But justices declined to block business group and red state suits against tougher curbs on mercury pollutants from coal-fired power plants and methane emissions from oil and natural gas facilities.
Justices will rule on arguments against EPA "generic" effluent discharge permitting, but declined to consider landowners' eminent domain challenge on the Mountain Valley gas pipeline.
New contaminant levels for two key PFAS chemicals, each 4 parts per trillion, are near the current U.S. practical detection limit, industry expert tells ENR, but EPA says more federal funding and added compliance time would boost fixes by drinking water systems.