Physical Characteristics of Water

The physical characteristics of water are perhaps the oldest set of factors that people have used to assess water quality.  For the most part, these features can be crudely evaluated simply by using our five senses, although special instruments are used to accurately measure them.  The five most commonly considered physical characteristics are temperature, taste, colour, odour and turbidity.

Biological Characteristics of Water

The biological characteristics of a water body refer to a variety of living organisms that can be found in water.  These include microscopic viruses, bacteria and protozoans as well as phytoplankton (microscopic algae), zooplankton (tiny water animals), insects, worms, large plants and fish.  Of significance to humans is that disease-causing viruses and bacteria can be present and transported in water.  Many of these pathogens can enter the water system in sewage (human and animal waste).

 

Chemical Characteristics of Water

The chemical characteristics of water are numerous.  Every substance that dissolves in water can be called a chemical water quality characteristic.  This would include gases (like oxygen and carbon dioxide), salts, substances that stimulate plant growth (such as nitrates and phosphorus) and other naturally occurring and man-made substances.  Some naturally occurring chemicals such as iron and manganese which are often present in groundwater, can be responsible for staining clothes and plumbing fixtures.  Other chemicals, such as Dioxins and Furans are tested in specific sites where their presence is known to occur.  There are hundreds of other chemicals that might be tested or monitored, but only a few are done routinely because of the cost and effort involved in such testing.

 

The amount of dissolved oxygen (DO) available in water is a very important factor in determining the types of organisms that can survive.  Trout, for example, cannot survive if the dissolved oxygen concentrations are less than 5.5 milligrams/litre.  Dissolved oxygen is one of the most standard water chemistry tests.  Other common tests include determining pH and phosphorous values.

 

Changes in Water Quality

Water quality changes can be the result of naturally occurring events or as a result of human activity.  When water vapour in the air condenses to form rain, it may pick up tiny air-borne impurities that become part of the rain drop.  As rainwater seeps through rocks or soil, it may dissolve minerals or other water soluble substances that give the water some of its chemical characteristics.  Flowing water picks up many objects and carries sediments.  Water quality also changes with the seasons as temperature, volume of flow, turbidity and biological activity respond to the seasonal differences.

 

Apart from the natural changes, Humans are responsible for a great many changes to the quality of water.  These changes can be a result of industrial, agricultural, municipal or recreational activities.

 

 

Do We Need To Conserve Water? 

Conservation is simply the planned protection, improvement, and wise use of natural resources.  Water conservation means controlling, protecting, managing and planning for the wise use of our water resources.  In Alberta, we have to look at why we want to conserve water.  Realistically, we don't have the same water shortage problems that other parts of the world experience.  Except for agriculture, the water that most of us use is simply borrowed.  A large percentage is treated and returned to the same source from which it came.  Do we need to conserve water just because it sounds like a good idea?  Or are there other reasons that make water conservation a realistic practical option?  

Economically speaking, it makes sense.  Not only do we have to think about using our existing supplies wisely we also have to consider costs.  Water is getting more expensive.  It's costing us more to supply, to treat, to dispose of, and to treat again.  The energy required to meet these demands is enormous and also carries with it an environmental price tag.  Just because the water is available does not mean that we have to use it with such reckless abandon.  Studies have shown that our household water use could be reduced by 50% without significantly changing our lifestyle.

 

Water conservation makes sense and it saves money for individual families in rural and urban areas, for industries, and communities.  Consider the case of a leaking faucet in your home.  The drip is irritating but you might assume it really isn't wasting much water.  Think again.  A dripping faucet leaking one drop per second can amount to 25 litres per day and to more than 10 000 litres per year.  That is enough water to wash more than 65 loads of clothing have 140 five minute showers, or enough to wash 40 cars.  Imagine one leaking faucet in every home near you and it's easy to see why fixing a leak quickly makes sense and saves cents.  Another example is that a small toilet leak can cost you $30.00 per month.  A simple repair could save you $360.00 per year!

 

Water Conservation - What Can You Do? 

There are a number of things you can do to conserve water in your home.  By doing so, you will save money on water and utility bills, help to reduce taxes, save energy, and reduce environmental impacts.  There are four basic ways to conserve water:

 

Economize:  Avoid using water unnecessarily and try to become more aware of how much water you are using.  Think of ways that you can reduce.

 

Repair:  Even small leaks can add up to a lot of water.  Most repairs are very simple and can save you a great deal of money in the long term.

 

Install Water Saving Devices: Many inexpensive products are on the market, which can be used to reduce the amount of water you use.  When buying new water fixtures, look for products that have been designed to use less water.

 

Re-use Water:  Water used for one purpose can still be suitable for another use?  For example, water used for cleaning vegetables can be used for watering plants.  Consider installing a rain barrel to collect water to use on your garden.

If you live in the country or on a farm, here are some additional ideas you might want to consider:

use types and varieties of crops best suited to local growing conditions

increase the humus content of soil by adding manure or straw or using forage crops in rotation to improve the ability of the soil to store moisture

catch rain water in rain barrels or cisterns and use this water on your lawn and garden

We all use water and it is important for us to remember that someone else has to use our water when we are finished with it.  Water conservation, the wise use of our water resources, is one way we can demonstrate that we are willing to help take responsibility for our natural environment.

Water conservation is the right choice to make, for now and for the future.

 

Water Pollution

Water pollution occurs when the quality of the water is altered in a way that affects either the organisms living in the water or the suitability of the water for uses such as swimming, stock watering, and drinking.

