Maryland
The stormwater permit for construction in Maryland
Maryland runs its own NPDES programme, so a state issued construction general permit governs. Below is what our engine can say about it, and where we have not read that permit, what it will not say.
Governing permit
General Permit for Stormwater Discharge Associated with Construction Activity (State Discharge Permit No. 20CP0000A, General NPDES Permit No. MDRC0000), Modification A
- Issued by
- Maryland Department of the Environment (MDE), Water and Science Administration
- Permit number
- MDRC0000
- Version determined against
- as published by the state agency
- Effective
- 2023-04-01
- Expires
- 2028-03-31
Who may prepare the plan
Conditional, depends on the siteMaryland gates plan preparation conditionally. Confirm which case applies to your plan before relying on a generated document.
Qualifying routes
- No named 'SWPPP preparer' certification exists in the 20-CP permit text (unlike CESCL/CPESC-style regimes in other states)
- Operator's on-site 'stormwater team' must include at least one person holding a valid certificate of attendance at a training program under Environment Article §4-104 (Maryland's Erosion & Sediment Control 'Responsible Personnel' certification, obtained via class and exam through MDE/local Soil Conservation Districts; valid 3 years)
- The SWPPP document is signed/certified by a permit 'Signatory' — responsible corporate officer, general partner/proprietor, or public-agency official — or their duly authorized representative (Part II.A.8), an administrative signing role open to non-credentialed staff
A state specific training course or exam is layered on top of the qualifying credential.
Maryland's well-known 'Responsible Personnel'/erosion-control certification is referenced in the CGP as a requirement that at least one member of the site's 'stormwater team' hold it and be present on site — the permit does not state that this person must be the one who drafts the SWPPP, nor does it name any credential specifically for SWPPP preparation. Applies uniformly (no acreage-tiered gating found for this requirement). No PE stamp is required for the SWPPP by this general permit; it is signed by a corporate officer/partner/proprietor/public official or authorized representative, not a licensed engineer. The separately-approved Erosion & Sediment Control and Stormwater Management Plans the SWPPP references are certified per COMAR 26.17.01.07 and 26.17.02.09 respectively — those COMAR provisions were not independently verified in this pass and could impose their own professional-certification requirements, separate from the NPDES SWPPP signature itself.
Does a site in Maryland need coverage
Worked for a one acre site as a reference point. Change the acreage in the tool below and the answer, and its reasoning, change with it.
Coverage
Permit coverage required
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Determined against dataset version 2026-07-19.
Read these before you act on the answer
- Requirements below are what we have read and cited directly from General Permit for Stormwater Discharge Associated with Construction Activity (State Discharge Permit No. 20CP0000A, General NPDES Permit No. MDRC0000), Modification A, not the federal CGP. A category we have not yet transcribed from this permit is omitted here rather than assumed to match EPA's rule.
- MD has no arid/semi-arid/drought reduced-inspection provision; its analogous reduced-frequency trigger is stabilization/suspension of construction activity, captured as state.md.* ids instead. MD does not use an acreage-tiered stabilization completion deadline like federal Table 2; instead it ties the INITIATION deadline to area type (perimeter/steep slopes vs. all other areas) and defines completion via a 95% groundcover standard rather than a fixed day count after initiation. The Tier II increased-inspection frequency is stated as 'twice every week' rather than a fixed day-interval number, so intervalDays is null in that entry. The Notice of Termination has no fixed day-count filing deadline (it's condition-based), so deadline.not.submission.value.days is null. Appendix B (Stream Protection Zone appendix) was not separately fetched/quoted; the 50-ft/100-ft buffer figures were confirmed directly from the main permit body. MD's coverage threshold matches the federal 1-acre / common-plan-of-development standard, so no thresholds array is included.
- Maryland gates plan preparation conditionally. Confirm which case applies to your plan before relying on a generated document.
- Basinwise does not perform the physical site inspections the permit requires. Those must be carried out on site by a qualified person.
How this answer was reached, step by step
- 1
Coverage threshold
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
- 2
Permitting authority
Maryland. The state runs its own programme under MDRC0000.
- 3
Preparer credential
Maryland gates plan preparation conditionally. Confirm which case applies to your plan before relying on a generated document.
VerifiedMaryland General Discharge Permit No. 20CP (NPDES No. MDRC0000), Part III.E 'Staff Training Requirements' and Part II.A.8 'Signature Requirements'Source
What to do next
- 1. Confirm the governing permit. Read General Permit for Stormwater Discharge Associated with Construction Activity (State Discharge Permit No. 20CP0000A, General NPDES Permit No. MDRC0000), Modification A directly. It is linked above, and it is the document an inspector will hold you to. Maryland Department of the Environment (MDE), Water and Science Administration
- 2. Settle the preparer question before you draft. Getting this wrong costs a redraft at best. The detail is on the credential page for this state. Preparer credential in Maryland
- 3. Screen the site. Run the real acreage and receiving water facts through the tool below. You get the inspection frequency, the stabilisation deadlines and the filing path with the permit section behind each.
- 4. Read the requirements in full. SWPPP requirements in Maryland
Screen a Maryland site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the Maryland construction stormwater permit
Do I need a stormwater permit for a construction site in Maryland?
Permit coverage is triggered at one acre of land disturbance, and below one acre if the project is part of a larger common plan of development or sale that will ultimately disturb an acre or more. The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Who issues the construction stormwater permit in Maryland?
Maryland Department of the Environment (MDE), Water and Science Administration issues General Permit for Stormwater Discharge Associated with Construction Activity (State Discharge Permit No. 20CP0000A, General NPDES Permit No. MDRC0000), Modification A.
Does Maryland require a qualified preparer for the plan?
Maryland gates plan preparation conditionally. Confirm which case applies to your plan before relying on a generated document.
Keep the record Maryland will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.