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How to De-Risk Solar Projects & Permit Faster with a Stormwater Pollution Prevention Plan (SWPPP)

The majority of solar construction projects in the U.S. will fall under the National Pollutant Discharge Elimination System (NPDES) general permit. Created in 1972 by the Clean Water Act, the NPDES permit program is authorized to state governments by the EPA to perform many permitting, administrative, and enforcement aspects of the program.The NPDES general permit is not an application for a permit, but a requirement to file a Notice of Intent (NOI) to work under the NPDES general permit requirements. 

For your work to be covered under the NPDES general permit, you must file a Stormwater Pollution Prevention Plan (SWPPP) that meets these requirements. Fortunately, the EPA provides a fillable template that will aid you in preparing your SWPPP. However, many solar developers are surprised at the lengthy non-engineering and administrative requirements for the SWPPP. Here are a few highlights to keep in mind to help you de-risk your solar project and permit faster:

Designating Responsible Parties

  • Operators and subcontractors must be listed with contact information. Construction site operators are responsible for obtaining NPDES permit coverage for their stormwater discharges. Each state has its own definition of the term operator, which may include owners (e.g., developers), general contractors, independent subcontractors, corporations or government officials.

  • A certified inspector with contact information must be provided. The inspector should be knowledgeable in the principles and practices of erosion and sediment controls, and have the skills to assess conditions at the site that could impact stormwater quality as well as the efficacy of sediment and erosion control measures. Several states currently require that sites be inspected by someone that the state has certified as a qualified inspector. One national organization offers two certification programs: Certified Professional in Stormwater Quality (CPSWQ) and Certified Professional in Erosion and Sediment Control (CPESC). 

Necessary Documentation of Compliance with Other Federal Requirements 

  • Proof of endangered species protection. When conducting your site assessment, you should determine whether listed endangered species are on or near your property. You should also determine whether critical habitat areas have been designated in close proximity to your project. Contact your local offices of the National Marine Fisheries Service (NMFS), U.S. Fish and Wildlife Service (FWS), or your state or tribal heritage centers.

  • Historic property screening (SHPO). The National Historic Preservation Act (NHPA), and any local, state, and tribal historic preservation laws, apply to construction activities. As with endangered species, some permits may specifically require you to assess the potential impact of your stormwater discharges on historic sites. However, regardless of whether or not this is stated as a condition for permit coverage, the NHPA and any applicable state or tribal laws apply to you. Contact your Tribal Historic Preservation Officer and/or your State Historic Preservation Officer

  • Safe Drinking Water Act compliance. Impervious surfaces, such as homes, buildings, roads and parking lots can drastically alter the natural hydrology of the land by increasing the velocity, volume, and temperature of runoff and by decreasing its infiltration capacity. Reducing infiltration can lower groundwater levels and affect drinking water supplies.

Items to be Covered in Pollution Prevention Standards Plans

  • Spill prevention and response. This plan should clearly identify ways to reduce the chance of spills, stop the source of spills, contain and clean up spills, dispose of materials contaminated by spills, and train staff responsible for spill prevention and response. The plan should also specify material handling procedures and storage requirements and ensure that clear and concise spill cleanup procedures are provided and posted in areas where spills might take place. 

  • Vehicle fueling plan. Performing equipment and vehicle fueling and maintenance at an off-site facility is recommended instead of performing these activities on the site, particularly for road vehicles such as trucks or vans. For grading and excavating equipment, this is usually not possible or ideal. You should designate an on-site fueling and maintenance area that is clean and dry. The on-site fueling area should have a spill kit, and personnel should know how to use it. 

  • Washing equipment onsite. Environmentally friendly washing practices can be practiced at every site to prevent contamination of surface and groundwater from wash water. Procedures include washing in designated, contained areas only; using off-site facilities; eliminating discharges to the storm drain by infiltrating the wash water or routing to the sanitary sewer; and training staff and subcontractors on proper cleaning methods. 

  • Storage handling and disposal of building materials. Practices such as trash disposal, recycling, proper material handling, and cleanup measures can reduce the potential for stormwater runoff to pick up construction site wastes and discharge them to surface waters. Proper material use, storage, waste disposal, and training of employees and subcontractors can prevent or reduce the discharge of hazardous and toxic wastes to stormwater. 

Inspection, Maintenance & Corrective Action 

  • Inspection procedures. Your responsibility does not stop after best management practices are determined. Your permit requires that you conduct regular inspections and document the findings of those inspections in your SWPPP, including records on corrective actions taken.

  • Delegation of Authority. This form can be used for identifying additional and/or new SWPPP Administrators not identified on the Notice of Intent (NOI). 

As you can see, the SWPPP is a far-reaching document that requires project team effort to complete in a timely manner. It is far more than a plan depicting a temporary silt fence and a retention pond. The cost of implementing the above measures could be a significant part of your construction budget, and you will need to plan accordingly to mitigate costs and reduce project risks. Listed below are our top four SWPPP tips to help you along the way. 

  1. Understand the developer’s role in the SWPPP. Have someone on your staff assigned to the SWPPP.

  2. Make sure that compliance with the SWPPP is part of your construction contract.

  3. Ensure that all contractors and subcontractors sign the Section 8 Certification and Notification page of the SWPPP as part of the contracting process.

  4. Make sure you have a contractor with qualified inspectors.

If you have any SWPPP or other civil engineering questions related to your utility-scale solar project, get in touch with an expert at Castillo Engineering. 


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