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
Controlling Roadway Soil Erosion with Compost
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 Force MD State Highway Administration October 24, 2012
OutlineWhat is and why compost?Compost markets & applicationsFocus on soil erosion mitigation and stormwater managementSoil-amended soil as best management practicesSoils for Salmon and Building Soil projectsTexas DOT & other modelsSpotlight on FiltrexxMaryland 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.
Why not MD compost?Maine produced compostsold at Maryland retailoutlets
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 Applicationslandscape and nurseryagricultural and horticulturalvegetable and flower gardenstree and shrub plantingsod production and roadsideprojectswetlands creationsoil remediation and landreclamationsports fields and golf coursessediment 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 diversionSource: David McDonald, Seattle Public Utilities & Washington Organic RecyclingCouncil, Soils for Salmon Project.
WA Dept. of Ecology Stormwater BMP: “Post Construction Soil Quality & Depth”Retain native soil and vegetation whereverpossibleAll areas cleared and graded require 8-inchamended 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 SalmonProject; and Soils for Salmon website: http://www.soilsforsalmon.org/why.htm#compost
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 pollutantsSource: Ron Alexander, Compost Use on State Highway Applications, The Composting Research and EducationFoundation and US Composting Council, available online at:http://www.epa.gov/osw/conserve/rrr/composting/highway/index.htm
Potential “Roadside” Applications for Compost Photo Credit: Denbow, www.denbow.comSource: Ron Alexander, Compost Use on State Highway Applications, The Composting Research and EducationFoundation and US Composting Council, available online at:http://www.epa.gov/osw/conserve/rrr/composting/highway/index.htm
Compost BlanketsRetain large volumes of water, which aids invegetation growthActs as a cushion to absorb the impactenergy of rainfall which reduces erosion,Stimulates microbial activity that increasesthe decomposition of organic matter, whichincreases nutrient availability and improvesthe soil structure,Provides a suitable microclimate with theavailable nutrients for seed germination andplant growth, andRemoves pollutants such as heavy metals,nitrogen, phosphorus, fuels, grease and oilfrom stormwater runoff, thus improvingdownstream water quality.
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 SocksA compost filter sock is a type of contained compost filter berm. It is a mesh tube filledwith composted material that is placed perpendicular to sheet-flow runoff to controlerosion 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 filtersock can be used in place of a traditional sediment and erosion control tool such as a siltfence or straw bale barrier.
Photo credits: Dwayne Stenlund, CPESCMinnesota DOT; Tom Glanville, Iowa StateUniversity; 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
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
Changing Climate, also a driver Intense storm events – stormwater loading, flooding, wind damage Precipitation variability – alternate drought and flooding Agricultural productivity – soil loss, weatherSource: David McDonald, Seattle Public Utilities &Washington Organic Recycling Council, Soils for SalmonProject.
Contact Brenda Platt Institute for Local Self-Reliance firstname.lastname@example.org www.ilsr.orgFor model policies, please visit:http://www.ilsr.org/initiatives/composting/ and click on “Rules”