SWPPP: How to Develop a Stormwater Pollution Prevention Plan
So, you've heard your construction site need an SWPPP or Stormwater Pollution Prevention Plan, and you started frantically googling to find out what that means.
Here's what you need to know to get started.
What is Stormwater Pollution Control and Why Does it Matter?
Land development changes the way water moves through the environment because impervious surfaces like buildings, parking lots, and roads prevent rainwater from soaking directly into the ground. Instead, the water flows over these surfaces and eventually ends up in a body of water, either directly or via stormwater sewers.
As the water flows, it picks up pollutants and debris that ultimately contaminate the local water supply. Any commercial activity performed outdoors has the potential to introduce pollutants to manmade surfaces, which can then be picked up by surface runoff in the next storm.
Federal, state, and local governments often require stormwater pollution control measures for facilities and operations that could be a major source of pollutants in stormwater. They use a permit process developed by the U.S. Environmental Protection Agency (EPA) but it's often executed at the state level.
All state SWPPP requirements have to meet the federal minimum, but some are stricter than others. Local governments may have additional requirements. Some states accept the EPA minimums and the permitting process is handled by the federal agency.
Do your homework on your jurisdiction's rules. You can find your state's permitting authority on the EPA's website. Note that if a row is blank, that means the EPA handles permitting in that state. The EPA's website doesn't provide information on county or municipal authorities, so you'll need to check whether any local regulations also apply.
What is a Stormwater Pollution Prevention Plan?
A Stormwater Pollution Prevention Plan (SWPPP or sometimes SW3P) is a site-specific written document that identifies the activities and conditions that could cause water pollution and describes the steps you'll take to prevent discharge.
SWPPPs are a required step for a National Pollutant Discharge Elimination System (NPDES) permit. You'll sometimes hear NPDES permits referred to as SWPPP permits.
Who Needs an SWPPP Permit?
NPDES permits are only necessary when you discharge pollutants into the Waters of the United States. If you're discharging into a municipal sanitary sewer system that ultimately runs through a water treatment plant, you don’t need an NPDES permit (but your municipality may have its own requirements).
When Does a Construction Project Require an SWPPP Permit?
The EPA requires an NPDES Construction General Permit (CGP) for any construction activities that disturb 1 acre of land or more. Activities that disturb smaller amounts of land still count if they're part of a 1+ acre common plan of development or sale.
Relevant earth-disturbing construction activities include clearing, grading, and excavating land, as well as activities that could lead to the generation of pollutants, like stockpiling fill materials or placing raw materials at the site.
Why are permitting requirements dictated by the amount of disturbed land? Many construction sites involve pollutants that may be stored or used outdoors, of course, but disturbing soil introduces a whole new problem. Earth-disturbing activities free any pollutants that were locked in the soil by making it possible for contaminated sediment to enter the water supply.
The EPA has decided that construction activities don't cross the threshold to a "major" source of pollution until 1 acre of land will be disturbed in a single location.
This is just the federal minimum. As we said, state and local requirements can be more strict, so you'll want to check your state and local laws.
Who's Responsible for the SW3P under a Construction General Permit?
Legally, the operator of the construction site is responsible for creating and implementing an SWPPP.
The EPA considers the "operator" to be any party associated with a construction project that meets either of the following criteria:
- They have operational control over construction plans and specifications, including the ability to make modifications, or
- They have day-to-day operational control of activities necessary to ensure permit compliance
If operational control over plans and day-to-day activities are controlled by one party, then they will be the sole permittee – typically, a general contractor or the owner.
If those pieces are controlled by separate parties, the parties may need to apply as co-permittees. It's common for owners and contractors to share the responsibility.
What Are the EPA's SWPPP Requirements?
Your state and local authority may have additional requirements but knowing the EPA's minimum can give you some idea of what to expect.
Who Can Create the SWPPP?
The EPA minimum makes it possible for someone with construction experience to draft a Stormwater Pollution Prevention Plan, and there are templates you can use to get it done.
However, some states require the SWPPP to be developed by someone with a specific certification, so check if that applies.
What's the Deadline for the SWPPP?
The EPA requires all operators on the project to complete the SWPPP document and submit a Notice of Intent (NOI). In some states, it's called a Notice of Coverage (NOC).
Different types of operations have different deadlines, but usually the NOI needs to be submitted before construction activities start.
What Are the Required Elements of an SW3P?
All SWPPP documents must include a:
- Site description
- Member list for the pollution prevention team, including names and duties
- Details of activities that could cause pollution
- Control measures for preventing spills or minimizing pollution hazards
- Plans for how you will respond if a spill does occur
- Procedures for inspecting and monitoring pollution on-site
- Plans for training employees about the SWPPP
The SWPPP is supposed to be a "living document," so as work begins, you'll add records of inspections, monitoring, maintenance, and training. If conditions change, you'll also need to revise your written plans.
How Do You Develop Your SWPPP?
The EPA supplies really helpful and construction-specific guidance to help you develop your own SWPPP, including a very thorough step-by-step guide and example SWPPPs for a range of different construction projects.
That said, here's the basic process for developing your Stormwater Pollution Prevention Plan:
- Assess your site and your project. This involves identifying relevant elements like how stormwater drains before development, the way your stormwater will flow after it leaves the site, and more.
- Identify ways you can protect natural resources during development that will reduce runoff volume.
- Develop site maps, including those for the existing site and for each major phase of construction. Site maps need to indicate stormwater flow, slope gradation, features that need to be protected, areas that will be disturbed, and ultimately the location of best management practices (BMPs).
- Select the BMPS you'll use for erosion control (keeping the sediment in place) and sediment control (preventing dislodged sediment from being washed off-site).
- Pick the BMPs you'll use to prevent pollution, also called good housekeeping. Considerations include waste management, material staging areas, safe equipment fueling and maintenance practices, and more.
- Describe how you'll inspect and maintain your BMPs, including who will be responsible, how often they'll inspect, what special conditions call for an immediate inspection (like a certain amount of rainfall), how you'll dispose of sediment cleared from BMPs, and more.
- Include the format you'll use for recordkeeping, including inspection reports, maintenance reports, and events like non-stormwater discharges.
Regulatory authorities will expect your document to be site-specific and detailed, and they will expect to see that you've implemented the plan as written. Use all the examples and templates at your disposal, but you can't simply cheat off someone else's paper.
Learn More About Stormwater Discharges and Permits
This article barely skims the surface of everything you need to know about creating and implementing a stormwater discharge program.
Check out our construction-specific online course for a more thorough understanding of pollution sources, control measures, and more. It's self-paced and mobile-friendly for your convenience!
