In this presentation given to the Maryland Highway Administration's Recycled Materials Task Force, Brenda Platt outlines how compost use can control soil erosion.
1. Controlling Roadway Soil
Erosion with Compost
By Brenda Platt, Institute for Local Self-Reliance
Co-Chair, National Capital Region Organics Task Force
Presented to Recycled Materials Task Force
MD State Highway Administration
October 24, 2012
2. Outline
What is and why compost?
Compost markets & applications
Focus on soil erosion mitigation and stormwater management
Soil-amended soil as best management practices
Soils for Salmon and Building Soil projects
Texas DOT & other models
Spotlight on Filtrexx
Maryland drivers:
Green Maryland Act of 2010
Compost Bill: HB 817 (2011)
Chesapeake Bay & watershed problems
3. What is composting?
Composting is the aerobic, or oxygen-
requiring, decomposition of organic
materials by microorganisms under
controlled conditions.
During composting, the
microorganisms consume oxygen.
Active composting generates heat,
carbon dioxide, and water vapor.
Composting reduces the volume and
mass of the raw materials while
transforming them into a valuable soil
conditioner.
Source: Robert Rynk et al, On-Farm Composting Handbook, 1992.
7. Why not MD compost?
Maine produced compost
sold at Maryland retail
outlets
8. Benefits of Composting
Creates a rich nutrient-filled material, humus,
Increases the nutrient content in soils,
Helps soils retain moisture,
Reduces or eliminate the need for chemical
fertilizers,
Suppresses plant diseases and pests,
Promotes higher yields of agricultural crops,
Helps regenerate poor soils,
Has the ability to cleanup (remediate)
contaminated soil,
Can help prevent pollution and manage erosion
problems, and
Saves money and promotes the green economy.
9. Compost Applications
landscape and nursery
agricultural and horticultural
vegetable and flower gardens
tree and shrub planting
sod production and roadside
projects
wetlands creation
soil remediation and land
reclamation
sports fields and golf courses
sediment and erosion control
10. Compost: Foundation of healthy
soil and green infrastructure
Stormwater management (low-
impact development)
Water conservation (the cheapest
“new supply” of water)
Sustainable landscapes
Sustainable local/regional
agriculture
Added benefit of cost-effective waste diversion
Source: David McDonald, Seattle Public Utilities & Washington Organic Recycling
Council, Soils for Salmon Project.
11. WA Dept. of Ecology Stormwater BMP:
“Post Construction Soil Quality & Depth”
Retain native soil and vegetation wherever
possible
All areas cleared and graded require 8-inch
amended soil depth:
Soil organic matter content 10% for landscape beds,
Soil organic matter content 5% for turf areas
12. Benefits of Soil Best Practices
Better erosion control
Easier planting, healthier
plants
Easier maintenance
(healthier plants, fewer
weeds, less need for water,
fertilizer, pesticides)
Reduced stormwater run-
off, with better water
quality
Regulatory compliance
(current and upcoming
regs)
Source: David McDonald, Seattle Public Utilities & Washington Organic Recycling Council, Soils for Salmon
Project; and Soils for Salmon website: http://www.soilsforsalmon.org/why.htm#compost
15. Benefits of Compost Use on Roadside
Applications
Improves the soil structure, porosity, and bulk density, thus
creating a better plant root
Increases infiltration and permeability of heavy soils,
reducing erosion and runoff
Improves water holding capacity in sandy soils, reducing
water loss and leaching
Supplies a variety of macro and micronutrients
Controls or suppresses certain soil-borne plant pathogens
and nematodes
Supplies significant quantities of organic matter
Improves cation exchange capacity (CEC) of soils,
improving their ability to hold nutrients for plant use
Supplies beneficial microorganisms to soils
Improves and stabilizes soil pH
Can bind and degrade specific pollutants
Source: Ron Alexander, Compost Use on State Highway Applications, The Composting Research and Education
Foundation and US Composting Council, available online at:
http://www.epa.gov/osw/conserve/rrr/composting/highway/index.htm
16. Potential “Roadside” Applications for
Compost
Photo Credit: Denbow,
www.denbow.com
Source: Ron Alexander, Compost Use on State Highway Applications, The Composting Research and Education
Foundation and US Composting Council, available online at:
http://www.epa.gov/osw/conserve/rrr/composting/highway/index.htm
18. Compost Blankets
Retain large volumes of water, which aids in
vegetation growth
Acts as a cushion to absorb the impact
energy of rainfall which reduces erosion,
Stimulates microbial activity that increases
the decomposition of organic matter, which
increases nutrient availability and improves
the soil structure,
Provides a suitable microclimate with the
available nutrients for seed germination and
plant growth, and
Removes pollutants such as heavy metals,
nitrogen, phosphorus, fuels, grease and oil
from stormwater runoff, thus improving
downstream water quality.
20. Compost Filter Berms (sediment control)
The American Association of State Highway Transportation Officials
(AASHTO) and some state DOTs have issued specifications for filter berms
(AASHTO, 2003; USCC, 2001). These specifications describe the quality and
particle size distribution of compost to be used in filter berms, as well as the size
and shape of the berm for different scenarios.
