Suppliers should ensure that the testing of Sludge as detailed under Table 4A-4C in the ZDHC WWG 2,0 document is done and if there is non-conformity w.r.to the limit values applicable to the disposal pathway undertaken by the Supplier, a Root Cause Analysis should be done and a Corrective Action Plan developed by the Supplier. The methodology is as follows:
Explanation of methodology with examples for different disposal pathways:
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Example 1: Supplier has disposal pathway A or B, with proper documentation Sludge composite sample is tested for metals and cyanide as per Table 4A Case 1: All metals and cyanide tested are below the threshold values in Table 4B Test composite sample for conventional and MRSL parameters. Only report the values obtained Case 2: All or some metal values exceed the threshold values in Table 4B
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Example 2: Supplier has disposal pathway C, with proper documentation Sludge composite sample is tested for metals and cyanide as per Table 4A Case 1: All metals and cyanide tested are below the threshold values in Table 4B Test composite sample for conventional and MRSL parameters as per Table 4C. Check if pH test results meet the limit values of 5-11 s.u. For other parameters, only report the values obtained Case 2: All or some metal values exceed the threshold values in Table 4B
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Example 3: Supplier has disposal pathway D or E Sludge composite sample is tested for metals and cyanide as per Table 4A Case 1: All metals and cyanide tested are below the threshold values in Table 4B Test composite sample for conventional and MRSL parameters as per Table 4C. Check if pH, paint filter test results and MRSL parameters limit values are met. For other parameters (Solids and Fecal coliform), only report the values obtained Case 2: All or some metal values exceed the threshold values in Table 4B
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Example 4: Supplier has disposal pathway F Sludge composite sample is tested for metals and cyanide as per Table 4A Case 1: All metals and cyanide tested are below the threshold values in Table 4B Test composite sample for conventional and MRSL parameters as per Table 4C. Check if pH, paint filter test results, fecal coliform and MRSL parameters limit values are met as per Table 4C. For % Solids parameter, only report the value obtained Case 2: All or some metal values exceed the threshold values in Table 4B
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Example 5: Supplier has disposal pathway G Sludge composite sample is tested for metals and cyanide as per Table 4A Case 1: All metals and cyanide tested are below the threshold values in Table 4B Test composite sample for conventional and MRSL parameters as per Table 4C. Check if pH, paint filter test results, fecal coliform and MRSL parameters limit values are met as per Table 4C. For % Solids parameter, only report the value obtained Case 2: All or some metal values exceed the threshold values in Table 4B
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