The Environmental Protection Agency (EPA) broke the law with its social media and lobbying campaign when it advocated for its own Waters of the U.S. (WOTUS) proposed rule, the U.S. Government Accountability Office (GAO) found last week.

In a legal opinion issued last week, the GAO said the EPA violated prohibitions against publicity or propaganda and grassroots lobbying contained in appropriations acts for fiscal years 2014 and 2015.

"Because EPA obligated and...