Perchlorate in Drinking Water

Contaminant  In Water As Maximum Contaminant Level




California MCL (2007) = 6 µg/L
Massachusetts MCL (2006) = 2 µg/L
US EPA National MCL Pending

MCLG** (goal)
US EPA = 15 µg/L
Arizona = 14 µg/L
New York = 5 µg/L
Maryland, New Mexico, New Hampshire = 1 µg/L

Action Level***
New York = 18 µg/L
Nevada = 1 µg/L
Texas = 4 µg/L 

Sources of Contaminant

Both natural and manmade inorganic chemical used in the manufacturing of fireworks, explosives, and rocket propellants. 

Potential Health Effects

Inhibits the absorption of iodine by thyroid glands, leading to developmental and learning disabilities in children.

Treatment Methods

Reverse Osmosis
Anion Exchange (Regenerable and non-regenerable)

*Maximum Contaminant Level (MCL) — The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.

**Maximum Contaminant Level Goal (MCLG) - The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.

***A health based advisory level for contaminants for which there is no regulatory standard. If the Action Level is exceeded, the water treatment company is obliged to take appropriate action to reduce the concentration in water below Action Level.

Click here to open WQA's Technical Fact Sheet on Perchlorate.

Click here to access all of WQA's Technical Fact Sheets.