Getting to Know the SWPPP

What you need to know about the stormwater pollution prevention plan

Writing an effective stormwater pollution prevention plan (SWPPP) has now become easier, thanks to a user-friendly template offered by the EPA and to a number of classes, training sessions, and books that have emerged in the industry.

The template can be found at http://cfpub.epa.gov/npdes/stormwater/swppp.cfm and has the blessings from such industry experts as Jerry Fifield, Ph.D., CISEC, CPESC, president of HydroDynamics Inc. in Parker, CO, who has taught and written about the SWPPP. He is one of the founders of the Certified Inspector of Sediment and Erosion Control program.

Comprehensive background information to assist in gathering information for the SWPPP can also be found on the EPA’s Web site at www.epa.gov/npdes/swpppguide.

Fifield points out that there are two parts to a SWPPP: the narrative and the sediment and erosion control drawings, of which the latter, he says, is the weakest link in the process.

A SWPPP may be developed with other construction operators on the project; individual responsibilities should be clearly defined. The SWPPP should address construction general permit requirements as well as meet project needs.

A SWPPP addresses eight factors:

1. Site evaluation, assessment, and planning
2. Erosion and sediment control best management practices (BMPs)
3. Good housekeeping BMPs
4. Selecting post-construction BMPs
5. Inspections
6. Recordkeeping and training
7. Final stabilization
8. Certification and notification

Site Evaluation, Assessment, and Planning
This section of the SWPPP includes basic information when filing for permit coverage. It includes:

• Project/site information such as location, latitude/longitude, National Pollutant Discharge Elimination System (NPDES) project or permit tracking number, operators, SWPPP contacts, SWPPP preparation date, and project start and completion dates
• Nature and sequence of the construction activity, including the work scope (such as residential)
• Soils, slopes, vegetation, and current drainage patterns, and all topographic features that may affect erosion and sediment control
• Construction-site elements, including an estimate of the area to be disturbed by excavation, grading, and other construction activities. This includes a calculation of the percentage of impervious surface and the runoff coefficients pre- and post-construction.
• A description of receiving waters, storm sewer systems, and impaired waters, or waters subject to total maximum daily loads (TMDLs)
• Site features and sensitive areas to be protected, including streams, stream buffers, wetlands, specimen trees, natural vegetation, steep slopes, or highly erodible soils that are to be preserved and how that will be done. These features are included on site maps.
• Potential pollution sources, including sediment and nonsediment sources that could affect stormwater runoff
• Endangered or threatened species and critical habitats on or near the project area, as well as historic sites on or near the construction site
• Applicable federal, tribal, state, or local soil and erosion control, and stormwater requirements
• Maps that include the direction of stormwater flow; slopes before and after grading; areas and timing of soil disturbance; undisturbed areas; preserved natural features; structural and nonstructural BMPs; stabilization location and timing; location of areas containing offsite material; waste, borrow, or equipment storage areas; locations of US waters, including wetlands; locations of stormwater discharges to surface water; storm drain inlet locations; and areas where final stabilization has occurred

Shirley Morrow, CPESC, an industry veteran, says this section serves as a baseline in preparing a stormwater plan: “What do you have before you even touch it, and then, working from there with your design, how are you going to change or impact it? With a construction site, we usually start with bare ground that hasn’t been disturbed. The rainfall and erosion on that bare ground is naturally controlled with the vegetation.

“When you are doing a design, you want to look at how much runoff there is,” says Morrow. “What is the topography? The slope? What is the vegetation and how will the construction impact that? What controls are needed?”

Bulldozing an entire site naturally entails more controls than a small impact, she adds.

Changing the topography also dictates the extent of controls: “What if you put a big hill on a flat site and change the relief? What if you make a sloped site flat? That’s going to have a huge impact,” Morrow notes. Her company, StormwaterUSA, offers two online certification programs, the Certified Compliance Inspector of Stormwater (CCIS) and the Certified Preparer of SWPPP (CPSWPPP).

Fifield emphasizes the importance of such details as identifying project owners and the name of the person who prepared the SWPPP, for the sake of accountability.

“If I’m doing this for a developer or builder, that’s who the contact person is, because they’re the ones responsible for protecting the environment,” he says. “It’s a 24-hour contact; if there is a diesel fuel spill, they want to know who to get in touch with. As a designer, I want to be accountable for what I put on paper. If I’m not going to be accountable, I shouldn’t sign for it.”

