hey! there’s lead in my water!

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Hey! There’s Lead in my Water!

The Drinking Water Contamination Issue

Facing Residents of Flint, MI

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How Does Lead Get Into my Drinking Water?

Lead in Drinking Water

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• Most households contain lead pipes or pipes with lead solder joints


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• Corrosive water passes through

the pipes


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the pipes

• Chemical reactions take

place between the pipes

and the water


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the pipes



and the water

• Some of the lead dissolves

into the water


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the pipes



and the water

• Some of the lead dissolves

into the water


Let’s Look at This

in More Detail…

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• Acidic (pH ~4-7)

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• Acidic (pH ~4-7)

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• Low alkalinity

CO32-

CO32-

CO32-

CO32-

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• High temperature

water

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• Saline (high levels of dissolved salts)

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Attributes of Flint River

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• Low pH


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• Low pH

• High salinity

• High levels of chlorides


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There are 3 Common Sources For Chloride in Natural Waters:


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Cl-

Cl-

1) Naturally occurring chloride salts

Cl- Cl-

Cl- Cl-

Cl-

Cl-

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2) Runoff from road salts

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3) Water disinfection chemicals

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Challenges in Treating Flint River Water

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• Flint River has naturally excessive levels of chloride


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• Chloride reacts with iron pipes to form ferric chloride (FeCl3)

• Reaction with iron ties up chloride that should be disinfecting the water

• Additional chlorine must be added for disinfection


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• Organic matter present in Flint River


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• Additional chlorine reacts with the organic matter

• Reaction produces trihalomethane (THM) by-products

• THMs well-known for carcinogenic properties


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• Flint River has a naturally low pH


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• Flint River has a naturally low pH

• Reaction with iron and lack of corrosion inhibitors for water treatment help

maintain low pH

• Acidic environment promotes reaction with lead in pipes


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• Corrosive Water

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• Corrosive Water + Lead Pipes

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• Corrosive Water + Lead Pipes = Lead Contaminated Water

Pb

Pb

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How Can We Stop Pipes From Corroding?


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1. Water Treatment –

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• Filter to reduce the amount of chloride present

• Treat water to adjust pH, salinity, hardness

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2. Corrosion Control –

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2. Corrosion Control –

• Addition of certain chemicals

affects the chemistry in the water

• They can increase the pH of the water

• They can promote scale growth along the

walls of the pipes

• Orthophosphates found to be most effective

for a range of plumbing materials

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Corrosion Control


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Corrosion Control


The Plumbing Superhero to Fight Against Corrosion

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Corrosion Control



With Corrosion Inhibitors

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Corrosion Control


• Orthophosphates react to form lead compounds - low solubility



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Corrosion Control



• Insoluble precipitate forms protective layers on inside of pipes



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Corrosion Control






Without Corrosion Inhibitors

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Corrosion Control







• Water reacts with the lead-containing pipes

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Corrosion Control







• Water reacts with the lead-containing pipes

• Lead dissolves, generally as PbCO3 (PbCl2 soluble in hot water)

Pb Pb

Pb

Pb

Pb

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How Much is “Too Much” Lead in Drinking Water?


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Environmental Protection Agency (EPA)


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• Safe Water Drinking Act (SWDA) and Lead

Copper Rule (LCR)


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Copper Rule (LCR)

• Maximum Contaminant Level

• Goal Concentration = 0 µg/L Pb

• Action Level Concentration = 15 µg/L Pb


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Copper Rule (LCR)




Centers for Disease Control and Prevention (CDC)


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Copper Rule (LCR)





• No safe concentration for Pb in blood


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Copper Rule (LCR)





• No safe concentration for Pb in blood

• Blood lead levels (BLLs) containing 5 µg/dL could indicate

exposure to high levels of Pb


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Health Effects From Exposure to Lead

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• Well-known toxin



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• Affects most organ systems in humans

• Infants/children experience more severe effects



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• Symptoms in adults include:



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• Joint and muscle pain

• Abdominal pain

• Headaches

• High blood pressure

• Memory loss



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• Abdominal pain

• Headaches


• Memory loss

• Symptoms in children include:



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• Abdominal pain

• Headaches


• Memory loss

• Symptoms in children include:

• Developmental delays (physical and mental)

• Loss of appetite

• Abdominal pain

• Stunted growth



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How Much Lead is in Your Drinking Water?

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• Contact your local water municipality

• Collect and submit a water sample for testing



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Additional Resources

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• EPA document: Actions You Can Take to Reduce Lead in Drinking Water

(http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20001R4V.txt)

http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20001R4V.txt

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• EPA document: Actions You Can Take to Reduce Lead in Drinking Water

(http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20001R4V.txt)

• WHO guidelines and general education for lead

(http://www.who.int/ipcs/features/lead..pdf)

http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=20001R4V.txt

http://www.who.int/ipcs/features/lead..pdf




hey! there’s lead in my water!

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