 Despite criticism, EPA recommended this criterion again in 1976, however, the Agency initiated numerous studies in the 1970s and 1980s to overcome the weaknesses of the earlier studies.In 1986, EPA revised its bacteriological ambient water quality criteria recommendations to include "E. coli" and enterococci.Canada's National Agri-Environmental Standards Initiative's approach to characterizing risks associated with fecal water pollution bacterial water quality at agricultural sites is to compare these sites with those at reference sites away from human or livestock sources.