BioCycle April 2005, Vol. 46, No. 4, p. 20
New design manuals, regulations and incentives, demonstration projects and ongoing education of design professionals is bringing the innovative use of organics into wider acceptance at building sites around Puget Sound in the Pacific Northwest.
THE Soils for Salmon project, initiated by the Washington Organic Recycling Council (WORC) in 1999, continues to spread ripples of awareness and action through the storm water management and development communities around the Puget Sound in western Washington State. The project promotes “BMPs” (Best Management Practices) for protecting native soil and vegetation where possible, and especially for restoring soil functions on disturbed sites through the incorporation of organic amendments and mulches.
Over the years, the loose-knit volunteer Soils for Salmon team has worked with policy makers, planners, design professionals, regulators and builders. We aim to develop the basic awareness that “soil is alive, and soil life matters,” that we can help restore soil life and its essential functions by amending damaged soils with compost, and that soil protection and restoration are essential to restoring Northwest streams and salmon.
Soil amendment with compost increases storm water infiltration, reducing damaging runoff, and also helps filter out urban pollutants (oil and metals from roads, pesticides and fertilizers from landscapes) while creating more successful landscapes that need less chemicals and less summer irrigation. Surface applications (compost blankets, berms, and containment technologies) of the right organics (usually coarser mixes of compost and wood chips) are also becoming known for their exceptional short-term erosion control abilities, and their contribution to long-term plant establishment on difficult sites.
Background and history of the Soils for Salmon program are found in these BioCycle articles: “Organics Play Role In Salmon Recovery In Pacific Northwest,” April 2000; “Composting Advances In Oregon And Washington,” February 2001; “Organics Recycling Initiatives Spawned By Salmon Recovery,” September 2001; “Best Management Practices For Post-Construction Soils,” February 2004. This update highlights recent developments around the Puget Sound region.
WASHINGTON STATE STORM WATER MANUAL ADOPTS FLOW CREDITS FOR USE OF SOIL BMP
In 2001, based on input from the Soils for Salmon team, the Washington State Department of Ecology (DOE) included a “Post-Construction Soil Quality and Depth BMP” (BMP T5.13) in its new Stormwater Management Manual for Western Washington, which local governments are required to emulate. This January (2005), based on two years of input from an expert panel, the DOE added “flow credits” for the use of the soil BMP and other Low Impact Development BMPs that help slow runoff and increase infiltration. These credits give developers an incentive to use these best practices because they can reduce the size of expensive detention ponds and vaults.
The DOE also adopted the recommendations of the Soil Amendment Project (work by Stenn Design and Washington State University, funded by Snohomish County, a founding Soils for Salmon partner) to revise the soil BMP to require a lower amendment rate for turf areas and higher for landscape beds. The revised requirement for turf is five percent soil organic matter (SOM) which equals approximately 15 to 20 percent compost by volume mixed into low-organic post development subsoil and 10 percent SOM for landscape which equals about 30 to 35 percent compost by volume. The lower level for turf prevents the soil from getting too spongy to mow, while still significantly improving storm water infiltration and turf establishment on development sites. For details, see BMP T5.13 and related low impact BMPs in the revised Stormwater Manual for Western Washington, Volume V Chapter 5, and Volume III Chapter 3 at: www.ecy.wa.gov/programs/wq/storm water/manual.html
UPDATES TO SOIL BMP IMPLEMENTATION MANUAL AND SOILS FOR SALMON WEBSITE
The Soil Amendment Project worked with experts to produce an implementation manual, published in 2002. It helps designers and builders achieve the state’s soil BMP requirements with a practical set of options, including protecting existing soils and vegetation where possible, removing and stockpiling topsoils, amending disturbed soils on-site, and importing compost-amended topsoil. In response to the State DOE’s revisions, and input from builders and designers, we are in the process of updating that manual and revising the Soils for Salmon website to present the manual and other useful design tools (like specification language) in a handier format. See www.compostwashington.org or www.SoilsforSalmon.org.
FOCUS GROUP WITH DEVELOPERS IDENTIFIES PEER OUTREACH AS MOST EFFECTIVE
While successful over the years in educating many design professionals about soil best practices, the Soils for Salmon team has struggled to reach builders and developers. In a recent informal meeting with some interested large developers, we learned that they mostly do not get new ideas from professional organizations or publications, but instead from talking with their peers. In order to reach them with the benefits and techniques of soil amendment, we need to work directly with opinion leaders in their profession, create opportunities for them to share, see, demonstrate and endorse the new ideas, and then back that up with useful publications and especially accessible and useful design tools on the website.
