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^OPERATOR-IN-TRAINING 
EXAMINATION STUDY GUIDE 



PREPARED BY: 

ONTARIO MUNICIPAL WATER ASSOCIATION 

& 
MINISTRY OF ENVIRONMENT AND ENERGY 



For use by new operators preparing for the 

Operator-In-Training Examination 

as required under O.R. 435/93. 



"'--"-'V £.0 





© 1994 






Ontario Municipal Water Association 






and 




A 


Ministry of Environment and Energy 




>4ssooahon 


- 


/Z^S Ministry of 
[ vy 1 EnvtitHuncnt 
yvy and Energy 

Ontario 



a 



Copyright Provisions and Restrictions on Copying: 

This Ontario Ministry of the Environment work is protected by Crown copyright 
(unless otherwise indicated), which is held by the Queen's Printer for Ontario. It 
may be reproduced for non-commercial purposes if credit is given and Crown 
copyright is acknowledged. 

It may not be reproduced, in all or in part, for any commercial purpose except 
under a licence from the Queen's Printer for Ontario. 

For information on reproducing Government of Ontario works, please contact 
ServiceOntario Publications at co pyright(g)ontario.ca 



95-07265/ 



ACKNOWLEDGEMENTS 

This study guide was jointly prepared by M.G. Christie. REng of the Ontario Municipal Water 
Association, Dianne Howie, Ontario Environmental Training Consortium and Brian Gildner, 
Ministry of Environment & Energy. 

Numerous individuals within the Ministry, Municipalities and other organizations have provided 
helpful advice on the content of this guide. 

Additional copies of this guide may be obtained through the Certification Office of the Ministry, 
905-456-0266 ext 332 or 305. 



© 1994 
Revised, January 1995 



No part of this study guide may be reproduced, stored in a retrieval system, or transcribed, in any 
form or by any means, electronic, mechanical, photocopying, recording or otherwise, without 
prior written permission of the Ontario Municipal Water Association and the Ontario Ministry 
of Environment and Energy. 



10. '> 

/s!^ TGi...... ) ' 

iS SEP 9 1996 S] 

■ 



I 
I 



TABLE OF CONTENTS 

ACKNOWLEDGEMENTS i 

TABLE OF CONTENTS .'. ii 

ABOUT THIS STUDY GUIDE 1 

OVERVIEW (ALL) 1 

OPERATOR LICENSING REGULATION (O. REG. 435/93) (ALL) 2 

BASIC & APPLIED MATHEMATICS (ALL) 3 

METRIC SYSTEM . , 3 

UNIT CONVERSIONS 5 

AREA 5 

SURFACE AREA 8 

VOLUME 9 

GRAPHS 11 

PUBLIC HEALTH/MICROBIOLOGY (ALL) 12 

ENVIRONMENTAL HEALTH (ALL) 14 

WATER/WASTEWATER CHEMISTRY (ALL) 14 

BASIC CONCEPTS 14 

ACIDS, BASES & SALTS 16 

pH SCALE 16 

SOLUTIONS 17 

COMMON CHEMICALS AND PARAMETERS 18 

SAMPLING OF WATER/WASTEWATER 23 

MINISTRY OF ENVIRONMENT AND ENERGY OBJECTIVES 23 

BASIC ELECTRICITY (ALL) 24 

VOLTAGE 24 

CURRENT 24 

RESISTANCE 24 

POWER 25 

BASIC HYDRAULICS (ALL) 25 

VELOCITY 25 

FLOW RATE 25 

MEASURING FLOW RATE 27 

PRESSURE AND HEAD 27 

FRICTION LOSS IN PIPES 28 



n 



WATER HAMMER 28 

CAVITATION 28 

WATER TREATMENT (WT) 29 

WATER DISTRIBUTION (WD & WT) 32 

WASTEWATER TREATMENT (WWT) 35 

PRELIMINARY TREATMENT 35 

PRIMARY TREATMENT 35 

SECONDARY TREATMENT 37 

SLUDGE DIGESTION 37 

TERTIARY TREATMENT 38 

WASTEWATER COLLECTION (WWT and WWC) 39 

EQUIPMENT (ALL) 41 

PUMPS 41 

PIPES 42 

VALVES 42 

CONTROL AND INSTRUMENTATION 42 

CROSS CONNECTION CONTROL 43 

SAFETY (ALL) 43 

APPENDDC A: OPERATOR-IN-TRAINING FACT SHEET 47 

APPENDDC B: NEED-TO-KNOW 49 

APPENDDC C: REFERENCES 51 

APPENDK D: CONVERSION SHEET 54 

APPENDIX E: FORMULAS 55 

APPENDFX F: LIST OF THE ELEMENTS 57 

APPENDDC G: HELPFUL HINTS FOR STUDYING 59 

APPENDDC H: GLOSSARY 65 



in 



ABOUT THIS STUDY GUIDE 

This study guide provides background information to help you prepare to pass the Operator-In- 
Training (GIT) examination (information on becoming an Operator- In-Training and the 
Examination can be found in Appendix A). This guide is intended to familiarize new employees 
to terms and concepts which are common in the water/wastewater treatment industry. As such 
it is directed towards people with little or no exposure to the treatment industry. This guide is 
not a replacement for comprehensive training programs. 

The study guide is broken into categories which roughly correspond to the sections of the "Need- 
To-Know" for the Operator-In-Training examination (a copy of the Need-To-Know is provided 
in Appendix B). 

The study guide is applicable to all four Operator-In-Training examinations. For those parts 
which apply to any one examination, the code used to identify the exam is as follows: 

ALL - All four exams 
WT - Water Treatment 
WD - Water Distribution 
WWT - Wastewater Treatment 
WWC - Wastewater Collection 

Other more detailed study guides are available to help you prepare for future examinations. An 
abbreviated list of additional study materials for the OIT and Class 1 examinations is provided 
in Appendix C. 

OVERVIEW (ALL) 

As you prepare to write your Operator-In-Training examination you should be aware of the 
responsibilities being placed upon yourself when you become a qualified operator of water or 
wastewater facilities. 

As a qualified water treatment and/or water distribution operator you will be responsible for the 
delivery of drinking water which is treated to a point where it will not endanger human health. 
In addition this water must also be delivered in quantities sufficient to handle fire flow 

1 



requirements. Likewise, Wastewater Collection and Treatment Operators are responsible for the 
safe collection of sewage and for its treatment prior to its release to the natural environment. 
Consequently, all operators play a key role in public health and public safety. 

Ontario owes much of its high standard of health to the water/wastewater industry. Without 
adequate treatment facilities diseases such as cholera, hepatitis, and dysentery would kill 
thousands of Ontarians every year. Non-treated or inadequately treated sewage would not only 
lead to human health problems but would also degrade our natural stream and lake ecosystems. 

OPERATOR LICENSING REGULATION (O. REG. 435/93) (ALL) 

Operators of domestic wastewater treatment and collection systems, and operators of water 
treatment and collection systems require a license to work in the Province of Ontario. This 
license will ensure that all operators have the required knowledge, experience and training to 
perform their duties. As an operator you should be familiar with the legislation, particularly 
those parts which set out the duties and responsibilities of operators. Until you pass the OIT 
exam and subsequently receive your OIT license you are not permitted to adjust a process, 
change flows or adjust chemical dosing unless directly supervised by a licensed operator. 
(Directly supervised meaning "over the shoulder" supervision.) If you are presently working in 
a facility which requires licensing you should discuss your duties, and the limitations to your 
operating activities, with your supervisor. 

The Regulation divides the water/wastewater industry into 4 types: water treatment, water 
distribution, wastewater treatment and wastewater collection. In addition each type is divided 
into four classes (Classes 1-4) based upon the system's size and complexity (with Class 1 being 
the least complex). Each type and class of facility has a separate examination. 

As you progress as an operator, you will be expected to pass a series of examinations to 
demonstrate your knowledge of water treatment, water distribution, wastewater collection or 
wastewater treatment. Your supervisor will be able to provide advice on which level of 
examinations you should work towards. To pass these examinations you must demonstrate 
abilities in mathematics, chemistry, biology, hydraulics, safety and public health. All exams 
consist of multiple choice questions. 



BASIC & APPLIED MATHEMATICS (ALL) 

Basic calculation skills arc important for operators working in municipal systems. Operators 
must be able to calculate areas and volumes of reservoirs, lagoons, and cylindrical tanks. Dosage 
calculations and flow rates must also be determined. Operators should be familiar with both 
metric and Imperial units, and their conversions because equipment may be calibrated using either 
of these units. 

This section provides a brief review of metric prefixes, conversions between metric and Imperial 
units, areas, and volumes. In order to understand these topics, the candidate must also be 
comfortable using the following basic arithmetic skills: 

■ Addition, subtraction, multiplication and division of: 

whole numbers 
fractions 
decimals 
percentages 

■ Expressing numbers in scientific notation 

■ Direct and inverse proportions 

These skills are not reviewed in this manual. For further review of basic arithmetic, you may 
contact a local secondary school, community college or the Independent Learning Centre (See 
References, Appendix C). 

METRIC SYSTEM 

The Systeme International (SI) metric system is used throughout the world with the major 
exception of the United States where American (Imperial) units are common. Although, the 
metric system is used in Canada, operators will encounter equipment using both systems of 
measurement. 

