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5.0 REGULATORY CRITERIA FROM OTHER TECHNOLOGIES 



Several state, provincial and national regulatory agencies 

 have attempted to set limits for metal contaminants in soils 

 and/or to define metal hazard levels in waste materials. These 

 hazard levels have been developed from different technologies and 

 view soils from different perspectives. Much of the criteria come 

 from four sources: (1) sewage sludge amendment of agricultural 

 soils; (2) coal overburden materials used as rooting zone material 

 in revegetation attempts; (3) defining hazardous materials using 

 various extraction techniques; and (4) setting limits for metal 

 contaminants in soil based on the intended future use of the soil. 

 The criteria presented in this section are provided for a compari- 

 son to hazard levels suggested in this document for the Helena 

 Valley. These criteria were not used to determine the Helena 

 Valley hazard levels. Tables 47 to 51 summarize this regulatory 

 information . 



5.1 Criteria from Land Application of Sewage Sludge 



Metals commonly present in sludge have been classified (CAST, 

 1978) as those that are likely to pose little hazard (manganese, 

 iron, aluminum, chromium, arsenic, selenium, antimony, mercury and 

 lead) for land application and those which pose significant hazard 

 (cadmium, copper, molybdenium, nickel and zinc). Many national 

 regulatory agencies have set maximum cumulative loading levels of 

 these elements for agricultural lands (Table 47) . These loading 

 levels have been set to prevent toxicity to humans or animals from 

 crops grown on treated agricultural lands. It is of interest to 

 note that Norway and Sweden prescribe very low cumulative loading 

 levels while the Uni'ted Kindom and United States allow signifi- 

 cantly higher levels. Cumulative loading levels are given in kg 

 of metal/ha. Conversion to mg of metal/kg of soil is based on a 

 one acre furrow slice (6 to 7" depth) weighing two million pounds. 



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