Controlling Roadway Soil Erosion with Compost

By Brenda Platt, Institute for Local Self-RelianceCo-Chair, National Capital Region Organics Task Force

Presented to Recycled Materials Task ForceMD State Highway Administration

October 24, 2012

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

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.

Composting, lots of models

Growing in Maryland

University of MD program

Why not MD compost?

Maine produced compost sold at Maryland retail outlets

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.

Compost Applications

landscape and nursery agricultural and horticultural vegetable and flower gardenstree and shrub planting sod production and roadside projects wetlands creationsoil remediation and land reclamationsports fields and golf courses sediment and erosion control

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.

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

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

www.buildingsoil.org

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

Potential “Roadside” Applications for Compost

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

Photo Credit: Denbow, www.denbow.com

Erosion Control with Compost

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.

Photo Credit: Barrie Cogburn, Texas DOT

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.

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.

Photo credits: Dwayne Stenlund, CPESC Minnesota DOT; Tom Glanville, Iowa State University; and Jason Giles, CPESC, Rexius

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

US Composting Council

Filtrexx (many products/patents)

www.filtrexx.com

Old system: silt fence

Filtrexx: sample products

Vegetated Walls

Slope Protection and Erosion Control Blanket Sediment Trap

Maryland DriversGreen 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

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.

Contact

Brenda PlattInstitute for Local Self-Reliance

bplatt@ilsr.orgwww.ilsr.org

For model policies, please visit:http://www.ilsr.org/initiatives/composting/ and click on “Rules”