On a historic vote in the US Senate, an amendment offered by Senator Gillibrand (D-NY) that would have changed the definition of “underground injection” in the Safe Water Drinking Act was rejected on a 63-35 vote. As currently defined, “underground injection” specifically excludes hydraulic fracturing operations unless diesel fuel is used during the fracturing. Senator Gillibrand’s seemingly innocuous change to the SWDA would have allowed the EPA to fully regulate hydraulic fracturing operations. Senators Heinrich and Udall both voted against the amendment. All the Senate Republicans present also voted against the amendment.