A. Common Plan of Development (¼-mile rule)
Under the TPDES Construction General Permit TXR150000, your project is treated as part of a “common plan of development or sale” if it is one phase of a larger project, even if work is done in stages or by different contractors. Separate projects that are at least one-quarter (¼) mile apart, with no disturbed area between them, can be treated as separate plans. See the definition of Common Plan of Development here:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=6
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B. Final Stabilization & Soil Stabilization Timing
For purposes of terminating coverage, “Final Stabilization” under TXR150000 generally means all soil-disturbing activities are complete and all unpaved, unbuilt areas have a uniform perennial vegetative cover of at least 70% of background, or equivalent permanent stabilization (e.g., riprap, gabions) has been installed. See the definition of Final Stabilization:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=8
The permit also requires that stabilization be initiated immediately when construction activities have ceased on an area and will not resume within 14 days. “Immediately” is defined as as soon as practicable, but no later than the end of the next workday, with temporary stabilization completed within 14 days of initiation and final stabilization achieved before termination. See Soil Stabilization requirements:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=44
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C. Temporary Stabilization
When work is paused on a disturbed area, the permit requires temporary stabilization to prevent migration of pollutants. This can include temporary seeding, geotextiles, mulches, or other measures to reduce erosion until either permanent stabilization is installed or construction resumes. See the definition of Temporary Stabilization:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=11
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D. Pollutant / Pollution (Sediment is a pollutant)
TXR150000 defines “pollutant” broadly to include sediment, as well as a wide range of other materials. “Pollution” is defined as any alteration of water quality that renders the water harmful or impairs its use, consistent with TWC §26.001(14). This is why visible sediment-laden runoff is treated as a permit compliance issue. See Pollutant / Pollution / Rainfall Erosivity Factor definitions here:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=9
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E. Electronic SWP3 & Including the Permit
The SWP3 may be prepared and maintained electronically rather than on paper, as long as it is readable like a paper record, legally valid, and immediately accessible to inspectors during an inspection. See SWP3 availability / electronic format:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=31
The SWP3 is also required to contain either a copy of TXR150000 or an electronic copy / current link to the permit on TCEQ’s website. See SWP3 contents – permit copy/link:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=33
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F. SWP3 Revisions (7-Day Rule – Changes & Inspections)
TXR150000 requires the SWP3 (including the site map) to be revised within seven (7) days any time there is a change in design, construction, operation, or maintenance that significantly affects pollutant discharges; when new operators are added; or when conditions on the site change. See SWP3 revisions:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=32
In addition, when inspections show that existing controls are not sufficient, the SWP3 must again be revised within seven (7) days of the inspection to document new or modified BMPs and, where possible, those changes should be implemented before the next storm event. See post-inspection SWP3 revisions:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=42
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G. Receiving Waters Within One Mile
When preparing the SWP3 and site map, the permit requires identification of the receiving waters and whether they are impaired. “Surface waters adjacent to or in close proximity” includes waters on the site and all receiving waters within one mile downstream of where stormwater discharges from the site. See receiving waters / adjacency definition:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=33
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H. BMP Maintenance & Sediment Removal
All BMPs and protective measures identified in the SWP3 must be maintained in effective operating condition. If inspections or other observations show that BMPs are not operating effectively, maintenance or replacement must be performed as soon as possible and, where feasible, before the next rain event. Sediment must be removed from traps and ponds before capacity is significantly reduced and must also be removed if it has left the site and accumulated off-site. See BMP maintenance and sediment removal:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=38
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I. Inspection Frequency & Storm Triggers
For this project, inspection frequency is controlled by Part III.F of TXR150000. For storms producing 0.5 inches or more of rainfall, the permit requires that inspections occur within 24 hours of the first qualifying day and within 24 hours after the last qualifying day of the storm event. If the 24-hour window falls entirely outside normal working hours, the inspection must be conducted by the end of the next business day. See inspection frequency for storms ≥0.5”:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=40
The permit allows alternative inspection schedules, but any schedule change can only occur once per calendar month, must be implemented within the first five business days of that month, begin at the start of a calendar month, and the reason for the change must be documented in the SWP3. See alternative inspection schedule provisions:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=41
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=42
During adverse conditions (e.g., flooding, dangerous access), inspections may be temporarily suspended, but the permit requires documentation of the conditions, dates and times, and who observed them, plus follow-up actions and SWP3 updates. See adverse-condition inspection provisions:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=42
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J. Portable Toilets / Sanitary Waste
The permit specifically requires minimizing exposure of sanitary waste by positioning portable toilets so they are secure (cannot be tipped or knocked over) and are located away from streets, storm drain inlets, or other paths where spills could reach surface waters. See sanitary waste / portable toilets:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=45
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K. Sediment Basins & Impoundments – Surface Withdrawal
When discharging from sediment basins or impoundments, TXR150000 requires that outlet structures withdraw water from the surface wherever feasible. If it is infeasible to withdraw from the surface, the SWP3 must document the basis for that determination and the specific conditions or time periods when the exception applies. See basin/impoundment discharge requirements:
https://protexenvironmental.com/s/2023-TXR150000-CGP.pdf#page=45