Here is a useful link to the e-CFR: the Federal Drinking Water regulations
Templates for the Level 1 Assessment for different types of water systems:
The EPA develops criteria to protect people from organisms, such as viruses and bacteria, and their associated toxins in water bodies (e.g., lakes, rivers, beaches). Swimming and other recreational activities in contaminated water can make people ill.
The EPA recommends criteria for limiting certain organisms and their associated toxins in water bodies to protect human health. State and tribal governments can use the criteria as guidance when setting their own water quality standards to protect human health.
National Pollutant Discharge Elimination System (NPDES)