The table below gives some metric units for common quantities. Appropriate units for various 
quantities will be indicated in both the metric and Imperial systems in later sections. 



Quantity 


Metric Unit (Symbol) 


Length 


metre (m) 


Area 


square metre (m 2 ) 


Volume 


cubic metre (m 3 ) 




litre (L) 


Velocity 


metres per second (m/s) 


Flow rate 


cubic metres per second (m 3 /s) 


litres per second (L/s) 




megalitres per day (ML/d) 


Mass 


gram (g) 


Pressure 


pascal (Pa) 


Power 


watt (W) 



Prefixes are used in the metric system to indicate multiplication by a factor of 10. For example, 
the prefix kilo in kilometres indicates a multiplier of 1000; 34 kilometres is equivalent to 34 000 
metres. In general, numbers should be kept within the range of 0.1 to 1000. Prefixes can be 
used with the units to allow numbers within this range. Some commonly used prefixes are listed 
in the following table. 



Prefix 


Symbol 


Multiplier 


Some Basic Conversions 


nano 


n 


lQ" 9 = 0.000 000 001 


1 m 3 ~ ; 1 000 L 








micro 


P 


lo 6 = o.ooo ooi 








1L= 1 000 mL 
i kg= 1 000 g 


milli 


m 


ID" 3 = 0.001 


cenri 


c 


1Q- 2 = 0.01 


1 g = 1 OOOmg 




deci 


d 


10 l = 0.1 


ld=24hr 

1 A — 1 44ft min 






kilo 


k 


10 3 = 1 000 






mega 


M 


10 6 = 1 000 000 








i u = oo 4UU S 

i mg/L ~ I kg/1 000 m 3 






giga 


G 


10 9 - 1 000 000 000 



k 



UNIT CONVERSIONS 

Unit cancellation is one of the best ways to make sure that conversions are done correctly. The 
appropriate units are written next to each number and multiplied, divided, and "cancelled out" 
just like numbers in arithmetic operations. The factors used to convert from metric to Imperial 
units in these examples (for instance 3.281 in example 1 below) are taken from the aid sheet 
provided during the certification examinations (see Appendix D). The following examples will 
illustrate the process: 

Example 1: Convert 13 metres to an equivalent length expressed in feet. 

13 metres x 3.281 feet = 42.653 metres x feet = 43 feet (rounded) 
metres m e tr e s 

Example 2: Convert 960 cubic metres per day to an equivalent flow rate in cubic metres per 
second. 

960 m 3 x fftin x _h x d = 0.011 m 3 /s (rounded) 

d 60 s 60 mifi 24 b 

AREA 

The area of a figure is the surface enclosed within the lines of the figure. Area is measured in 
square units. Some metric units for measuring area are: m 2 or cm 2 . Some Imperial units for 
area are: in 2 and ft 2 . An aid sheet giving the formulas used in calculating the area of several 
common shapes is provided during the OiT examination. A copy of this aid sheet is included 
in Appendix E. When using these formulas, it is important to ensure that all of the 
measurements are in the same units. 

RECTANGLES 

A rectangle is a four-sided figure which has opposite sides that are parallel and equal in length. 
Each of the four angles within a rectangle is 90°. The area of a rectangle is length multiplied 
by width. 



■ vAiea 


= Lx 
L = 


W 

length of rectangle - ■ • 


';.:■'.. 


: 


w- 


: width of rectangle 






Example: Find the floor area (m 2 ) in a rectangular room with a length of 7 metres (m) and 
a width of 400 centimetres (cm). 

Solution: 

(1) Convert measurements to the same units 

L = 7 m 

W = 400 em x 1 m 

100 em 
= 4 m 

(2) Enter values of length and width in formula 

Area = L x W 

= 7 rn x 4 m 
= 28m 2 

TRIANGLES 

A triangle is a 3-sided figure in which the sum of enclosed angles equals 180°. The area of a 
triangle is equal to one half the base length multiplied by the height. 



A 


xt 


>» — t n xz v u 






A 


& —ifZr oxtl 






t> — icwgin oi oase 
H = height of triangle 






















Example: Find the area of a triangle with a base length of 27 inches and a height of 3.4 feet. 

Solution: 

(1) Convert measurements to the same units 

B = 27 inches x 1 feet 
12 inches 
= 2.25 feet 
H = 3.4 feet 

(2) Enter values of length and width in formula 

Area = 1/2 B x H 

= 1/2 (2.25 feet) x 3.4 feet 

= 3.825 ft 2 

= 3.8 ft 2 (rounded off) 

CIRCLES 

A circle is a figure enclosed by a curved line, every point on which is an equal distance from 
the centre. The curved line bounding the figure is called the circumference. The distance from 
the centre of the circle to any point of the circumference is called the radius. A line joining the 
circumference on either side of the circle and passing through the centre is called the diameter. 
The diameter is twice the length of the radius. The area of a circle is equal to the radius squared, 
multiplied by a constant. 



Area = k R 2 




or 




Area = %D 2 } 4 




K = constant = 


3.1416 


R= radius 




P = diameter 





^ m f e r 



o 




Example: Find the area of a circle with a radius of 3 metres. 

7 



Solution: 

(la) Enter value of radius in formula 
Area = n R 2 

- 3.1416 x (3 m) 2 

= 28.2744 m 2 

= 28.3 m 2 (rounded off) 
The area may also be calculated using the diameter. 

(lb) Enter the value of diameter in formula 
Area = % D 2 / 4 

= 3.1416 x (6 m) 2 / 4 
= 28.2744 m 2 or 28.3 m 2 

SURFACE AREA 

Surface area is the total of the areas of all the surfaces of a figure. The formulas used above for 
area calculations are also used to calculate surface areas. First the figure must be broken down 
into its component parts, then the total area of these parts must be calculated. 

CYLINDERS 

The surface area of a cylinder is composed of 3 parts: the top surface (a circle), the bottom 
surface (a circle), and the curved side surface (a rectangle). The areas of the top and bottom 
surfaces are the same, and can be calculated using the formula for the area of a circle. 



At¥*5J 



=M 






or 



=::1t: 



The area of the side surface can be determined by imagining that the side surface is unrolled 
into a rectangle as illustrated below. The length of the rectangle is equal to the circumference 
of the top or bottom circle, and the width is the height of the cylinder. 



Area = U 



:--:■-.-- ■■.•■.■.■•...•.• J .-\^.^y:^.<'/y. 



or 



Area-2TCR H 



M«MM*M*M^Mi^« 



The surface area of a cylinder is the total of these 3 areas. 

a 




n D- 




H 

4- 



Example: Find the total surface area of a cylindrical tank with a base diameter of 18 metres 
and a height of 4 metres. 

(1) Find the area of the top surface 
Area = a D 2 / 4 

= (3.1416) x (18 m) 2 / 4 
= 254.5 m 2 

(2) Find the area of the bottom surface 
Area = n D 2 / 4 

= 254.5 m 2 

(3) Find the area of the side surface 
Area = k D x H 

= 3.1416 x 18 m x 4 m 
- 226.2 m 2 

(4) Find the total surface area 

Surface area = 254.5 m 2 + 254.5 m 2 + 226.2 m 2 
= 735 m 2 
VOLUME 



The volume of a three dimensional figure is the amount of space the figure occupies. Volume 
is measured in cubic units. Some metric units for measuring volume are: m\ cm 3 , and L. Some 
Imperial units for volume are: in 3 and ft 3 . The aid sheet gives formulas for calculating the 
volumes of several common shapes. Be careful to keep your units consistent! 



RECTANGULAR SOLIDS 



The volume of a rectangular solid is equal to the area of the base multiplied by the height. 




T 

H 

i 



r 



W 



Example: Find the volume of a reservoir that has a surface area of 100 m 2 and a depth of 
2.4 metres. 

Volume = Area of base x H 
= (100 m 2 ) x 2.4 m 
= 240m 3 



CONES 

The volumes of cylinders, prisms, and cones are also calculated by multiplying the area of the 
base by the height of the figure. Some of the formulas also need to be multiplied by a fraction, 
as shown on the aid sheet. For example, the formula for the volume of a cone is one third of 
the area of the base multiplied by the height. 



Volume 
Volume 



1/3 Area of base x H 




= i/3rcR 2 xH 



or Volume - 



1/3 (jt D 2 / 4) x H 
1/12 it&xR 




10 



Example: Find the volume of a conical shaped hopper with a diameter of 2.1 metres and a 

height of 3.4 metres. 
Volume = 1/12 % D 2 x H 

= 1/12 (3.1416) x (2.1 m) 2 x 3.4 m 

= 3.9 m 3 

SPHERES 

The volume of a sphere can be calculated using the following formula: 



1 «. n>3 



•Volume = 4/3 it R 



or 



Volume =7t D 3 / 6 



Example: Find the volume of a ball with a radius of 0.33 m. 



Volume = 4/3 it R 3 

= 4/3 (3.1416) (0.33) 3 
= 0.15 m 3 




GRAPHS 

Graphs and tables are convenient ways to present a large volume of data in a useable format. 
Operators should be able to create and interpret graphs and tables. 

