This document provides an overview of environmental health issues related to clean water. It discusses the importance of safe drinking water, key legislation like the Clean Water Act and Safe Drinking Water Act, and challenges in ensuring water quality. Major points covered include a history of water pollution incidents in the US, the process of water treatment, regulated contaminants, and ongoing dilemmas around compliance and shortages. The Flint water crisis is examined as an example of ongoing lead issues. Discussion questions prompt reflection on local water quality information and outbreak data.

1. Environmental Health
Clean Water:
A Limited Resource
Karlyn G. Emile, D.H.Sc. MPH, CHES
July, 21, 2020

2. Objectives
• Background on Safe Drinking Water
• Learn about the Clean Water Act
• Discuss Safe Drinking Water and Regulated Contaminants
• Review the Water Crisis in Flint, Michigan
• Examine Some Dilemmas in Compliance
• Evaluate Shortages of Potable Water
• Discussion Questions
• Conclusion

3. Key Terms
• Clean Water Act
• Nonpoint-source pollution
• Point-source pollution
• Safe Drinking Water Act

4. Background
• Importance of safe drinking water to public health
o Since 1855, John Snow-father of epidemiology, identified polluted water as the
source of London’s cholera epidemic.
• Major epidemics of cholera and other waterborne diseases broke out in
the United States until the end of the 19th century.
• 647 outbreaks of waterborne diseases documented by the Centers for
Disease Control and Prevention (CDC) between 1971 and 1994.
• Contaminated water remains a major cause of disease and death in the
United States—to some extent.

5. Water Pollution Incidents
• Lake Michigan, Chicago—cholera, 1885
• Minamata Bay, Japan—mercury, 1950s
• Hudson River, New York—PCBs, 1970s
o 1.3 million pounds of polychlorinated biphenyls (PCBs)
• Lake Superior, Duluth—asbestos, 1970s
• James River, Virginia—Kepone, 1960s
o A toxic pesticide secretly dumped.
• Cuyahoga River, Ohio—oil caught fire, 1969
o An oil slick on the river caught fire
• Lake Michigan, Milwaukee—cryptosporidiosis, 1993
o largest documented waterborne disease outbreak in the US.

6. Federal Legislation
• Clean Water Act—1972, 1977, 1987
o Lakes and rivers should be fishable and swimmable.
o All pollution discharges should be eliminated.
o Imposes controls on point-source pollution-discharges from municipal sewage systems
and from industry.
o Nonpoint-source pollution-pollutants washed into waterways from the air and land.
• Safe Drinking Water Act—1974, 1996 (and later amendments)
o EPA should set standards for local systems.
o States should enforce the standards.

7. Clean Water Act
• Lakes and rivers should be fishable and swimmable:
– Point-source pollution
• Requirements for treating wastewater
• Sewage treatment plants or septic systems
o Treat with chlorine or other disinfectant
• Sludge: Congress prohibited ocean dumping
• Pretreatment of industrial wastes
– Non-point-source pollution
• Agricultural runoff
• Urban runoff
• Air pollutants deposited by rain

8. Safe Drinking Water
• Nearly half of drinking water in the U.S. comes from rivers and
lakes.
• Surface water
o Helped by the Clean Water Act
• Ground water
o Generally cleaner
• Community water treatment to produce potable water
• Amendments in 2011, 2015, 2016, and 2018 helped fill in gaps.

9. Typical Drinking-Water Purification Plant
• Laboratory tests are performed on
the final treated product.
• This process is directed primarily
against bacterial diseases.
o Most common and devastating type of
waterborne disease.

10. Safe Drinking Water (cont.)
• EPA has set standards for 87 identified contaminants.
• Secondary standards have been set for 15 contaminants that may
affect taste, odor, or color, or that cause discoloration of skin or
teeth.
• Annual reports are required for customers’ “right-to-know” about
contaminants and health effects.
• CDC collects data on water-borne disease outbreaks.

