Most Americans don’t think twice about drinking a glass of water. A report released Wednesday, though, found more than 270 harmful contaminants in local drinking water across the nation, including in Orange County. The substances are linked to cancer, damage to the brain and nervous system, hormonal disruption, problems in pregnancy and other serious health conditions.

The nonprofit Environmental Working Group, collaborating with outside scientists, aggregated and analyzed data from almost 50,000 local water utilities in all 50 states.

The organization found a troubling discrepancy between the current legal limits for contaminants and the most recent authoritative studies of what is safe to consume.