Listing subcontractors’ names can be difficult, because the companies installing pipelines or utilities are not always determined by the time a project begins, says Fifield.

Having a drainage analysis on hand prior to filling out the SWPPP aids in providing information on soil type, drainage patterns, and vegetation, as all relate to erosion, Fifield says. Vegetation information ranges from whether the site has cornfields, mangroves, ponds, or other regional features, he adds.

Hazardous waste sites or coalmines are examples of historic site contaminations that also must be recorded in the SWPPP’s first section, Fifield says.

Estimating construction site calculations focuses on the area’s drainage pictures and how land disturbance through construction will change impervious areas’ percentages, outlining what will ultimately happen when the site is built out, Fifield says.

“As soon as you go from natural conditions to putting up a lot of houses, all of a sudden, water that used to infiltrate into the ground is now going to run everywhere,” he points out. With the runoff coefficient, higher numbers means greater runoff.

“Water quality is going to be our next big parameter to deal with,” says Fifield. “How much water we can infiltrate into the ground will help the water quality, and that runoff coefficient may be used as an indicator.”

Identifying receiving waters is becoming an increasingly crucial factor, Fifield notes. “You are going to see a lot with the total maximum daily loads allowed for streams in the next EPA reauthorization,” Fifield predicts. “There are certain streams into which we cannot allow a lot of pollutants to enter, and the TMDL is all we’re going to accept.

“Designers are going to have to start thinking about what they can put in place to achieve that,” he says, predicting such measures will entail increased construction-site costs.

The SWPPP includes an area describing the storm sewer system, a reference to municipal separate storm sewer systems (MS4s). Fifield says the area addresses such questions as, “If there are a lot of pollutants going into the storm sewer systems, where do they come out? Are they being treated? Are they going into a lake or river? Is there a pond?”

Information on potential sources of pollution identifies prospective construction-activity sediment sources, such as stockpiles and basements excavations. Other possible sources could be fuel tanks, gasoline, and equipment that could encounter a hydraulic line break.

“How are they going to take care of it? Where are they going to repair them? It’s a list of things that could conceivably happen on every construction site,” Fifield points out.

Because any excavation material can be potential sources of sediment to stormwater runoff whenever land is disturbed, it’s important to stabilize or put a barrier around the area, Fifield says.

While historic preservation and endangered species at face value don’t have a direct connection to stormwater, “If you were to develop land or build diversion ditches and it goes through an historic area, they’re destroying that particular heritage,” says Fifield. “Same thing with endangered species.”

A comprehensive drainage analysis aids in filling out the map portion of the SWPPP. “That impacts how your stormwater is going to be done,” says Fifield.

Assessing historic vegetation is critical because the EPA defines stabilization as being on areas that are not paved. “It’s basically when you have achieved 70% of what was the historic cover,” notes Fifield.

“In Colorado or Kansas, historic cover may be a wheat field or corn field. Nobody has really pushed that issue, but to me historic means what it was like before any disturbance, such as grasslands or forest lands,” he says.

Erosion and Sediment Control BMPs
This section of the SWPPP categorizes BMPs into 10 areas:

1. Minimize disturbed area and protect natural features in soil. Describe areas that will be disturbed with each phase of construction and the methods used to protect them.
2. Phase construction activity. Describe intended construction sequencing and timing of major activities, including opportunities for phasing grading and stabilization activities to minimize the overall amount of disturbed soil subject to potential erosion at one time. Describe opportunities for timing grading and stabilization so all or a majority of the soil disturbance occurs during a time of year with less erosion potential.
3. Control stormwater flowing onto and through the project. Describe structural practices (such as diversions, berms, ditches, storage basins), including design specifications and details used to divert flows from exposed soils, retaining or detaining flows, or otherwise limit runoff and the discharge of pollutants from the site’s exposed areas.
4. Stabilize soils. Describe controls such as hydroseeding or interim seeding with native vegetation to stabilize exposed soils where construction activities have temporarily or permanently ceased. Describe measures to control dust. Avoid using impervious services for stabilization whenever possible.
5. Protect slopes. Describe erosion control measures (such as erosion control blankets and tackifiers), including design specifications and details that will be implemented to protect slopes.
6. Protect storm drain inlets. Describe controls that will be implemented to protect all stormwater inlets during the project.
7. Establish perimeter controls and sentiment barriers. Describe practices such as silt fences or fiber rolls, including design specifications and details to filter and trap sediment before it leaves the construction site.
8. Retain sediment onsite. Describe sediment control practices, such as sediment traps or sediment basins, including design specifications and details to be implemented on the construction site.
9. Establish stabilized construction exits, describing vehicle entry and exit locations, procedures to remove accumulated sediment offsite and stabilization practices to minimize off-site vehicle tracking of sediments and discharges to stormwater.
10. Describe additional sediment and erosion control BMPs.