11. Safe Drinking Water (cont.)
• Private wells not regulated under Safe Water Drinking Act
• Bottled water regulated by FDA, 44% of bottled water is obtained
from municipal water
• Lead problems still a concern in many cities

12. Regulated Contaminants
• Disinfectants: chlorine
• Disinfection byproducts: chlorite
• Inorganic chemicals: metals, asbestos, cyanide
• Organic chemicals: herbicides, pesticides, PCBs
• Microorganisms: bacteria, viruses, cryptosporidium
• Radionuclides
• Turbidity

13. Flint Michigan Water Crisis
• Lead-contaminated drinking water is a recurring problem in
municipalities across the United States.
o It took a major crisis in Flint, Michigan, to bring attention to this issue.
• Legionnaire’s disease outbreak occurred in Flint, Michigan in 2014
and 2015
o Killed 12/sickened at least 87 people.
o Corroded pipes allowed the Legionella bacteria to multiply in the water.

14. Dilemmas in Compliance
• New York City fought the EPA in order not to filter its water.
o Cost was too high.
o Instead, NYC wanted to protect the watershed reservoirs in the Catskill Mountains.
I. Cost is a huge problem in many communities. Who should pay for
improvements?
o EPA estimates addressing these needs will cost $384.2 billion—next two decades.
II. Disinfectants that purifies water may produce harmful byproducts—e.g.
chlorine may be carcinogenic.
• A new concern is trace amounts of hormones, pharmaceuticals, and household
chemicals in many waterways.

15. Shortages of Potable Water
• Most water on the earth’s surface is salt water or ice.
• Less than 1% is fresh water suitable for drinking, cooking, bathing,
etc.
• Water shortages exist in much of the world.
• There are water shortages in the U.S. south and west.
• Political disputes already occur in the U.S. over water.
• Clear and pure water is a limited resource and very essential to
public health.

16. Discussion Question 1
• Has your household received information from your community
water provider on contaminants in your water?
• The information should also be posted on the EPA website,
www.epa.gov/your-drinking-water/basic-information-about-your-
drinking-water.
• Does your community’s water meet EPA standards?

17. Discussion Question 2
• Visit the EPA website, www.epa.gov, and locate your watershed.
• Does the EPA identify any problems with the water in your area?

18. Discussion Question 3
• Visit the Morbidity and Mortality Weekly Report website,
www.cdc.gov/mmwr.
• Search the “Surveillance Summaries” for the past two years for
the most recent summary of waterborne disease outbreaks.
• Has your state been listed as having an outbreak?
• How serious was the problem?

19. Conclusion
• Outbreaks of waterborne illness are not uncommon in the United States.
o The 1993 cryptosporidiosis outbreak in Milwaukee is the most dramatic example.
• Two federal laws focus on keeping the water supply clean and safe:
o The Clean Water Act
o The Safe Drinking Water Act
• The Clean Water Act specifies that-
o Rivers should be fishable and swimmable.
o It imposes controls on point-source pollution and nonpoint-source pollution.
o States are mandated to enforce these standards.
• 1996 legislation requires that customers receive annual reports on water
contaminants.
o Public pressure will force better compliance with the standards.

20. References
• Centers for Disease Control and Prevention, “Surveillance for Waterborne-Disease
Outbreaks—United States, 1993–1994,” Morbidity and Mortality Weekly Report 45 (1996):
SS-1.
• Centers for Disease Control and Prevention, “Surveillance Reports for Drinking Water-
Associated Disease and Outbreaks,” June 2, 2015,
https://www.cdc.gov/healthywater/surveillance/drinking-surveillance-reports.html,
accessed August 1, 2015.
• D. Zwick and M. Benstock, Water Wasteland: Ralph Nader’s Study Group Report on Water
Pollution (New York, NY: Grossman Publishers, 1971).
• G. F. Craun et al., “Waterborne Outbreaks Reported in the United States,” Journal of
Water and Health 4 (2006 suppl 2): 19–30.
• Schneider, M. (2020). Introduction to Public Health. [VitalSource Bookshelf]. Retrieved
from https://bookshelf.vitalsource.com/#/books/9781284220230/
• U.S. Environmental Protection Agency, “Water on Tap: What You Need to Know,”
December 2009, https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=P1008ZP0.TXT, accessed
December 20, 2019.