The D.C. Circuit dismissed five states' petition to review EPA's extension of a compliance deadline for a revised national drinking water regulation, which in turn extended the deadline for states to enforce conforming regulations to their own. The states argued the extension would cause their resid...

The D.C. Circuit vacated EPA's withdrawal of its determination to regulate perchlorate in drinking water. An environmental group argued EPA lacked the authority to withdraw the determination under the SDWA, and that even if it did have such authority, it acted arbitrarily and capriciously in doing s...