The framework of a graph consists of a grid of lines. Two of the lines, one horizontal line and 
one vertical line, are labelled with numbers giving the ranges of values shown on the graph. The 
horizontal line is called the x-axis and the vertical line is called the y-axis. In the case below, 
the x-axis shows the days of the month with values ranging from day 1 to day 30. The y-axis 
in this example shows the flow rates in million gallons per day (MGD) ranging from to 1.2 
MGD. 



A line laid on top of this grid shows the relationship between the values of the x-axis variable 
and the y-axis variable. In this example, the irregular line shows the relationship between flow 

11 



rate and days of the month. If we want to determine the flow rate on any day of the month, we 
can find this on the graph. For example, on the 15th day of the month the flow rate was about 
0.6 MGD. You can find any other value in a similar way by following a grid line vertically to 
touch the irregular graph line, then following a grid line horizontally to see where it touches the 
y-axis (as shown below). 




To is £T~ 

DAYS OF THE MONTH 



Example: The graph above, the rate of flow for each day of the month is shown. The 
design flow for this treatment plant is 1 MGD. On which days does the flow 
exceed the design flow? 

First draw a line on the graph to show where the design flow occurs (dashed line). At the points 
where the irregular graph line crosses the dashed line showing the design flow, draw vertical 
lines to the x-axis and read the values. In this case the irregular graph line is above the dashed 
line between days 20 and 24. That means that the flow exceeded the design flow between the 
20th and the 24th days of this month. 

PUBLIC HEALTH/MICROBIOLOGY (ALL) 

By definition microorganisms are those animals, plants and other living organisms which can 
not be seen or are barely visible by the naked eye. These include bacteria, algae (single celled 
photosynthesizing organisms), and viruses. The majority of microorganisms are harmless to 
humans, and may even aid human endeavours such as the digestion of food in the intestine, and 
the production of beer, cheese or yogurt. These bacteria are call non-pathogenic. Bacteria and 
other microorganisms which cause disease in humans are called pathogens. 



12 



Microorganisms share a number of different characteristics, apart from their small size. 
Generally, given the right conditions and enough food, microorganisms can reproduce extremely 
rapidly. This allows small bacteria populations to rapidly expand, potentially causing serious 
health problems. Many microorganisms can also form hard protective shells known as cysts. 
This characteristic allows the microorganisms to survive difficult periods such as low food, 
cold/hot temperatures or drought. This characteristic may also make microorganisms difficult 
to control. 

Microorganisms are found in all surface water bodies. They originate from improperly treated 
sewage, storrnwater runoff, septic beds, farm animal faeces, and natural sources. Water which 
has undergone the effective elimination or destruction of organisms capable of causing disease 
is said to be disinfected. Water may be disinfected through the use of chemicals such as 
chlorine, ultraviolet radiation or ozonation. 

Aside from microorganisms, water treatment facilities may need to treat or monitor other 
potentially dangerous substances such as pesticides, organic chemicals, heavy metals, and ions 
such as cyanide. These chemicals may be natural or a result of human activities. As well 
drinking water treatment facilities are concerned with aesthetic characteristics (i.e. aspects of 
drinking water that are noticeable to the drinker) such as colour, taste, and odour. 

Microorganisms also serve very important functions in the biological treatment of wastewater. 
In order to survive microorganisms require energy, carbon and other nutrients, which can be 
found in wastewater. Microorganisms which require dissolved oxygen to grow are known as 
aerobic. Those which can only grow in the absence of dissolved oxygen are called anaerobic. 
Both types can play an important role in a wastewater treatment facility, by breaking complex 
organic substances found in wastewater into simpler compounds, such as methane, carbon 
dioxide, nitrates, phosphates and water. 

Most microorganisms can survive only in a limited range of conditions (oxygen level, 
temperature, pH, toxin levels, nutrients etc.). It is very important that an operator be aware of, 
and maintain these conditions in a biological treatment process. 



13 



ENVIRONMENTAL HEALTH (ALL) 

Raw or improperly treated sewage can lead to the degradation of the environment. Sewage has 
a high nitrogen and phosphorus content. These are the same chemicals which are used to fertilize 
lawns or gardens. In natural streams and lakes excessive amounts of these chemicals will lead 
to increases in the population of algae and other microorganisms. These organisms will in turn 
deplete the amount of oxygen in the water, causing the death of fish and other important animals 
and plants. Long term release of sewage will reduce the diversity of life in a body of water. 
Temporarily diverting wastewater around treatment processes (known as a bypass event) may 
also cause large "fish kills" which greatiy effect the long term health of the stream or lake. In 
addition to the fertilizer effect of sewage, heavy metals and other toxins will lead to severe 
environmental damage if treated inadequately. High discharge of suspended solids may also 
result in habitat destruction of streams, rivers and lakes. 

WATER/WASTEWATER CHEMISTRY (ALL) 

Chemistry may be defined as the science that deals with the composition, properties and changes 
undergone by matter under certain conditions. The treatment, distribution or collection of water 
and wastewater involves many chemical concepts and terminology. A basic understanding of 
chemistry is a pre-requisite to successful plant operation. 

BASIC CONCEPTS 

The term matter refers to anything which occupies space and has a mass. Matter may exist in 
solid, liquid or gaseous states. Depending on temperature and pressure, matter may undergo a 
change of state. For example as the temperature of ice raises above 0°C it will become a liquid, 
and as the temperature raises above 100°C the liquid will become a vapour. 

The basic building block of all matter is known as an atom. There are many different types of 
atoms, each with their own mass and physical properties. Each type of atom is known as an 
element. Common examples of elements include hydrogen (the chemical symbol for which is 
(H), carbon (C), nitrogen (N), oxygen (O), phosphorus (P), and chlorine (CI). If you wish to 
identify an element and many of its properties, a complete listing is provided in a Table of 
Elements (Appendix F). 



14 



If two or more different elements combine a compound is formed. When a compound is altered 
to form a new type of compound a chemical change has occurred. The burning of fuel is an 
example of a chemical change. As a result of this reaction, the elements of fuel are recombined 
with oxygen to create new compounds such as water and carbon dioxide. A chemical change 
is different from a change of state. A change of state does not result in compounds with different 
composition of elements. 

Often chemical compounds are placed into categories based on their composition and 
characteristics. The presence of carbon is often used to divide chemicals into two groups. 
Organic compounds are those which are composed of carbon, hydrogen, oxygen and other 
elements. Inorganic compounds tend to be simpler and usually do not contain carbon. 

When a compound undergoes a chemical change this is called a chemical reaction. Chemical 
reactions are often summarized in the form of equations. For example; 

Cl 2 + H 2 +> HOCl + HCl 

Chorine + Water <* Hypochlorous Acid + Hydrochloric Acid 

In the above chemical equation, two chlorine atoms (Cy will react with one water atom to form 
one molecule each of hypochlorous and hydrochloric acids. Chemical reactions may proceed 
quickly or slowly depending on various conditions such as temperature, pressure and pH. 
Chemical reactions may also proceed in the reverse direction. In the above example under the 
right conditions hydrochloric and hypochlorous acids may form water and chlorine. The **■ 
symbol indicates that the reaction may proceed in either direction. Often chemical reactions will 
be written using the — symbol, indicating that under normal conditions the reaction will proceed 
in this direction. 

Oxidation is a common chemical reaction in water/wastewater treatment. Oxidation is the 
addition of oxygen, removal of hydrogen, or the removal of electrons (a component of an atom) 
from an element or compound. In treatment processes, oxidation results in the transformation 
of organic matter to more stable substances. Oxygen and chlorine are two strong compounds 
which aid in the oxidation of organic material. 



15 



ACIDS, BASES & SALTS 

In the water/wastewater industry one group of reactions which are very important involve acids, 
bases and salts. Acids, bases and salts are commonly used for pH adjustment, flocculation, 
sedimentation, disinfection, corrosion control, water softening and taste, colour and odour control. 

When an acid, base or salt is added to water, the compound will split into two separate parts. 
When this occurs the compound is said to have disassociated. An acid is a compound which 
will release hydrogen ions (H + ) when it disassociates. The stronger the acid the more hydrogen 
ions the compound will release. An example of an acid is hydrochloric acid; 

hci +> cr + H + 

Hydrochloric Acid Chloride ion + Hydrogen ion 

When a base is added to water and disassociates it will release hydroxyl ions (OH). The 
stronger the base the more hydroxyl ions will be released. This is illustrated in the equation 
below. 

NaOH +> Na + + OH~ 

Soctium Hydroxide Sodium ion + Hydroxyl ion 

A salt will not release hydrogen or hydroxyl ions when it dissociates. A good example is 
common salt, sodium chloride; 

NaCl ^ Na + + C7~ 

Sodium Chloride Sodium ion Chloride ion 

pH SCALE 

The pH scale is a method used to measure the strength of an acidic or basic solution (basic 
solutions may also be referred to as alkaline solutions). The scale ranges from 0-14 with acids 
having a pH of less than 7, and bases a pH greater than 7. A solution which is neither acidic 
or basic is called a neutral solution and has a pH of 7. Each increase in 1 in the pH scale, 
indicates a solution which is 10 times more basic. For example a liquid with a pH of 8 is ten 
times more basic than a liquid with a pH of 7. 



