Part1 - Properties of Water & Basic WQ

7/27/2019 Part1 - Properties of Water & Basic WQ

1/25

TOPIC 1:

WATER RESOURCES

AND QUALITY


2/25

INTRODUCTION

Water quality refers to the basic chemical andphysical characteristics of water that determineits suitability for life or for human uses

Importance of water usage


3/25

SOURCES OF WATER

SUPPLY

Surface water resources

-rivers, lakes, reservoirs, dams

Ground water resources

- Aquifer


4/25

PHYSICAL CHARACTERISTIC

Turbidity

Taste and odor

Colour

Temperature


5/25

Water Quality: Turbidity

Turbidity is a measure of water clarity which is how much the material

suspended in water decreases the passage of light through the water.

Suspended materials include soil particles (clay, silt, and sand), algae,

plankton, microbes, and other substances. These materials are typically in

the size range of 0.004 mm (clay) to 1.0 mm (sand).

Turbidity can affect the colour of the water.

Low levels of turbidity may indicate a healthy, well-functioning ecosystem,

with moderate amounts of plankton present to fuel the fuel the food chain.

However, higher levels of turbidity pose several problems for stream

systems.

Turbidity blocks out the light needed by submerged aquatic vegetation.

It also can raise surface water temperatures above normal because

suspended particles near the surface facilitate the absorption of heat from

sunlight.


6/25

Water Quality: Colour, Taste & Odour

Colour

Although colour in raw water can be present in groundwater due to

certain minerals, it is primarily a concern for surface water sources.

This is due to the decomposition of organic material.

Taste and Odou r

Taste and odour in water can be due to factors such as chemicals,

minerals, decaying organic matter, and dissolved gases.

The most common causes of odour in drinking water are the

presence of hydrogen sulphide, iron, or sulphur-reducing bacteria.

Even though taste and odour are considered more of an aesthetic

concern, they can also indicate the presence of contaminants that

are harmful to a persons health.


7/25

Water Quality: Temperature

Temperature is a basic waterquality variable

Temperature determines thesuitability of water forvarious forms of aquatic life

For example, trout andsalmon require cooltemperature for survival andreproduction whereas bassand sunfish do better at

warmer temperatures Temperature in water bodies

generally follows mean dailyair temperature


8/25

CHEMICAL CHARACTERISTIC

pH

Acidity

Alkalinity

Hardness

Sulphates

Iron

Solid

Nitrate


9/25

Water Quality: pH

pH is a measure ofthe acidic or basiccharacteristics ofwater

Specifically, pH= -log [H+]

So a pH of 7 meansthe [H+]=10-7

A pH of 7 isconsidered neutral,below 7 is acidicand above 7 isbasic


10/25

Water Quality: pH

Organismsgenerally prefer apH of 5-9 with

some being evenmore picky

A near neutral pHwill allow the

greatest diversityof life


11/25

Water Quality: pH

Precipitation in our area has apH of 4-4.5 and is called acidrain

This is due to air pollution byNOx and SOx from vehicles

and power plants Even where there no pollution

rain has a pH of about 5.4because of dissolution of CO2from the air

Many species are vulnerable toacid rain


12/25

Water Quality: Alkalinity

The ability of a waterbody to resistacidification is calledalkalinity

Alkalinity is generallyattributable to theamount ofcarbonate(CO3

-2) andbicarbonate (HCO3

-)

in the water Alkalinity is generally

measured in units ofmg/L as CaCO3


13/25

Water Quality: Alkalinty

Streams, lakes andwetlands with moderate tohigh alkalinity are notsubject to acidification

whereas low alkalinitywaters are very vulnerable

Development tends toincrease alkalinitysomewhat due to the

mobilization and washin ofcarbonates andbicarbonates


14/25

Water Quality: Hardness

Hardness is a measure of theamount of calcium (Ca+2) andmagnesium (Mg+2) ions in thewater

Hardness determines how hard oreasy it is to lather soap

The units are, like alkalinity, mg/Las CaCO3

Hardness also affects the toxicityof heavy metals

Hardness also tends to increasesomewhat with increasingwatershed development

Ca++

Mg++


15/25

Water Quality: Dissolve Solid

Solids in water occur either in solution or in suspension. The solids

in the water that remain after filtration and evaporation as residue

are called total dissolved solids, or TDS.

Dissolved solids can be removed from water by filtration and

evaporation, and also by electro dialysis, reverse osmosis, or ionexchange.

Dissolved solids may be organic or inorganic, and come from water's

contact with substances in soil, on surfaces, and in the atmosphere.

Organic dissolved constituents come from decayed vegetation, and

from organic chemicals and gases.

These dissolved minerals, gases, and organic constituents may

cause physiological effects, as well as color, taste, and odor

problems.


16/25

BIOLOGICAL

CHARACTERISTIC

Fecal coliform

Total coliform

Virus

protozoa


17/25

Water Quality:Total Coliform

Total coliform is a group of several species of bacteria

with similar characteristics. They all may be found

naturally in the environment; in the soil, in plants and

animals. Most coliform bacteria can be found in the

intestinal tract of warm-blooded animals.

