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U.S. Biosolids Scene

In the United States, approximately 7 million tons (dry weight basis) of biosolids are produced each year. At the national level, the management of biosolids is regulated by the U.S. Environmental Protection Agency (EPA). The EPA's official "Policy on Municipal Sewage Sludge (Biosolids) Management" is given below.

The EPA will actively promote those municipal (biosolids) management practices that provide for the beneficial use of (biosolids) while maintaining or improving environmental quality and protecting public health. (Volume 49, Federal Register, p 24358)

The majority of biosolids produced in the United States are recycled as soil amendments and conditioners in the following way

• 54% - Biosolids Recycled
• 19% - Incinerated
• 18% - Disposed in a Landfill
• 9% - Other

Pie-chart of the above data

Around the country there are many examples of interesting and successful recycling programs. The following provide a summary of some existing and past biosolids recycling programs.

Milorganite - Milwaukee, Wisconsin

One of the country's oldest and most recognized biosolids recycling programs is conducted by the city of Milwaukee, Wisconsin. Since the 1920's this city has been producing a granular, heat-dried biosolids product called Milorganite. Milorganite is sold in bulk to fertilizer manufactures, as well as to the citrus industry in Florida. Forty pound bags of Milorganite are sold to the retail market for distribution by nurseries and garden centers and 50 pound bags are marketed commercially to the turf and landscape industry for use at schools, parks and golf courses. Besides being sold throughout the United States, Milorganite has been sold in Japan, Puerto Rico, Canada,Venezuela and India. Approximately 50,000 tons of Milorganite are produced per year.

Hou-Actinite - Houston, Texas

A product similar to Milorganite is Hou-Actinite which is a granular, heat-dried biosolids product produced by the City of Houston, Texas since the 1920's HouActinite is sold to specialty fertilizer blenders in several states. A byproduct of making Hou-Actinite are the "fines", which are dry dusty product. The fines are sold to directly to local agriculture.

ComPro - Montgomery County Regional Composting Facility, Silver Spring, Maryland

The Washington Suburban Sanitary commission operates several wastewater treatment plants in and around the Washington, D.C. area. Biosolids recovered from one of the plants, the Blue Plains Regional Plant in Washington, D.C., is transported to the Montgomery County Regional Composting Facility where it is processed into a valuable, marketable product, called ComPro. ComPro is sold to retail outlets in bags or in bulk to professional landscapers, contractors, grounds managers, nurserymen, and homeowners. ComPro has been used on the lawns at the White House, Mount Vernon, The Maryland Governors Mansion and the National Arboretum. The demand for ComPro greatly exceeds its supply.

Nutri-Green - Hampton Roads Sanitary District, Virginia Beach,Virginia

Two biosolids product are marketed under the Nutri-Green name by the Hampton Roads Sanitary District in Virginia Beach, Virginia. One product is a biosolids compost which has a marketing program that is focused on retail outlets, trade shows and coops. The sanitary district also provides anaerobically-digested biosolids to local agriculture. This program has more than 7,000 private farmland acres enrolled in it. Only 1,000 to 1,500 acres are applied each year.

Mine Mix - Philadelphia, Pennsylvania

The city of Philadelphia, Pennsylvania produces two kinds of biosolids - composted and anaerobically - digested. A high-quality, screened biosolids compost is commercially marketed throughout the Delaware Valley region to greenhouse and nursery producers, landscape contractors, county clubs and homeowners. This program markets approximately 25,000 tons of high-quality compost product every year. The city also blends its anaerobically-digested biosolids with unscreened compost to make a product called Mine Mix. Thousands of acres of stripmines have been successfully reclaimed using Philadelphia's Mine Mix biosolids product. The anaerobically-digested biosolids produced by the city is also offered to Pennsylvania farmers within 80 miles of the city.

MetroGro - Madison WS

The city of Madison, Wisconsin produces an anaerobically-digested biosolids product, called MetroGro, that is marketed to local agriculture. Every year, about 30 million gallons of MetroGro are sold to fertilize 3,000 to 4,000 acres of farm land. More that 30,000 acres of private farm land are enrolled in the MetroGro program. MetroGro is delivered to the farm sites in 6,000-gallon semi-tanker trucks and the biosolids are applied using 3,500-gallon application vehicles which inject the product into the soil. MetroGro is applied primarily to fertilize corn, soybeans and alfalfa.

Dillo Dirt - Austin, Texas

The city of Austin, Texas composts biosolids with wood chips, yard wastes, and sawdust. The resulting product is called Dillo Dirt. Dillo Dirt is sold to vendors under contract with the city. The vendors include topsoil companies, nurseries, garden suppliers, landscapers, and a turf farm. The demand for Dillo Dirt far exceeds the available supply.

Nitrohumus, Amend and Topper - Kellogg Supply, Inc., Los Angeles, CA

Kellogg Supply, In is a private company which purchases composted biosolids from the sanitary district of Los Angeles, California. The company manufactures a variety of lawn and garden soil conditioner and fertilizer products from this compost. The products, which include Nitrohumus, Gromulch, Amend and Topper, are bagged and sold to homeowners and landscapers through retail centers in California and other states. About 70% of Kelloggs total annual sales are of composted biosolids products. This represents about 250,000 cubic yards per year.

SilviGrow and GroCo - King County, Seattle, Washington

King County operates several wastewater treatment plants in and around the Seattle, Washington area. Some of the biosolids from these plants are anaerobically-digested and dewatered to produce a biosolids "cake". The cake is either composted with sawdust to produce a product called GroCo or delivered directly to forest application sites as SilviGrow. King County has a long history of developing the SilviGrow program in association with the University of Washington College of Forest Resources. SilviGrow application to forest land is safe and beneficial. Trees fertilized with SilviGrow grow twice as fast as unfertilized trees. Thousands of forest land acres have been fertilized with SilviGrow.

Recently, King County has entered into a partnership with Washington DNR, University of Washington, Sierra Club, Weyerhaeuser, and others in what's called the "Mountains to Sound Re-Greening Program." This program involves hundreds of volunteers in the restoration and revegetation of logging roads no longer needed along the scenic Interstate 90 corridor from Puget Sound to the east side of the Cascades. GroCo is being used to restore revegetate the unsightly, barren scars left by many old logging roads.