16 



pH 



EXAMPLE 



** High 



o 

I 



1 

i 



Low 





1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 



Highly Acidic 



Neutral 



I 



Highly Basic 



(5% Sulfuric Acid) 
Lime Juice 



Milk 

Pure Water 
Borax 



4% Caustic Soda 



When acid and base solutions are combined a salt will form and the hydrogen (H + ) and the 
hydroxyl (OH") ions will combine to form water (H 2 0). If the acid and base solutions are 
approximately the same strength (i.e. the same amount of hydrogen and hydroxyl ion 
concentrations) the solutions will neutralize. This is an important reaction in the 
water/waste water treatment industry. 

Acidity and alkalinity are terms used to describe a water's ability to buffer a base or an acid 
respectively. Acidity and alkalinity are measured in milligrams per litre equivalent amounts of 
calcium carbonate. 

SOLUTIONS 

A solution is made up of two or more different parts. One component is known as the solvent 
which will dissolve the other component(s) which are called the solute(s). For example when 
sugar is dissolved in water, the sugar is the solute and the water is the solvent. The 
concentration of a solution refers to the amount of solute which is dissolved in the solvent. The 
greater the amount of solute the higher the concentration. There are several methods for 
measuring the concentration of a solution. These include molarity (M), normality (N), and 
calculating the mass of a solute as a percent of the total mass of the solution. 



17 



mass of solute tnr . - 
x 100 - %concentratton 

mass of solution 

30 g sugar x m = 25% concentratim 
120 g solution 



In water/wastewaier treatment it is often desirable to remove a solute from solution. Often 
chemicals will be added to the solution which causes a chemical change in the solute into an 
insoluble compound. This reaction is known as precipitation and the compound which setdes 
out of the solution a precipitate. 

COMMON CHEMICALS AND PARAMETERS 

The following list includes many of the chemicals or chemical concepts which you will come 
across as an operator of a treatment, distribution or collection system. Additional terms are 
defined in the glossary (Appendix H). In water chemistry, the most common unit of 
measurement is milligrams dissolved, or suspended particles in a litre of water. The expression 
used is mg/L. Occasionally mg/L will be expressed as Parts Per Million (PPM), although the two 
are not strictly equivalent. 

Activated Carbon 

Activated carbon is a very porous material which is used to adsorb particles from water. 
Adsorption is a process where particles are trapped on the surface of a material. This differs 
from absorption, which refers to the trapping a particles within the body of another material. 
Because of its high surface area, activated carbon is able to remove soluble and colloidal 
materials which sand filters cannot. It can be cleaned by intense heat and reused. 

Alum (Aluminum Sulphate) 

This metallic salt is often used in the water treatment as a chemical coagulant. Coagulants will 
react with the water and cause the de stabilization of suspended particles. This destabilization 
results in the particles sticking together to form a floe. With gentle mixing of the water the floes 
will gather together and be easily removed through filtration or sedimentation. Although alum 



18 



is the most common coagulant, many other chemicals are used. 

Chlorine (CI) 

Chlorine is the most common method of disinfection used in Ontario. Chlorine is available as 
a solution in water (sodium hypochlorite), powder (calcium hypochlorite) or gas. The liquid 
is similar to a strong "Javex" solution and is relatively safe to handle. Chlorine gas, on the other 
hand, is extremely dangerous to handle, a severe respiratory irritant which may result in death, 
and is flammable and explosive. 

Chlorine gas is a greenish/yellow colour. It has a penetrating odour. It is heavier than air and 
thus will concentrate in low lying enclosed areas. 

Chlorine gas is supplied in pressurized metal cylinders. These cylinders must be handled with 
special care. Because of the pressure within the cylinders, chlorine is in liquid form. As the 
chlorine is depressurized into a gas its volume increases 450 times. Before working with chlorine 
gas, operators must ensure that they are aware of the mechanical procedures, safety procedures 
and how to use emergency leak stoppage equipment. 

Leaks of chlorine gas can be detected by using commercial ammonia, which when passed below 
the leak produces a white smoke. To work on a chlorine gas leak an operator must wear a self 
contained breathing apparatus. 

Chlorine, in both solution and gas forms, is an effective low cost method of disinfection. When 
using chlorine, it is important to ask how much chlorine is required and how long the chlorine 
should be in contact with the water. The amount of chlorine used is called the dosage. The time 
required for disinfection to occur is called the contact time. When chlorine is first introduced 
to water it will combine with organic and inorganic compounds. The chlorine which is required 
to combine with these compounds is called the chlorine demand. Some of the chlorine will 
react with ammonia to create what is often called combined chlorine. This form of chlorine has 
good disinfecting properties. Chlorine which does not combine with other compounds is known 
as free chlorine. The sum of the combined chlorine compounds and free chlorine is known as 
the chlorine residual. 



19 



chlorine dosage = chlorine demand + chlorine residual 
mg/L mg/L mg/L 

chlorine residual = combined chlorine + free chlorine 
mgjL mg/L mg/L 



Free chlorine is a more effective disinfectant than combined chlorine but is not as stable or as 
long lasting. An advantage of chlorine over other disinfection techniques is its ability to disinfect 
long after it was applied. This is important for ensuring that water remains safe in a distribution 
system or water storage tank. 

Alternative methods of disinfection are becoming ever more common as a result of concerns 
regarding the long term effects of chlorine compounds (trihalomethanes) on humans and the 
environment. Trihalomethanes are produced when chlorine reacts organic material. These 
alternatives include ozone, ultra violet light as well as alternative chemicals such as chlorine 
dioxide. 

Colour 

Many surface waters, particularly those originating from waters with decaying or organic debris, 
will have colour which is unacceptable to domestic customers and to some industrial processes. 
Colour is one of the more difficult problems to handle in the treatment of water. Colour 
compounds may also be precursors to trihalomethane formation. 

Hardness 

Hard waters are those that, as a result of high dissolved mineral salts, require considerable 
amount of soap to produce a foam or lather. Hard water will also leave a scale in hot water 
heaters and boilers. Hardness is primarily caused by the presence of dissolved calcium and 
magnesium salts. Hardness is normally found in waters running through or over limestone. 
Hardness is expressed in milligrams per litre as calcium carbonate (mg/L as CaC0 3 ). Hardness 
can be removed using chemicals in treatment plants or using ion exchange water softeners in the 
home. 



20 



Nitrogen (N) 

Nitrogen is a vital element for the life processes of living organisms. Any discussion of nitrogen 
in this regard is very complex because of the very large numbers of compounds, both organic and 
inorganic, associated with nitrogen. Nitrogen is an important consideration for wastewater 
effluent since it acts as a nutrient which stimulates plant growth. In terms of drinking water, 
nitrites are known to be toxic, particularly to infants. In addition the presence of nitrogen 
compounds is often an indication of pollution. 

Oxygen (O) 

The amount of free oxygen in water is known a dissolved oxygen. The total amount of oxygen 
which can be dissolved in water is dependant upon temperature. The level of oxygen in water 
will determine what types of organisms can survive. The release of untreated or partially treated 
sewage may lower a stream's dissolved oxygen level, thereby making it uninhabitable to many 
species of plants, fish and other animals. In the absence of oxygen a body of water is said to 
be septic. From a treatment perspective certain types of wastewater treatment processes can only 
occur in the presence or absence of oxygen. Thus maintaining the correct dissolved oxygen 
content is very important in many processes within a wastewater treatment plant. 

The effect wastewater has upon a stream is often estimated based upon the Biochemical Oxygen 
Demand (BOD) of the wastewater. BOD is the amount of oxygen required by bacteria while 
stabilizing decomposable organic matter under aerobic conditions. The BOD test is used to 
determine the organic strength (i.e amount of organic pollution) of wastewater. The higher the 
BOD (expressed as mg/L) the greater the amount of organic material. 

Phosphorus (P) 

Phosphorus and phosphorus compounds are important in both water treatment and wastewater 
ffeatment. In industrial water treatment, phosphates are applied to water to control scaling in 
boilers. Phosphorus is also a requirement for plant and bacterial growth. Therefore, some 
phosphorus is necessary in biological wastewater treatment processes (i.e. activated sludge) to 
ensure that there is sufficient nutrients for the microorganisms to remain viable. On the other 
hand, excessive phosphorus discharged into a receiving stream promotes plant growth leading to 
high levels of algae and other plant materials in the water. Wastewater treatment plants which 
discharge to the Lower Great Lakes area are required to remove excess phosphorus from their 

21 



effluents. 



Solids 



The determination of solids concentrations in water is quick and simple. These measurements 
thus provide a very quick indication of water quality. There are numerous types of solids that 
are analyzed, including: 



Dissolved solids 
Settleable solids 
Suspended solids 
Total solids 

Volatile solids 



- solids which are able to pass through an extremely fine mesh 
filter. 

- those solids which, when left for a given period of time, will 
settle out 

- solids which either float or are suspended in water, and are 
measured by entrapment in/on a filter. 

- includes dissolved, settleable and suspended solids. Measured by 
weighing the residue left when a given volume of water is 
evaporated. 

- solids which, when a total solid sample or suspended solid sample 
is heated to a high temperature, are burnt off. These solids 
approximate the amount of organic material in the water. 



