1. Groundwater Pollution
0331 – Types of Pollution

3. Contaminants are separated into four main categories:
Physical
Biological
Inorganic chemicals
Organic chemicals

4. These categories may overlap sometimes
These categories may overlap sometimes. eg a biological organism might make organic chemicals and the organisms have a physical effect on the water.

5. Contaminants can have effects at very small concentrations.
Measure amounts of contaminants in terms of concentration.
ppm and ppb and ppt, which are parts per million and parts per billion and parts per trillion.
PPM is the amount of contaminant units in 1,000,000 (1 million) units of groundwater.
PPB is lthe amount of contaminant units in 1,000,000,000 (1 billion) units of groundwater.
PPT is the amount of contaminant units in 1,000,000,000,000 (1 trillion) units of groundwater.

7. Very small concentrations of some groundwater contaminants could have serious health effects.
Different kinds of contaminants have different concentration limits.
It is necessary to find out both the specific type of contaminant and the concentration of the contaminant.

9. Contamination Movement
As contamination moves it disperses.
The concentration decreases as it moves farther away from the source of the pollution.
So there are different concentrations of contaminants at different points in the aquifer.

10. The representation of these different concentrations is called a contamination plume.

11. Area of Contamination
A contaminant may be released into the groundwater for only a short time and in a very small area, but as it disperses the contaminant can affect a very large area and number of people.

12. Plumes can be very irregular

13. http://techalive.mtu.edu/meec/module04/PlumeExample.htm Watch and say:
Where is the source of the contamination?
Is the source continuous or a one-time event?
Based on the direction of the plume, which way is the groundwater moving?
How far does the contamination travel in 16 years?
What important areas of the city are affected by the contamination?

14. Finding Contaminants Look at the history of the site.
See if a nearby river is contaminated or what possible above-surface sources exists.
To find the contaminant plume drill test wells or use other technology to find concentrations at different points underground.

15. Some specific contaminants.

17. Sites to search for contaminants
has a large list of sites, including

18. Suspended Solids
Organic and inorganic particles in water are termed suspended solids
May be distinguished from colloids, particles that do not settle readily
Measured by filtering a water sample, drying and weighing the filter

19. Suspended Solids Problems Sources sedimentation
may exert oxygen demand
primary transport mechanism for many metals, organics and pathogens
aesthetic
complicates drinking water treatment
Sources
storm water
wastes
erosion

20. Pathogenic Organisms
Many organims that cause human or animal diseases colonize the instinal tract but can live for a period of time outside the body
Carriers (who may or may not exhibit disease symptoms) excrete these intestinal tract organims in very large numbers
When water is contaminated by excretia, the organisms can be transmitted to those who contact the water

21. Pathogenic Organisms

22. Pathogenic Organisms

23. Toxic and Hazardous Substances
Heavy metals
Other inorganic elements
Acids/bases
Oxidants/reductants
Chlorination by-products
Combustion by-products
Volatile organic compounds
Hydrophobic organic compounds
Endocrine disruptors
Surfactants
Petroleum Additives
Pesticides

24. Volatile Organic Compounds
Petroleum constituents:
benzene and substituted benzenes
prevalent in gasoline, diesel fuel, heating oil
most easily transported, slow degradation, toxic

25. Volatile Organic Compounds
Oxygentated gasoline additives
added to gasoline to improve air quality
very soluble, resistant to degradation, toxic
attempt to solve one problem caused another (spills)
Methyl tertiary butyl ether (MTBE)

26. Volatile Organic Compounds
Chlorinated solvents
C1 and C2 aliphatics
widely used in degreasing, dry cleaning, extraction
somewhat soluble, volatile, difficult to degrade

27. Hydrophobic Organic Compounds
Polycyclic aromatic hydrocarbons (PAHs)
potent carcinogens, tend to associate with particles
also combustion by-products

28. Hydrophobic Organics/ Chlorinated Aromatics
Chlorinated Pesticides
Polychlorinated dibenzodioxins (PCDDs)
Polychlorinated biphenyls (PCBs)

29. Some Other Categories Trihalomethanes Explosives and Propellants
Phenolics
Aldehydes
Organometallics
Asbestos

30. Arsenic Occurs naturally in rock and soil
Released to groundwater under some conditions
Health effects include cardiovascular diseases, skin cancer, nervous system effects, and kidney disease
Major problem in Bangladesh
Drinking water standard being lowered in U.S.