Compost Use for Soil Erosion and Sediment Control (SESC)
A reference to an increasingly popular and expanding use of compost as an erosion control material was made in our previously published article. This application is slowly but surely replacing traditional SESC measures, such as synthetic soil blankets and silt fencing. State DOTs, where sources of compost are available, are being drawn to the ease and effectiveness of this compost application for the reasons listed below.
The American Association of State Highway and Transportation Officials (AASHTO)
is a nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of Columbia and Puerto Rico. Its primary goal is to foster the development, operation and maintenance of an integrated national transportation system. The mission of AASHTO is to advocate transportation policies, provide technical services, demonstrate the contributions of transportation and facilitate institutional change.
AASHTO published two specifications for the use of compost for erosion control back in 2003. They were labeled; MP-9 Filter Berms and MP-10 Compost Blankets. These specifications were the result of several years of study, demonstration projects and review by highway officials across the country. They are now available for implementation by highway officials and others involved in soil erosion and sediment control work.
Their findings are that compost, that meets prescribed physical specifications, is a very viable alternative to conventional products in this important environmental application. Please visit their website (www.transportation.org) for more information. Various types of compost products were used (e.g. yard trimmings, biosolids, manure, food residuals, etc.) and the results were fairly uniform provided the compost met the final specifications. The benefits of using compost in these applications include:
- Compost is cost competitive with existing methods and practices
- Compost provides immediate and effective control
- Compost helps improve the establishment of vegetative cover
- Compost captures sediment, but allows water to pass through
- Compost binds and degrades specific chemical contaminants
- Compost is a recycled product!
Compost “Blanket” Use for SESC
A compost blanket is a layer of loosely applied compost that covers the soil on which it has been applied. Application rates will vary depending on; the steepness of the slope, the total precipitation in the area, the rainfall erosivity index and whether the area will be seeded or not. Compost blankets provide many benefits when used according to the AASHTO specifications. These include:
- Acts as a buffer to absorb rainfall energy
- Immediately reduces wind and water erosion
- Stimulates microbial activity to increase decomposition of organic materials in soil, thereby adding to the soil structure
- Slows the flow of water over the soil surface
- Captures and retains moisture, reducing soil moisture loss and thereby facilitating plant growth
- Provides a suitable microclimate for seed germination
- Captures blowing snow to increase the insulating effect of winter protection
Annual Rainfall/Flow Rate |
Total Precipitation & Rainfall Erosivity Index |
Application Rate For Vegetated* Compost Surface Mulch |
Application Rate For Unvegetated Compost Surface Mulch |
Low |
1-25”,
20-90 |
½ - ¾ ”
(12.5 mm - 19 mm) |
1” – 1 ½”
(25 mm – 37.5mm) |
Average |
26-50”,
91-200 |
¾ - 1”
(19 mm - 25 mm) |
1 ½” – 2”
(37 mm – 50 mm) |
High |
51” and above,
201 and above |
1-2”
(25 mm - 50 mm) |
2-4”
(50mm – 100mm) |
*these lower application rates should only be used in conjunction with seeding, and for compost blankets applied during the prescribed planting season for the particular region.
Compost Filter Berm Use for SESC
A compost filter berm is a triangular dike of compost that is placed perpendicular to the water sheet flow at any area where the soil has been disturbed. They replace traditional products such as hay bales or synthetic silt fencing. They are designed to allow water to pass while trapping sediment and can either be vegetated or left unvegetated. The benefits of using compost filter berms include:
- Acts as an effective physical barrier in sheet flow conditions
- Slows the flow of water over the surface of the soil
- Retains large volumes of sediment in their mass
- Effectively performs at a competitive price compared to traditional products
- Filters contaminants from water including very fine sediment with adsorbed chemicals and binds and degrades chemicals pollutants
- Can be left on the site after project completion, eliminating removal costs
- Provides suitable microclimate for seed germination
Table 2 – Compost Filter Berm Dimensions
Annual Rainfall/Flow Rate |
Total Precipitation & Rainfall Erosivity Index |
Dimensions for the
Compost Filter Berm
(height x width) |
Low |
1-25”,
20-90 |
1’x 2’ – 1.5’ x 3’
(30 cm x 60 cm – 45 cm x 90 cm) |
Average |
26-50”,
91-200 |
1’x 2’ - 1.5’ x 3’
(30 cm x 60 cm – 45 cm x 90 cm) |
High |
51” and above,
201 and above |
1.5’x 3’ – 2’ x 4’
(45 cm x 90 cm – 60cm x 120 cm) |
Space constraints prohibit the listing of individual SESC compost quality
specifications. Compost use specifications can be found on the USCC website (www.compostingcouncil.org). Please contact AASHTO (www.transportation.org)
for their full SESC specifications.
How to Select a Suitable Compost Product for SESC
There are many different kinds of compost available, made from many different kinds of organic feedstock. A user needs to have access to appropriate product analysis to make a determination if a compost is suitable for SESC uses and meets the AASHTO specifications. AASHTO has selected to utilize and require that the United States Composting Council’s (USCC) “Test Methods for the Examination of Compost and Composting (TMECC)” be the analytical standard for evaluating the quality of compost used in SESC applications. Any composter who participates in the USCC’s “Seal of Testing Assurance (STA)” Program will have this data on their products as a requirement of program participation.
To learn more about compost benefits, applications, and how to use compost in your landscaping and other projects that require improved soil and planting media, join us at the US Composting Council's 17th Annual Conference & Trade Show, January 26-29, 2009 at the Westin Galleria, Houston, TX. The USCC hosts the Largest Conference & Exhibition in North America for the Composting, Wood Waste & Organics Recycling Industry. Attendees participate in the most comprehensive program of training courses, educational & technical sessions, and facility tours & equipment demonstrations. Register at www.compostingcouncil.org
The USCC is a national not-for-profit organization dedicated to the development, expansion and promotion of the composting industry in the U.S.The USCC also directs the Composting Council Research and Education Foundation (CCREF), a charitable foundation, which administers public and private research and education activities. For more information about the composting industry and membership in the USCC, visit www.compostingcouncil.org or call the USCC office at 631.737.4931.
