R-RANCH IN THE SEQUOIAS

What this violation means

Fluoride at the optimal level (~0.7 mg/L) reduces tooth decay, which is why most US utilities add it. The MCL of 4.0 mg/L exists to protect against skeletal fluorosis from naturally high-fluoride groundwater, while the EPA's secondary standard of 2.0 mg/L addresses dental fluorosis in children.

Recommended precautions

• →Reverse osmosis removes fluoride; standard carbon filters do NOT.
• →If your child uses fluoride toothpaste and drinks fluoridated water, supervise brushing to limit ingestion.
• →Bone meal supplements often contain fluoride and should be used cautiously.

What this violation means

Arsenic is a known human carcinogen that occurs naturally in groundwater across many parts of the United States, especially the Southwest and parts of New England. Long-term exposure even at low levels has been linked to bladder, lung, and skin cancer, as well as cardiovascular disease and developmental effects in children.

Recommended precautions

• →Reverse osmosis filtration removes arsenic effectively.
• →Distillation also removes arsenic — point-of-use distillers work for drinking and cooking water.
• →Boiling does NOT remove arsenic. It actually concentrates it as water evaporates.
• →If your well water has arsenic, test annually and treat at the point of entry.