Water Quality Indicators
What are Water Quality Standards and Indicators Water quality and indicators are measurements of the substances in water beside water molecules that determine the healthiness of the water or its level of pollution
How do we treat our drinking water? Water from both public and private supplies often need some type of treatment to ensure it is safe. First filtration and coagulation, Second chlorination, Third aeration and additional treatment, Fourth testing samples
What is water pollution? Water pollution is the addition of any substance that has a negative effect on water or the living things that depend on the water. Pollutants are the substances that pollute the water.
What are the three main sources of water pollution? Three main sources of water pollution are human waste, industrial waste, and chemical runoff.
Why is this important? In addition to drinking water , we also eat fish on a regular basis. • Some of these fish have toxic chemicals stored in their bodies. • Over time the chemicals are stored in our body fat. • This can lead to birth defects and or cancer to name a few.
Water Quality Indicators • Turbidity • pH • Dissolved oxygen • Temperature • Nitrates (nutrients) , NH3, NO-2 • Bio-Indicators • Hardness - amount of calcium and magnesium
Turbidity refers to water clarity. • Ideal Level: low turbidity is clear water • High Level: unclear water /unhealthy water
Causes of increased Turbidity • Erosion causes loose soil toenter • the waterways Increased Algae blooms Waste drainage Agricultural and urban runoff
Result of High Turbidity Suspended sediment blocks sunlight to plants (photosynthesis) and reduces dissolved oxygen. Increased levels of sediments absorbs more thermal energy (Heat) making water warmer which lowers dissolved oxygen This causes fish and larvae to die -Fish kill
pH the acidity of water –presence of hydrogen ion (H+). The pH scale is zero to 14. 7 is neutral, below 7 is acidic, and above 7 is basic (or alkaline). High or low pH are signs of unhealthy water
pH Surface Freshwater: 6.5 - 8.0 • Swamp: 3.5 to 4.0 Salt Water: 7.5 to 8.4 • Most aquatic organisms exist within a pH range of 6.5 to 8.2.
Carbon dioxide reacts with water to form a weak acid called carbonic acid. pH tolerance for most aquatic life
Factors effecting pH levels Natural phenomenal such as algae blooms or man made events such as dumping in water or runoff
DISSOLVED OXYGEN Is the measure of gaseous oxygen (O2) dissolved in water. It’s a product of photosynthesis and diffusion. The warmer the water, the less oxygen it can hold.
DISSOLVED OXYGEN levels • Average Level: • 9.0 ppm • Must be 4-5 ppm to support diverse population of fish
Causes of Changes in Dissolved Oxygen • turbulent action – rapid waves • Solubility decreases with increasing temperature and water depth • Increase algae growth decreases DO • Increase plant growth increases DO
Resultsofchangesindissolvedoxygen When DO drops too low fish die. When DO is high, the water actually tastes better but can corrode water pipes.
TEMPERATURE Measure of the average kinetic energy (movement of particles in matter). The higher the temperature the lower the amount of dissolved oxygen. Most aquatic organisms live within a temperature range of +32º F (+0º C) to 90º F (32º C).
Levels of Temperature • Low: cannot be tolerated below 320F • High: only rough fish can tolerate temperatures above 970F
Cause of change in TEMPERATURE source of water time of year suspended sediment depth of water shade from shoreline vegetation Result of change in TEMPERATURE changes in temperature can make aquatic life susceptible to disease and at extreme levels can result in death
Rapid temperature change and temperature extremes can stress aquatic organisms. Temperature affects the oxygen-carrying capacity of water. 14 Dissolved Oxygen (ppm) 12 10 8 6 4 ____________________________________ Winter Summer As the water warms, the amount of dissolved oxygen decreases.
Nutrients –Nitrates and phosphates (Nitrogen and Phosphorous) Although nutrients are essential elements for plants and animals, their presence in excessive amounts cause undesirable conditions and negatively impact fish and other aquatic life.
Nitrates Nitrates: compound that contains the nitrogen based polyatomic ion NO3 (Ex: Sodium Nitrate)
Levels of Nitrates in drinking water Drinking Water Max: 10 mg/L Fish: Below 90 mg/L seems to have no effect on warm water fish
Causes of Nitrates in water Fertilizer runoff (farm and home) Manure pits Septic system leaks Animal waste Rain trapping car exhaust
Potential Consequences of Nutrient Overenrichment • Low Dissolved Oxygen • Nuisance Algal Growth • Harmful Algal Blooms • Fish & Shellfish Kills • Human Health Effects
Results of presence of nitrates: nitrates can increase the plant production and fish population resulting in overcrowding. If algae increases due to nitrates, the DO levels can decrease, killing fish. Nitrates are converted to nitrites in humans (can kill children)
Bio-Indicators • Organisms (macro-invertibrates) found living in water (they tend to remain in one place ) that have specific living conditions and are very sensitive to pollution. The presence or absence of particular organisms can tell us a lot about the quality of the body of water being studied.
