What is the definition of a pollutant and how is “water pollution” defined.
Pollutant: Any substance that does not belong in the natural system and disrupts the natural balance Water pollution: Degradation of water quality in a manner that disrupts/prevents its intended or original use.
Know what an MCL, and know what a secondary MCL is.
MCL=Maximum Contaminant Level – The highest concentration of a pollutant allowed in drinking water by law – Concentration above which adverse health affects are believed to occur Secondary MCL – Concentration of a pollutant above which the water is unpleasant in odor or taste – May not be hazardous to your health at that level
What is the term for the idea that small doses of toxins can be beneficial for an organism?
Know the difference between point source and non-point source pollution and give examples of each.
• Point-source: any source of a pollutant that you can point to – Smokestack /industrial effluent – Oil Tanker spill • Non point source: area-wide discharge – Atmospheric deposition – Farm field runoff
Besides water itself, what are the three essential ingredients for an aquatic ecosystem?
Light, oxygen, and nutrients
What are the main differences between the limnetic, metalimnion, and hypolimnion zones of a lake in terms of its abiotic factors?
Limnetic – top, high light more photosynthesis, warmer, less dense, thinner, more DO Metalimnion – middle Hypolimnion – bottom, darker, colder, denser, less DO
Know how the photic/euphotic zone is defined and what controls its depth.
• Photic or Euphotic Zone –Depth to which adequate light for photosynthesis can penetrate. –Controlled by amount of particulate matter (sediment, plankton, and organic debris) in the water column.
Know the definition of and the influences of DO and BOD and what level they tend to take on in polluted waters.
Dissolved Oxygen – DO – Amount of oxygen available in the water. – Oxygen in water maintained by • exchange with the atmosphere • Production of oxygen by photosynthetic organisms (vegetation) • Circulation of water (essential to maintain oxygen levels in deeper portions) – Oxygen consumed by decaying organic matter and oxygen breathing organism. • Biochemical Oxygen Demand –Measure of the amount of oxygen required for the aerobic degradation of organic and non-organic compounds in the water. –Highly polluted waters have very high BOD implying that oxygen is consumed rapidly.
Know how the relative levels of DO and BOD respond downstream from an organic pollution point source. How could you measure to determine the level of pollution for an organic pollutant?
Polluted: high BOD low DO Measure DO and put in an opaque jar, in a room at 70 degrees then check DO
Be able to describe an oligotrophic and eutrophic body of water and how an oligotrophic becomes eutrophic.
Oligotrophic Condition • Under normal conditions (preanthropogenic perturbation) most surface water are: 1. low in nutrients (particularly phosphorous and nitrogen) 2. well oxygenated 3. have few particulates in the water column
Eutrophic Condition • Caused by the excess nutrient and sediments (sequence of event outlined in prior slides). • Major cause is the use of fertilizers, excess erosion from farmland or nutrient rich soils (deforestation), and disposal of phosphate bearing compounds (many detergents) through sewer systems.
What can be done to reduce eutrophic conditions?
• Reduce nutrients and sediments • Chemical Treatment • Aeration • Harvesting plants • Dredging
What type of water pollution causes the most stream pollution in the U.S. and what is the major source of this pollution type?
Sediment pollution from agriculture
What is the most serious form of pollution for most Rocky Mountain streams like Clear Creek, and what is a good remediation technique for this problem?
Mining Pollution Artificial Wetland Construction
What is the term for the increased concentration of a toxin as it is passed along a biological food chain?
Where is the “Dead Zone” and what type of pollution is it?
Coast of Louisiana and Mexico Farmers, sediment, pesticides
What is the largest source of groundwater contamination in the U.S.?
Leaky underground gas storage tanks
Know the difference between a DNAPL and an LNAPL, which one is more mobile, and which one is harder to clean up.
•DNAPL: harder to clean up –Dense Non-Aqueous Phase Liquid •LNAPL: mobile –Light Non-Aqueous Phase Liquid