EPA sued for failing to regulate perchlorate (Cl04-)
https://www.newsweek.com/epa-sued-not-regulating-rocket-fuel-chemical-drinking-water-1529601
EPA fails to regulate perchlorate (ClO4-)
https://www.epa.gov/sdwa/perchlorate-drinking-water https://www.epa.gov/newsreleases/epa-issues-final-action-perchlorate-drinking-water
Safe level of perchlorate in water is 1/10th as much as prior thought
https://www.hopkinsmedicine.org/news/newsroom/news-releases/research-story-tip-something-in-the-water-environmental-pollutant-may-be-more-hazardous-than-previously-thought https://www.nature.com/articles/s41594-020-0417-5