The Great Lakes Water Authority is making changes to how it treats drinking water ahead of some new, more stringent rules limiting lead and copper levels in water.
The GLWA provides drinking water and wastewater services to most of southeast Michigan. According to a statement from the utility, the change will involve gradually doubling the amount of orthophosphate used in the water treatment process, starting next month. That chemical additive acts to coat pipes, preventing lead or copper from seeping into the water.
A failure to use the proper amount of orthophosphates in the treatment process was the root cause of the Flint water crisis, after a state-appointed emergency manager made the ill-fated decision to switch the city’s drinking water source to the Flint River. The improperly treated water corroded lead pipes in many Flint homes, leading to elevated lead levels in a number of the city’s children.
While there are no lead pipes in the GLWA’s larger water transmission system, some homes in older communities still get their drinking water through lead service lines. There are already state and federal mandates that require municipalities to eventually replace them, but that’s an ongoing process that will take years.
Michigan’s “action level” for lead in drinking water will drop from 15 to 12 parts per billion at the start of 2025. And according to GLWA, in 2027 “a host of changes will also go into effect with the federal LCR, including a decrease in the time that municipalities have to remove lead service lines and a new trigger level for additional testing.” Lead is a known neurotoxin, and no level of it is considered safe.
“The change to GLWA’s corrosion control strategy was informed by a proactive, multi-year study conducted as part of its process of continual improvement and regulatory compliance,” the Authority said in a statement. “During the study, tests were performed using variable amounts of anti-corrosion chemicals to determine the most effective dosage recommendation.”
The GLWA also noted that “Due to the increase in orthophosphate in the water treatment process, there will be an increase in the amount of phosphate that GLWA must remove during the wastewater treatment process,” but added that “GLWA remains committed to ensuring that we continue to meet the federal and state regulators’ goal of reaching a 40 percent reduction in phosphorus.”
Excessive amounts of phosphorus can cause problems in waterways, notably fish kills and toxic cyanobacterial blooms like the ones that have plagued Lake Erie in recent years and caused Toledo to issue a do not drink order to residents for three days in 2014.
