In case you are unfamiliar with the acronym "SWPPP," it refers to a Stormwater Pollution Prevention Plan. This document serves as a guide to site workers, inspectors, and others involved in the construction and approval process for earth disturbing work. The SWPPP is very comprehensive and includes sections discussing project details (location, area, present soils & conditions, construction activities), Best Management Practices (BMPs) to be implemented, erosion & sediment controls, spill prevention and response strategies, inspections, and maintenance of stormwater management practices. The SWPPP is prepared by an engineer and/or certified erosion and sediment control professional.
The United States Environmental Protection Agency has created a Construction Stormwater Pollution Prevention Plan template with placeholders for all the required information to be included. The link to this document can be found at https://www.epa.gov/npdes/construction-general-permit-resources-tools-and-templates#swppp. More than half of the plans that are submitted to Warren Co SWCD for review are generated using this template, and it includes some appendices such as the corrective action and amendment logs. A construction site inspection form is also provided. Warren Co SWCD along with Ohio EPA requires that soil types are presented on a site map. If you are not collecting field data or have a GIS layer for the area of interest, an easy way to obtain that information would be to use the USDA Web Soil Survey tool using the following link: https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx. Web Soil Survey is very easy to navigate and gives the user access to other soil data such as erosion factors, conductivity, hydric status, and hydrologic group. An Area of Interest can be uploaded or drawn by the user and the generated report can be added directly to the SWPPP Appendix. To verify that a sediment basin/trap is designed to accommodate storage for the drainage and disturbed areas contributing to it, reviewers often ask that calculations are provided to demonstrate compliance with the permit. An alternative to submitting design calculations would be to use the OEPA Sediment Basin Compliance tool which can be found at https://epa.ohio.gov/divisions-and-offices/surface-water/permitting/stormwater-program under Tools and Spreadsheets. The spreadsheet prompts the user to input data and automatically outputs whether the contours and selected orifice sizing meets requirements. Directions, OEPA contacts, and applicable regulations are also provided to better aid the engineer in filling out the worksheet. One of the best resources to consult while preparing a SWPPP is the Ohio EPA Construction General Permit (CGP), which lists all the requirements to be met by the NOI applicant. The CGP, specifically Parts 2 and 3, include the minimum components of the document and what information needs to be included in the site maps and each section. Additionally, all the required language and timing requirements for sediment & erosion control maintenance/installation, stabilization measures, and inspections are stated and can be copied directly into the project SWPPP. A link to the general permit can be found at https://epa.ohio.gov/divisions-and-offices/surface-water/permitting/storm-water-discharges-from-small-and-large-construction-activities--general-permit. Still have questions or need help getting started? Call our offices at 513-695-2901 for assistance!
0 Comments
In order to effectively manage stormwater for an increasing population (and therefore impervious cover), engineers design sites with retention or detention basins for more storage. Before an area is disturbed or developed, the land is classified as an permeable surface meaning water can infiltrate into the subsurface. Roads, sidewalks, houses, and other structures prevent infiltration, and to accommodate for the quantity of water that is no longer able to infiltrate we build storm sewers that direct water to basins for storage. In addition to accommodating runoff, basins provide many other benefits including treatment by allowing for settling time and regulating the amount of water being released preventing erosion down a watershed. A detention pond does not contain a permanent pool of water and is designed to store water temporarily before leaving the outfall structure and releasing to a stream. Detention ponds are constructed for flood events and have shorter settling and retention times than retention basins. A retention basin stores water year-round, and the outfall structure contains an orifice at a higher elevation compared to a detention pond. In Ohio, we primarily see retention ponds surrounding developments due to the higher amounts of precipitation we receive compared to out west.
Many variables are considered when determining size and location of these stormwater control measures. Properties include rainfall intensity in the geographic location, soil type(s), land cover, distance to creek, and total impervious area after development. To learn more about basin sizing & structure requirements you can read through the Ohio EPA Construction General Permit Parts III.G.2.d.ii. and III.G.2.e. Questions? Contact our office at (513) 695-1337 for more information from your local basin experts! Is there a basin on your property in Warren County? You can view the latest inspection report on its functionality here. Green Infrastructure is defined in the Water Infrastructure Improvement Act as “the range of measures that use plant or soil systems, permeable pavement or other permeable surfaces or substrates, stormwater harvest and reuse, or landscaping to store, infiltrate, or evapotranspirate stormwater and reduce flows to sewer systems or to surface waters.” Examples of some local green infrastructure include rain barrels or gardens, designating areas as open space, and bioswales. Most stormwater management materials used in development are considered “grey infrastructure” which includes pipes, culverts, tunnels, and more. These engineered systems regulate our watershed drainage and will likely never be phased out; however, many developers are now supplementing the grey with the green for a variety of reasons. The naming convention alone promotes sustainability—these practices have significantly lower carbon footprints just by the reduction in the amount of material that must be mined/extracted, used in production, and transported to the site where they will be installed. Along with requiring less energy and resources to route stormwater runoff, these practices have aesthetic value and economic benefits. Communities have been able to save money by reducing the diameters of piping by directing flow through a rain garden or an open space to allow for infiltration. A lower flow rate can also lead to less transport of pollutants from urban stormwater runoff and the ability to manage higher volumes during flood events.
