APPENDIX 



Use of Nomograph 



Find the sludge concentration of the element of interest in Column A.Find 

 the "safe" increase in soil concentration in Column B (normally, an addition 

 equal to the common concentration, Table 3, can be considered "safe"). When a 

 ruler is laid to intersect these two points, Column C will be intersected at the 

 maximum amount of sludge, in tons per acre, that can be applied to the land in 

 order not to exceed the "safe" increase (see example, below). Either wet or dry 

 basis can be used for columns A and C, but they should not be mixed. If the 

 concentration (Column A) is on a dry weight basis, the addition will be in dry 

 tons per acre, and if the concentration is on a wet basis, the addition will be on a 

 wet ton basis. The values in Column C are calculated on the assumption that the 

 sludge will be thoroughly mixed with the upper six inches of soil. If it is not 

 mixed to this level, the amount applied should be decreased accordingly, i.e., if 

 it mixed to three inches, apply only half the indicated amount. 



EXAMPLE: The Keene sludge contained 8,500 ppm lead (Table 2). Soils 

 commonly contain about 10 ppm lead (Table 3), so it would 

 probably be safe to add this amount to the land. Drawing a line 

 to intersect 8,500 in Column A and 10 in Column B, we find 

 that we should not add more than l-'/a tons of dry Keene sludge 

 per acre. 



The amount of any given sludge applied should be the lowest quantity 

 indicated by the presence of different elements. Although the total effects of all 

 elements should be considered, no appreciable problems should be encountered 

 if the common soil concentration of the most restricting element is not increased 

 by more than 100 percent (see Table 3). 



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