Turbidity 

The term turbidity is applied to waters containing suspended matter which interferes with the 
passage of light. It can be caused by a wide variety of suspended materials ranging in size from 
colloidal to coarse particles. Colloids are very small particles suspended in water which cannot 
be removed through sedimentation or filtration without the use of chemicals. Turbidity can result 
from erosion or disturbance of river bottoms, and material originating from domestic and 
industrial wastewaters. Turbidity itself may not be dangerous to human health but may provide 
an indication of pathogenic or other harmful material. 

From a public perspective turbidity has two main effects. The first is aesthetic; a customer of 
drinking water expects to receive water with no noticeable cloudiness. Secondly, turbidity allows 
harmful microorganisms to become enveloped within solids and therefore protect themselves from 
disinfection. Turbidity removal normally requires both physical and chemical processes. 



22 



SAMPLING OF WATER/WASTEWATER 

One of the most common activities in any water treatment, wastewater treatment, water 
distribution and wastewater collection facility, is obtaining samples of the water. Provincial laws 
and the facility's Certificate of Approval set specific sampling requirements to ensure that the 
final product of the treatment facility meets the required health and environmental standards. In 
addition sampling within a facility is an important tool for optimizing the operation of the 
treatment processes. 

Whatever the purpose of the sampling, it is essential to sample in a consistent, accurate manner. 
All steps must be taken to eliminate any chance of contaminating the sample or the containers 
used in sampling. Sampling should be performed using a set routine to maintain consistency 
between sampling periods. Sample locations should also be consistent and must be chosen in 
order to obtain a water/wastewater sample which is representative of the actual flow of 
water/was tewater. It is important to remember that depending on how the sample is going to be 
analyzed, different sampling procedures may be required. Finally it is essential to label all 
samples, making any notes which may impact the interpretation of the test results. 

Typically two types of sampling occur in water/wastewater facilities: grab sample and composite 
sample. A grab sample is a single sample taken at one place and time. These samples may be 
appropriate where the water quality and quantity are not variable. A composite sample is a series 
of samples taken over a period of time which are combined to form a single sample. This type 
of sampling is necessary if the water quality changes gready over time. Composite samples are 
often collected using automatic samplers. 

MINISTRY OF ENVIRONMENT AND ENERGY OBJECTIVES 

The Ministry of Environment and Energy sets objectives for the quality of the ambient water and 
for treated drinking water. The objectives are based on the latest medical and environmental 
evidence. The Ministry refers to these objectives when establishing specific criteria for the 
drinking water quality or effluent quality which must be met at each facility. These plant specific 
criteria are stated in the Certificate of Approval which the Ministry issues to each facility. As 
an operator it is important to realize that your facility has legal requirements for maintaining 
certain chemical and physical parameters within established limits. 



23 



BASIC ELECTRICITY (ALL) 

Municipal facilities contain a variety of electrical equipment. It is important for operators to 
understand the basic electrical vocabulary used to describe this equipment. 

VOLTAGE 

Voltage (V) is the electrical potential or potential difference between two points. It indicates the 
strength of the "push" or "pressure" on current in an electrical circuit. Voltage is measured in 
volts (V). 

CURRENT 

Current (I) is a flow of electric charge. It can be compared to the current, or rate of flow of 
water, in a river. Current is measured in amperes (A). 

Current may either be alternating or direct. Alternating current (AC) changes strength and 
direction in a wave pattern with respect to time (t). The typical rate of change (or frequency) 
of alternating current is 60 cycles per second (Hz). Direct current (DC) remains at a constant 
strength and direction. 

I 4t I A> 



AC 




DC 



■> t 



Wires, fuses and circuit breakers are rated as to the maximum current which they may carry. 
When carrying more than their rated capacity wires or appliances may overheat and cause fires. 
Fuses and circuit breakers are designed to burn out or to break a circuit in preference to the 
burning of wire conductors. 

RESISTANCE 

Resistance (R) is the opposition offered by the wires of a circuit to the passage of electric 
current. This is similar to friction loss in pipes. Resistance is measured in ohms (Q.). 



24 



Voltage, current and resistance are related using the formula: 



Voltage (V) = CuneiH (I) x Resistance (R) 
V = IR 



POWER 

Power (P) is the rate at which work is done, or energy is produced. It can be compared to the 
horsepower of a car's engine. Power is measured in Watts (W). 

Power is related to voltage and current using the formula: 



Power (P) 
P 


= Voltage (V) x Current (I) 
~V 1 



BASIC HYDRAULICS (ALL) 

Hydraulics is the study of water or liquid at rest or in motion. Some common terms used when 
discussing hydraulics are defined below, along with their standard units of measurement, 

VELOCITY 

Velocity is the average speed at which water moves through a certain cross section or past a 
certain point. This is usually measured in kilometres per hour (km/h) and metres per second 
(m/s) in the metric system and miles per hour (mph) and feet per second (fps) in the Imperial 
system. 

FLOW RATE 

The flow rate is the measurement of water or liquid that flows through a conduit or pipe during 
a certain time period. This is usually measured in litres per second (L/s), cubic metres per 
second (m 3 /s) and megalitres per day (ML/d) in the metric system or gallons per day (gpd) in the 
Imperial system. 



25 



Rate of flow may be calculated by multiplying the velocity of the fluid by the cross-sectional 
area at right angles to the direction of flow. Formulas for rate of flow are given on the aid sheet 
found in Appendix E. 




Example 1 : Calculate the flow rate in a 400 mm diameter pipe if the velocity is 0.7 m/s. 



400 mm 



(1) Calculate cross-sectional area of pipe. 
. Area - n D 2 / 4 

= 3.1416 x (0.4 m) 2 / 4 
= 0.126 m 2 



0.7 m/s 



I 
I 
I 



(2) Calculate the flow rate 
Flow Rate = A x V 

= 0.126 m 2 x 0.7 m/s 
- 0.088 m 3 /s 



Example 2: Calculate the flow rate (m 3 /s) through a rectangular channel with a width of 3 
metres and a depth of 2.1 metres. The water has a velocity of 0.5 m/s. 



26 






3.0 m 



rt^V* 



SSb 



^N 



0.5 m/s 



How Rate = W x D x V 

= 3 m x 2.1 m x 0.5 m/s 

= 3.15 m 3 /s 

MEASURING FLOW RATE 

Flow rate is one of the most important measurements which an operator uses. This measurement 
will provide information on the detention times in tanks, flow between various processes or 
sections of a distribution/collection system, chemical feed rates, amount of water treated/pumped, 
costs of treatment, and the need for system expansion. There are numerous methods for 
measuring flow rate. The types of measurement are dependent on whether the water is flowing 
in a closed pipe or in an open channel. Open channels are measured using weirs or flumes. A 
weir is a dam or obstruction in the channel. A flume is a specially shaped constriction in the 
channel. In both cases the flow rate is related to the height of water at a particular point. Some 
of the common methods of measuring closed pipes include venturi meters, ultrasonic meters, 
magnetic meters, Doppler meters and orifice meters. Although flow meters are vital in the 
operation of a system, their usefulness depends on proper operation, calibration and maintenance. 

PRESSURE AND HEAD 

When water flows through a system under force, that force measured per unit of area is termed 
pressure. Pressure is usually measured in kilopascals (kPa) in the metric system and pounds per 
square inch (psi) in the Imperial system. Static pressure refers to the force exerted when water 
is at rest and not flowing. Pressure exerted by flowing water is known as dynamic pressure. 

It is often more convenient to express pressure in terms of a height of a column of fluid of 
constant unit weight. Therefore, the pressure at the bottom of a water column depends directly, 
and only, on the height of the column. When pressure is expressed in this way it is commonly 
referred to as pressure head. The head may be expressed in terms of feet of water column or 
inches of mercury in the Imperial system, or metres in the metric system. 



27 



Pressure can be measured using pressure gauges (a Bourdon pressure gauge is the most common) 
or with the use of manometers. 

FRICTION LOSS IN PIPES 

Friction occurs whenever there is flow through pipes. Friction causes a loss of head. Friction 
losses depend on the velocity or rate of flow, the length and size or diameter of a pipe and the 
apparent roughness of the pipe surface contacting the water. For a particular pipe, the larger the 
pipe diameter or the smoother the interior pipe surface, the lower the head loss due to friction. 
For this reason, pipe size will influence the velocity at which the water can flow through the 
system. If all else is equal (i.e. smoothness, pipe material and head) the smaller the pipe 
diameter the higher the velocity. As velocity increases friction losses increase, reducing the 
pressure at the outlet. This friction loss must be made up by way of higher energy inputs (for 
example additional pumping). 

WATER HAMMER 

When operating a distribution system it is important to understand the effects of pipe size and 
water hammer. As velocity increases friction losses increase, reducing the pressure at the outlet. 
This friction loss must be made up by way of higher energy inputs. 

Water hammer occurs when a moving fluid is suddenly stopped. The energy which must be 
absorbed within the system can create pressures which will destroy the piping and appurtenances. 
One can think of water hammer like a speeding train which is forced to stop very suddenly. 
Although the locomotive stops in its tracks the cars which follow derail since their energy cannot 
be absorbed by the train. To avoid water hammer, valves must be operated very slowly. 
Operators must be aware of situations where water hammer can have costly or disastrous effects. 

