Bacteria fear may be factor in tainting of Flint water
A Flint water official was concerned that using phosphates to protect the city’s water from lead might feed bacteria in the system, according to a September email from Flint’s former director of public works.
In the Sept. 3 email to city and state officials indicating that the city had returned to safe drinking water standards, Flint Public Works Director Howard Croft also addressed an earlier decision to avoid corrosion controls in the system until further testing was done.
“Most chemicals used in this process are phosphate-based and phosphate can be a ‘food’ for bacteria,” wrote Croft, who resigned two months later.
“At the onset of our plant design, optimization for lead was addressed and discussed with the engineering firm and with the (Michigan Department of Environmental Quality),” he wrote. “It was determined that having more data was advisable to the commitment of a specific optimization method.”
The email, obtained under an open records request, introduces a possible new factor that may have contributed to the decision not to add protective chemicals when Flint switched from buying water from the Detroit water system to drawing it from the Flint River. Flint needed a temporary source of water after its contract with Detroit expired and before a new water system came online.
Water from the river is more corrosive than the water drawn by Detroit from Lake Huron.
Michigan Department of Environmental Quality officials have acknowledged their officials were too literal in their reading of the federal Lead and Copper Rule and insisted on conducting two, six-month periods of testing before making a decision on adding corrosion controls like phosphates into Flint’s drinking water.
The city and state’s failure to utilize corrosion controls — chemicals added to prevent lead fittings from corroding and polluting the water — have been identified as a key contributor to the problem.
Problems with lead contamination in Flint’s system have been traced back to the city’s April 2014 switch from the Detroit water system to the Flint River as its source of drinking water.
That reasoning was shared by DEQ officials at the outset of Flint’s switch — an interpretation of the federal Lead and Copper Rule that has since proven to be problematic. Administrators in DEQ’s Office of Drinking Water and Municipal Assistance believed the law required two, six-month periods of water testing to determine what corrosion controls were necessary in the system.
Former DEQ Director Dan Wyant, who resigned in December, previously stated that interpretation was incorrect, and that corrosion controls should have been implemented from the outset of the switch.
Bacteria would turn out to be a problem for the city. Shortly after the city switched sources, between June 2014 and November 2015, Genesee County reported 87 cases of Legionnaires’ disease, including nine deaths, compared with the six to 13 annual cases of the bacterial respiratory disease the county experienced before the April 2014 switch.