Basics Water quality – measurements and standards for safe drinking water and water that is conducive with a healthy ecosystem, Affects the number and types of organisms that can live in an aquatic ecosystem Can be determined by measuring various properties

Dissolved Oxygen (DO) Different organisms can tolerate different levels of dissolved oxygen Trout – at least 6.5 mg per liter Catfish – 2.5 mg/L Cooler water can hold more dissolved oxygen than warmer water Bacteria use up oxygen as they decompose dead algae and decrease dissolved oxygen

pH pH scale ranges from 0 (most acidic) to 14 (most basic). Typical pH for a stream/lake is between 7 and 8 Typical pH for the ocean is 8.1 – 8.3 Trout require a pH between 7 and 9; tolerable range for most fish is 5 – 9; upper limit for good fishing waters is 8.7 Water becomes acidic due to acid rain, pollution, etc.

Hard/Soft Hard water is due to calcium carbonate and magnesium carbonate These minerals are picked up from rocks as the water flows through the ground Hard water can leave spots and films on glasses and clog pipes Can be bad for appliances but does not pose a health hazard 0 – 60 soft water; 61 – 120 moderately hard water; 121 – 180 hard water; 181 and up very hard water (in mg/L of calcium carbonate)

Coliform Bacteria Coliform bacteria are organisms that are present in the environment and in the feces of all warm-blooded animals and humans 3 different groups: total coliform, fecal coliform, E. coli Total Coliform – common, harmless, come from environmental source, fecal contamination not likely Fecal Coliform - Indicates recent fecal contamination E. coli – indicates recent fecal contamination; boil water advisory

Carbon Dioxide When green plants burn the food they make through photosynthesis, they release carbon dioxide This happens a lot more at night and on cloudy days because photosynthesis only occurs in the presence of light Most fish are able to tolerate a carbon dioxide level of 20 mg/L without bad effects

Carbon Dioxide Carbon dioxide in water creates carbonic acid, a weak acid If water is already alkaline (high pH) this acid will neutralize it but if water is already acidic it will only become more acidic At 1 – 6 mg/L CO 2 fish will avoid waters; at greater than 12 mg/L CO 2 few fresh fish can survive for long periods of time; at 30 mg/L CO 2 most sensitive fish die immediately; 45 mg/L CO 2 is the maximum limit for trout; above 50 mg/L CO 2 trout eggs won’t hatch

Phosphates Contained in fertilizers and laundry detergent; when it rains phosphates wash from farm soil into waterways Stimulate growth of plankton and water plants Too much phosphate and water plants grow wildly and choke out the waterway (remove all oxygen so that there is none left for fish – eutrophication) 0.01 – 0.03 mg/L is the amount of phosphate in most uncontaminated lakes; mg/L will accelerate the eutrophication process; 0.1 mg/L is the recommended maximum for rivers and streams

Water Quality Testing We will be testing 2 locations at a time beginning with… One test will be assigned to each group That group is to perform the assigned test on both water samples and record their results on the board Each group should record class data and answer analysis questions

Water Quality Testing Dissolved Oxygen – Nick Price, Dylan, Abby BE VERY CAREFUL Coliform Bacteria & pH – Stevie, Dillon, Santos Phosphates – Eva, Garrett Carbon Dioxide – Lindsay, Austin, Colin Hardness – JD, Stephen