Download presentation
Presentation is loading. Please wait.
Published byRose Todd Modified over 9 years ago
1
The Blue Planet The Blue Planet Indicators of Water Quality
2
Water quality refers to the chemical, physical, biological, and radiological characteristics of water. It is a measure of the condition of water relative to the requirements of one or more biotic species and or to any human need or purpose.
3
Most dissolved substances found in water are measured in parts per million (ppm) or even smaller amounts. This means that for every one million parts (units) of water there is a certain number of parts of the substance.
4
It is also expressed as milligrams per liter. There are 1000 milliliters in a liter and 1000 milligrams in a gram. For example, a dissolved oxygen reading of 8 ppm means there are 8 milligrams of oxygen for every 1000 milliliters of water. 8/1000 gram 1000 milliliters = 8/1,000,000 (8 parts per million)
5
A measure of the degree to which water looses its transparency due to the presence of suspended particulates Ideal Level: 1 NTU High Level: 5 NTU and above Causes: –Increased levels of phytoplankton –Algae growth –Urban Runoff Results: –Increases absorption of sunlight makes water warmer –Lowers levels of dissolved oxygen –As the suspended particles settle, the benthic organisms are smothered.
6
Turbid WaterClear Water
7
The acidity of the water (presence of the hydrogen ion [H+]) –0 7 is acidic –7 is neutral –7 14 is basic Surface freshwater: 6.0- 9.0 Swamps: as low as 4.3 Salt Water: 8.1 but as low as 7.7 Causes: –Natural conditions (especially in swamps) –Dumping of waste (batteries) –Farm runoff (lime) Results –A change in pH by 2 units results in a water system having 100x a difference in acidity –Most aquatic life can’t withstand water outside the optimum pH resulting in death
9
Alkalinity refers to the water’s ability to neutralize acids. Alkalinity is produced by minerals such as limestone Limestone is a type of ocean sediment composed of calcium carbonate. Water with low alkalinity is usually acidic.
10
Ammonia is produced by the decay of organic matter and animal waste. It is toxic to most aquatic life, especially at high pH. Bacteria readily convert ammonia to nitrate. Ammonia is a form of nitrogen and part of the Nitrogen Cycle.
11
Oxygen dissolved in the water Average Level: 9.0 ppm Warmer water = less oxygen –Must be 4-5 ppm to support diverse population of fish –Cold water rarely has more than 15 ppm. Summer is often a time of oxygen stress for aquatic organisms. Causes –Turbulent Actions (waves, rapids) –Water depth –Plant growth Results –When DO drops too low fish die –When DO is high, water actually tastes better but can corrode water pipes
13
Measure of average kinetic energy Low: cannot be tolerated below 32°F High: only rough fish can tolerate temperatures above 97°F Causes –Source of water –Time of year –Suspended sediment –Depth of water –Shade from shoreline vegetation Results –Changes make aquatic life susceptible to diseases –At extreme levels can result in death
14
Rapid temperate 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 ____________________________________ WinterSummer As the water warms, the amount of dissolved oxygen decreases
15
Compound that contains the nitrogen based polyatomic ion NO 3 (Ex. Sodium Nitrate) Nitrates are water soluble and can move easily from surface to groundwater. Drinking Water Max: –10 mg/L Fish: –Below 90 mg/L seems to have no effect on warm water fish Causes –Fertilizer runoff –Manure pits –Rain trapping car exhaust Results –Nitrates can increase the plant production and algal blooms –If algae increases due to nitrates, the DO levels can decrease, killing fish –Convert to nitrites can kill children
16
Under normal conditions, the nitrogen cycle keeps the amount of available nitrogen in balance with the demands. However, excessive use of fertilizers and nutrient rich sewage release have created a surplus of nitrate. The result is EUTROPHICATION from excess algae and bacteria with reduced dissolved oxygen.
19
Phosphorus is a naturally occurring element. Phosphates enter waterways from human and animal waste, phosphorus rich bedrock, laundry, cleaning, industrial effluents, and fertilizer runoff.
20
High levels of phosphates can overstimulate the growth of aquatic plants and algae. This will cause high D.O. consumption and death to fish and other aquatic organisms.
21
Animals found living in water that are sensitive to pollution High Variety healthy water source Low Variety Poor water source (high levels of pollution) Causes –Pollution results in changes to pH, temperature, dissolved oxygen, or nitrate levels Results –Lack of varied animals indicative of pollution
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.