2.3 EPA Construction Permit Coverage and Operational Clocks

EPA 2022 Construction General Permit (CGP) Structure and Thresholds

For the separate Part A rules assessment and the Part B general-permit competencies of the CESSWI examination, candidates are tested rigorously on the operational mechanics, numeric thresholds, and compliance deadlines of the EPA 2022 National Pollutant Discharge Elimination System (NPDES) Construction General Permit (CGP).

Coverage Threshold and the Common Plan of Development

CGP authorization is required for any construction activity—including clearing, grading, excavating, and earth-moving—that disturbs:

• 1 acre or more of total land area; OR
• Less than 1 acre of total land area if the activity is part of a "larger common plan of development or sale" that will ultimately disturb 1 acre or more.

A common plan of development or sale is any contiguous area where multiple separate and distinct construction activities may be taking place at different times on different schedules under one plan (such as a residential subdivision, industrial park, or phased retail complex). Even if an individual homebuilder purchases and grades a single $0.20\text{-acre}$ lot within a $15\text{-acre}$ subdivision, that $0.20\text{-acre}$ lot requires CGP coverage.

Two-Prong Definition of "Operator"

Under the construction-specific CGP Appendix A operator definition, an Operator is any party associated with a construction project that meets either of two criteria:

1. Control Over Plans and Specifications: The party has operational control over construction plans and specifications, including the ability to make modifications to those plans and specifications (typically the project owner, developer, or municipal agency).
2. Day-to-Day Operational Control: The party has day-to-day operational control of those activities at a project that are necessary to ensure compliance with the permit conditions (typically the general contractor or earthwork prime contractor responsible for implementing the Stormwater Pollution Prevention Plan [SWPPP]).

When one entity owns the project and controls the engineering plans while a separate general contractor manages daily site grading and BMP maintenance, both entities are Operators and each must submit its own Notice of Intent as co-permittees. Subcontractors who work under the direction of the general contractor do not need to file an NOI unless they independently meet one of the two operator prongs.

NOI, LEW, NOT, and NEC Permitting Instruments

• Notice of Intent (NOI): Before submitting an NOI, the operator must develop a complete, site-specific SWPPP. The operator then submits the NOI electronically through EPA's NPDES eReporting Tool (NeT-CGP). For a new project, authorization to discharge does not begin until 14 calendar days after EPA notifies the operator that it has received a complete NOI (unless EPA delays authorization due to Endangered Species Act, National Historic Preservation Act, or water quality concerns). Earth-disturbing activities are strictly prohibited during the 14-calendar-day waiting period.
• Low Erosivity Waiver (LEW): Available only for small construction activities disturbing at least 1 acre and less than 5 acres (never for sites $\ge 5$ acres) when the Revised Universal Soil Loss Equation (RUSLE) rainfall erosivity factor ($R$) is less than 5 ($R < 5$) during the entire period of construction from initial disturbance through final stabilization. If construction extends beyond the certified completion date and the recalculated $R$-factor reaches or exceeds $5$, the operator must cease earth disturbance, prepare a SWPPP, submit an NOI, and wait 14 calendar days.
• Notice of Termination (NOT): Submitted electronically via NeT-CGP within 30 calendar days after one of the termination conditions is met: (1) final stabilization has been achieved on all disturbed portions of the site (uniform perennial vegetative cover with a density of at least 70% of the native background vegetative cover, or permanent non-vegetative cover such as riprap or pavement), all temporary erosion and sediment controls have been removed and any resulting soil disturbance stabilized, and construction-generated pollutants and pollutant-generating activities meet the Part 8.2 removal conditions; (2) another operator has assumed control over all areas of the site and obtained CGP coverage; or (3) for residential construction only, temporary stabilization has been completed and the residence has been transferred to the homeowner.
• No Exposure Certification (NEC): A frequently tested exam distractor! An NEC is not available for construction sites; it applies exclusively to industrial facilities under the Multi-Sector General Permit (MSGP) where industrial materials and activities meet 40 CFR 122.26(g)’s no-exposure conditions, including its limited exceptions for items such as adequately maintained vehicles.

Effluent Limitations (40 CFR Part 450), Natural Buffers, and Stabilization

Part 2 of the CGP incorporates the mandatory federal Construction and Development Effluent Limitation Guidelines (C&D ELGs) codified at 40 CFR Part 450.

