1. Drinking Water Quality and Health

2. Engineered Water Systems

3. Water and Health
80% of sickness in the world is caused by inadequate water supply or sanitation
40% of the world population does not have access to safe drinking water
It is estimated that water-borne diseases kill 25,000 people per day
In many populated areas of the world, water-borne diseases represent the leading cause of death

4. Drinking Water Regulation in the U.S.
1912 – First regulated in U.S. with Public Health Service Act
relied on voluntary and local efforts
dramatic decrease in water-borne disease over the next 30 years
1974 – Federal oversight of all public water supplies with Safe Drinking Water Act (SDWA)
1986 – Current framework established with SWDA Amendments

5. Sizes of Particles in Water

6. Palatable vs. Potable Palatable aesthetically pleasing
considers the presence of chemicals that do not pose a threat to human health
palatability affected by chloride, color, corrosivity, iron, manganese, taste and odor, total dissolved solids, turbidity

7. Potable Water Potable safe to drink
not necessarily aesthetically pleasing
potability affected by
microbials (e.g. Giardia, Cryptosporidium)
organic chemicals (e.g., alachor, chlordane, 1,2-dichloroethylene, disinfection by-products)
inorganic chemicals (e.g., cadmium, copper, lead, mercury)
Radio-nuclides

8. Palatable and Potable
The goal of municipal water treatment is to provide water that is both palatable and potable
Palatability and Potability regulated under Safe Drinking Water Act
Palatability: Secondary Maximum Contaminant Levels (SMCLs)
Potability: Primary Maximum Contaminant Levels (MCLs) - (for systems serving more than 25 persons per day for greater than 60 days per year)

9. Primary MCLs (mg/L)

10. Primary MCLs (mg/L)

11. Primary MCLs (mg/L)

12. Primary MCLs (mg/L)

13. Secondary MCLs (mg/L)

14. Sources of Drinking Water
Groundwater
shallow wells
deep wells
Surface water
rivers
lakes
reservoirs

15. Ground- vs. Surface Water
Groundwater
constant composition
high mineral content
low turbidity
low color
low or no D.O.
high hardness
high Fe, Mn
Surface water
variable composition
low mineral content
high turbidity
colored
D.O. present
low hardness
taste and odor

16. Surface Water Treatment
Primary objectives are to
Remove suspended material (turbidity) and color
Eliminate pathogenic organisms
Treatment technologies largely based on coagulation and flocculation

17. Surface Water Treatment
Sedimentation
basin
Screen
Surface water
from supply
Rapid
Mix
Flocculation
Basin
Rapid Sand Filter
Sludge
Disinfection To
Distribution
System
Storage

18. Groundwater Treatment
Primary objectives are to
Remove hardness and other minerals
Eliminate pathogenic organisms
Treatment technologies largely based on precipitation

19. Groundwater Treatment
from wells
Sedimentation
basin
Sludge
Recarbo-nation
To Distri-
bution
System
Rapid
Mix
Flocculation
Basin
Disinfection
Storage
CO2