Does Your Construction Site Need a Construction Stormwater Discharge Permit?
Stormwater that discharges from construction activities is regulated under Texas Pollution Discharge Elimination System General Permit No. TXR150000. This permit is also called the Construction General Permit (CGP) and is written and administered by the Texas Commission on Environmental Quality (TCEQ). Regulatory requirements under the CGP are based on the area of land disturbed.
The TCEQ requires any construction activity disturbing one or more acres of land to obtain coverage under, and comply with, the CGP. This includes construction activities that disturb less than one acre but are part of a larger Common Plan of Development. A construction activity is part of a Common Plan of Development if it is completed in separate stages, separate phases, or in combination with other construction activities. The TCEQ has more specific requirements that depend on whether the site is large or small as defined in the CGP.
Small Construction Sites are sites that disturb one or more acres of land or are part of a Common Plan of Development that disturbs more than one acre. The following documentation is required for Small Construction Sites:
- Stormwater Pollution Prevention Plan (SWP3) (must be prepared and implemented before construction activities begin)
Large Construction Sites disturb five or more acres of land or are part of a Common Plan of Development that disturbs five or more acres. The following documentation is required for Small Construction Sites:
- Stormwater Pollution Prevention Plan (SWP3) (must be prepared and implemented before construction activities begin)
Additional Guidance on Determining Site Classification
Example 1:
A subdivision is being built. You are grading 0.75 acres, another company is clearing four different acres, and a contractor is excavating another 0.5 acres. In this case, the total area that would be disturbed is 5.25 acres, so each contractor would fall under the requirements associated with Large Construction Sites (disturbing five or more acres).
Example 2:
At first, your project calls for you to grade, clear, or excavate a total of 0.93 acres. But after your project begins, you learn that you must disturb another 0.15 acres. Since this project has grown to disturb a total of 1.08 acres, you must obtain coverage under the requirements associated with Small Construction Sites (disturbing one to less than five acres).
For more guidance, please see the TCEQ Assistance Tools webpage.
Construction Activity and Storm Drains
Land clearing and construction activities such as excavation and development can cause dirt, trash, and materials to enter City storm drains. A storm drain is considered part of the City’s Municipal Separate Storm Sewer System (MS4). Unlike our treated sanitary sewer system, water in the MS4 is not treated before being released to our creeks, streams, rivers, and lakes. However, measures can be taken to ensure that water from the MS4 is free from pollutants before being released into surface water bodies. Best Management Practices (BMPs) are implemented to prevent pollutants from entering stormwater.
Best Management Practices
Best management practices, or BMPs, are strategies and devices used to reduce stormwater pollution. State and local regulations require all construction activities that disturb more than one acre to implement BMPs. Best management practices include such measures as installing storm inlet protection devices, silt fencing, and proper concrete washout areas. Activities such as street sweeping and good housekeeping are also BMPs that help prevent stormwater pollution.
Erosion Control
Measures to mitigate the effects of erosion and resulting sedimentation are divided into two categories: temporary and permanent.
Temporary measures are designed to manage soil materials in a manner that will minimize their mitigation away from any land development or site improvement project during clearing, grubbing, grading, excavation, filling, and construction activities.
Permanent measures are designed to prevent erosion and resulting sedimentation from occurring over time, whether within earthen channels, in various facilities constructed for purposes of managing storm flow, or across unpaved land areas.
The B/CS Unified Stormwater Design Guidelines provide further details on permanent and non-permanent erosion control measures.
Site Maintenance
Construction sites should be inspected frequently to ensure the effective operation of all BMPs. All personnel are responsible for ensuring that the BMPs that are in place are properly working. Monitoring and maintenance are needed as BMPs fill with sediment and debris. Some BMPs are often susceptible to weather damage, so it is essential to repair such controls as needed in order to be in full compliance with the Construction General Permit.
Stormwater Pollution Prevention Plan (SWP3)
A stormwater pollution prevention plan (SWP3) identifies and addresses potential sources of pollution that are reasonably expected to affect the quality of stormwater discharges from the construction site including off-site material storage areas, overburden and stockpiles of dirt, borrow areas, equipment staging areas, vehicle repair areas, fueling areas, etc.
The development of a SWP3 contains several elements. The contents of which include the following:
1. A site or project description
2. A description of the best management practices (BMPs) that will be used to minimize pollution runoff
3. A description of permanent stormwater controls
4. Other required controls and BMPs
5. Documentation of compliance with approved state and local plans
6. Maintenance requirements
7. Inspection of controls
8. Must identify and ensure the implementation of appropriate pollution prevention measures for all eligible non-stormwater components of the discharge and
9. Other information as required per TPDES General Permit TXR150000
If you have any questions or comments concerning:
- Plans Review Process
- Construction Stormwater Permit
- Development/Post-Development Procedures
- Construction/Post-Construction Inspection Process
- Stormwater Ordinance
Please contact the Planning & Development Services Staff at: [email protected] Or call: 979.764.3570
Stormwater Inspection Report
The stormwater ordinance as developed by the City of College Station permits the inspection of construction site activity and post-construction stabilization. The stormwater inspection report for construction sites seeks to meet the requirements of the State by inspecting for any activity that may contribute to stormwater pollution.
Construction owners and operators will allow an Administrator of the City ready access for the sole purpose of inspection, surveillance, and monitoring for the following:
1. Access to NOI, Site Notice (i.e., Small or Large), and Stormwater Pollution Prevention Plan (SWPPP or SWP3) or Erosion Control Plan (ECP)
2. Evaluation of Best Management Practices (BMPs)
3. Illicit connections and discharge
4. Overall compliance with the TPDES CGP and MS4 permits.
The City will inspect the construction site periodically or as requested upon complaint. See the Stormwater Inspection Report Instructions for definitions.
Post-Construction Inspection - Site Stabilization
Additional inspections will be conducted post-construction within the 1-year warranty period to look for the following items:
1. Full landscape coverage
2. Silt detention device removal
3. Detention pond effectiveness
4. Floodplain protection
5. Significant drainage/channel repair
Development Permit (DP)
In order to meet permit requirements, the development permit application should include the following:
1. An Erosion Control Plan (ECP) is required for most all development permits, even those that are exempt from TPDES and SWP3 (i.e., development less than one acre and not part of a larger plan of development). Note: A Stormwater Pollution Prevention Plan (SWP3) is NOT an Erosion Control Plan.
2. A copy of the NOI (if > 5 acres) and Site Notice (must be provided by contractor/developer prior to issuance of the Development Permit).
Notice of Termination (NOT)
Each operator that has submitted a Notice of Intent (NOI) for authorization of large construction activities under the CGP must apply to terminate that authorization within 30 days after any of the following conditions are met:
- Final stabilization has been achieved on all portions of the site that are the responsibility of the operator.
- A transfer of operational control has occurred.
- The operator has obtained alternative authorization under an individual TPDES permit or general permit.
The NOT can be submitted online through the STEERS website.