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Environmental and Health Issues and Recommendations  Recycled Content:
Mulch can be generated from virgin or postconsumer organic materials. Postconsumer or "recycled content" mulch comes from landscape trimmings, agricultural prunings, and source-separated construction and demolition materials that have been collected through recycling programs. Using recycled content mulch keeps waste out of landfills.
 Material Availability:
Using source-separated construction and demolition materials, agricultural residues, tree prunings, and landscape trimmings to make mulch offers a beneficial use for what could otherwise be a waste product.  Conserves Water:
Mulch helps hold soil moisture, reducing the need for watering.  Less Hazardous:
Mulch controls weeds, reducing or eliminating the need for herbicides. Mulch contributes to plant health, reducing the need for fertilizers and pesticides.  End-of-Life Management:
Mulch generated from wood containing lead-based paint or wood preservative should not be used.
- Help others to recycle by not mixing wood containing lead-based paint or wood preservative with organic (e.g., green waste) recyclables.
See the Introduction for complete descriptions of these environmental and health issues.
BACKGROUND AND ENVIRONMENTAL AND HEALTH ISSUES
Environmental and Health Issues
Recycled Content
Compared to virgin mulch production, making mulch from recycled content material conserves landfill space.
What to look for: Look for mulch that meets or exceeds the minimum content requirements of the State Agency Buy Recycled Campaign.
Stormwater Runoff
Mulch reduces soil compaction and increases soil porosity. Mulch protects soil by deflecting raindrops and irrigation spray, which reduces erosion. Since mulch allows soil to hold more water, this can help reduce stormwater runoff and protect water quality.
Fertilizers and Pesticides
Mulch gradually adds organic matter to the soil, attracting beneficial organisms that improve soil fertility which reduces the need for fertilizers. Mulch improves soil health, increases disease and pest resistance, and reduces chemical and pesticide usage. Mulch controls weed growth, especially annuals by a much as 90 percent which reduces the need for applying herbicides.
Water Conservation
Mulch conserves water by reducing evaporation from the soil surface. In the summer, two inches of mulch can reduce water loss by 20 percent and lowers temperature in the top four inches of the soil by 10 degrees. Young shrubs and trees can grow stronger roots and establish better under mulch than under bare ground. A thicker layer of mulch can reduce irrigation needs by approximately 50 percent. [1]
Material to Avoid
Forests can be rich sources of biodiversity. [2] They are important for fish and wildlife habitat; provide food, shelter, and aesthetic and recreational benefits to humans; help slow global warming by storing and sequestering carbon; and help regulate local and regional rainfall. [3] Avoid mulch made from fiber from old growth forests, endangered forests, and unsustainably harvested forests. These terms may be defined differently by different parties, so to be on the safe side, consider purchasing mulch generated from 100 percent recycled content materials, which does not require logging more trees.
LAWS AND GUIDELINES
California
Statute
State Agency Buy Recycled Campaign (SABRC)
- Recycled-Content Product Procurement Requirements
- Public Contract Code (PCC) section 12203 requires State agencies (including California State Universities) to ensure that at least 50 percent of the dollars spent on compost, cocompost, and mulch products be spent on products that meet the minimum content requirements set forth in PCC section 12209. PCC section 12209(c) states "For recycled compost, cocompost, and mulch, at least 80 percent of the product shall consist of materials, including, but not limited to, the materials listed in subdivision (c) of Section 12207, that would otherwise be normally disposed of in landfills." Note: See PCC section 12207(c) for detailed definitions of compost, cocompost, and mulch for the SABRC.
- The SABRC compost, cocompost, and mulch category includes mulch, compost, and cocompost products including soil amendments, erosion controls, soil toppings, ground covers, weed suppressants, and organic materials used for water conservation. Note: See PCC section 12207(c) for detailed definitions of compost, cocompost, and mulch for the SABRC.
- Recycled-Content Certification Requirements
- PCC section 12205 requires all State agencies to obtain from all suppliers written certification of the postconsumer recycled content of each product offered or sold to the State. Recycled-content certification forms are available in the SABRC training manual.
- Recycled-Content Product Procurement Report
- Recycled-Content Product Procurement Contract Language
- PCC section 12217(f) directs State agencies to remove contract provisions that impede the consideration of recycled products and to replace them with performance standards.
Federal
- Since 2000, under federal Executive Order 13148, federal agencies have been required, in implementing landscaping policies, to purchase environmentally preferable and recycled content products, including United States Environmental Protection Agency (USEPA)-designated items such as compost and mulch that contribute to environmentally and economically beneficial practices.
