I am doing research on detecting and enumerating pseudomonas aeruginosa in drinking water using mpn and i would like to compare my findings with the standard quality of drinking water. But so far the only data i can find is on the standard level for e. coli and total coliform acceptable in drinking water. Is there an standard level for p. aeruginosa in drinking water? I remember reading somewhere that the acceptable amount was 2.2 mpn/100ml and below but i dont remember which standard data this was from.