Water Pollution

Question 1

Unsafe water

Answer 1

44% of lakes, 
37% of rives 
32% of estuaries
in USA are 
unsafe for 
recreation due 
to toxic water 
pollutants

Question 2

Point Source Pollution

Answer 2

Factories/Industry 
Wastewater Treatment 
Landfills 
Underground Storage 
Tanks 
Mines

Question 3

Non-Point Source Pollution

Answer 3

Lawns, Gardens 
Golf Courses 
Agriculture 
Urban Runoff 
Fertilizers (N and P) 
Pesticides (organics) 
Animal Wastes

Question 4

Where does groundwater

pollution come from?

Answer 4

Fertilizer, farm animal sewage, acid mine waste, garbage landfill, waste containers, water table, gas, tank, salt pile, surface tank,

Question 5

Pollutant

Answer 5

Any substance that, in excess, is known to

be harmful to desirable living organisms

Question 6

Where does pollution

come from?

Answer 6

> 70,000 chemicals are used; effects of many are not
known
• Each year another 700-800 new chemicals are
produced
• 55 million tons of hazardous chemical wastes are
produced in the US each year
• The 20 most abundant compounds in groundwater at
industrial waste disposal sites include TCE, benzene,
vinyl chloride…all are carcinogens, and also affect
liver, brain, and nervous system

Question 7

What are some types of
water pollution?
1. oxygen-demanding waste

Answer 7

Dead organic matter decomposed by bacteria, an oxygen-demanding process
BOD (biological oxygen demand) the amount of oxygen required for bacterial decay of dead organics

Question 8

What are some types of
water pollution?
2. nutrients

Answer 8

Overabundance of two important nutrients: N, P;
• Major problem is eutrophication—algae bloom,
triggering BOD problem;
• Major sources of nutrients: Fertilizer, feedlots, and
discharge from wastewater treatment plants (over 90%
of anthropogenic N in the environment is from
agriculture);
• High concentrations of once limiting nutrients lead to algal blooms, which increase BOD, decrease DO, and
degrade ecosystem;
• When accelerated by human processes, it is called
cultural eutrophication.

Question 9

What are some types of
water pollution?
3. pathogenic waste

Answer 9

• Pathogenic microbes
• Fecal coliform bacteria
• Harmful risks (diseases and death) of E. coli
• Billions exposed to waterborne diseases, especially
in poor countries and
• Epidemic risks of waterborne diseases during natural
disasters, such as earthquake, tsunami, flooding

Question 10

What are some types of
water pollution?
4. toxic waste

Answer 10

Toxic waste
• Synthetic organic chemicals, up to 100,000 chemicals in
use, especially those POPs (persistent organic pollutants)
• Heavy Metals: Pb, Hg, Zn, Cd – often deposited at the
bottom of stream channels
• If deposited in floodplains will be incorporated into
plants, crops and animals
• Ex. Mercury contamination of aquatic ecosystems:
- from volcanoes and erosion of natural mercury deposits
- from burning coal, incinerating waste, processing metals
!
• Radioactive materials

Question 11

What are some types of
water pollution?
5. oil

Answer 11

Oil
•Major problems: Polluted water, ecosystem damage,
interrupted socioeconomic conditions of a community
•Major sources: Oil spills from tankers and pipelines,
on- or offshore oil production, war (e.g., the Gulf
War, 2006 war in Lebanon)

Question 12

What are some types of
water pollution?
6. sediment

Answer 12

Sediment pollution
• Sand and smaller particles
• Polluted streams, lakes, reservoirs, even ocean water
• Major sources: Soil erosion, dust storms, floods
• Greatest water pollutant by volume

Question 13

What are some types of
water pollution?
7. temperature

Answer 13

• Thermal pollution
•Temperature increases, less dissolved oxygen
• Adverse changes to the habitats of organisms
•Economic impacts
•Major sources: Hot-water discharge from industrial
operations, power plants, abnormal ocean currents,
dams, removal of vegetation
Runoff from roads and other impervious surfaces
reduces groundwater recharge
increases stream temperatures
carries pollutants
increases bank erosion and flooding

Question 14

Clean Water Act 1972

Answer 14

1. Established water quality standards!
2. System for ID’ing point sources!
3. Pretreatment for industry!
4. Federal funding for sewage treatment!
5. Provided for enforcement!
   • Works fairly well for point sources!
   • Nonpoint-source pollution is not regulated
   under the Clean Water Act

The Clean Water Act does not directly
address groundwater contamination

Question 15

Flaws in the Clean Water Act

Answer 15

Funding 
cost issues for monitoring	
Enforcement 
self-monitoring and self-reporting	
tensions between state and federal government	
Ambiguity of the Clean Water Act
protects all waters with a “significant 
nexus” to “navigable waters”

Question 16

Safe Water Drinking Act

Answer 16

Requires EPA to establish “National Primary Drinking Water
Regulations” (NPDWRs) for contaminants that may cause adverse
public health effects.
!
•These include “Maximum Contaminant Levels” (MCLs) and
nonenforceable health goals for each included contaminant.
!
•1986: EPA must set standards limiting the concentration of lead and
copper in drinking water
!
•2009: Commercial aircraft must follow similar guidelines for drinking
water as established in NPDWR. (in 2004, the EPA found that 15% of
aircraft water systems tested positive for total coliform bacteria)
!
•CWA and SWDA are slow to amend:
•Currently reviewing water pollution due to hydraulic fracking