Chemical Water Chemical Water TestingTesting

TemperatureTemperature

• Remember water-temperature and oxygen relationship:

• High temperature= Low DO• Low temperature= High DO• Causes: industry (power plants)• AKA thermal pollution

pHpH

• Scale from 0 to 14• 0 is acidic• 14 is basic• 7 is neutral (ideal for most streams)• Limestone bedrock tends to

neutralize a lot of acid in our area

Total Dissolved SolidsTotal Dissolved Solids

• AKA “TDS”• Includes mineral, organic matter, and

nutrients• Regulates osmosis• Found in rock, bedrock and soil• Pollution caused by road salt,

fertilizers, acid rain

Dissolved OxygenDissolved Oxygen

• Oxygen molecules suspended between water molecules

• Diffuses into water when it travels over rocks, in riffles

• Valuable to water breathers• Low DO caused by: fertilizers, sewage

treatment, animal waste, soil erosion, paper mills, food processing plants

Nitrogen NONitrogen NO33

• N2 gas makes up 79% of atmosphere but not useful to plants and animals

• Must be converted to nitrates or ammonia through nitrogen cycle

• Humans can disrupt the cycle: farmers add too much fertilizer, crops removed from a site

The Nitrogen CycleThe Nitrogen Cycle

PhosphorousPhosphorous

• Necessary for growth and metabolism in plants and animals

• Can be washed into streams if attached to soil particles, with human/animal waste

• Causes: faulty septic tanks, livestock in streams, industrial waste

• Effects: rapid growth in algae and plants in stream, eutrophication

Phosphorus CyclePhosphorus Cycle

EutrophicationEutrophication

• Explosion of algae or plant life• Eventually these die• Decomposition of dead plants uses

up oxygen• DO level drops: kills animal

life/creates toxic situation

EutrophicationEutrophication

Examples of EutrophicationExamples of Eutrophication

• Nutrient Pollution Video

AlkalinityAlkalinity

• Ability of a water system to resist changes in pH when acid is added

• High alkalinity= stream can handle addition of acid

• Low alkalinity= stream pH will go down with the addition of acid

• Limestone can neutralize acid and increase alkalinity (PA has a lot of limestone)

TurbidityTurbidity

• Measures cloudiness of the water• High turbidity=cloudy water• Causes: suspended organic

matter/minerals EROSION• Effects: clouds water blocks sunlight• Reduces visibility• Clogs fish gills, covers eggs• Absorbs heat, raises temp. of stream, DO

goes down

High TurbidityHigh Turbidity

Review Exit Ticket….Review Exit Ticket….

1. How are temperature and DO related?

2. What biological process is affected by the Total Dissolved Solids in a waterway?

3. Why is acid rain not a big problem in western PA?

4. Name 2 problems caused by high turbidity.