A publication of Work On Waste USA, Inc., 82 Judson, Canton, NY 13617 315-379-9200 July 1993

The following is reprinted, with permission, from Composting Frontiers, Spring 1993, page 23. Editor: Susan Mazzocchi.

This is an excellent quarterly newsletter that is designed to provide “direction on composting for waste management.”

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Comparison of United States, Dutch, German and
Canadian Compost Quality Standards

mg/kg dry weight

Excerpts from COMPOSTING FRONTIERS, Spring 1993. Edited by Susan Mazzocchi.

UNITED STATES                 THE NETHERLANDS                ONTARIO, CANADA               
“The United States            “The Netherlands were the      “Ontario has issued interim   
Environmental Protection      first of the European          guidelines for compost        
Agency (USEPA) has no plans,  Community (EC) members to      production and use.  The      
at present, to develop        develop standards for soil     guidelines contain metals     
standards for composts        quality conservation under     standards, based on           
derived from municipal solid  their Soil Protection Act of   concentrations in rural       
waste (MSW).  However, the    1987.  Guided by the           ‘background’ -defined as      
Agency has indicated that     principle of ‘good             non-point-                    
such standards ultimately     stewardship,’ or               source-contaminated- Ontario  
will be established           sustainability, of the land,   soils.  These levels are      
utilizing risk assessment     compost quality standards      thought to provide an         
methodology similar to that   were calculated to reverse     appropriate foundation for    
developed for the Clean       presently occuring             compost quality standards,    
Water Act, Section 503        accumulation of pollutants in  pending additional            
Sludge Regulations (CWA 503   soil by preventing their       research-based information.   
Regulations) promulgated in   addition in amounts greater    An element in this decision   
November, 1992.  The CWA 503  than are acceptably removed    is the desire to leave open   
Regulations concern the use   via leaching and plant         the possibility for future    
or disposition of sewage      uptake.  Acceptable leaching   agricultural use of           
sludge and sludge products,   means no addition of           nonagricultural lands.        
including composts derived    contaminants to ground water   Ontario standards assume      
from sludge alone or in       beyond current mean values,    minimal metals leaching and   
admixture with MSW.           and acceptable plant uptake    plant uptake, and a compost   
Unrestricted use of such      is defined by food quality     application rate of 100 tons  
materials is permitted if     standards.  Central to the     per hectare every five years  
they meet quality sludge      Dutch concept of good          for 55 years before           
specifications for metals     stewardship is maintenance of  relatively conserva-tive      
concentrations, pathogen      land use options for future    maximum allowable metals      
reduction, and vector         generations through            concentrations in soil are    
(disease-carrying animals,    preservation of essential      reached.  Neal Ahlberg, of    
such as rodents and vermin)   soil functions - such things   the Ontario Ministry of       
attraction prevention.        as recreation, water           Environment and Energy’s      
According to USEPA, the       filtering, plant growth, crop  Waste Reduction Office, has   
standards for metals          production, and the cycling    been involved in the ongoing  
concentrations in sludge set  of carbon, nitrogen and        process of standards          
forth in the CWA 503          sulfur.  In order to           development.  ‘For us         
Regulations should be         establish                      deciding on standards was     
acceptable for MSW compost    scientifically-based soil      different than choosing       
products...USEPA has          quality standards, the Dutch   acceptable levels for         
characterized the approach    Government requires more       cleaning up already           
used to develop the           research-derived information   contaminated lands,’ he       
Regulations as science-based  than presently exists.  In     said.  ‘We did not want to    
‘reasonable-risk’             the meantime, the stringent    set limits for how much we    
methodology.  Under-lying it  Dutch compost quality          could dirty-up clean          
are the following             standards are meant to guard,  lands.’... Risk assessment    
assumptions:  that change in  or allow for timely            was not utilized for          
soil is inevitable; that      reparation of, soil            establishing Ontario’s        
safety factors can be         multifunctionality, feared     standards.  ‘The problem      
mathematically predicted      threatened by the current      with risk assessment is that  
with certainty utilizing      rate of heavy metals           there are too many unknowns.  
exist-ing scientific data;    accumulation in soil.  Since    To us, it seems a bit        
and that currently available  protection of essential soil   dangerous; our knowledge is   
scientific information is     functions is thought to rely   too limited.  There are many  
sufficient to set standards   on the eventual elimination    differences of opinion, even  
ensuring no harm to human     of all sources of soil         among experts.  And there     
health or the environment.    contamination, fertilizers     are historical examples of    
While acknowledging that      and diffuse atmospheric        significant harm caused by    
neither the dynamics of       deposition are also targeted   insufficient knowledge,’      
contaminant and soil          for regulation.”               said Dr. Lambert Otten,       
interaction, nor ecological   *  * *                         former member of two          
risks are well understood,    “The following [is a]          Canadian                      
EPA has concluded that,       statement by U.S. Government   standards-development         
‘...there are virtually no    scientists involved in the     advisory bodies...”           
effects when sludge is        development of CWA 503                                       
disposed of on the land or    Regulations ‘...just because   * * *                         
used as a soil conditioner    lower concentrations of metal  “Results from pilot projects  
or fertilizer in compliance   residue can be reached in MSW  in Ontario indicate that      
with...[CWA 503]...rules.’    composts [through source       composts produced from        
And that, ‘...MSW composts    separation of organic waste]   source-separated food and     
and sewage sludge can         doesn’t mean that they have    yard wastes are able to       
provide significant benefit   to be attained to make         comply with the contaminant   
to sustainable agriculture;   utilization of MSW compost on  limits in the Guidelines.     
compost utilization can       cropland a valuable practice   Several Ontario               
safely continue for an        of sustainable agriculture.’   municipalities are planning   
indefinite period without     The marked contrast between    composting projects based on  
risk to agriculture or the    EPA’s conception of            source-separated organic      
environment.’  The U.S.       agricultural sustainability    materials from residential,   
standards are permissive      and that of the Dutch is       commercial and industrial     
compared ... particularly     striking.”                     sources...”  “Ontario’s       
[with] those of The                                          Guidelines for Compost        
Netherlands and the Canadian                                 Production and Use,” by Neal  
Province of Ontario.”                                        Ahlberg                       

WASTE NOT # 241. A publication of Work on Waste USA, published 48 times a year. Annual rates are: Groups & Non-Profits $50; Students & Seniors $35; Individual $40; Consultants & For-Profits $125; Canadian $US50; Overseas $65. Editors: Ellen & Paul Connett, 82 Judson Street, Canton, NY 13617. Tel: 315-379-9200. Fax: 315-379-0448.