California Plans to Cut Detection Level for Perchlorate in Water

California water regulators announced Monday they planned to cut the level at which water suppliers must sample for and report detections of the chemical perchlorate, which has been linked to thyroid conditions.

Water suppliers in California currently must test for perchlorate in drinking water down to 4 parts per billion. The State Water Resources Control Board said it plans to cut that level to 2 parts per billion and then again down to 1 part per billion in 2024.

• Cutting the level will help California expand monitoring and gather more information about the contamination, regulators have said.
• Perchlorate, ...