 

Organic Pollutants are usually produced by biological activity, especially during the decay of once-living materials.  Sources include runoff from barnyards and dumps, improper disposal of human wastes, and dead plants and animals.  Other sources include gasoline and oil from automobiles and trucks.  A new class of organic pollutants has been manufactured by man.  Man-made organic compounds that do not occur naturally are another source of organic pollutants. 

 

The insecticide, DDT is one of these.  Because DDT is not easily broken down by natural processes, it lasts for a long time in the environment.

 

Inorganic pollutants are the minerals and salts dissolved in water and the silt suspended in water as a direct result of the actions of man.  Many of these substances are found naturally in water.  The actions of man can increase the amounts to where it is not possible to drink the water safely.  Sources include fertilizer runoff from farm fields, sand and salt from our roads, erosion from fields and banks, ore mining, burning fossil fuels and industrial wastes.  Metals like mercury, lead, arsenic and cadmium are also inorganic pollutants.  They can create serious health problems at very low concentrations.  Sources include industrial wastes, improper disposal of car and truck batteries, and household products like nickel-cadmium batteries and small watch and transistor batteries.

Biological pollutants are the bacteria, viruses, protozoans and worms which are carried by water from one host to another.  Algae can also be a biological pollutant when they occur in large numbers.  Some of these pollutants can cause diseases in humans and animals.  "Beaver Fever", or Giardiasis, is a well-known disease.  Although it is called Beaver Fever, it is really a human disease caused by a single-celled parasite which lives in the intestines of humans and many other animals.  When the parasites reproduce, they form cysts which pass out of the intestines with wastes.  These cysts can live for two months in water.  If you drink water contaminated with these cysts, you can become ill.  The giardiasis parasite is removed from our water by the filters in the water treatment plant.  The disease is mainly a problem in wilderness areas where people tend to assume that untreated water is safe to drink or in communities that do not have effective filtration systems.  Sources of biological pollution include treated and untreated human sewage, organic pollution, and animal waste.

Water Quality

Water is a very important and necessary natural resource that all living things require.  The fluids and food we consume provides us with the three litres of water our bodies require each day.  Besides drinking water, each Albertan uses an average of 300 litres, everyday.  This water is used for bathing, washing dishes and clothes, toilet flushing and lawn watering.  Even more water is used per person if we include all the water required to manufacture the many products we purchase.

 

In Canada, we have vast water supplies that were once the lifeline of early Canadians.  Much of our history is based on the ways in which we used this natural resource.  Today, these same lakes and rivers are being used in many other ways.  Some of these activities have stressed the natural cleansing abilities of these ecosystems to the point where there have been dramatic changes in the quality of water.  The Great Lakes for example, have lost several different types of fish, the result of the 360 different chemicals which have been identified in these waters.  Even so, our water systems have a remarkable ability to recover and through positive action by Government, industry and individual citizens, a concerted effort can reverse much of the environmental damage.

For most Canadians access to good quality drinking water is not a problem and is often taken for granted.  This is not the case in many other parts of the world.  Each day, 30 000 deaths are attributed to contaminated water supplies.  Many of these deaths are children under the age of five.  This poor water quality is often the result of inadequate sanitation where drinking water supplies are not separate from other human activities.

 

High quality drinking water has dissolved gases and minerals that add to the flavour of the water as well as providing us with some of the important minerals that we need to survive.  A fish living in an Alberta lake would not enjoy living in pure water, or even tap water.  To a fish, high quality water would be defined differently.  Fish require water with tiny organisms floating in it, a bit of algae, and other characteristics that make the water an important part of a healthy ecosystem.  Yet, you probably would not want to drink it!  Water quality really is a matter of perspective.  

 

Water quality features can be placed into one of three categories: physical, biological, or chemical.  When scientists describe a sample of water, they take into account all three of these characteristics.

 

Water and the Effects on Living Things

As humans, we often forget that we are sharing this natural resource with many other organisms.  Many of our activities can change the quality of the water in a way that affects the health and behaviour of other organisms.  The addition of pollutants to a river or lake tends to reduce the amount of oxygen available to organisms in the water.  There are at least two reasons why this occurs.  Effluents containing organic waste are broken down by bacteria which require the use of oxygen.  Secondly, some of the compounds within the waste may change chemically if oxygen is present in the water.  As this process, known as oxidation, occurs the dissolved oxygen concentration in the water decreases.

One way of determining water quality is to sample the types of organisms that are living in a specific area.  As water quality changes, the types of organisms that live there will also change.  Organisms that can tolerate lower quality water will be more evident as the intolerant organisms die off or move away.

Water Quality - What Can You Do?

Most people use and dispose of far more water than they need.  There are things that individuals can do to cut down on the amount of sewage water they produce and still have the comforts of modern life:

 

 

 

Don't Waste Water

• showers use less water than baths
• repair leaky taps
• keep cold water in the fridge so you don't have to run the water until it is cold 

Use Your Garbage Pail

• food scraps should be thrown into the garbage or onto the compost heap
• fats and oils gum up the sewage system so use the garbage to dispose of these items
• the sewage treatment plant cannot handle solid wastes (things that should go to a landfill site), the only things that should go into your toilet is human waste and tissue paper

Watch What You Throw Down the Sink

• an important source of heavy metal contamination is household products, zinc in shampoos and ointments and lead in some paints are two sources
• don't throw solvents, paints, or oil based compounds down the sink
• pesticides and herbicides can kill bacteria in the sewage treatment plant, these materials should be disposed of through your local toxic round-up program
• use biodegradable detergents

Every person has a role to play and a responsibility toward maintaining water quality.  Your small contributions can add up to a great deal.  Think of how much fun you can have fishing, swimming, boating, or camping near a lake or river.  Water is important.  We need it to live.

SOURCE:

ENGR. ALEX C. LUIS