Issues
Issue #2 Too Much Lead in the Water
What is Happening:
Toxic chemicals such as lead are getting into the water supply.
Causes:
Water in lead pipes is treated with phosphates to maintain a coating on the inside of a lead pipe by preventing oxygen from reacting with it. When Flint switched its water supply to a new source, it didn't add these protective chemicals, which allowed the dissolved oxygen to undergo redox reactions with the lead, allowing it to leach into the drinking water. Both the oxidation of lead and the redox of lead create dissolved lead and compunds containing it.
Impacts:
Due to these reactions, lead and its compounds appear in the water. The impacts of lead poisoning are severe and permanent, and there is no amount of exposure to lead that is considered healthy. Lead poisoning can cause developmental delays, decreased IQ, organ problems, and even death.
Equations:
Oxidation reaction:
2 Pb(s) → 2 Pb2+(aq) + 4 e–
Reduction reaction:
4 e– + 2 H2O (l) + O2 (aq) → 4 OH– (aq)
Full redox reaction:
2 Pb (s) + O2 (g) + 2 H2O (l) → 2 Pb(OH)2 (s)
Issue #3: Trihalomethanes Found in Water
What is happening:
After Flint switched its water source, the concentration of Trihalomethanes (THM) found in the water significantly increased. THM's are 4 different chemicals: chloroform, bromodichloromethane, dibromochloromethane, and bromoform. These chemicals are formed when a halogen reacts with various compounds, and replaces 3 out of 4 of the hydrogens with a halogen group member.
Causes:
The city of Flint also heavily salts its roads during winter, and the Cl is dissolved, and reacts with other chemicals to form THM's.
Causes:
When Flint started to use the Flint River as its water source, the city had to use significantly more chlorine to cleanse the water of bacteria, and the water was also treated with other chemicals to kill the bacteria as well. The chlorine reacts with certain biproducts of these chemicals, which forms the THM molecules. These molecule then travel throughout the drinking water.
Impacts:
THM's are an EPA chemical group which can cause kidney, liver, and central nervous system problems. These molecules have also been found to greatly increase the likeliness of developing cancer.
Equations:
Chloroform creation:
2CH4(aq) + 3Cl2(aq) → 2CHCl3 + 3H2
Issue #1 Dirty, Discolored Water
What is happening:
Ever since Flint switched its water source, iron and iron oxides have been found in the water in great concentrations.
Causes:
Due to an inadequate water treatment system, the iron-rich water from the Flint River is not softened, and this iron builds up in the pipes and is put into the drinking water.
Causes:
A minuscule amount of iron of exposed iron is dissolved into the water from the pipes.
Causes:
The pipes carrying Flint's water have too much dissolved oxygen, which causes the iron to undergo a redox reaction to form iron oxide (rust). The rust is carried through the pipes, and into the faucets of thousands of people.
Impacts: Iron has no severe impacts on the health, but it does affect the appearance and taste of the water.
Equation:
Oxidation reaction:
2 Fe(s) → 2Fe2+(aq) + 4e−
Reduction reaction:
4 e– + 2 H2O (l) + O2 (aq) → 4 OH– (aq)
Redox reaction:
2 Fe (s) + O2 (g) + 2 H2O (l) → 2 Fe(OH)2 (s)
Flint Water Crisis
