Lesson 18: Water Quality

• Water pollution: Water that is contaminated with chemicals
• Refers to the chemical, physical, biological, and radiological characteristics of water - Water quality
• Water Quality Parameters:

  Chemical:

  Dissolved Oxygen, Nitrates, Total Phosphates, pH, Hardness, Total Dissolved Solids
• Water Quality Parameters

  Physical:

  Temperature, Turbidity, Conductivity, Color, Odor
• Fecal Coliform Bacteria - Biological Parameter
• Dissolved Oxygen:

  -The amount of free oxygen dissolved in water

  -directly affected by temperature and pressure
• Hypoxia - low dissolved oxygen levels in water

  Anoxia - the absence of oxygen; dissolved oxygen levels in the water below 0.5 ppm
• pH - Measurement of acidity or alkalinity of water
• Nitrates - naturally occurring forms of nitrogen
• Total Phosphates:

  organic = decay of organism

  inorganic = laundry and household materials
• Eutrophication - excessive nutrient enrichment of water, leading to algal blooms and ecological balance
• 6 - 1= acidic

  8-14 = alkaline

  7 = netural
• Hardness- measure of concentration of dissolved minerals: calcium, magnesium, strontium, iron, and manganese
• Hard water - rich in mineral content
• Total Dissolved Solids (TDS) - amount of material dissolved in water
• Temperature - the measure of hotness or coldness

  • affects the biological and chemical processes of an aquatic organism
  • reduces capacity to hold dissolved oxygen
• Turbidity - amount of light scattered in water as a result of suspended particles (clarity)
• Relative turbidity can be measured with a Secchi Disk.
• Conductivity - the ability of water to conduct electricity
• Color - indicates the existence of suspended particles and organic matter in the water
• Apparent color - the color of the water sample

  True color - the color of the filtered version of the water sample
• Color: Cause:

  • blue low level of dissolved materials
  • yellow/brown a lot of dissolved organic material
  • red certain algae
  • green presence of phytoplankton and other algae
  • mixture of colors soil runoff
• Biological Parameter:

  Fecal Coliform: harmful bacteria causing diseases like severe diarrhea, cholera, leptospirosis, and kidney damage

  Total Coliform - a group of rod-shape bacteria

  E. Coli - a single species of fecal coliform
• Bioindicator - organisms sensitive to environmental changes and can indicate when pollution is present