Method 1682: Salmonella in Sewage Sludge (Biosolids) by Modified Semisolid Rappaport-Vassiliadis (MSRV) Medium is a performance-based method for detecting Salmonella in biosolids. It is intended to enumerate Salmonella to help determine the suitability of biosolids for land application in compliance with 40 Code of Federal Regulations (CFR) Part 503. The method is used for the analysis of solids and various chemical matrices: soil, food, additives, fertilizers, biosolids, etc.

  • Salmonella are pathogenic enteric bacteria that can cause salmonellosis in animals and humans
  • The mean bacterial density of Salmonella in Class A biosolids for unrestricted use is to be below 3 MPN / 4 g of total solids (dry weight basis) at the time the biosolids are used or disposed
  • Salmonella density is reported as MPN / 4 g dry weight

Sampling and Shipping

Part 503 regulation does not specify the total number of samples for Class A biosolids, but suggests a sampling event extend several weeks and at least seven samples to confirm the mean bacterial density of the samples is below 3 MPN / 4 g of total solids (dry weight basis). The analysis of multiple samples increases the method precision by reducing the standard error caused by inherent variations in biosolid quality.

Note: client shall verify hold time requirements with their regulatory agency

Collect sample in a 250 ml or larger sterile container and refrigerate immediately. During transit maintain sample at < 10°C (do NOT freeze) in a cold insulated cooler with ice and/or frozen ice packs. Include a Chain of Custody with all appropriate information provided