This section is important because anytime construction involves removing vegetation, which is a natural control, something has to replace it, “otherwise the soil is just going to run right off the site unimpeded,” Morrow points out.

Typically, many people’s first thought is to put in silt fence and hay bales as controls. However, on many sites, other potential pollutants besides sediment, such as trash and petroleum spills, could enter waterways. “When you think of BMPs, you have to encompass those as well,” Morrow says.

Fifield adds that designers need to be confident that they’re choosing the correct BMP at the correct time.

“Sometimes designers put BMPs in without thinking of how much maintenance it is going to take,” he says. “Silt fence is a case in point: putting silt fence everywhere may not be the best thing if you have concentrated water flowing down to that silt fence that’s going to wipe it out; maybe you need a rock check dam.”

Fifield finds the instruction on categorizing each BMP under one of 10 areas as “overkill,” but he acknowledges that “it does point out that if you are going to use BMPs, you ought to know what part of the project you are going to put it in—are you doing it to stabilize the slopes, for example?”

And while he would rather see the word “approximate” for the location of BMPs on the site map because the placement can vary, he concedes some regulators insist on BMPs in certain locations. Fifield himself indicates them with symbols and wording on the map.

Good Housekeeping BMPs
This section describes the good housekeeping and pollution prevention BMPs implemented to control pollutants in stormwater in the following areas.

• Practice material handling and waste management measures (trash disposal, sanitary wastes, recycling, and proper material handling) to prevent solid waste discharge into receiving waters, except as authorized by permit.
• Establish proper building material staging areas to minimize exposure to stormwater.
• Designate washout area location and controls to eliminate potential for discharge of such materials as concrete mixers, paint, and stucco.
• Establish proper equipment/vehicle fueling and maintenance practices to control pollutants to stormwater.
• Control equipment and vehicle washing practices to prevent pollutants from entering stormwater.
• Have a spill prevention and control plan to reduce the potential for spills, stop their sources, contain and clean up spills, dispose of materials contaminated by spills, and train personnel to handle spill prevention and control.
• Manage non-stormwater discharge, including water used to wash vehicles without the use of detergents; water used to control dust; water from external building washdown without detergents; pavement washing where no spills, leaks, or release of toxic or hazardous materials have occurred; uncontaminated air conditioning or compressor condensate; uncontaminated groundwater or spring water; foundation or footing drain flows; uncontaminated excavation dewatering; and landscape irrigation.

“Good housekeeping is a big thing with the EPA,” says Fifield. “They are saying to not throw oil cans and other things anywhere you want—get rid of it in a proper manner so you keep the site relatively clean, so when it rains there is less chance of stuff flowing off the site.

“The washout area is a big one,” he adds. “There are various regulations at the local level of where you are going to wash out concrete, paint, stucco, and so forth. The EPA doesn’t necessarily suggest a specific technique as much as asking the designers how they’d handle it.”

For example, he says, on many sites, concrete trucks wash their waste into a ground pit that is contained and occasionally emptied. An alternative is a portable unit into which a concrete truck can dump its waste, which is hauled offsite. Rather than using a washout site, one of Fifield’s Indianapolis client companies uses the concrete as part of the constructed homes’ driveways, for example; the company does all of its concrete work at once to effectively execute the practice.

Fueling is another opportunity for innovation, Fifield says. “Are you going to go out in the middle of a field and let a lot of gas go in the ground, or go to a contained area where if there was spillage, there would be visqueen underneath?

“The problem we have as designers is establishing proper equipment fueling and maintenance practices. My recommendation is that designers don’t identify where that place is going to be—let the contractor determine where it is going to be—and once he knows where he wants to refuel his trucks, then put in these preventative measures and update the drawings. Who knows more what’s happening on the site: the designer or the contractor?”

