PFAS can get into drinking water when products or wastes containing them are disposed of, used or spilled onto the ground or into lakes and rivers.

PFAS move easily through the ground, getting into groundwater that is used for some water supplies or for private drinking water wells. When released into lakes or rivers used as sources of drinking water, they can get into drinking water supplies.

PFAS released by facilities into the air can also end up in rivers and lakes used for drinking water.

Drinking water and groundwater sample results are compared to:

Learn more about drinking water PFAS maximum contaminant levels

 The majority of surface water (i.e., waterbody) samples collected are compared to:

Some water supplies draw water from a waterbody, treat the water, and then use it for drinking water.

If surface water samples are collected directly from a waterbody that is also used as a source for drinking water, then surface water samples are compared to:

ppt = parts per trillion

Health effects associated with PFAS include:

• Lowering a woman's chance of getting pregnant
• Increasing the chance of high blood pressure in pregnant women
• Increasing the chance of thyroid disease
• Increasing cholesterol levels
• Changing immune response
• Increasing chance of cancer, especially kidney and testicular cancers

Studies in animals help us understand what could happen in people. Animals given very high amounts of PFOS and PFOA showed:

• Harm to the liver.
• Harm to the animal's ability to fight off sickness.
• Birth defects, slow growth, and pup deaths.

If you have medical questions, talk with your doctor. You may find ATSDR's fact sheet, "Talking to Your Healthcare Provider about Exposure to PFAS" helpful.

Test results can vary depending on several factors including the depth of the drinking water wells, groundwater flow direction, and geological characteristics underground. PFAS contamination in groundwater can be found at different depths in the ground depending on the aquifer thickness, type, and whether sand or clay are present.  Groundwater flows in certain directions and paths, and depending on your home's and drinking water well's location in relation to the PFAS contamination source, your testing results might show different levels of PFAS than your neighbors well.