Water clarity in lakes and reservoirs

The National Resources Defense Council asserts that an increasing number of Americans are open to the elements of tap water contamination at levels over those set by U.S. Environmental Protection Agency standards. According to a survey conducted in 1999 by the Water Quality Association, around sixty percent of adults consider that the quality of water they are drinking affects their health, and about three-quarters have distresses regarding the quality of their household water supply.Contrary to popular belief, crystal clear water is not necessarily the true measure to which all lakes should be compared. It is also not entirely true that lakes with low levels of visibility and transparency are due to pollution or degradation in water. Another common belief is that clearer water is safer to swim in or to drink which is also not entirely true. On the contrary, clear water may likely be just as filled with pathogens, bacteria and other contaminants that could be harmful to human health as cloudy water is generally perceived to be.The water treatment experts at Amway Corporation laid down suggestions regarding the following tests and resources for beneficiaries who would want to know if their drinking water is safe: 1) Look at it. Water should look clear and have no floating particles. 2) Smell it. Water should be free of unpleasant odors. 3) Taste it. Water that tastes unusual should be tested. 4) Contact the local health department to have the water tested if it looks, smells, or tastes unusual. 5) Request a copy of the Consumer Confidence Report from the community water supplier. (Journal of Environmental Health, 2000)
This paper covers issues related to water clarity, what it is, how it is measured, what causes clarity problems and how to tackle such problems

Literature Review
Water clarity can be defined as a measure of the amount of sunlight that passes into the water and reaches the leaves of underwater grasses. Water clarity can be termed as dependant on three factors. proper water chemistry, sufficient and effective filtration, and good circulation. (Pool Chlor, 2006)
Water chemistry relates to the alkalinity levels within water. In case these levels are out of balance, the result can be in the form of turbidity. Turbidity is the cloudiness caused in water because of suspended or dissolved material. It can also be said that insufficient chlorine in the water, small, perched algae and bacteria can result in turbid water. (Pool Chlor, 2006)
How to Measure Water Clarity
Measurement of water clarity is quite helpful in monitoring any changes in water componential balances and enables communication for these changes to concerned persons. One common method to measure water clarity is by the use of a disk, more commonly known as the Secchi disk.
A Secchi disk is by far the simplest, standardized instrument used to determine water clarity. It is an 8-inch (20 centimeter) diameter, black and white disk attached to a dowel rod, PVC pipe, rope or chain. Inch or centimeter intervals are marked on the rod, pipe, rope or chain with permanent ink, paint or clamps. Ideal clarity for aquatic plant production is generally greater than 36-inch visibility (Porter, 2002)
The measurements taken by the use of Secchi disk are likely to be quicker through the use of rod or pipe as against a rope of chain, except when water is very clear, in which case, an extremely long rod or pipe may be required. When measuring water clarity, the date of measurement, the measurement itself and the source of turbidity, usually sediment (brownish muddy color), phytoplankton (greenish color), humic stain (tea color from decaying leaves or plants) or some combination of these, should be recorded for reference purposes. Secchi disk measurements are mainly precise when taken on comparatively still, sunny days, preferably during the middle of the day from a dock or some sort of floating mechanism such as a boat, float tube, air mattress or life preserver. (Porter, 2002)