The same is true of the spill prevention plan, Fifield adds.

“This can best be taken care of by the contractor, because he or she has probably gone to classes that deal with heavy equipment and most designers don’t have that education.”

When it comes to outlining non-stormwater management, Fifield says all the EPA wants to know is if there is going to be water on the site, how is it going to be handled—will it be treated or piped offsite?

Other questions to consider in this section of the SWPPP: What should be done when there are springs on the property? If there are occasional high groundwater conditions, will the water go into a sediment pond? Will it be diverted?

How construction is executed is a BMP, says Morrow. This might involve conforming closely to the existing contour of the land to minimize grading activity. “Another is to disturb as little of the vegetation as you can. Those are things you can do so you don’t have to buy or install products, but are design elements that will alleviate or reduce the amount of erosion during construction because you’re keeping some of the original controls.”

Many people think mainly of silt fence when they hear the term BMPs, says Morrow. “A BMP can be anything from a portable sanitation unit, a Dumpster, a rock stone entrance, an entrance/exit pad, and silt fence to a pond inlet protection. But it can also be leaving buffer strips in place and not disturbing areas.”

Selecting Post-Construction BMPs
This section of the SWPPP describes the post-construction stormwater management measures that will be installed during construction to control pollutants in stormwater discharges after the project is completed. Examples include biofilters; detention/retention devices; earth dikes, drainage swales, lined ditches; infiltration basins; porous pavement; proprietary permanent structural BMPs; outlet protection and velocity dissipation devices; slope protection; and vegetated strips or swales. This section of the SWPPP also includes an identification of design and installation, a description of how low-impact designs or Smart Growth considerations have been incorporated into the design, and design specifications and details for structural BMPs.

Fifield calls this one of his favorite sections of the SWPPP.

“If you look at biofilters, earth dikes, porous pavement—these are getting to the water-quality aspect, and that’s going to be the next big thing beginning in 2008,” he says.

“We have to know what we are doing as far as the phosphorus, the hydrocarbons, and all of the other matter that is going to come off after something is built,” he says.

“That’s a weak area in the process. Designers need to get ready to learn about this, because this is going to require a lot of their skills as well as the skills of everybody else involved in this business.”

Morrow explains that the NPDES program covers different types of stormwater issues—among them are BMPs during construction and another being what she calls “operational.”

“A post-construction stormwater management system would be an operational system. If you’re building a gas station or a car wash, you know you are going to have pollutants on those sites while they are operating,” she explains.

“During construction, they want you to show the evidence in your stormwater plan of what you are going to do for the post-construction discharges,” she adds.

“That’s a big thing now in the industry; before you can even start construction, many of these Phase II communities want to see what your post-construction design is so that once you are done with construction and your NPDES permit is terminated, you have post-construction BMPs in place to help with stormwater management, flooding, or pollutants from the site you constructed.”

Inspections
This section of the SWPPP identifies those responsible for conducting inspections and describes their qualifications; the frequency of inspections (including correlation to storm frequency and intensity); inspection details for particular BMPs onsite; documentation needed for maintenance and repairs taken as a result of inspections; and those delegated to sign inspection reports, certifications, and other information.

Inspections are a key element, says Fifield.

“While contractors must provide their own inspectors, every designer should also know how to do an inspection,” he says. “If the designers know what the state does in an inspection—and how to do the maintenance—they would be a lot more cognizant of what they are putting on their plans.

“If they put in a fiber log BMP, for example, what are the maintenance issues? What size logs should be used? Designers should be doing an inspection every once in awhile themselves.”

The effective action logs in the inspection report refer to “noting when something got repaired or replaced; it is part of the records that have to be kept up to three years after the project itself is closed out,” says Fifield. “Some cases could be even longer.”

A municipality regards inspections as enforcement, says Morrow. “But the permit holder does their own inspections according to the permitting—every 7 or 14 days or after a half-inch rain event,” she says. “The reason you do those is to make sure your practices are working. If they are not working, you’ve got to fix them.

“If a bulldozer runs over a silt fence and you don’t do an inspection, you’re never going to know about it and could have sediment leaving your site,” she adds. “Self-inspection is to make sure the practices you put in place according to the stormwater plan are properly maintained and in proper working order throughout the entire construction site.”

