Water QualityGuzmán 4/21/14

Dissolved OxygenThe amount of oxygen gas dissolved in liquid

waterEssential for maintenance of healthy lakes

and rivers because all animals need oxygen to survive.

High levels = good, low levels = badSources come from churning water and

aquatic plants

Fecal ColoformBacteria found in the feces of humans and

other animalsEnter water from direct discharge,

agricultural runoff, storm runoff, or human sewage discharged into water

These bacteria themselves are not harmful, but will indicate the presence of other possibly harmful disease causing organisms

Enter the body through cuts, nose, mouth, or ears. Can cause typhoid fever, hepatitis, gastroenteronitis, dysentery, and ear infections.

Some coloform bacteria in water is completely normal

pHMeasures how acidic (more H ions than OH)

or how basic (less H ions than OH) there is in water

Normal = 6.5 to 8.5Increased SO2(sulfur dioxide) and NOx

(nitrogen oxides) are converted into acid and increase acidity of water by mixing with water vapor and coming down as acid rain.

Common sources = auto exhaust, coal-power plant emissions

TemperatureTemperature is a factor in how much oxygen can

be dissolved (cool holds more)Reasons why water might be warmer:

Adding hotter water from factories or nuclear power plants

Runoff from concrete/blacktop is warmer than natural surfaces

Cutting down trees eliminates shade Adding soil or dark debris from erosion attracts more

sunlight Erosion collects at bottom, making streams wider and

more shallow. Heats up easier.

Temperature (cont.)Most of the physical, biological and chemical

processes of water are related to temperatureEx: how much oxygen can be dissolved (cool

holds more)Higher temps make photosynthesis rates

increase > more plants > more plant death > more bacteria decomposing > less available oxygen for aquatic organisms

Fish get “stressed” and get sick easier when it’s warmer

High levels = bad, low levels = good

PhosphatesA group of compounds containing the

element phosphorous. Needed for plant and animal survival.

Comes from organic sources such as animal waste, human waste, vegetation, etc.

Can also come from detergentsFertilizers used for crops or lawns usually

contain phosphorous. Too much will cause overgrowth of plants called eutrophication

High levels = bad, low levels = good

NitratesNO3Needed by all plants and animals for survivalUsed as a fertilizer and can eventually lead to

eutrophicationSewage is the main sourceHigh levels = bad, low levels = good

TurbidityMeasure of how cloudy or clear water isCloudy water indicates erosionCloudy water attracts more sunlight and can

lead to thermal pollutionHigh levels = bad, low levels = good

Total SolidsSimilar to turbidity, but also includes

dissolved solidsHigh levels = bad, low levels = good