- The Resource Conservation and Recovery Act requires procuring agencies to buy recycled-content products designated by the USEPA in the Comprehensive Procurement Guidelines (CPG). Hydraulic mulch is a USEPA-designated item. [4] Procuring agencies include all federal agencies, and any state or local government agencies or government contractors that use appropriated federal funds to purchase the designated items. If your agency spends more than $10,000 per year on a product designated in the CPG, you are required to purchase it with the highest recycled-content level practicable. [5] This means that the recycled-content ranges recommended in the USEPA's Recovered Materials Advisory Notice (RMAN) for the item in question are met. [6],[7] The USEPA's recommended recovered materials content levels for hydraulic mulch are available on-line.
Executive Order 13101 and the Federal Acquisition Regulation also call for an increase in the federal government's use of recycled-content and environmentally preferable products. [8]
PERFORMANCE
Since many types of materials can be used as mulch, performance is best determined by examining product type and intended use.
- "Coarse" grade material. (Particle size up to five inches) is used for temporary road surface, mud control, and for erosion control.
- "Medium" grade material. (Particle size up to 3.5 inches) is used for surface material, horticultural mulch, and erosion control.
- "Fine" grade material. (Particle size up to two inches) is used for horticultural mulch and soil amendment.
Concerns about physical contaminants in mulch such as plastic, glass, and metal, can be addressed by requiring that the product contains no visible contaminants. Weed seeds and pathogens can be a problem unless the material is maintained, using a windrow composting process, at a temperature of 55 degrees Celsius (131 degrees Fahrenheit) or higher for a period of 15 days or longer, and there is a minimum of five (5) turnings of the windrow. Mulch produced by an aerated static pile process, in which all active material is covered with six to 12 inches of insulating material, only requires that these temperatures be maintained for a period of three days.
The Minnesota Solid Waste Management Coordinating Board has developed an on-line Environmentally Preferable Purchasing Guide that includes sections on the following:
AVAILABILITY
Mulch is widely available in large or small quantities from public and private mulch and compost producers, landscape companies, and scrap wood processors. Sources of mulch can be found in the yellow pages under such headings as "Rock" and "Landscaping Equipment and Supplies." Some cities, prisons, public utilities, and colleges also produce and sell mulch to offset program operating costs. See the Vendor section for a link to a partial list of several mulch and compost suppliers in California.
COST
Mulch prices vary based upon a number of factors, such as processing required for a given product, transportation distance to application site, and type of feedstock. Mulch purchased in bulk instead of bags is considerably less expensive. Mulch produced from shredded urban wood waste is significantly less expensive than virgin wood mulch or landscape rock.
Although mulch might initially be more expensive to apply compared to commonly-used materials such as herbicides or weed barrier fabric, mulch can offer long-term cost benefits. The use of mulch minimizes the need to dispose organic material in landfills, which reduces transportation and disposal costs. Mulch suppresses weeds, reducing the need for herbicides and costly hand labor. Mulch helps retain soil moisture and rain runoff, reducing irrigation costs. Mulch increases disease and pest resistance, reducing chemical and pesticide usage. Mulch applied for erosion control can reduce costs related to deposition of sediment on roadways and can help agencies avoid fines for illegal discharge of pollutants into waterways.
Tips on Buying Compost
Buy mulch that meets the requirements of the application type. For example, mulch used to suppress weeds requires different performance characteristics than mulch used in filter socks for erosion control. Remember - it is important to determine the appropriate product for a specific application.
SPECIFICATIONS
California
The Procurement Engineering Team of the Procurement Division of the Department of General Services develops and reviews specifications for statewide commodity standards and information technology. If you have questions regarding developing specifications, or would like a copy of one of their specifications, please contact the team.
The California Department of Transportation (Caltrans) develops specifications on roadside application of mulch for their statewide projects. If you have questions regarding developing specifications for roadside applications, contact the Caltrans Office of Landscape Architecture.
Tips for Writing Specifications
Sample Language
It may be useful to contact several local mulch suppliers in order to develop specifications that meet the end use application. The language can specify feedstock type, particle size, pathogen reduction, maximum contaminant levels, etc. When purchasing mulch, consider including specifications which require recycled content mulch, not virgin materials. Besides environmental and health benefits, specifications can ultimately help lead to better prices by increasing demand for recycled-content mulch. For more information on sample specifications, see the California Integrated Waste Management Board (CIWMB) publication titled "Guidelines for Writing Compost or Mulch Procurement Specifications".
