirm against your permitting authority's current permit before you break ground.
FAQ
How the engine behaves
What exactly does the engine return?
A coverage verdict, the governing permit with the version it was determined against, the jurisdiction, the eligibility screens with their status, the requirements with citations and a per site explanation, the notices you must read, a confidence flag and the full derivation trail. The same object is what the API returns.
Why does it sometimes return no requirements?
Because we hold requirements only for permits we have actually read. If the governing permit is a state one we have not loaded, showing the federal requirements in its place would be inventing an answer, so the requirements section stays empty and a notice names the agency to confirm with. An empty section is the honest output, not a bug.
How current is the permit data?
The federal dataset is EPA's 2022 Construction General Permit, effective 17 February 2022 and expiring 16 February 2027. Every determination is stamped with the dataset version that produced it, so a saved answer stays defensible after a permit is reissued. Nothing watches for a reissue on your behalf, and that gap is named on the pricing page rather than left for you to discover.
Can it handle industrial sites?
It tells you the truth about them, which at the moment is uncomfortable. EPA's Multi-Sector General Permit expired on 28 February 2026 and is administratively continued. EPA has stated that new facilities, and new operators of existing facilities, cannot submit a Notice of Intent until a new permit issues. The engine returns a verify verdict and says so rather than instructing you to file something you cannot file.
Does it file the Notice of Intent for me?
No. It tells you which Notice of Intent applies, where it is filed and by when. You file it yourself with EPA NeT or your state agency. That gap is listed by name on the pricing page.
Does it tell me when it rains?
No. The permit ties an inspection to a qualifying rain event, and the record you keep here shows the trigger depth that applies to your site, but nothing watches the weather and nothing will message you. You have to come and look, so do not build a process that depends on being told.
Run your own site through it
Free and private. Pro at $49 a month generates the plan document and retains the inspection record.