Water resources

Introduction

On the previous report, Malaysia has received rainfall of 324 billion m³/year in year 2000. It distributed surface runoff and evapo-transpiration about 152 billion m³/year, respectively and only 20 billion m³/year becomes groundwater. Malaysia‘s water status are diverse, increase and competing needs. However the future forecast indicated that water supply demand cannot be met in many locations due to uneven rainfall distribution, temporarily or spatially, degradation in the raw water supply catchments, because of a-control opening of forested areas (logging, roads, urbanizations) resulting in massive sedimentation flow into rivers, pollution in rivers as it passes urban areas, reaches between raw water source catchment/storages and downstream water supply intake.

Water quality is most important to preventing and protect humans from disease. However, water treatment at the plant should treated before contributing to the consumers. Water quality must be according to the specification of water drinking with the Nation Standard for Drinking Water Quality. Actually, raw water resource has a differences classification such as turbidity, chemical content, color and pH. The treatment process at treatment plants have various types that considered of raw water respectively. There are three water quality parameters are physical parameter, chemical parameter and biological parameter.

Water recycles processes 

Stages of the cycle are:

1)      Evaporation

2)      Transportation

3)      Precipitation

4)      Groundwater

5)      Run-off

Water cycle process

 Evaporation

Water is transferred from the surface to the atmosphere through evaporation, the process by which water changes from a liquid to a gas. The sun's heat provides energy to evaporate water from the earth’s surface. Land, lakes, rivers and oceans send up a steady stream of water vapor and plants also lose water to the air (transpiration).

 Transportation

Transportation means the movement of water through the atmosphere, specifically from over the oceans to over land. Some of the earth’s moisture transport is visible as clouds, which themselves consist of ice crystals and/or tiny water droplets.

Clouds are propelled from one place to another by either the jet stream, surface-based circulations like land and sea breezes or other mechanisms. Most water is transported in the form of water vapor, which is actually the third most abundant gas in the atmosphere. Water vapor may be invisible to us, but not to satellites which are capable of collecting data about moisture patterns in the atmosphere.

 Condensation

The transported water vapor eventually condenses, forming tiny droplets in clouds.

 Precipitation

The primary mechanism for transporting water from the atmosphere to the surface of the earth is precipitation.

When the clouds meet cool air over land, precipitation, in the form of rain, sleet or snow, is triggered and water returns to the land or sea. A proportion of atmospheric precipitation evaporates.

 Groundwater

Some of the precipitation soaks into the ground and this is the main source of the formation of the waters found on land - rivers, lakes, groundwater and glaciers.

Some of the underground water is trapped between rock or clay layers - this is called groundwater. Water that infiltrates the soil flows downward until it encounters impermeable rock and then travels laterally. The locations where water moves laterally are called ‘aquifers’. Groundwater returns to the surface through these aquifers, which empty into lakes, rivers and the oceans.

Run-Off

Most of the water, which returns to land flows downhill as run-off. Some of it penetrates and charges groundwater while the rest, as river flow, returns to the oceans where it evaporates. As the amount of groundwater increases or decreases, the water table rises or falls accordingly. When the entire area below the ground is saturated, flooding occurs because all subsequent precipitation is forced to remain on the surface.

Different surfaces hold different amounts of water and absorb water at different rates. As a surface becomes less permeable, an increasing amount of water remains on the surface, creating a greater potential for flooding. Flooding is very common during winter and early spring because frozen ground has no permeability, causing most rainwater and melt water to become run-off.

Water Source

Sources of water in treatment plants have a differences source which is groundwater, seawater and surface water. However, the difference source has a difference of characteristic in term chemical parameter, physical parameter and microbiological as shown in table 3.1.

Groundwater	Surface water
Ø  Constant composition Ø  High mineral content Ø  Low turbidity Ø  Low colour Ø  Low or no dissolved oxygen (D.O). Ø  May have CO₂, H₂S. Ø  High hardness Ø  High Fe and Mn	Ø  Variable composition Ø  Low mineral content Ø  High turbidity Ø  Colored Ø  D.O present Ø  Low hardness Ø  Taste and odor Ø  Clay and silt

Table 3.1 Chemical, physical and microbiological parameter

Water Treatment Plant

3.3.1 Water treatment Processes (Plant)

Water is very important in our daily lives in every human being and the environment. Therefore, the water treatment systems are required to achieve their drinking water quality standard and supplying water to consume. Water treatment is based on the standards set by the World Health Organization (WHO) for the raw water or potable water (Standard drinking water).

3.3.2 General Introduction

Typically, the water supply system in the district has major components that encompass the entire department a day trip. These components are Water Production System (production rate), Water Distribution System, Quality Control System and Water Revenue Collection System.

3.3.3 Water Supply objective

To supply adequate drinking water for all users and water quality in accordance with a predetermined standard.

3.3.4 Water Requirements

Water requirements divided into three (3) types such as domestic needs, industrial or commercial and water loss.

Water Treatment process

Definition

3.3.5.1 Raw water

Water pumped from the source which is to be treated. The raw water must be pumped to the water treatment plant to treat and take from the catchment.

3.3.5.2 Fleece Blanket/Floc Formation

A layer of fine silt suspended in the clarifier which acts as a blanket to trap other silt materials in the incoming raw water.

3.3.5.3 Desludging

The process of removing excess flows/sediment from the sedimentation tank.

3.3.5.4 Backwashing

A process for cleaning filter media with clean water.

3.3.5.5 Clear Water Well

Storage tank which receives the water after the filtration process.

3.3.5.6 Storage tank

A storage tank for treating water, usually located on an elevated platform.

3.3.5.7 Clarifier

A tank structure whereby the fleece blanket is allowed to form. A compartment to separate out the finer fleece particles from the water which passes through the filter media.

3.3.5.8 PH

A measurement of acidity and alkalinity of the raw water and clear water. The range of clear water should be 6 to 7 of pH by followed of the National Standard water drinking.  

3.3.5.9 Color

The color of the water as determined at the time of analysis. Color should be white or clear.

3.3.5.10 Residual Aluminum

The amount of aluminum left in the water after the reaction with other foreign materials present in the same water.

3.3.5.11 Fluoride residual

The amount of fluoride left in the water after the reaction with other foreign materials present in the same water.