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Land Development > Stormwater Pollution Prevention Plan (SWPPP) Compliance
Stormwater Pollution Prevention Plan (SWPPP) Compliance
A good storm water control plan always starts with a thorough Storm Water Pollution Prevention Plan (SWPPP). A SWPPP not only specifies specific methods of controlling storm water onsite, but provides the required characterization information required by State and Federal regulations.
A “BMP” or Best Management Practice, is often thought of as an engineered or structural control used to control erosion, such as silt fence or detention ponds. In reality, BMP’s are any product, structure or administrative control, such as an ordinance or written practice, which is designed to prevent, mitigate, or treat contaminated storm water runoff.
A good SWPPP will always include background information such as:
- Soil types
- Runoff coefficients for pre- and post-development conditions
- Characterization of existing water quality
- Descriptions of existing impairments
- Existing rainfall information to know how much water you may need to address
Although there are many forms of stormwater management and BMP’s, the best BMP’s are the ones keep you from impacting storm water to start with. The easiest storm water contamination to treat, is that which never gets impacted to start with. These types of BMP’s include:
- Limiting the amount of area exposed prior to construction
- Preserving natural stream buffers and maintaining native vegetation as long as possible
- Diverting upstream storm water runoff from around a site
When all preventative measures have been taken Storm Water control from your site can begin in earnest. These types of BMP’s will include:
- establishing perimeter controls
- beginning soil stabilization as soon as possible
- Establishing temporary vegetation
- Installation of BMP’s designed to slow water velocity and further reduce erosion potential such as check dams and rip rap and other outlet protection
Even the best SWPPP will not completely prevent all erosion from occurring, and when it does good BMP’s will help reduce sediment which can leave the site and wash downstream. These types of BMP’s will include:
- Installation of tire washing stations or other track-out control
- Silt fence
- Inlet protection
- Sediment traps
- Well-designed and maintained outlet control
Even after your project is complete, there are many, many ways to help protect our resources. Many of these post construction BMP’s include:
- Acquiring control of natural waterways where they still exist or can be rehabilitated
- Encouraging proper maintenance of structures to increase life expectancy
- Staying current on proposed and pending stormwater regulations which could impace your site
- Educating the community about water quality issues so the public can be a partner to help improve water quality
Phase I of the Clean Water Act (CWA) required that all municipalities of 100,000 persons or more, industrial dischargers, and construction sites of 5 acres or more have NPDES permits for their stormwater discharges. Phase I permits were issued in much of the U.S. in 1991. Phase II required that all municipalities, industrial dischargers, construction sites of 1 acre or more, and other large property owners (such as school districts) have NPDES permits for their stormwater discharges. Phase II rules came into effect in 2003.
EPA issued a new Construction General Permit in July 2008. This permit expires in 2011 and continues the provisions of the previous permit. In December 2009 EPA issued new discharge standards, called effluent guidelines, for construction sites. These requirements set a new national minimum standard for erosion controls and sediment controls, and pollution prevention measures. The effluent guideline provisions will be incorporated into the next round of EPA and state general permits.
As the Federal and State governments move forward with new regulations keeping up with these changes is not only a good idea, but an absolute necessity in order properly plan for your clients, In years past we have assisted clients as they learned the in’s and out’s of new acronyms and terms such as MS4, CSO, Phase 1, and Phase 2 controls. However, the learning never stops. In December 2009 EPA for the first time proposed a new set of discharge standards , for construction sites and the term “NTU” entered the storm water lexicon.
Originally, the standards were set to take affect in 2011, but Federal courts have remanded to NTU limits back to USEPA for further study. Although the Federal government is set to reissue general permits, it is not at all clear if the new effluent guidelines will be included. This makes it all the more important that people stay involved and informed on all pending changes and how they can impact your site.
In addition to implementing the NPDES requirements, many states and local governments have enacted their own stormwater management laws and ordinances, and some have published stormwater treatment design manuals. Some of these state and local requirements have expanded coverage beyond the federal requirements.
CMT has extensive experience in SWPPP compliance, with certified trainers & certified erosion control inspectors/specialists on staff. If you have questions or need assistance in preparing a SWPPP - Contact Us
Should you have an interest in becoming a Certified Professional in Erosion & Sediment Control (CPESC), you may register for the CMT-Hosted review course and exam at: CPESC Certification
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Examples & References of the many Design Manuals available for use include:
Indiana Storm Water Quality Manual
Indianapolis Stormwater Design and Construction Specifications Manual