 Water Pollution: Contaminants and Testing Procedures

What is Water Pollution?  Water pollution - any change in water quality that harms humans or other living organisms or makes water unsuitable for desired uses.

Application: “The Mistake by the River” Cuyahoga River in the Fall ©Tom Jones hibits/items/show/1328

A Burning River? The Plain Dealer File kits/pollution/02history.html elated

What are the sources of water pollution?  Point Sources  Can be traced back to one particular origin  Industrial Plants (Power, Chemical, Waste Treatment)  Drain pipes, Sewer Lines, Underground Mines  Nonpoint Sources  Tend to be widespread with many regions contributing to the water pollution.  Agricultural Runoff  Stormwater Runoff (Roads and Parking Lots) Fig , p. 260

Types of Contaminants  Pathogens – Wastes from Humans and Animals  Plant Nutrients – Nitrates & Phosphates  Organics – Oil, Gasoline, Plastics, & Pesticides  Inorganics – Salt, Metal Compounds  Sediment – Total Suspended Solids  Heavy Metals  Thermal

Most Commonly Tested Parameters  Temperature  pH  Nitrates  Phosphates  Dissolved Oxygen  Turbidity  Specific Conductivity  Total Dissolved Solids  Total Suspended Solids

Water Quality Index Water Quality Index (WQI) is a measure of how polluted a body of water actually is. It can take many different parameters into consideration. (6 parameters are typically used to calculate WQI) Utilizes a weighting factor to differentiate between important parameters and less-important parameters. Q-Values are numbers that are given in a table and correlate to the level of each parameter to characterize each on a scale of (100 being best)

Water Quality Index

Test ResultsQ-Value Q-Value X Weighting Factor Add all Subtotals

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen Nitrate Phosphate pH Totals

Water Quality Index Dissolved Oxygen: % saturation = 90 1.In the DO column find the value equal to Write down the Q-Value to the right of that number (Q-value = 95).

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen X 0.3 = 28.5 Nitrate Phosphate pH Totals

Water Quality Index Nitrate: 1.75 mg/L 1. In the Nitrate-N Column find the values closest to This number falls between 1.5 and 2 in this column 2. Since there is no value matching exactly to 1.75, estimate the Q-value between 92 and 90 (Q-value = 91).

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen Nitrate X 0.2 = 18.2 Phosphate pH Totals

Water Quality Index Phosphate: 0.3 mg/L

Water Quality Index Phosphate: 0.3 mg/L 1. In the Total Phosphate column find the value equal to 0.3 (similar to the dissolved oxygen). 2. Write down the Q-Value to the right of that number (Q-value = 90).

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen Nitrate Phosphate X 0.2 = 18.0 pH Totals

Water Quality Index pH: In the pH column find the values closest to This number falls between 6 and Since there is no value matching exactly to 6.70, estimate the Q-value between 55 and 90 (Q-value = 81).

Water Quality Index pH 6 7 Q-value 55 90

Water Quality Index pH Q-value (55+90) / 2 = 72.5

Water Quality Index pH Q-value ( ) / 2 = 81.25

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen Nitrate Phosphate pH X 0.3 = 24.3 Totals

Water Quality Index Parameter Tested Value Q-Value Weighting Factor Calculation Dissolved Oxygen Nitrate Phosphate pH Totals = 89.0

Water Quality Index Water Quality Percentages Excellent90-100% Good70-90% Medium50-70% Bad25-50% Very Bad0-25%