More about green infrastructure can be found at: https://www.epa.gov/green-infrastructure/what-green-infrastructure Questions? Call our Urban Team at (513) 695-2901! Thank you to everyone who attended the first program of our newly relaunched series, Urban Chats. We're grateful to Margaret Minzner, Environmetnal Senior Planner at the Ohio-Kentucky-Indiana Regional Council of Governments (OKI), for sharing her expertise. If you were unable to make it to the program, never fear! You can check out the recording below or on our YouTube channel. If you have any questions, feel free to contact Veronica Buchanan at [email protected] or Margaret Minzner at [email protected]. What is a watershed? In the simplest terms, a watershed is an area of land which drains to a central water body such as a river or lake. Also called drainage basins, watersheds range in size from a small retention pond in your neighborhood to the Mississippi River Basin, which transports water from over 30 states to the Gulf of Mexico. Why are watersheds important? Examining our communities and the broader region in terms of watersheds can help us make decisions regarding our personal and professional water use. The earth is covered in water - 96.5% is in the oceans, which cover 70% of the earth’s surface. A tiny fraction of earth’s water, only 1.7%, is found in groundwater, rivers, lakes, wetlands, and soils. Groundwater makes up 30% of all freshwater, which is 35 times more water than all the lakes and rivers combined. So why are we so concerned with surface water if it’s such a small portion of the earth’s tremendous water resource? The United States has over 4.8 million kilometers of rivers, streams, creeks, and brooks. These bodies of water flow through heavily urbanized cities as well as sparsely populated rural areas and pick up sediment, debris, and other pollutants along the way. Our local stormwater sewer systems (MS4s) contribute water to many streams and creeks as well as the Little Miami River and the Ohio River. By actively managing the materials discharged into local waterways we can maintain the health of our regional watersheds, thereby providing clean water for creatures and communities downstream. For more information on watersheds, see the EPA’s Healthy Watersheds Protection FAQ page: https://www.epa.gov/hwp/basic-information-and-answers-frequent-questions Additional Resources: https://www.neefusa.org/nature/water/lesson-1-watershed-basics https://eec.ky.gov/Environmental-Protection/Water/Protection/DocsGuidebook/KY%20Watershed%20Planning%20Guidebook%20-%20Watershed%20Basics.pdf Tuesday, January 25th 12:00pm-1:00pm Join us for an overview of Web Soil Survey and a discussion of Environmental Viewer with Margaret Minzner, Environmental Senior Planner with Ohio Kentucky Indiana Regional Council of Governments. This program is part of a year-long series designed to highlight online databases and tools for development planning. This session is online and registration is required. To register, complete the form below. Questions? Contact Veronica Buchanan at (513) 695-2901 or [email protected]. To develop within certain jurisdictions located in Warren County, the site owner is required to obtain an Earth Disturbing Permit (EDP) on any project where the proposed disturbed area is greater than one acre. The jurisdictions where our MS4 services are provided, and therefore EDPs issued by Warren Co SWCD, can be found on the Earth Disturbing portion of our website. To complete an application, site owners will need a Stormwater Pollution Prevention Plan (SWP3) prepared along with construction drawings, basin calculations (if applicable), basin operation and maintenance documents, and a completed Earth Disturbing Permit application. A SWP3 template along with the sediment basin compliance tool used for design calculations can be found on the Ohio EPA website. Once the SWP3 has been developed, site owners can apply for a Notice of Intent (NOI) through the Ohio EPA. The NOI permit number is needed on the EDP application. Construction drawings and other related details must also be approved by the engineer overseeing post-construction for a permit to be issued. All documents can be submitted electronically on our website. Once a full application submission has been received, a member of Warren Co SWCD’s Urban Team will send an email receipt and add it to the review queue. After the disturbed acreage has been verified an invoice will be emailed to the point of contact. Warren SWCD will send either an approval or request for additional information within two weeks of receiving the submittal. If you have additional questions on preparing the required documents or the application process, please contact out office at (513) 695-1337. We look forward to helping you with your next project! Welcome to Development Digest - a place where Warren Co SWCD shares information, updates, and trainings for professionals in stormwater management, land development, and stream protection.
Winter is quickly approaching in Warren County, and the snowfall that occurs during winter months can result in excessive amounts of soil erosion and transport of sediment into our local waterways. For your construction site to be compliant with Ohio EPA Construction General Permit regulations, workers should begin applying temporary stabilization measures for areas that will be left idle over winter months. For a disturbed site, stabilization techniques are required if areas are to remain dormant for more than 14 days. Preparing the disturbed area for winter conditions by providing cover over bare soil and ensuring proper function of controls will result in minimal environmental impact. For all disturbed sites it is essential to install perimeter and inlet protection so that snowmelt leaving the site passes through a filter prior to discharging into the drainage network. Additionally, it is necessary to install rock check dams and construction entrances prior to the onset of weather to avoid loss of sediment downslope. Other stabilization measure providing cover over a large portion of the site include seeding, mulching, and sodding. The goal is to apply these vegetative treatments by November, but sometimes this is not always practical with varying schedules. To learn more about coverage options, specifications, and seeding schedules, browse through Chapter 7 of the Ohio Rainwater and Land Development Manual. Warren Co SWCD’s expert Urban Team is also available to help – call us at 513-695-2901. |
Details
Urban team BLOGEvery month, the Warren Co SWCD Urban Team dives deep into the world of land development as it relates to stormwater pollution prevention. The blog covers topics like erosion & sediment control best management practices (BMPs), state and local regulations, retention/detention basins, and the conservation of our natural resources. Stay up to date with Development Digest by signing up for WCSWCD Urban eNews!
Categories
All
Archives
July 2024
|