KING COUNTY IS FIRST LOCAL GOVERNMENT TO ADOPT SOIL BMP
King County recently approved a new Clearing and Grading ordinance that includes a similar soil BMP, and now is first to have the challenge of educating builders about how to implement the soil protection and soil amendment requirements. Other local governments, like Seattle, have had voluntary soil BMPs and are working on local storm water manual revisions, compliant with the new State manual, that will require these and other on-site BMPs. See the new King County ordinance language (Section 10, parts G1 and G2) at http:// www.metrokc.gov/mkcc/cao/clearing_grading_15053.pdf.
NEW “LOW IMPACT DEVELOPMENT” MANUAL INCLUDES SOIL BMPS IN THE LID TOOLBOX
Another collaborative project, led by the state’s Puget Sound Action Team and Washington State University, has published the first comprehensive “Low Impact Development Technical Manual” for this region, which refers to and includes information from WORC’s soil BMP manual. Low Impact Development (LID) is the whole “toolbox” of methods to slow and infiltrate storm water runoff on-site, reducing dependence on giant pipes, ponds, and vaults downstream, filtering out pollutants, and reducing damage to streams and other receiving water bodies. “LID” is the new mantra for storm water planners, and this manual provides the design information to help developers meet the new state storm water requirements, including the soil BMP. This LID toolbox has design options for every site that will help protect water quality, streams, and property. Download the manual and other tools at www.psat.wa.gov/Programs/LID.htm.
SEATTLE’S “NATURAL DRAINAGE” REDEVELOPMENT PROJECTS PROVE THE SOIL BMPS WORK
Starting with the Street Edge Alternative project in 2001, where deep compost-amended soils in swales have reduced storm runoff by 98 percent, the City of Seattle has used these BMPs in a variety of urban retrofits to detain and clean up storm flows and protect property, while enhancing neighborhood landscapes. Redevelopment of a large public housing project in the High Point neighborhood, will demonstrate a wide range of techniques, including very shallow grassy swales in parking strips, deeper swales and infiltration basins (known as “rain gardens”), and more natural landscape design, all underlain by compost-amended soils. Pre and post construction monitoring will provide the best data yet on the benefits these methods provide for reducing storm flows and cleaning out urban pollutants before the water runs into salmon-bearing Longfellow Creek. For pictures, explanations, and specifications on these projects see: www.seattle.gov/util/NaturalSystems.
WSDOT SAVES MONEY, REDUCES EROSION, AND CLEANS UP STORMWATER USING COMPOST
The Washington State Department of Transportation has been a leader in the use and specification of compost to solve persistent erosion problems on road cuts and fills, and is now the largest user of compost products in the state. Storm water regulators, however, have questioned the application of organics because of concerns about pollution from nutrient wash-off (especially phosphorus) into sensitive streams. Addressing this issue, a recent field experiment by WsDOT yielded data that show compost-amended soils are among the best BMPs to clean up contamination. A narrow “compost-amended vegetated filter strip,” planted with grass, was installed to catch and convey runoff from two lanes of the heavily trafficked Interstate 5 corridor. Did phosphorus concentrations at the project’s drain increase for the first few months after the compost was installed? Yes, but flows (the total amount of runoff) were cut more than 60 percent by increased on-site infiltration, so the total phosphorus loading at the drain stayed about the same. For all other pollutants measured, however, including copper, lead, zinc, dissolved and suspended solids, and oxygen demand, the contaminant loading decreased by 63 to 97 percent. WsDOT’s specifications for general use compost (for soil amendment) and erosion-control compost (chunkier, more wood chip), and a wide range of soil and plant “bioengineering” design guidelines are available at: http://www.wsdot.wa.gov/eesc/design/roadside/sb.htm.
JUST KEEP TALKING!
The Washington Organic Recycling Council, Puget Sound Action Team, and staff from Seattle, King and Snohomish Counties, WsDOT, Washington State University (WSU), and private partners in the loose Soils for Salmon movement continue to take every opportunity to educate policy-makers and especially design and development professionals on the benefits and practical techniques for using organics to restore soil functions. Recent workshops have targeted civil engineers, landscape architects, landscape contractors, storm water planners, and (with limited success to date) builders and developers. A WSU workshop this spring will focus on the summer water conservation benefits of amended soils. Perhaps the biggest recent breakthrough was an invitation from the International Erosion Control Association to teach a full day course at its annual conference in Dallas, which was well-received and hopefully will lead to further acceptance of these practical soil restoration techniques among professionals. Next is more one-to-one work with developers – we’ll keep you posted!
David McDonald is a Resource Conservation Specialist with Seattle Public Utilities, and part of the “Soils for Salmon Gang,” including founder Sego Jackson of Snohomish County, Josh Marx and Kris Beatty at King County, Andy Bary and Craig Cogger at Washington State University, Holly Wescott of Washington Department of Ecology, Jeff Gage of Compost Design Services, Howard Stenn of Stenn Design, and Connie Allison at the Washington Organic Recycling Council. For current information check www.SoilsforSalmon.org.