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  • Writer's pictureMahika Weerasekare

Salt Corrodes - Flint Water Crisis 2014-2021

Updated: Sep 1, 2021

Overview –

Fresh water sources are drying up and getting more and more polluted, driving up the cost of safe drinking water- both due to scarcity and to higher cost of water treatment. In North America one such pollutant that is highly corrosive is chloride, a component of rock salt used to de-ice roads in winter. Lead contamination of Flint drinking water was linked to the high levels of chloride in the Flint River water.

Exposure to lead is unsafe, particularly to children and pregnant women. Since 1991, as a measure to prevent lead contamination in drinking water, the US Environmental Protection Agency has required drinking water providers to add chemicals that inhibit corrosion in lead pipes. Flint water crisis showed the limitations of the rule. Replacing lead (and galvanized steel, cast iron) service lines is now adopted as a better, more permanent solution.

Cost of Safe Drinking water

In 2013, as a cost-cutting goal City of Flint officials decided to switch water providers. In the spring of 2014, in a further effort to save money while waiting for new pipelines to be built to join a new regional water system, they switched from a water source they had used for 50 years, to getting their water from the Flint River and treating water at the Flint Water Service Center. This was a treatment center that had not been in use since 1967 and was maintained only as a backup water treatment facility.

When treating Flint River water, they did not follow Federal corrosion control laws and did not use corrosion control methods commonly used in water treatment. Their inactions were helped along by State and Federal authorities that failed to enforce the Safe Drinking Water Act. Drinking Water The resulting public health crisis exposed thousands of Flint residents to unsafe levels of lead, bacteria, and unhealthy levels of carcinogenic disinfectant byproducts.(1,2) Some would die and others left harmed for life.

Villains and Heroes (3)

In the summer of 2014 people of Flint Michigan started to get brown, foul smelling water that had a metallic taste. Between May 2014 and September 2015 citizen’s complaints and concerns of contaminated water to the City of Flint authorities went disregarded.

By October 2014, seeing corrosion in their machines General Motors had stopped using Flint City water. Despite finding high lead levels in water at LeeAnn Walters home in February 2015 and her family showing symptoms of lead poisoning, the city of Flint does not take any action on corrosion control. In April 2015 she contacts Professor Marc Edwards a Civil and Environmental Engineer at Virginia Tech who finds lead levels in Walter’s home to be hundreds of times higher than what EPA considers toxic.

LeeAnn Walters with the help of Dr. Marc Edwards was instrumental to exposing and resolving the Flint Water Crisis. After finding elevated lead levels in Ms. Walters house and in the face of inaction of City and State officials, who in July 2015 were still insisting Flint water was safe to drink, in August of 2015 Dr. Edwards and his students distributed 300 lead testing kits to residents and found one in five homes in Flint showed elevated lead levels. These findings again were ignored.

It was pediatrician Dr. Mona Hanna-Attisha’s findings in September 2015 that lead in water was poisoning Flint’s children that finally forced the State of Michigan and City of Flint to acknowledge the crisis they had created and to switch back to their original water source.

How a change to a new water source high in chloride and not adding corrosion inhibitors poisoned Flint drinking water with dangerous levels of lead, bacteria and carcinogens(4,5)


Chloride (that comes from salt) is corrosive. While water from the old water source, Lake Huron, was treated with corrosion inhibitors, no inhibitors were added to Flint River water. This was despite the fact Flint River water was known to be highly corrosive with eight times more chloride ions than Lake Huron water. The choice of ferric chloride as a coagulant, ignoring safer sulfate alternatives to treat contaminants added more chloride to already corrosive water. No pilot studies were done to evaluate the effect of changes of these water chemistries on the aging water lines. Their wait-and- see approach resulted in unprotected service lines leaching lead and iron into drinking water.


The damaged water lines also became a breeding ground for bacteria. Iron in exposed lines reacted with chlorine added for bacteria control depleting the chlorine levels available for bacteria treatment. An E. coli contamination came first. Legionella, the bacteria responsible for the Legionnaires’ disease, accounted for at least nine deaths in the period 2014-2015.


Next the excessive amounts of chlorine added to prevent bacteria growth also formed excess TTHMs-carcinogenic disinfectant by products.

At what price?

In addition to the preventable and incalculable cost to health and life, ruined property, and lost trust in Government and Public Agencies, the decision Flint Authorities took to save $140 per day that took to add corrosion inhibitors has so far resulted in a cost of half a billion dollars in repairs and social services.(6)

Flint 2021

1. A lawsuit mandated all lead and galvanized steel service lines in Flint to be replaced by 2020.(7) According to Public Media from Michigan State University, as of December 2020, service lines in 9700 homes have been replaced with fewer than 500 remaining.(8)

2. In August 2020 the state of Michigan agreed to pay $640 million to settle lawsuits stemming from the crisis that left Flint residents with contaminated drinking water. When it is paid out, the State of Michigan will have spent over one billion dollars in total9.

3. In January 2021 nine people including the former governor were charged with various crimes for their role in exposing an entire community to lead and bacteria contaminated water. Two Health officials were charged with involuntary manslaughter in the 2015 deaths of nine people with Legionnaires’ disease.

Beyond Flint-Ensure you have safe drinking water

1. Make sure your water provider follows EPA Drinking water rules. Drinking Water

2. Change your home water treatment methods accordingly.

3. Be vigilant if your water provider changes the water source.

4. If you must, use a GREEN water treatment method that does not add corrosive chloride (salt) that would end up in water sources. Remember water is becoming a scarce resource, and the more you pollute, the more expensive water becomes.

5. The Federal government is looking to replace all lead service lines in the country. Check for availability of funding from state and federal agencies for metal (lead, steel, and galvanized steel) pipeline replacement in your home.(10) Salt Corrodes

About the Author

Dr. Mahika Weerasekare is a synthetic organic, and analytical chemist with over 20 years of work in research and development. Her experience ranges from small molecular drug development to biomaterial synthesis. Dr. Weerasekare became interested in water chemistry while developing synthetic biopolymers that mimic natural underwater glues for use as water-borne surgical adhesives.



2. Flint Water Crisis: What Happened and Why? J Am Water Works Assoc. 2016 December; 108(12): 22–34. doi:10.5942/jawwa.2016.108.0195

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