Water quality

color

• when water looksmilky white water or hazy? This is almost always caused by air in the water.
• dissolved substances is tannin, which is caused by organic matter coming from leaves, roots, and plant remains .
• Most of the color in water you see around you comes from suspended material,
• Suspended material in water bodies may be a result of natural causes and/or human activity. Transparent water with a low accumulation of dissolved materials appears blue. Dissolved organic matter, such as humus, peat or decaying plant matter, can produce a yellow or brown color.

dissovled oxygen

• The U.S. Geological Survey (USGS) has been measuring water for decades. Millions of measurements and analyses have been made. Some measurements, such as temperature, pH, and specific conductance are taken almost every time water is sampled and investigated, no matter where in the U.S. the water is being studied.
• The oxygen dissolved in lakes, rivers, and oceans is crucial for the organisms and creatures living in it. As the amount of dissolved oxygen drops below normal levels in water bodies, the water quality is harmed and creatures begin to die off.
• Although water molecules contain an oxygen atom, this oxygen is not what is needed by aquatic organisms living in natural waters. A small amount of oxygen, up to about ten molecules of oxygen per million of water, is actually dissolved in water.
• Rapidly moving water, such as in a mountain stream or large river, tends to contain a lot of dissolved oxygen, whereas stagnant water contains less.
• when dissolved-oxygen levels are at a seasonal low. Water near the surface of the lake the epilimnion is too warm for them, while water near the bottom of the hypolimnion has too little oxygen. Conditions may become especially serious during a period of hot, calm weather, resulting in the loss of many fish.
• Dissolved oxygen in surface water is used by all forms of aquatic life; therefore, this constituent typically is measured to assess the "health" of lakes and streams. Oxygen enters a stream from the atmosphere and from groundwater discharge
• Field and lab meters to measure dissolved oxygen have been around for a long time.

ph

• pH is a important measurement of water. Not only does the pH of a stream affect organisms living in the water, but changing pH in a stream can be an indicator of increasing pollution or some other environmental factor.
• pH is a measure of how acidic/basic water is. The range goes from 0 - 14, with 7 being neutral. pHs of less than 7 indicate acidity, whereas a pH of greater than 7 indicates a base.
• The pH of water determines the solubility (amount that can be dissolved in the water) and biological availability (amount that can be utilized by aquatic life) of chemical constituents such as nutrients (phosphorus, nitrogen, and carbon) and heavy metals (lead, copper, cadmium, etc.).
• Ph's less than 7 are acidic while pHs greater than 7 are alkaline (basic). Normal rainfall has a pH of about 5.6—slightly acidic due to carbon dioxide gas from the atmosphere.

turbidItY

• Turbidity is the measure of relative clarity of a liquid. It is an optical characteristic of water and is an expression of the amount of light that is scattered by material in the water when a light is shined through the water sample.
• Turbidity makes water cloudy or opaque.
• High concentrations of particulate matter affect light penetration and productivity, recreational values, and habitat quality, and cause lakes to fill in faster.
• Excessive turbidity, or cloudiness, in drinking water is aesthetically unappealing, and may also represent a health concern. Turbidity can provide food and shelter for pathogens. If not removed, turbidity can promote regrowth of pathogens in the distribution system, leading to waterborne disease outbreaks, which have caused significant cases of gastroenteritis throughout the United States and the world. Although turbidity is not a direct indicator of health risk, numerous studies show a strong relationship between removal of turbidity and removal of protozoa.

SeDiMeNT SuSpEnDeD SeDiMeNt

• Fast-moving water can pick up, suspend, and move larger particles more easily than slow-moving waters. This is why rivers are more muddy-looking during storms—they are carrying a LOT more sediment than they carry during a low-flow period.
• If you scoop up some muddy river water in a glass you are viewing the suspended sediment in the water. If you leave your glass in a quiet spot for a while the sediment will start to settle to the bottom of the glass. The same thing happens in rivers in spots where the water is not moving so quickly—much of the suspended sediment falls to the stream bed to become bottom sediment yes, mud.
• On the positive side, sediment deposited on the banks and flood plains of a river is often mineral-rich and makes excellent farmland. The fertile floodplains of the Nile in Egypt and of the Mississippi River in the United States have flooding rivers to thank fo rtheir excellent soils.
• Sediment in rivers can also shorten the lifespan of dams and reservoirs. When a river is dammed and a reservoir is created, the sediments that used to flow along with the relatively fast-moving river water are, instead, deposited in the reservoir.
• The U.S. Geological Survey (USGS) does quite a lot of work across the country measuring how much sediment is transported by streams.
• Streamflow is measured by making a discharge measurement. Suspended sediment, the kind of sediment that is moved in the water itself, is measured by collecting bottles of water and sending them to a lab to determine the concentration.

HARDNESS

• The amount of dissolved calcium and magnesium in water determines its "hardness." Water hardness varies throughout the United States. If you live in an area where the water is "soft," then you may never have even heard of water hardness.

TEMPerATURE

• The U.S. Geological Survey (USGS) has been measuring how much water is flowing in rivers, determining the water levels in groundwater, and collecting water samples to describe what the quality of those waters are for over a century.
• Temperature exerts a major influence on biological activity and growth. Temperature governs the kinds of organisms that can live in rivers and lakes. Fish, insects, zooplankton, phytoplankton, and other aquatic species all have a preferred temperature range.
• Temperature is also important because of its influence on water chemistry. The rate of chemical reactions generally increases at higher temperature.
• You might not think that water temperature is considered an important water-quality measurement. After all, temperature is not a chemical and it doesn't have physical properties.
• Parking lots and roads, which are examples of impervious surfaces, where water runs off into local streams instead of soaking into the ground, as in natural environments, act as "fast lanes" for rainfall to make its way into streams.
• Along with the heat, runoff from parking lots can contain pollutants, such as leaking motor oil, hydrocarbons from exhaust, leftover fertilizer, and normal trash.
• Temperature is also important in lakes and reservoirs. It is related to the dissolvedoxygen concentration in water, which is very important to all aquatic life.
• The way that temperatures vary in lakes over seasons depends on where they are located.

Sources

• www.wkipedia.com
• www.tudwater.com
• www.britannica.com
• water-quality-information-sheets-updated1.pdf