Two more employees in the city of Atlanta’s Watershed Management Department were arrested for felony theft Thursday, bringing the number of employees charged in the on-going corruption probe to seven since March.

Corey Green, a Watershed crew supervisor employed by the city since 2006, is alleged to have exchanged water meters, copper and brass at recycling centers for cash. Reginald White, a water distribution operator also employed since 2006, allegedly made more than $78,000 by doing the same thing.

A press release about the arrests does not say how much Green is alleged to have made.

Earlier this week, four Watershed employees — Larry Tyler, Aaron Avery, Kenneth Carson and Antonio Denson — were charged with theft for also allegedly recycling meters, brass and copper.

The thefts date to at least 2008, the city has said.

“The Atlanta Police Department and the Department of Watershed Management have my full support in their investigation of theft from taxpayers and the arrests made today,” Mayor Kasim Reed said in a prepared statement. “Unlawful activity will not be tolerated by my administration, and swift action will be taken to protect the taxpayers and residents of the city.”

Earlier this week, the city’s auditor released a report that found some city employees may not have been compensated for hours worked, and that there were concerns about theft of time by destroying or altering time clocks. About one-third of those incidents occurred in Watershed Management, according to the audit.