CAVITATION 

When operating pumps it is important to follow the pump directions. Cavitation can occur as 
a result of very low pressure within a pump. This low pressure causes the water to boil, releasing 
tiny bubbles. The bubbles will then collapse, with enough force to damage the pump impeller. 
Cavitation can be avoided if the pump capacity, speed, head and suction lift are properly 
determined. Cavitation can cause rapid damage to the impeller of a pump. A noise, similar to 
hammering of the pump impeller, will indicate to the operator that cavitation is occurring. 

28 



WATER TREATMENT (WT) 

Water in the natural environment contains many contaminants which make it unsuitable for 
human consumption. These contaminants include pathogenic microorganisms, colour, odour, 
suspended matter and chemicals which either endanger public health, are unappealing to the 
senses, or cause engineering problems. Treatment processes remove or decrease the contaminant 
levels so as to make the water fit for human consumption. The process described below is a 
typical process used in Ontario when water is drawn from a relatively clean body of surface 
water. Figure 1 illustrates the flow of water through a treatment facility. Groundwater supplied 
systems may have simpler treatment facilities due to the quality of the source water. 

Raw water is pumped from the source. The types of treatment processes which follow will 
depend on the overall water quality of the raw water. Often water (especially surface water) will 
initially pass through screens to ensure that large debris does not damage pumps and other 
equipment. The water may be dosed with chlorine or other chemicals to remove potential 
odours, to kill algae, or to control zebra mussels. This stage of chlorine dosing is sometimes 
referred to as pre-chlorination. (See the Water/Wastewater Chemistry section for more details). 

Raw water will contain small particles, known as colloids. These colloids produce a cloudy 
appearance known as turbidity. Turbidity can shield microorganisms from disinfection. Colloidal 
particles either do not settle or are very slow to settle. For this reason chemicals are added which 
will react with the colloids and the water to form relatively large, easily settleable particles. The 
mixing of these chemicals (coagulants) with the water is known as coagulation. The reaction 
between the coagulant and the particles is very fast and thus the chemicals must be mixed 
quickly and thoroughly in the water to assure that it has achieved maximum effect. For this 
reason the process is called rapid or flash mixing. The most commonly added chemical for this 
purpose is aluminum sulphate (Alum). Ferrous sulphate, ferric sulphate and various polymers 
are also commonly used coagulants. The water then passes into a flocculation tank. In the 
flocculation process the water is mixed slowly and the particles (fioc) build in size and density. 
The purpose of flocculation is to achieve optimum size particles which will readily settle out of 
the water. 



29 



Cx* 



TOR rSHKT MOCVASH LIHE 

ATIOH UMi r-FtLTtW 




ASH PUMPS 

[<M L1TT PUMPS 



ra Tovw and usmnur: 





D □ 

OH 



-»■- 



raSTCHUMNATlIM 



TTLO tO-IW UME 



FIGURE 1: SIMPLIFIED SCHEMATIC OF A 
TYPICAL WATER TREATMENT FACILITY 



The addition of too much or too little coagulant decreases the efficiency of the treatment process. 
For this reason it is very important to determine the correct dosage. The optimal chemical dose 
is determined in the laboratory using a "jar test" which simulates the conditions in the plant on 
a small scale. 

From this point the water normally flows into sedimentation tanks (or clarifiers) wherein the 
heavier matter settles due to gravity. The time the water remains in these tanks is known as 
detention time. The settled material is usually disposed of in the sanitary sewers. Surface 
waters may also require a pre-sedimentation period, before any other treatment process in order 
to remove very large material, such as sand and organic debris. 

The next step in the process is filtration. Removing as much suspended particles as possible is 
very important for the operation of a treatment facility. Not only will the water appear clean to 
the consumer, but removing suspended particles eliminates the possibility of dangerous bacteria 
being protected from the disinfection process. The most common type of filtration process is 
known as the rapid sand filtration. Although there are various types of rapid sand filters, most 
operate using the same general principles. These filters normally contain layers of anthracite, 
sand, and/or gravel. The tiny pore spaces in the filter "media" trap the suspended particles. Most 
matter which has not settled in the flocculation tank is entrapped by the filter media. Activated 
carbon may also be used to remove taste and odour problems. The quality of the water, as it 
leaves the filtration process can be determined by its turbidity. High turbidity may indicate that 
the filters require cleaning. 

Filters are cleaned on a regular basis (usually between 1 - 4 days depending on the facility) by 
a process known as backwashing. During this process the normal water flow is shut off and 
fully treated water is pumped up, backwards, through the filter media to remove the entrapped 
matter. The backwash water will be further treated to remove the solids or routed to the sanitary 
sewer. 

Before the water is distributed to the community one or more chemicals may be added to help 
disinfect, adjust pH, or remove other impurities. The most common addition is chlorine, used, 
primarily, to kill harmful microorganisms in the water. Chlorine, when used as a disinfectant, 
is added after solids removal but at a point which will allow complete mixing. It is necessary 
to ensure that the chlorine has sufficient time to react with the water and the microorganisms 
(this period of time is known as the chlorine contact time). For this reason the water and 
chlorine will be allowed to react in a chlorine contact chamber or clearwell. In this chamber 

31 



the chlorine residuals are raised to the required standards. (Additional information on 
chlorination can be found in the Water/Wastewater Chemistry section above). Other disinfection 
methods such as ozonation and ultraviolet radiation (UV), are also used. 

Taste and odour in drinking water is a common consumer complaint. By themselves taste and 
odour do not cause any health problems. To encourage consumer usage it is important for 
treatment facilities to minimize their impact. Several methods are in common use to combat taste 
and odour including aeration (i.e. mixing air in water), addition of chemicals such as chlorine 
or potassium permanganate, and the use of activated carbon. Generally, water of high oxygen 
content and low temperature produce a superior tasting water. 

Other compounds such as iron and manganese may also be treated if their concentration is too 
high. The most common methods of treatment are aeration, chlorination, addition of chemicals 
or ion exchange. Many treatment systems will also add fluorine to the water to prevent tooth 
decay. Chemicals may also be added to adjust the pH of the water. pH adjustment is often 
necessary to optimize the coagulation process. Waters which are corrosive in nature may also 
be treated chemically before distribution. 

After the water is treated it flows to a large tank, normally called a clearwell or chlorine contact 
chamber, where it is pumped to the distribution system. 

WATER DISTRIBUTION (WD & WT) 

Operators of water distribution systems must ensure that their clients have access to clean, safe 
water, while maintaining a sufficient pressure and volume to meet all of the users demands. 
Duties of a distribution system operator typically include operation of pump stations, location and 
repair of water main breaks, cleaning of distribution lines, chlorination of water distribution lines, 
reservoirs or storage containers and thawing of distribution lines during winter. Operators should 
always be aware of the consequences of cross-connections between a water distribution system 
and an unapproved source of water. Cross connections have lead to serious public health 
problems in many cities. 

Water distribution systems are designed to meet peak flows and fire fighting needs while 
maintaining uniform pumping and treatment rate. The systems consist of piping, pump stations, 
and storage facilities such as reservoirs, elevated tanks and standpipes. In addition, there are 



32 



numerous appurtenances such as valves, fire hydrants, meters and service connections. It is 
essential that distribution systems are operated to minimize supply interruptions, protect the water 
from contamination and maintain a positive pressure in the system at all times. Pressure within 
the system is provided by elevated storage reservoirs and/or pumps (in most systems the pressure 
is maintained between 240-550 kPa). It is extremely important to maintain a positive pressure 
within all portions of the system, not only to serve firefighting and customer needs, but also to 
prevent contamination of the system. Lack of positive pressure can cause contaminated ground 
water to enter pipes through cracks. As well, negative pressure may draw contaminated water 
from an unapproved source of water. 

Water distribution systems must also be prepared to operate under unusual conditions. These can 
include excessive demands caused by firefighting, or broken or frozen water mains. In addition 
pump failures can create serious problems. Plans need to be prepared and taught to all staff 
before an emergency occurs. 

Storage tanks and reservoirs are used to provide the community with emergency storage 
capabilities. It also allows the treatment facility to produce excess water during slow periods for 
use during periods of high demand. In this way the water treatment facility can be designed for 
the average demand rather than the peak demand. 

In most distribution systems the topography of the land requires the use of pumping stations to 
lift the water to a higher elevation and to maintain a positive pressure within all sections of the 
system. Several type of pumping stations are in common use. Stations may elect to use a pump 
large enough to handle the maximum flow rate although this tends to be inefficient. Stations may 
also use a variable speed motor to decrease the pumps capacity during low flow periods. 
Alternatively the station may consist of two or more pumps of different sizes to match the 
required rate of flow. Usually backup pumps will be available in the case of failure. 

The main distribution pipes within a system are known as the trunk mains. Smaller diameter 
pipes branch off and distribute water to individual streets and houses. Commonly used piping 
materials include, polyvinyl chloride plastic (PVC), asbestos cement (AC), ductile iron (DI), and 
concrete pressure pipe (CCP). 

Valves are used within a distribution system to isolate portions of the system for repair, cleaning, 
maintenance or adding additional lines. Valves may also be used to regulate the flow or pressure 
of water within a pipe. Different type of valves may be used for different applications. 

