Erosion Prevention and Sediment Control Guide - Kentucky Energy and Environment Cabinet

Kentucky Energy and Environment Cabinet

Sediment washing into streams is one of the biggest water quality problems in Kentucky. Sediment muddies up the water, kills or weakens fish and other organisms, and ruins wildlife habitat. It is not difficult to reduce erosion and prevent sediment from leaving construction sites.

Basic Principles for Erosion Prevention

Preserve existing vegetation.
Divert upland runoff around exposed soil.
Seed/mulch/cover bare soil immediately.
Use sediment barriers to trap soil in runoff.
Protect slopes and channels from gullying.
Install sediment traps and settling basins.
Preserve vegetation near all waterways.

For more basic information about Erosion Prevention, visit our

introduction page.

Pre-construction Planning

Planning your construction project can help you avoid costly mistakes in controlling erosion and sediment loss to nearby waterways. Follow the steps below before you begin clearing, grading and excavation work. If your project is one acre or larger, you will need a stormwater permit from the Kentucky Division of Water. More information about stormwater permitting is available at eec.ky.gov/Environmental-Protection/Water/PermitCert/KPDES/Pages/default.aspx.

Pre-construction Planning

Construction Phase Operations

Divide your construction site into natural drainage areas, so you can deal with each one individually. You will be controlling erosion on bare soil areas by applying seed, mulch, or sediment filters, and minimizing the time bare soil is exposed to the weather. Control point for sediment in runoff will be at the curb inlets or in the ditches, channels or sediment traps/basins installed where concentrated flow leaves the site.

Install clean water diversions, sediment traps/basins and stabilize drainage channels with grass, liners, and silt check dams before excavation, fill or grading work begins. Install silt fences and other sediment barriers downhill from bare soil areas before clearing or excavation work begins.

Construction Phase Operations

Diverting Upland Runoff Around Exposed Soils

Keep clean upland runoff from flowing through your construction site or route it through stable ditches so it won’t get muddy. Included are some simple approaches for dealing with uphill sources of runoff.

Diverting Upland Runoff around Exposed Soils

Protecting Soils with Seed, Mulch or Other Products

Seeding or covering bare soil with mulch, blankets, mats or other products as soon as possible is the cheapest and best way to prevent erosion. Grass seeding alone can reduce erosion by more than 90%. Sod, mulch, blankets, and other products can further increase protection.

Using Silt Fence and Other Sediment Barriers

Using Silt Fence and Other Sediment Barriers

Protecting Slopes to Prevent Gullies

Slopes – especially long ones – must be protected to prevent sheet, rill, and gully erosion. Slopes are stabilized immediately after grading work is completed. Seeding and mulching provide the best and cheapest protection. Erosion control blankets or turf reinforcement mats are needed on most slopes greater than 3:1.

Protecting Slopes to Prevent Gullies

Protecting Culvert and Ditch Inlets and Outlets

Culverts and ditches are designed to carry moderate and large flows of stormwater. They can transport a lot of sediment to streams, rivers, wetlands, and lakes if they are not properly protected. In addition, culvert and ditch outlets can become severely eroded if high velocity flows are not controlled.

Stabilizing Drainage Ditches

Man-made drainage ditches with gently sloping bottoms (less than 3%) can be stabilized with thick grass seeding and erosion control blankets.

Natural (i.e., not “man-made”) drainage channels and creeks or streams cannot be cleared, re-routed, or otherwise altered without one of more permits from the U.S. Army Corps of Engineers and the Kentucky Division of Water. Moderately sloping ditches (3%-6% slopes) will likely require turf reinforcement mats and perhaps some riprap if soils are silty. Steeply sloping ditches (greater than 10%) need heavier armoring with concrete, riprap, gabion baskets, geogrid, retaining walls, or other approved products.

Stabilizing Drainage Ditches

Installing Sediment Traps and Basins

The purpose of a trap or basin is to provide an area where muddy runoff is allowed to pool, so sediment will settle out. Sediment traps and basins are installed in natural drainage areas before excavation or fill work begins. Do not depend on sediment traps and basins alone to control sediment loss from your construction site. Other uphill controls on bare areas, slopes, and in ditches and channels are needed to prevent overloading traps and basins.

Containment for the pooling area can be an excavated hole or a dike made of earth or stone. Straw bales and silt fencing are not approved use as containment for concentrated runoff flows.

Installing Sediment Traps and Basins

Protecting Stream Channels, Wetlands and Lakes

Streams must not have sediment control devices or stabilization structures placed into them without one or more permits. For more information about 401 and 404 permits, visit

Regulatory Information.

Maintaining and Closing Out Your Construction Project

Erosion and sediment controls need to be inspected and maintained. Temporary controls must be removed and permanently stabilized when the project is completed. Failing to fill, grade, and seed temporary sediment traps or basins or failing to remove silt fences, silt check dams, and other controls can result in legal liabilities and KPDES stormwater permit violations. See details of the stormwater KPDES construction permit (KYR10) for more information on post-construction closeout requirements.

Maintaining and Closing Out Your Construction Project

Regulatory Information

Good Housekeeping and Other Runoff Controls

Good housekeeping practices are not typically entered on site maps or drawings but are described in the Stormwater Pollution Prevention Plan and standard notes. These practices are included as part of the construction operations and management process. Good housekeeping practices include plans, procedures, and activities designed to prevent or minimize the use or exposure of materials that could become pollutants.

Good housekeeping practices seek to reduce or eliminate pollutants being added to construction site runoff through analysis of pollutant sources, implementing proper handling and disposal practices, employee education, and other actions.

In general, good housekeeping focuses on keeping the work site clean and orderly, storing materials under roof or tarps whenever possible, and handling materials and wastes in manner that minimizes risk and potential pollutant runoff. A variety of good housekeeping practices have been developed to reduce or eliminate runoff pollutants. These practices—along with relevant application information—are summarized in the following sections.

Resources

This information was first published in 2004 with guidance from a Technical Review Committee. Funding was provided in part by a grant from the U.S. Environmental Protection Agency (USEPA) through the Kentucky Division of Water (KDOW), Nonpoint Source Program and the Kentucky Division of Conservation (KDOC) to TetraTech, as authorized by the Clean Water Act Amendments of 1987, Section 319(h) Nonpoint Source Implementation Grant #C9994861-01. The information was revised in 2009 by TetraTech with support from the Kentucky Energy and Environment Cabinet. Illustrations were developed by Emily Faalasli of TetraTech; photographs were provided by the Kentucky Transportation Cabinet, Kentucky Division of Water, Sanitation District #1, the Upper Chattahoochee Riverkeeper and TetraTech. Mention of trade names or commercial products, if any, does not constitute endorsement.