Technology-Based Non-Numeric Effluent Limits and Prohibited Discharges

1. Erosion and Sediment Controls: Install all downgradient perimeter controls (silt fence, fiber rolls, filter berms) before initiating upgradient earth disturbance; minimize steep slope disturbance; preserve topsoil where feasible; minimize soil compaction in areas designated for infiltration or vegetative stabilization; and for any common drainage location serving 10 or more acres disturbed at one time, install a sediment basin providing storage for either the calculated runoff volume from a 2-year, 24-hour storm or at least 3,600 cubic feet of storage per acre drained.
2. Surface Outlet Requirement: When discharging from any sediment basin or impoundment, operators must utilize outlet structures that withdraw water from the surface of the water column (such as floating surface skimmers or decant risers), unless infeasible, so that cleaner surface water is discharged while heavier sediment particles settle below.
3. Dewatering Practices (CGP Part 2.4): Discharges of ground water or accumulated stormwater pumped from excavations or trenches must be routed through sediment controls (such as dewatering sediment filter bags, weir tanks, or vegetated upland areas) to prevent visible plumes, sheen, or downstream erosion. Under the 2022 CGP, sites discharging dewatering water to sediment-impaired waters or Tier 2, 2.5, or 3 waters must also collect at least one turbidity sample per day of dewatering discharge and compare it against a 50 NTU benchmark (calculating a weekly average; exceeding 50 NTU triggers corrective action).
4. Strictly Prohibited Discharges (40 CFR § 450.21(e)): Operators are prohibited from discharging:
   • Wastewater from washout of concrete, unless managed by an appropriate, leak-proof containment facility that does not discharge to surface waters or storm drains;
   • Wastewater from washout and cleanout of stucco, paint, form release oils, curing compounds, and other construction materials;
   • Fuels, oils, or other pollutants used in vehicle and equipment operation and maintenance;
   • Soaps, solvents, or detergents used in vehicle and equipment washing; and
   • Toxic or hazardous substances from a spill or other release.

Natural Buffer Requirements (CGP Part 2.2.1 & Appendix F)

Whenever a Water of the United States (WOTUS) is located within 50 feet of the site's earth disturbances, the operator must comply with one of three Natural Buffer Compliance Alternatives:

• Alternative 1: Provide and maintain an undisturbed natural buffer of at least 50 feet between the earth disturbance and the receiving water.
• Alternative 2: Provide and maintain an undisturbed natural buffer that is less than 50 feet supplemented by additional erosion and sediment controls that, together with the narrower buffer, achieve the sediment load reduction equivalent to a 50-foot undisturbed natural buffer.
• Alternative 3: Where it is infeasible to provide and maintain an undisturbed natural buffer of any size, implement erosion and sediment controls that alone achieve the sediment load reduction equivalent to a 50-foot undisturbed natural buffer.

Current EPA CGP inspection, maintenance, and corrective-action clocks

Use the 2022 CGP as modified April 8, 2025, checked October 13, 2026. The proposed 2027 permit is not yet the applicable permit. State permits can have different schedules; the federal effluent rules do not make every EPA CGP detail a nationwide requirement.

Part 4 footnotes limit inspections to normal working hours. If the 24-hour window falls entirely outside those hours, inspect by the end of the next business day. Record the actual trigger and deadline rather than assuming 24 business hours. Part 4.4 allows reductions for qualifying stabilized areas, dry-season arid areas, and frozen conditions: stabilized portions may move to twice-monthly inspections for the first month, followed by monthly inspections or the alternative qualifying-storm verification route. Arid dry-season inspections are monthly plus qualifying rain/snowmelt. Frozen-ground suspension requires its stated conditions and resumes when thaw or discharge warrants it; there is no universal “24 hours before thaw” rule.

Part 2.1.4 routine maintenance is distinct from Part 5 corrective action. It requires immediate reasonable steps, generally next-business-day completion for minor work, and seven-day completion for more extensive maintenance with documented infeasibility. The same routine fix three or more times at the same location normally becomes corrective action unless the report explains why it remains routine. A missed repair deadline cannot be relabeled as maintenance to erase it.

For example, a major truck-damaged fence gap discovered Thursday at 10:00 requires immediate interim protection, a discovery log by Friday 10:00, and operational replacement by the following Thursday. A minor adjustment with no significant repair is due by Friday’s close. A 0.15-inch shower Monday and a 0.15-inch shower Wednesday do not add to a trigger unless 0.25 inch fell in some single 24-hour window. By contrast, two showers within the same 24 hours totaling 0.30 inch do trigger inspection.