Which treatment method is NOT associated with Class A biosolids?

Class A biosolids refer to treated sewage solids that meet specific criteria for pathogen reduction and are therefore considered safe for use in a wider variety of applications, such as land application or as a soil amendment. The methods associated with achieving Class A certification focus on ensuring the material is free of harmful pathogens and contaminants.

Thermally treated biosolids involve processes that use heat to kill pathogens, which aligns with the criteria for Class A standards. Similarly, high pH treatment helps in pathogen reduction by creating an inhospitable environment for microbial life. High temperatures are also a critical aspect of certain processes that ensure the destruction of pathogens, thereby contributing to the Class A classification.

Low moisture, on the other hand, does not directly relate to the classification as Class A. While moisture content can influence the handling and physical characteristics of biosolids, it is not a specific treatment method that contributes to the achievement of Class A compliance. Consequently, low moisture is not a method associated with ensuring the safety or pathogenic quality of biosolids, making it the correct choice for this question.