TESTING FOR DISEASE CAUSING ORGANISMS IN SLUDGE/BIOSOLIDS
Common sense vs. EPA Science
EPA assures the public that sludge/biosolids treatment processes create a safe Class A product for direct contact with
food crops and children as long as indicator organism E.coli is non-detectable - that is that there are less than 1,000
colony forming units per gram of sludge/bisolids.
For over 30 years, EPA has known that the sludge/biosolids treatment processes does not destroy all disease causing
organisms. The treatment processes only causes most disease organisms to be hidden for a little while. In effect, the
disease organisms do not continue to reproduce under laboratory conditions. This condition is referred to as Viable,
but non-culturable.
What does 1,000 colony forming units of E. coli per gram represent to people exposed to Class A sludge/biosolids?
First, it means that there are actually 1,000,000 of the organisms in every kilogram of sludge/biosolids. That does not
indicate how many deadly infectious viable, but non-culturable vegetable cell bacteria or spore forming bacteria or
viruses are in the sludge/biosolids.