Outside agencies, such as a state agency or municipality that has jurisdiction over the area, will do more of an audit inspection to make sure everything is being done according to the general permit, Morrow says.

“Are you inspecting them as you should? Are you maintaining them? Do you have a SWPPP onsite? Unfortunately, many of the inspections are just a matter of ‘Do you have this site permitted?’ We’re still finding a lot of sites where there’s no permit, no SWPPP, and people are saying, ‘I don’t know what you’re talking about.’”

Recordkeeping and Training
Records for inspectors to review include dates of grading, construction activity, and stabilization; a copy of the construction general permit; the signed and certified Notice of Intent (NOI) form or permit application; a copy of a letter from the EPA or the state permitting authority acknowledging receipt of the completed NOI or application; inspection reports; records relating to endangered species and historic preservation; and any other details as required.

This section of the SWPPP also includes a log of changes to the SWPPP, such as the addition of new BMPs, replacement of failed BMPs, and other significant changes to the construction activities.

Recordkeeping is part of the inspection, says Morrow. “In essence, it’s evidence of compliance in case an agency asks for information.”

Training is another component of this section. Training is documented for those who have specific stormwater responsibilities.

Fifield calls training “an effective BMP.”

“We’re starting to get general contractors and other people trained, but where we really need to see more training is at the lower levels—the subcontractors, concrete truck drivers, painters, landscapers, and all of the people who have a great impact on the site,” says Morrow.

Final Stabilization
The procedures for final site stabilization are outlined in this section of the SWPPP. As parts of the site are completed and stabilized—that is, documented—and many permits allow inspection activities to be discontinued for those areas. This section of the SWPPP can be amended as the project is finally stabilized.

“You start out with native vegetation as your control,” Morrow points out. “You have changed that site dramatically—you’ve probably added a building or something else that is impervious to rainwater, so there is going to be an increase of stormwater runoff.

“You’ve also probably changed the soil—its texture and its type—so that infiltration may be different, which also will increase your runoff,” she says.

Morrow says that with regard to final stabilization, “you have to make sure that whatever soil was disturbed has some type of protection on it so the site doesn’t keep eroding. I don’t think you are ever going to get a site back to the way it was before, because you’ve constructed something on it. But to the best of your ability, you have to reduce erosion as though it were preconstruction. That’s final stabilization.”

While the industry has improved in terms of final stabilization, it still faces two challenges, Morrow contends.

“One is that we’ve removed the topsoil, and we have a hard time growing grass in subsoil. It doesn’t grow in subsoil,” she says. “Secondly, we’re just not good at knowing how to grow grass.”

Final stabilization is documented with maps and drawings, says Fifield. “When you do your drawings, they show the historic contours and identify what items need to be installed right away,” he says. “Sometimes we will have a second map that shows what’s occurring on the site during the construction phase with a lot of grading going on. That’s what I call the interim drawing: it shows the proposed contours, where the sediment pond is going to be, and other factors.”

The final stabilization is shown on a third map that Fifield provides to contractors. This map includes color-coding or other marks indicating where certain erosion control measures need to be applied.

“I separate the erosion control design from the sediment control necessary while the building is going on,” says Fifield. “It helps the contractor. Some drawings are appalling. They combine everything on a single piece of paper—silt fences, sediment ponds, tracking pads, vegetation. It is such a hodge-podge, you can’t figure out what is going on.

“Three maps take care of that. The final stabilization says to update site plans that receive final stabilization. If it is color-coded on the maps—identifying, for example, the area that had been seeded, the area that had been mulched—and if you are working on the job two years later and the vegetation is established, you’re simply giving a dynamic record to everything is going fine.”

Certification and Notification
The SWPPP is signed and certified by the construction operators. A copy of the NOI and the permit authorization letter received by the EPA or state is attached.

Fifield adds that he’d like to see the SWPPP signed by the designer as well, to establish accountability for its contents.

Certification and notification depends on a general permit’s requirements, Morrow points out.

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“The NOI has a certification statement; the permit holder has to certify that they are going to be in compliance and have done everything they’re supposed to do as per the permit requirements,” she notes.

Depending on the state and how the permit is written, contractors have to certify they will abide by the general permit,” she says. “Some states require you notify them under certain circumstances and in other states, you have to notify if there’s a noncompliance issue, such as accidental stormwater discharge.