33 



Hydrants are used to fight fires and to flush lines and may be used to obtain water for 
construction purposes. It is important to be properly trained to operate hydrants. Improper use 
may result in damage, which could jeopardize the community's firefighting abilities. 

Some chlorine should remain in the water distribution system in order to continue disinfecting 
the water. Problems of taste and odour can occur because of an excessive chlorine residual or 
no residual. In drinking water, a residual of about 0.2 mg/L is optimal. Operators must be 
particularly careful to always have a chlorine residual in reservoirs and on dead ends. The 
chlorine residual should be tested regularly. The Ministry of Environment and Energy provides 
guidelines regarding appropriate sampling frequencies. Taste and odour complaints in part of the 
distribution system may indicate low levels of chlorine residuals in portions of the distribution 
systems. In these cases it is often necessary to rechlorinate the water at various locations 
throughout the distribution system to ensure the optimal residual level is maintained. Failure to 
maintain sufficient chlorine residual in the distribution system has lead to the out break of disease 
in some North American communities. 

The chlorine residual may be in the form of free chlorine or combined chlorine. Combined 
chlorine has a considerably lower disinfecting power than free chlorine. On the other hand, free 
chlorine does not last as long. The choice of which type of residual should be at least partly 
based on the bacteriological and chemical quality of the water and the type of treatment used. 

Periodically, the mains should be flushed to remove deposits from the pipelines. Hushing is 
normally achieved by opening a hydrant. Failure to flush the distribution pipes may lead to taste, 
odour, turbidity and disease problems. Leaks in the distribution system are also a concern for 
operators. Not only do leaks increase the amount of water which must be treated but can also 
result in contamination of the drinking water during backflow events. Backflow may occur under 
certain circumstances when the water pressure is turned off, resulting in a negative pressure in 
the pipe. This negative pressure results in the flow of water in the reverse direction. Backflow 
preventers are commonly used to prevent contamination of the lines. 

All of the components of a distribution system operate together as one. An operator must be 
aware of the system hydraulics, operating limitations, water quality, maintenance requirements 
and response times in order to meet the demands of the community. 



34 



WASTEWATER TREATMENT (WWT) 

Sewage contains many contaminants which must be removed or reduced before it can be returned 
to the natural environment. These contaminants include solids, BOD (a term to describe the 
amount of oxygen required by microorganisms to stabilize the matter), nutrients such as nitrogen 
(N) and phosphorous (P) which promote algae growth, pathogenic microorganisms and harmful 
chemicals. The process described below is typical of those found in wastewater treatment 
facilities in Ontario and is illustrated in Figure 2. The treatment processes are commonly divided 
into four steps: preliminary, primary, secondary and tertiary treatment. 

PRELIMINARY TREATMENT 

Sewage entering a wastewater treatment plant (WWTP) initially passes through a series of 
devices designed to remove or reduce in size large solids, grease, scum and grit before it enters 
further treatment processes. Coarse screens (also known as bar screens) are used to remove 
large objects from the wastewater. Larger particles may also be removed from the wastewater 
by chopping or shredding, in a process commonly known as comminution. After the screens 
and shredders, grit, such as sand, eggshells, stones and gravel, is removed in grit channels or 
chambers. These initial, preliminary treatment steps are necessary to ensure that large objects 
or grit do not damage piping or equipment in the treatment facility. Preliminary treatment 
precedes all municipal wastewater treatment facilities, no matter what other treatment processes 
are used. 

PRIMARY TREATMENT 

In some facilities, the sewage then flows to primary settling basins (often called the primary 
clarifier). In this process flow velocity is slowed so that solids settie or float to the surface. The 
settled and floated material is then removed and pumped to sludge handling facilities, while the 
decanted liquid proceeds to secondary treatment. This process is a physical process since it relies 
on gravity to separate settleable materials from the liquid. Primary treatment will remove 30 - 
40% of the BOD and 40 - 60% of the suspended solids from the sewage. 



35 




' D P 

LOB 




rfMTE VATW COLLECTION FACILITY 
OUT W*CL 



-ACMTUM IMM 



i— mil UMi 
/ /-COHWMUTC* ,-PWMARY ttfltKCHTATTON 



I — AEKAniM I 

/ r SECnw»Alt1 SCDOCXTATmN 

/ / f ■ CHLORINE CONTACT CHAMMX 



V 



— J " |o«jroc| 

El I u 

1 -TMIOCWJI 



£ 




X3 



IVJND STREAM 



\J "•" METHANE 



"V./ - 



TO LANDFILL 



-D10ESTOR 



SEASONAL LANS AmjCATlON V SLUDGE 



— xL 



FIGURE 2: SIMPLIFIED SCHEMATIC OF A 
TYPICAL WASTEWATER TREATMENT FACILITY 



SECONDARY TREATMENT 

Although the primary treatment has removed large settleable and floatable materials, the 
wastewater still contains a large amount of dissolved or unsettleable impurities. In most 
treatment facilities in Ontario a greater degree of treatment is desired. To achieve this higher 
quality the effluent from primary treatment (or occasionally directly from the preliminary 
treatment) is routed to aeration tanks where it is mixed with a bacterial mass, known as 
activated sludge. The bacteria mass (also known as the biomass) consumes the BOD as "food". 
Because these aerobic microorganisms require dissolved oxygen to survive air must be added in 
the aeration tanks. This is achieved with the use of surface aerators or air diffusers. The 
dissolved oxygen level must be monitored carefully since the microorganisms are sensitive to 
drops in the dissolved oxygen. 

As the microorganisms multiply they will tend to clump together. The mixture of wastewater 
and microorganisms is known as mixed liquor and is then sent to secondary ciarifiers where 
the activated sludge and other suspended material settle out. Part of the settled material is 
returned to the aeration basins to maintain the mass of activated sludge. The remainder of the 
sludge is sent to the sludge handling facilities. 

After the secondary clarifier the wastewater will be disinfected (see the section on chlorine in the 
Water/Wastewater Chemistry section). The most common method of disinfection is chlorination. 
The sewage is moved to chlorine contact chambers where chlorine is added to kill harmful 
organisms. The sewage may undergo further treatment (tertiary treatment) or it may be 
discharged to the environment. 

Although the activated sludge process, described above, is the most common in Ontario, other 
secondary treatment methods include aerated lagoons, trickling filters, and Rotating Biological 
Contactors (RBC). Like activated sludge process these methods depend upon the action of 
aerobic bacteria to break down the solids and BOD, and as such secondary treatment includes 
both physical and biological processes. 

Secondary treatment typically removes 80-99% of the BOD and suspended solids. 

SLUDGE DIGESTION 

During the treatment processes sludges will be created which must be further treated before their 

37 



final disposal. There are several different methods of treating sludge. The prime objective of 
all of these methods is to 'stabilize' the sludge so that there is a low oxygen demand. One of 
the more common methods is known as anaerobic digestion. In this method raw sludge which 
has settled in the primary and secondary clarifiers is "wasted" to anaerobic sludge digesters. It 
is held in the digesters for several weeks. During this period anaerobic bacteria (those which do 
not require dissolved oxygen) further break down the solids in the sludge to methane gas, carbon 
dioxide and inert solids. The gas may be further used as a fuel. 

Sludge may also be treated in aerobic digesters. In this process the same types of 
microorganisms used in the activated sludge process will further breakdown the sludge. 
Eventually as food runs out the microorganisms will use their own stored body mass for energy, 
resulting in a stable final product. 

The sludge which is removed from both anaerobic and aerobic digesters will often be further 
treated to remove water (dewatering). Often chemicals will be added to the sludge to assist in 
the dewatering process. Some common methods of dewatering include vacuum filtering, 
centrifuging, pressing, or drying beds. The final sludge may be spread on agricultural land or 
landfilled. Some facilities incinerate their sludge due to the high cost of transport to agricultural 
areas or high heavy metal content of the sludge. Sludge may also be composted to produce a 
valuable humus or soil conditioner. 

TERTIARY TREATMENT 

Some WWTPs also have tertiary processes to further treat the wastewater. There are many 
different types of tertiary processes but most involve physical/chemical processes. They include 
chemical precipitation, reverse osmosis, carbon adsorption, and filtration. 

* 

LAGOONS 

Many smaller communities within Ontario do not use a conventional activated sludge process but 
^nstead operate waste stabilization ponds (lagoons). Lagoons use natural physical and biological 
processes which occur in ponds to treat wastewater. Within the pond or lagoon solids settle to 
the bottom, while algae and bacteria process dissolved organic particles. Since raw wastewater 
usually enters the lagoons directly primary treatment is not required. Many different types of 
lagoons exist within Ontario, including aerobic, aerated and facultative lagoons. Aerobic 
lagoons are shallow (around 3 feet) and have a high concentration of dissolved oxygen. The 

38 



oxygen is required for the aerobic bacteria to break down organic materials. Anaerobic lagoons, 
on the other hand, do not require dissolved oxygen in the wastewater for the bacteria to process 
the organic material. Before the effluent is released to the receiving stream it may be chlorinated 
to kill any pathogenic microorganisms. 