Other Specifications
VENDORS
LOCAL AGENCY PROCUREMENT
Public Contract Code 10298 allows local agencies to participate in State procurement, including agreements for goods and services. The Department of General Services (DGS) Master Agreements Web page contains information on such programs as the Master Agreements and Statewide Contracts and California Multiple Awards Schedules. These programs specifically offer a vast array of goods and services that a particular local agency may not have the expertise in procuring.
SUCCESS STORIES
A Case Study: Mulch
This case study provides an example in Alameda County (California) of a local landscaper's success with chipping and reusing plant debris as mulch on the landscapes they maintain.
Mulch Demonstration Project, Napa and Sonoma Counties: Utilization of Composted Mulch for Erosion Control in Hillside Vineyards
Data from this partnership demonstration project substantiate the effectiveness of using composted mulch in the vine row only to control soil erosion in four California vineyard plots. The report includes data tables, graphs, and a glossary as well as a plot layout, plot schematic, and mulch manufacturing information.
Mulch Demonstration Project, Napa County: The Effects of Green Material Mulches on Erosion and Dissolved Organic Nutrient Loss from Recently Disturbed Hillside Vineyard Soils
Data from this partnership demonstration project compare the effectiveness of using composted mulch generally broadcast in three California vineyard plots vs. the traditional straw treatment to control soil erosion. The report includes data tables, graphs, and charts as well as cost-benefit analyses, specifications for mulch production, and application guidelines.
RESOURCES AND WEBSITES
California Integrated Waste Management Board (CIWMB)
Sacramento, CA
(916) 341-6000
The CIWMB's mission is to reduce waste, promote the management of all materials to their highest and best use, and protect public health and safety and the environment, in partnership with all Californians. Visit the CIWMB's Organic Materials Management -- Compost and Mulch Web pages.
King County Environmental Purchasing Program
Seattle, WA
(206) 296-0100
(800) 325-6165
A pioneer and contemporary model in environmental procurement, King County provides sample contract specifications for compost and landscape mulch, and information on a variety of other products. In addition, its Web site contains procurement case studies along with resources for environmental purchasing and waste reduction.
Mulch and Soil Council
Manassas, VA
(703) 257-0111
The mission of the Mission and Soil Council is to define quality products and promote an open marketplace for producers of horticultural mulches, consumer soils and commercial growing media.
The Office of the Federal Environmental Executive (OFEE)
Washington, DC
(202) 564-1297
As part of its broader mission to promote sustainable environmental stewardship throughout the federal government, the OFEE promotes the acquisition of recycled-content, environmentally preferable, and biobased products.
United States Environmental Protection Agency (USEPA)
Washington, DC
(202) 272-0167
In order to assist federal agencies in purchasing environmentally preferable products and services, the USEPA offers a range of information about products such as compost. Visit the USEPA's Comprehensive Procurement Guidelines (CPG) Web site for Recovered Materials Advisory Notices (RMANs), which recommend recycled-content levels. The site includes information on landscaping products, such as hydraulic mulch, and a fact sheet on procurement guidelines for landscaping products.
[1] California Integrated Waste Management Board. A Landscaper's Guide to Mulch: Save Money, Control Weeds, and Create Healthy Landscapes. Available at www.ciwmb.ca.gov/Publications/default.asp?pubid=958.
[2] United States Environmental Protection Agency. Technical Document: EPA's Draft Report on the Environment 2003, p. 5-9. Available at http://www.epa.gov/Envindicators/roe/pdf/EPA_Draft_ROE.pdf.
[3] Union of Concerned Scientists. Invasive Species - Forests Web page. Available at www.ucsusa.org/invasive_species/forests-index.html. Accessed on January 12, 2006.
[4] United States Environmental Protection Agency. 2004 Comprehensive Procurement Guidelines EPA Expands Comprehensive Procurement Guideline (CPG) fact sheet. Available at www.epa.gov/cpg/pdf/cpg-fs.pdf.
[5] United States Environmental Protection Agency. 2004 Comprehensive Procurement Guidelines Buy-Recycled Series Landscaping Products fact sheet. Available at www.epa.gov/cpg/factshts.htm.
[6] From California Integrated Waste Management Board staff communication with Office of the Federal Environmental Executive staff on December 12, 2005.
[7] United States Environmental Protection Agency. 2004 Comprehensive Procurement Guidelines Buy-Recycled Series Landscaping Products fact sheet. Available at: www.epa.gov/cpg/factshts.htm.
[8] Ibid.
Special Note: Portions of the Environmentally Preferable Purchasing Best Practices Manual were borrowed or adapted from the Environmentally Preferable Purchasing Guide published by the Solid Waste Management Coordinating Board of Minnesota.
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