Total coliform are indicator bacteria. Their presence

indicates the possible presence of disease-causing

organisms; other bacteria, viruses or protozoa, such as

Giardia, Salmonella, Cryptosporidium, andShigella. These pathogens cause diseases like typhoid

fever, cholera, and gastroenteritis.


18/25

Water Quality: Fecal Coliform

Fecal coliform bacteria are non-disease

causing organisms which are found in the

intestinal tract of all warm-blooded animals.

Each discharge of body wastes contains largeamounts of these organisms.

The presence of fecal coliform bacteria in a

stream or lake indicates the presence ofhuman or animal wastes.

The number of fecal coliform bacteria present

is a good indicator of the amount of pollution

present in the water.


19/25

Water Quality: Protozoa

Protozoa are single-celled organisms that live mainly in

water. Many protozoa we know as parasites, but like

bacteria, they can be classified as helpful or harmful.

At times, drinking water can become infested with

certain protozoa which are not disease causing, but will

give the water a fish taste and odor.

Protozoa are often found in groundwater that has being

influenced by surface water sources.

Usually 2 to 50 microns in diameter, much larger than

bacteria.


20/25

Water Quality:Viruses

Viruses are the smallest of the infectious microorganisms. They

cannot be seen under a microscope, as they are only 0.004 to 0.1

micron in diameter, and thus can pass through porcelain filters

capable of screening out bacteria.

Viruses are a unique kind of parasite that are incapable of growthunless they are in the presence of living cells. They can survive

both freezing and drying.

While viruses are more difficult to directly detect in a water source,

they can be carried in feces of both animals and humans. This is

why fecal coliform bacteria is a good indicator of sewagecontamination. The presence of coliform bacteria in sewage may

mean that the water source itself is contaminated with other

parasites.

It is important to note, however, that the absence of coliform

bacteria in a water source does not necessarily indicate theabsence of parasites in that water source.


21/25

Water Contamination

Contaminants that may be in untreated water include:

microorganisms (viruses and bacteria)

inorganic contaminants (salts and metals)

pesticides and herbicides

sediments

organic chemical contaminants from industrialprocesses and petroleum use

radioactive contaminants.

Water quality depends on the local geology andecosystem, as well as human uses (sewage dispersion,industrial pollution, use of water bodies as a heat sink


22/25

Malaysian Laws & Regulations

Parliamentary Acts National Policies of Government of Malaysia - Third National Agricultural Policy

(1998 - 2010)

Federal Constitutions

Ministerial Functions Act (1969) (Perintah Menteri-Menteri Persekutuan 2004) : DID Role In

River Management In On Flood Mitigation and River Conservancy

Other Legislations

Land Acts National Land Code 1965 And Waters

Land Conservation Act 1960

Flood Mitigation Drainage Works Act 1954 (1988)

Local Government Act (1976): (Peninsular) Earthworks Bylaws

Street, Drainage and Building Act 1974 (1994)

Town and Country Planning Act 1976


23/25


River Management

Waters Act 1920 (Act 418) & Water Supply (Federal Territory of Kuala Lumpur) Act 1998 (Act

581)

Mining Enactment 1962 (F.M.S. Cap 147)

Environmental Quality Act 1974 (Act 127) & Subsidiary Legislation

Ministerial Functions Act 1969 (Act 2)

National Forestry Act 1984 (Act 313) & Wood-Based Industries (State Legislatures

Competency) Act 1984 (Act 314)

Fisheries Act 1985 (Act 317) and Regulations

Water Act 1989 - Chapter 15

Sewerage Services Act 1993 (Act 508) & Regulations And Orders

Coastal Management

Town and Country Planning Act 1976

Environmental Quality Act 1974: (1985)

Environmental Quality Order 1987 (Environmental Impact Assessment - Prescribed Activities)

Mining Enactment 1936 (F.M.S. Cap 147)

Fisheries Act 1963 (1985) / Inland Fisheries Act


24/25


Hydrological & Water Resources

Drainage Works Act 1954 (1988)

Waters Act 1920 (Cap 146) (1989)

Urban Stormwater

Street, Drainage and Building 1974 (Act 133) - Section 70A(9)

Street, Drainage and Building 1974 (Act 133) - Section 71

Agriculture Drainage

Third National Agricultural Policy (1998-2010)

Irrigation Areas Act 1953 (1989)

Drainage Works Act 1954 (1988)

Waters Act 1920 (Cap 146) (1989)

Fisheries Act 1963 (1985) / Inland Fisheries Act


25/25

References

Source: Water Treatment Dealer, July/August

2002, What are bacteria, protozoa and

viruses? by Lou Smith, Water Quality

Consultant, Canadian Water QualityAssociation)

The official portal of DID Malaysia

Documents

Part1 - Properties of Water & Basic WQ