Follow up to previous postings on perchlorate and drinking water contamination, from EPA today: “the agency’s decision to move forward with the development of a regulation for perchlorate to protect Americans from any potential health impacts, while also continuing to take steps to ensure the quality of the water they drink. The decision to undertake a first-ever national standard for perchlorate reverses a decision made by the previous administration and comes after Administrator Jackson ordered EPA scientists to undertake a thorough review of the emerging science of perchlorate. Perchlorate is both a naturally occurring and man-made chemical, and scientific research indicates that it may impact the normal function of the thyroid, which produces important developmental hormones. Thyroid hormones are critical to the normal development and growth of fetuses, infants and children. Based on this potential concern, EPA will move forward with proposing a formal rule. This process will include receiving input from key stakeholders as well as submitting any formal rule to a public comment process…Monitoring data show more than 4 percent of public water systems have detected perchlorate and between 5 million and 17 million people may be served drinking water containing perchlorate.”