APC. Aerobic plate counts are generally very useful as an indication of general microbial growth in most factory environments, as well as the effectiveness of sanitation. Some areas may exist in the facility where microbial growth and the presence of high microbial populations can be assumed (e.g., drains or both operational or post-operational samples of product contact surfaes used for the manufacture of fermented fods before drying, such as cheese for cheese powder). In these instances, APC data may not be useful. A factory may wish to monitor such areas for microorganisms of particular concern, such as pathogens.