21. Compost Filter Socks
A compost filter sock is a type of contained compost filter berm. It is a mesh tube filled
with composted material that is placed perpendicular to sheet-flow runoff to control
erosion and retain sediment in disturbed areas. The compost filter sock provides a three-
dimensional filter that retains sediment and other pollutants (e.g., suspended solids,
nutrients, and motor oil) while allowing the cleaned water to flow through. The filter
sock can be used in place of a traditional sediment and erosion control tool such as a silt
fence or straw bale barrier.
22. Photo credits: Dwayne Stenlund, CPESC
Minnesota DOT; Tom Glanville, Iowa State
University; and Jason Giles, CPESC, Rexius
23. TxDOT: award-winning model
BMP Materials for Storm
Water Pollution Prevention
Plans:
Compost manufactured
topsoil
Erosion control compost
General use compost
Erosion control logs
TxDOT one of the largest compost markets for
compost nationally: 400,000 cubic yards/year
28. Filtrexx: sample products
Slope Protection and
Erosion Control
Vegetated Walls Blanket Sediment Trap
29. Maryland Drivers
Green Maryland Act of 2010 (SB 693):
“each state unit shall review annually the
procurement specifications currently used by the unit
[commodities using recycled materials]” & “A state
or local unit responsible for the maintenance of
public lands in the state, to the maximum extent
practicable, shall give consideration and preference to
the use of compost in any land maintenance activity
that is to be paid for with public funds.”
Compost Bill (HB 817): “make
recommendations about how to promote composting
in the State, including any necessary programmatic,
legislative, or regulatory changes”
Bay watershed implementation plans
30. Changing Climate, also a driver
Intense storm events – stormwater loading, flooding,
wind damage
Precipitation variability – alternate drought and
flooding
Agricultural productivity – soil loss, weather
Source: David McDonald, Seattle Public Utilities &
Washington Organic Recycling Council, Soils for Salmon
Project.
31. Contact
Brenda Platt
Institute for Local Self-Reliance
bplatt@ilsr.org
www.ilsr.org
For model policies, please visit:
http://www.ilsr.org/initiatives/composting/
and click on “Rules”
Editor's Notes
In 1999, several species of Puget Sound salmon were officially listed by the federal government as threatened under the Endangered Species Act. A significant cause of the decline in the Puget Sound Chinook salmon and the bull trout was urbanization and the resulting surface water runoff that directly degraded the salmon habitat, especially their spawning grounds in the region's streams. In response to the salmon becoming an endangered species as a result of stream and river degradation due to runoff, the Washington Organic Recycling Council (WORC) launched the Soils For Salmon campaign. At the heart of the campaign was the critical need to retain native soils and/or repair damaged soils, using compost and mulch, so that surface water from storm events could infiltrate the soil. dramatic reduction in surface water runoff — from 55 to 70 percent on a disturbed soil to 15 percent on an amended soil surface that mimics native soil. http://www.landandwater.com/features/vol52no2/vol52no2_2.html The high percentage of organic matter in compost (40-60%) also allows the soil to retain more water. Microbial organisms in the soil create pore spaces for air and water, increasing storage capacity. Compost can hold up to twenty times its weight in water and “increase water storage by sixteen thousand gallons per acre foot for each one percent of organic matter.”
10% SOM = approx. 30-40% compost by volume to low-organic subsoil Establishing soil quality and depth regains greater stormwater functions in the post-development landscape, provides increased treatment of pollutants and sediments that result from development, and minimizes the need for landscaping chemicals, thus reducing pollution through prevention. In addition to pollution management, compost serves as an erosion and sedimentation control. Compost contains a substance called humus, which acts as a glue that keeps soil particles stuck together and resilient to eroding forces. Washington State’s Soils for Salmon project states that as the soil properties are altered, the surface structure becomes stabilized and “less prone to crusting and erosion.” This program’s best management practices recommend amending soils with organic matter (such as compost) at a rate of 15-40% by volume, depending on the land use.
The CEC is the number of positive charges that a soil can contain. CEC is used as a measure of fertility , nutrient retention capacity, and the capacity to protect groundwater from cation contamination.
Temporary Erosion and Sediment Control (TESC)
A compost filter berm is a dike of compost or a compost product that is placed perpendicular to sheet flow runoff to control erosion in disturbed areas and retain sediment. It can be used in place of a traditional sediment and erosion control tool such as a silt fence. The compost filter berm, which is trapezoidal in cross section, provides a three-dimensional filter that retains sediment and other pollutants (e.g., suspended solids, metals, oil and grease) while allowing the cleaned water to flow through the berm. Composts used in filter berms are made from a variety of feedstocks, including municipal yard trimmings, food residuals, separated municipal solid waste, biosolids, and manure. http://cfpub.epa.gov/npdes/stormwater/menuofbmps/index.cfm?action=browse&Rbutton=detail&bmp=119&minmeasure=4