Chapter 5
Characteristics and Standards for Processed Biosolids in the Manufacture and Marketing of Horticultural Fertilizers and Soil Blends 1
1
Downloaded by COLUMBIA UNIV on September 6, 2012 | http://pubs.acs.org Publication Date: July 1, 1997 | doi: 10.1021/bk-1997-0668.ch005
Terry J. Logan , Billie J. Lindsay , and Steve Titko
2
1
School of Natural Resources, Ohio State University, 2021 Coffey Road, Columbus, OH 43210 Scotts Company, 14310 Scottslawn Road, Marysville, OH 43041 2
Beneficial use of treated biosolids is not a new practice, but it has increased in the last two decades, primarily in the U.S., and to a lesser extent in other countries. Biosolids at small treatment plants were often dried on sand beds and made available to farmers and gardeners at no cost, and with virtually no regulation. Application to dedicated sites for agricultural production was practiced in the U.S. and Europe. In none of these cases, however, were biosolids viewed as products in the sense that fertilizer, limestone or pesticides were viewed. A few well known exceptions to this are the heat-dried biosolids marketed by the City of Milwaukee for at least six decades as Milorganite, and the composted biosolids marketed by the Kelloggs Company in Southern California. There are no similar early experiences in Europe and other countries. This paper considers characteristics (e.g., solids, nutrient, organic matter and lime contents) and suitability of EQ biosolids (compost, advanced alkaline stabilized biosolids, heat dried pellets) for horticultural markets (greenhouse, comercial nurserys, turfgrass, home gardening), and uniform national product quality standards and labels are proposed.
Beneficial use of treated biosolids is not a new practice, but it has increased in the last two decades, primarily in the U.S., and to a lesser extent in other countries. Biosolids at small treatment plants were often dried on sand beds and made available to farmers and gardeners at no cost, and with virtually no regulation. Application to dedicated sites for agricultural production was practiced in the U.S. and Europe. In none of these cases, however, were biosolids viewed as products in the sense that fertilizer, limestone or pesticides were viewed. A few well known exceptions to this are the heat-dried biosolids marketed by the City of Milwaukee for at least six decades as Milorganite, and the composted biosolids marketed by the Kelloggs Company in Southern California. There are no similar early experiences in Europe and other countries. © 1997 American Chemical Society
In Agricultural Uses of By-Products and Wastes; Rechcigl, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1997.
63
64
AGRICULTURAL USES OF BY-PRODUCTS AND WASTES
Downloaded by COLUMBIA UNIV on September 6, 2012 | http://pubs.acs.org Publication Date: July 1, 1997 | doi: 10.1021/bk-1997-0668.ch005
Current Conditions By the 1990s, a number of factors had led to the development of true potential market opportunities for biosolids derived products. One was the publication of the USEPA 503 biosolids rule (EPA, 1993) that established the Exceptional Quality (EQ) biosolids concept: a class of highly treated biosolids that could meet high, quantifiable standards for pathogen destruction, trace elements and vector attraction reduction; having met these standards, these biosolids would be deregulated under federal law. It is interesting to note that the EQ biosolids status has been de facto awarded to Milorganite for many years in most states. Secondly, there has been a ban or schedule for phasing out ocean dumping of biosolids in the U.S., Canada, the EC, and Australia, thereby increasing pressure on land-based options, including beneficial use. Large cities are commonly located on the coast, and shifting biosolids from cities like New York, Boston, Los Angeles, Dublin, and Sydney from the ocean to the land has had, or will have, enormous impact on beneficial use of biosolids. Since many of these communities have opted to produce EQ biosolids materials, the opportunity to penetrate agricultural and horticultural markets with these products is great. The third factor affecting the potential to bring biosolidsderived products to the marketplace is the increased number of technologies available to produce EQ biosolids: composting (static pile, aerated static pile, envessel), advanced alkaline stabilization, and thermal drying/pelletization. Horticultural Markets for Soil Additives Horticultural markets are distinctly different in their use of soil additives (these include fertilizer, limestone, organic matter and pesticides) than agriculture. In a study to determine national potential markets for compost, Slivka et al. (1992) identified horticultural markets that included landscaping, delivered topsoil, bagged/retail products (unidentified), container nurseries and sod production (Table 1). The horticultural markets are small compared to the potential use in agriculture. Taken together, the horticultural markets amount to 38.6 million cubic yards, and most of this (20 million cubic yards) is in sod production (Table 1). We feel that the actual and potential horticultural markets are underestimated and that there will be significant increases in demand if low-cost materials like biosolids or other organic waste-derived products enter the market. It is difficult to compare market demand against biosolids production. Biosolids production is given as dry tons (Table 2) and the potential to shift from incineration and landfilling to beneficial use in general, and product development in particular, is complicated by socio-economic forces that are regional and even local. If we use an approximate density of biosolids products of 0.5 metric tons/m , and assume that a yard is approximately equal to a meter, then 38.6 million cubic yards is approximately 20 million metric tons. If we assume that all biosolids that were land applied or marketed in 1988 were converted to EQ products and used in horticulture, this would be about 2 million metric tons, or 10 % of the potential market. We do not have accurate national statistics on current biosolids use and disposal, but we suggest that the trend is in the direction of beneficial use and towards EQ biosolids production. For example, a significant portion of the 4 million metric tons ocean dumped in 1988 (Table 2) are going into pellets (New 3
In Agricultural Uses of By-Products and Wastes; Rechcigl, J., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1997.
5. LOGAN ETAL.
Horticultural Fertilizers and Soil Blends
65
Table 1. Potential demand for compost in the U.S. (Slivka et al., 1992) Market Segment
Potential Demand (10 cubic yards)
Current Saturation (Percent)
2.0 3.7 8.0 0.6 0.2 0.9 4.0 20 104 895