Levels of Bio-indicators High Level of Variety: healthy water source Small Level of Variety: poor water source (indicator of high levels of pollution)
Causes of Changes in Bio-Indicator pollution that results in changes in pH, temperature, dissolved oxygen, or nitrate levels
Results of Few Varieties of bio-indicators the lack of a large number of different varieties of bio-indicators is indicative of pollution
Indicators of Water Quality Turbidity: measure of the degree to which water looses its transparency due to the presence of suspended particulates pH: the acidity of the water (presence of hydrogen ion) 07 is acidic 7 is neutral 714 is basic Dissolved Oxygen: the oxygen dissolved in the water Definition: Ideal Level: 1 NTU High Level: 5 NTU and above Surface Freshwater: 6.0 9.0 Swamps: as low as 4.3 Salt Water: 8.1 but as low as 7.7 Average Level: 9.0 ppm Must be 4-5 ppm to support diverse population of fish Levels: Causes of changes in dissolved oxygen: turbulent actions waves, rapids), water depth, and plant growth Causes of increased turbidity: increased levels of phytoplankton, sediment from erosion, re-suspended sediments from the bottom (stirred by bottom dwellers), waste discharge, algae growth, and urban runoff Causes of changes in pH: natural conditions (especially in swamps), dumping of waste (batteries) and farm runoff (lime) Causes: Results of high turbidity: high turbidity increases the absorption of sunlight thus making the water warmer. Warmer water has lower levels of dissolved oxygen causing fish and larvae to die. Results of changes in pH: a change in pH by 2 units results in a water system having 100 times a difference in acidity. Most aquatic life cannot withstand water outside of the optimum pH thus resulting in death. Results of changes in dissolved oxygen: When DO drops too low fish die. When DO is high, the water actually tastes better but can corrode water pipes. Results:
Indicators of Water Quality Temperature: measure of average kinetic energy Nitrates: compound that contains the nitrogen based polyatomic ion NO3 (Ex: Sodium Nitrate) Bio-indicators: macroinvertibrates found living in water (they tend to remain in one place) that are sensitive to pollution Definition: Low: cannot be tolerated below 320F High: only rough fish can tolerate temperatures above 970F Drinking Water Max: 10 mg/L Fish: Below 90 mg/L seems to have no effect on warm water fish High Level of Variety: healthy water source Small Level of Variety: poor water source (indicator of high levels of pollution) Levels: Causes of change in temperature: source of water, time of year, suspended sediment, depth of water, and shade from shoreline vegetation Causes of nitrates: fertilizer runoff (both farm and home), manure pits, leaks in septic systems, animal waste, and rain trapping car exhaust Causes of changes in bio-indicators: pollution that results in changes in pH, temperature, dissolved oxygen, or nitrate levels Causes: Results of changes in temperature: changes in temperature can make aquatic life susceptible to disease and at extreme levels can result in death Results of presence of nitrates: nitrates can increase the plant production and fish population resulting in overcrowding. If algae increases due to nitrates, the DO levels can decrease, killing fish. Nitrates are converted to nitrites in humans (can kill children) Results of few varieties of bio-indicators present: the lack of a large number of different varieties of bio-indicators is indicative of pollution Results:
Indicators of Water Quality Turbidity: pH: Dissolved Oxygen: Definition: Ideal Level: High Level: Surface Freshwater: Swamps: Salt Water: Average Level: Levels: Causes of changes in dissolved oxygen: Causes of increased turbidity: Causes of changes in pH: Causes: Results of high turbidity. Results of changes in pH: Results of changes in dissolved oxygen: Results:
Indicators of Water Quality Temperature: Nitrates: Bio-indicators: Definition: Low: High: Drinking Water Max: Fish: High Level of Variety Small Level of Variety: Levels: Causes of change in temperature: Causes of nitrates: Causes of changes in bio-indicators: Causes: Results of changes in temperature: Results of presence of nitrates: Results of few varieties of bio-indicators present: Results: