1. Simplified Hydrologic (Water) Cycle
Condensation
Rain clouds
Transpiration
Evaporation
Precipitation
to land
Transpiration
from plants
Precipitation
Precipitation
Evaporation
From
ocean
Evaporation
From
ocean
Surface runoff (rapid)
Precipitation to ocean
Rapid
Infiltration and
percolation
Surface runoff (rapid)
Groundwater movement (slow)
Ocean storage
Fig. 3-24, p. 54

2. Use of Water Resources Agriculture – 70% world-wide
EX: Ogallala Aquifer – Midwest US
Industrial – in-stream vs. withdrawl
Hydropower, cooling, process water
Domestic
Drinking water, bathing, sewer, cleaning, etc

3. Ogallala Aquifer One of world’s larges aquifers -174,000 square miles
30% of ground water used for agriculture in US is from here
Supplies drinking water for 82% of high plains area of US
Being used up considerably faster than can be replenished through rainfall

4. Types of Pollution
Point Source Pollution
Non-point Source Pollution

5. point source pollution
coming from a known source like a pipe, tank, or specific site
easier to monitor
easier to address

6. non-point source pollution
nonspecific source
Could be multiple sources
diffuse like runoff from storm drains or atmospheric fallout
harder to control and pinpoint a source
accounts for 90% of water pollution today

7. organic from life processes
examples include: sewage, animal waste, decomposing vegetation
may contain pathogens
Disease causing organisms

8. inorganic
nonliving
examples: road salt, dust, silt, clay, from construction

9. thermal
heat pollution
example: industrial cooling

10. toxic
poisonous
examples: pesticides, heavy metals, chemicals

11. Clean Water Act Water Classification
Class A – potable water, suitable for drinking supply
Class B – suitable for full body contact, “fishable, swimmable”
Class C – suitable for partial body contact, safe for boating

12. NSF Water Quality Index
a series of 9 weighted tests that yield a single, comprehensive assessment of the overall health of the river
our most important assessment tool
used world-wide to assess river water quality

13. Dissolved Oxygen (DO) the highest weighted test
sources: photosynthesis and atmospheric mixing
levels peak in late afternoon and bottom out just before sunrise – why?
the colder the water, the higher the solubility of DO
results must be converted to % saturation
low DO indicates organic pollution

14. Fecal Coliform
a type of bacteria found in the intestines of warm-blooded animals
2nd most important test
not dangerous but high levels may indicate the presence of pathogens
expressed as colonies/100ml of water
class B water must not exceed col/100ml

15. pH a measure of water acidity measured on a scale 0 – 14
below 7 is acidic, the lower the number, the more acidic
each change of one on the scale indicates a 10-fold change in pH
a pH of 7.5 is best for aquatic ecosystems

16. BOD
a measure of the dissolved oxygen used by bacteria when breaking down organic pollution
high BOD means low water quality
BOD = DO(day1) – DO(day 5)

17. Temperature measured as temperature change along the river
temperature at site – temperature one mile upstream
an indication of thermal pollution

18. Phosphates and Nitrates
two important plant nutrients
if levels are too high – excessive plant growth and algal blooms occur, and eventually, a drop in DO when plant material decays
sources: runoff from farms, lawns; effluent from wastewater treatment plants

19. Turbidity a measure of water clarity high turbidity means low clarity
high turbidity can increase water temps. (lowering DO) and make respiration difficult for aquatic organisms
sources: runoff from construction sites, farms, roads

20. Total Dissolved Solids
same water quality issues as with turbidity
can be measured with a conductivity meter

21. Assessing Water Quality Using Benthic Macroinvertebrate
“bottom-dwelling, big enough to see with the unaided eye, backbone-less organisms”
loosely referred to as “bugs”

24. Aquatic Insect Metamorphosis
Incomplete: egg – nymph – adult
complete: egg – larva – pupa - adult

25. water quality is based on pollution tolerance and/or species diversity
pollution tolerance is based on indicator organisms – organisms that are highly sensitive to pollution; their presence is a good sign, their absence, a bad sign
species diversity as an indicator of water quality – the greater the number of different types of organisms (richness), and the more evenly distributed (evenness), the better the water quality