How it all started

CANADA

Lake

Huron

WI

MI

NY

IL

Detail

PA

IN

OH

100 mi.

Flint water

treatment plant

Lake

Huron

Intake

69

Flint

75

94

MICHIGAN

CAN.

96

Lake

St. Clair

Detroit

20 mi.

In 2013, in an effort to reduce costs, the city of Flint decided to stop buying water from the Detroit Water and Sewerage Department (), which draws its supply from Lake Huron, and switch to the Karegnondi Water Authority (). Construction of a KWA pipeline between Flint and Lake Huron is expected to be completed by mid-2016. In April 2014, as a temporary measure, Flint began using water from the Flint River ().

After the switch, residents began complaining about the smell, color and taste of the water. The city of Flint issued boil-water advisories because of coliform bacteria in the water. Water from the Flint River also was more corrosive and the state failed to ensure that anti-corrosion chemicals were added to the water. That caused lead to leach from pipes into drinking water.

In October 2015, Flint switched back to the Detroit water system.

Bottles owned by Flint residents Jessica Owens and Tonya Williams, filled with water, sit on the table outside of city council chambers as Michigan Gov. Rick Snyder speaks during a news conference in Flint, Mich., Monday, Jan. 11, 2016. Pastor David Bullock holds up a bottle of Flint water as Michigan State Police hold a barrier to keep protestors out of the Romney Building, where Gov. Rick Snyder's office resides on Thursday, Jan. 14, 2016, in Lansing, Mich.

Bottles of water from Flint in January. (Jake May/Flint Journal-MLive.com via AP)

More instances of elevated blood lead levels

Children younger than 6 with elevated blood lead levels

Flint

7.0%

5.8%

Michigan

Genesee

County

’10

Q1

’14

Q3

’15

Q3

’16

Q1

Flint data includes only Zip codes that are fully serviced with Flint city water. Each child is counted once per year in the quarter of his or her highest blood-lead test. Data as of Feb. 12.

In 2014, the percent of tested children with elevated levels of lead in their blood spiked to 7 percent, the highest since 2010. An elevated level of lead in the blood is concentrations of 5 mcg/dL or more.

According to the Michigan Department of Health and Human Services, blood lead levels usually spike in the third quarter of each year because of increased exposure to sources of lead in the summer months: Lead can be found in outdoor sources, such as soil. Lead dust from lead paint can also get into the air as windows are opened.

Aside from these seasonal fluctuations, the percent of children with elevated blood lead levels was on the decline in Genesee County, where Flint is located, until 2014, spiking in that year and in 2015.

How does lead affect the human body?

Adults can experience kidney problems and high blood pressure. Children can experience behavioral problems, learning delays and mental impairments.

Kidney problems

High blood pressure

Delayed physical or mental development

Delayed physical or mental development

Kidney problems

High blood pressure

Six types of water contaminants

MICROORGANISMS

Common sources:

Human and animal waste

DISINFECTANTS

 

Water additive used to control microbes

DISINFECTION

BYPRODUCTS

 

Formed when water treatment chemicals react with organic matter

 

INORGANIC CHEMICALS

 

Corrosion of household

plumbing — such as lead or copper pipes, runoff from fertilizer

ORGANIC CHEMICALS

 

Runoff from herbicide use, discharge from industrial chemical factories

RADIONUCLIDES

 

Erosion of natural and man-made deposits

MICROORGANISMS

DISINFECTANTS

 

DISINFECTION

BYPRODUCTS

 

Common sources:

Human and animal waste

Water additive used to control microbes

Formed when water treatment chemicals react with organic matter

 

RADIONUCLIDES

 

INORGANIC CHEMICALS

 

ORGANIC CHEMICALS

 

Erosion of natural and man-made deposits

Corrosion of household plumbing — such as lead or copper pipes, runoff from fertilizer

Runoff from herbicide use, discharge from industrial chemical factories

DISINFECTANTS

 

INORGANIC CHEMICALS

 

ORGANIC CHEMICALS

 

MICROORGANISMS

DISINFECTION

BYPRODUCTS

 

RADIONUCLIDES

 

Erosion of natural and man-made deposits

Common sources:

Human and animal waste

Water additive used to control microbes

Runoff from herbicide use, discharge from industrial chemical factories

Formed when water treatment chemicals react with organic matter

Corrosion of household plumbing — such as lead or copper pipes, runoff from fertilizer

The EPA sets drinking-water limits for more than 90 contaminants, organized into six categories including microorganisms, industrial chemicals and radionuclides. Many of the contaminants aren’t supposed to be in drinking water at all, though some are permitted in trace amounts.

The impact on the human body depends on the contaminant and its concentration. Some contaminants, like coliform bacteria, can cause acute illnesses, while others have been linked to cancer. Lead is part of a class of inorganic chemical contaminants that can damage internal organs at high exposure rates. Others in this class include cyanide, asbestos and arsenic.

Editor's picks

This is how toxic Flint’s water really is

See how Flint’s water compares to that of surrounding areas.

Take a closer look at Flint from the ground level

In downtrodden Flint, lead contamination in the water is the worst blow yet.