Water report cites testing lapse
Marion’s required annual report on quality of city drinking water lists no contaminants above federally mandated safety limits but does indicate a lapse in testing.
The city’s report for 2017, released as a link to a website within a city newsletter last week, indicates that the city failed to monitor for a chemical called bromate in May 2017 and did not provide public notice of the failure.
Public works director Marty Fredrickson said Tuesday that the test was performed but that a laboratory that tests city water did not send results to authorities within a mandatory time limit
Bromate is a byproduct of a reaction between naturally occurring bromine in water and ozone that the city uses to disinfect the water.
The report offers no indication of excessive amounts of bromate in city water, only that the level was not monitored as required in May 2017.
Excessive exposure to bromate can lead to nausea, vomiting, diarrhea, and abdominal pain, according to public health authorities.
Massive or prolonged exposure has been linked to problems with kidneys, hearing, and the central nervous system and has been associated with cancer in laboratory animals, though not necessarily in humans.
Women who are pregnant or nursing are thought to be at the greatest risk.
Aside from the failure to monitor for bromate in a timely fashion one month, all other tests in the city report indicated contaminants significantly below the safety level allowed by state and federal regulations.
In some cases, they were even below levels established not as maximum limits but as aspirational goals.
The one exception was aluminum. Although regulations have not established a mandatory maximum level of aluminum allowed in safe drinking water, Marion’s water exceeded a suggested limit by tenfold in a sample collected in April 2017.
Excessive amounts of aluminum are more likely to impact the color of water than they are to pose health risks, according to the Water Quality Association, an industry group. But aluminum does pose a risk for dialysis patients, the group says.
In many water systems, excess amounts of aluminum may be associated with chemicals used as coagulants to remove impurities in preliminary processing of water.
Water softeners typically do not remove aluminum, but distillation and reverse osmosis systems remove most of it, according to the industry group.
“There’s no limit, so it’s not a violation, but I have no idea why it was high,” Fredrickson said.
Bromate, the group says, is extremely difficult to remove and is best avoided by carefully monitoring levels of ozone used to treat water.
Annual notices about water quality formerly were published in their entirety as public notices in newspapers or included with utility bills.
This appears to be the first year that Marion’s report was available only to customers with Internet access and a willingness to dial up a web address published in a city newsletter.
Last modified July 12, 2018