Michigan attorney general Bill Schutee, in a continuing criminal investigation, has announced additional charges relating to the Flint water crisis that has left much of the population of the industrial city without suitable drinking and bathing water, the Detroit Free Press reported.

Former state-appointed emergency managers Darnell Earley and Gerald Ambrose were charged with 20-year felonies for knowingly conspiring to run the Flint Water Treatment Plant when it wasn’t safe, and Flint city employees Howard Croft and Daugherty Johnson with felony counts of false pretenses and conspiracy to commit false pretenses in the issuance of bonds to pay for a portion of the water project that led to the crisis.

These add to the nine people already facing criminal charges including current or former employees of the state of Michigan and a Flint water treatment plant employee.

Flint’s water system became contaminated with lead because water from the Flint River wasn’t treated for corrosion for 18 months. The water ate away at a protective coating inside old pipes and fixtures, releasing lead. The economically struggling city of nearly 100,000 switched from the Detroit system, which draws from Lake Huron, to the Flint River in April 2014 as a short-term measure to save money while another pipeline to the lake was under construction.

Initially, thousands of people had been forced to use bottled water or to get it from some other source in the crisis, which made international headlines.

Earlier this year, municipal water in Flint was reported by scientists to have improved significantly and was deemed safe for bathing and showering, although they said people should continue filtering the water before drinking it.

Flint Mayor Karen Weaver says the charges are actually an indictment on the state emergency manager system. “It’s taken the voice of the people and taken our democracy,” Weaver said to reporters after the announcement.

With AP