Aerated lagoons are often used for high BOD loads, where the necessary area required for 
conventional lagoons is not available. Aerators are used to increase the oxygen content of the 
lagoon, in order to maximize aerobic bacterial action. The overall process is very similar to an 
conventional activated sludge system. Unlike most other lagoon systems, aerated lagoons may 
be operated with a continuous flow through of wastewater. (Other lagoons normally require a 
long retention time of wastewater, thereby requiring discharge of wastewater on a seasonal basis.) 

Lagoons which combine the features of an aerobic and anaerobic lagoon can also be used. These 
are known as facultative lagoons. In these relatively deep ponds, the upper layer of water is 
aerobic, while the bottom layer is anaerobic. Algae will use the energy from the sun will convert 
the wastewater nutrients into cell mass. As the algae die the cells settle to the anaerobic zone 
where anaerobic bacteria break the cells down into methane, organic acids, hydrogen sulphide 
and carbon dioxide. Oxygen is added to the lagoon through wind action, the photosynthesis of 
algae, or by mechanical mixing. Facultative lagoons are very common in Ontario. 

Lagoons can provide an economical alternative to conventional treatment, but require a large area 
of land and are less effective during the winter months. In some communities, with sufficiently 
large volume of wastewater, several ponds may be operated in parallel (several ponds operate 
independently) or in series (wastewater flows through several ponds before discharge). 

WASTEWATER COLLECTION (WWT and WWC) 

Wastewater collection facilities serve the purpose of transporting potentially hazardous materials 
in a safe manner for treatment and disposal. Wastes may include domestic sewage, industrial or 
commercial effluent, The waste is removed through sanitary sewers. Sewers which transport 
storm water runoff are called storm sewers. In older parts of some cities wastewater and storm 
runoff are carried by the same sewer, called a combined sewer. Cross connections between 
storm sewers and sanitary sewers should be avoided. Such connections will lead to the discharge 
of domestic and industrial waste into streams, rivers and lakes. 



39 



Operators of wastewater collection systems ensure that the flow of wastewater is not impeded. 
Operators will operate lift stations, flush and clean sewers, remove debris from sewers, repair 
sewer lines, and regulate flow. 

Wastewater is originally collected by service connections from a home/industry into a lateral or 
branch sewer. Main sewers will transport waste from the branch sewers to larger trunk sewers. 
Wherever possible, the wastewater will be conveyed by gravity, but often lift stations will be 
necessary to raise the wastewater to a higher elevation. A lift station will normally contain two 
pumps and an alternative source of power. Without constant pumping ability wastewater may 
backup the sewer resulting in flooded basements. From a lift station wastewater is pumped 
through a forcemain, or pressurized pipe, to a treatment facility or to an elevated gravity sewer. 
Sewers pipes can commonly made of concrete, asbestos concrete (AC), polyvinyl chloride (PVC), 
or vitrified clay pipe. 

Access to sewers are obtained through maintenance access points (manholes). Entry into a sewer 
is potentially dangerous, and should only be conducted by fully trained and equipped personnel. 
Provincial laws and regulations strictly regulate this activity. 

One of the primary concerns of an operator of a wastewater collection system is the avoidance 
of sewer surcharges. A surcharge occurs when a sewer is hydraulically overloaded (i.e. too 
much wastewater is trying to flow through a sewer) resulting in sewage backing up the collection 
system. A surcharge can result in the flooding of basements or the release of sewage through 
maintenance access points onto roads. Some of the contributing factors of surcharging are the 
inflow of surface water into sewers and the infiltration of groundwater through cracks in the 
sewer wall. Infiltration of groundwater can be a serious problem resulting in the collection and 
treatment of much larger volumes of water than is required. Exfiltration (the flow of wastewater 
through cracks in the sewer wall into the ground) is another serious problem which can result in 
the contamination of groundwater. 

Operators also must ensure that organic/inorganic material does not build up in the sewer. The 
easiest method of avoiding accumulation of material is to maintain a sufficiently high wastewater 
flow rate, or periods of high flow rates. Build up of organic materials may result in the 
production of hydrogen sulphide (H 2 S) and other potentially dangerous gases. These gases not 
only produce an unpleasant odour, but can also cause corrosion of sewer lines. When operating 
wastewater collection facilities, operators must be aware of the potential toxic, or explosive 
hazards of these gases. Due to the corrosive nature of sewage gases, mains must be kept clear 

40 



to allow sewage to move through the system quickly. 

Occasionally a sewer pipe will require cleaning to remove blockages or constrictions. These 
blockages may be caused by greases, roots or accumulation of organic materials. Several 
methods of cleaning are used, including using high velocity jet cleaners, flushing, power rodders, 
or bucket machines. 

EQUIPMENT (ALL) 

PUMPS 

Working as an operator, the most common machines you will encounter are pumps. It is 
important that you understand how each pump operates and the procedures for starting and 
stopping pumps. The consequences of operating pumps incorrectly can include system 
breakdown as well as component failure. The full consequence of starting or stopping any pump 
must be understood clearly before any action is taken. There are two basic types of pumps which 
are described below. 

The centrifugal pump pressurizes water by "throwing it" at high speeds from the centre of the 
impeller to the outside. Such pumps should normally be started with the oudet closed. The 
various types of centrifugal pumps are normally described by their impeller shapes. Common 
types are radial vane, Francis vane, mixed flow and axial flow. 

Positive displacement pumps operate by "pushing" the fluid mechanically. Such pumps are 
normally started with the suction valve and discharge valve open. Types of positive displacement 
pumps commonly encountered by operators include: screw, gear, piston, diaphragm and 
progressive cavity. 

Packing glands prevent the pumped fluid from leaking from a pump. The seal also prevents air 
from entering the pump casing. Packing failure can be expensive if not noticed in time. Signs 
of wear include poor pump performance, flooding and rusted or damaged components. 
Mechanical seals which use smooth contact surfaces to seal the fluid are also common. 



41 



PIPES 

Water and wastewater transportation systems can use cast iron pipe, ductile iron pipe, steel and 
reinforced concrete pipe, asbestos cement and plastic pipes (PVC, PE, ABS). New materials and 
compositions are constantly being developed. The most common pipe used in water systems 
generally has been the cast iron pipe, however PVC pipes are used increasingly, particularly in 
smaller pipes. The type of pipes used in a system depend on a combination of factors such as 
economy (material and installation), surrounding soil, strength, and anticipated life of the pipe 
material. 

VALVES 

Valves are used to stop or control the flow and pressure of a liquid or gas in a pipe. Many 
different types of valves are used in water/wastewater systems. These include gate valves, globe 
valves, butterfly valves, check valves, eccentric valves, air and vacuum relief valves. Each valve 
has a specific use. For example gate valves are used to completely stop the flow of liquid or gas. 
Globe valves and butterfly valves, on the other hand, can be used to control the amount of flow 
or pressure through the pipe (i.e. it can be set in between fully open and fully closed). Check 
valves are used to ensure that the liquid or gas can only travel in one direction in the pipe. Air 
and vacuum relief valves are used to release or admit air into a piping system. 

CONTROL AND INSTRUMENTATION 

Operators routinely monitor and control the flow of water/wastewater in their systems. An 
operator's efficiency depends on his/her ability to understand measurement and control devices. 
A measurement is a comparison between the process variable (i.e. pressure) and an acceptable 
standard. Water/wastewater facilities have a wide assortment of measuring or metering devices, 
including flow measurement (discussed above), temperature, and pressure. Control devices are 
used to change the processes within the system, if a certain condition exists. For example, a flow 
measuring devices will measure the rate of flow of water within a pipe and send an electronic 
signal to the controller. The controller will compare this rate of flow with the desired rate of 
flow for the pipe. If the rate of flow is beyond the acceptable range the controller will send an 
electronic signal to a valve. The valve in turn will either open or close in order for the desired 
rate of flow to be achieved. This type of system is known as a "feedback loop". The same 
principle is used to control your house's temperature with a thermostat 



42 



CROSS CONNECTION CONTROL 

Cross connection is a serious hazard. Operators should be aware of the problem of cross 
connection and how to prevent it. A cross connection is any connection to a potable water 
system which can allow any solid, liquid, or gaseous substance(s) to enter the potable water 
system, contaminating the disinfected water. Contamination occurs by backflow, which is a 
reversal of flow within a potable water system. 

Siphonic backflow is caused by a drop in or negative mains pressure. Back pressure backflow 
is caused through an unprotected connection to any equipment or device having a pressure higher 
than that available to the water main. 

Backflow prevention includes any effective device, method or construction used to prevent 
backflow into a potable water system. For example, check valves contain a hinged disc or flap 
that opens automatically in the direction of liquid flow, but prevents backflow. 

All outside taps on new residential buildings in Ontario must have a backflow valve attached to 
prevent syphoning of household chemicals such as pesticides. 

SAFETY (ALL) 

The most important knowledge required by inexperienced operators is that of safety. The person 
most responsible for your safety is yourself. New operators should be given an extensive safety 
briefing when starting work and they should question every activity where they are not sure of 
the safety procedures and risks. You should also know the location and use of all safety 
equipment such as eye wash fountains, first aid kits, self contained breathing apparatus (SCBA), 
fire extinguishers, Material Safety Data Sheets, etc. 

Treatment plants or distribution/collection systems are potentially dangerous places to work. 
Physical injuries and body infections are a continuous threat. Explosions and asphyxiations from 
gases or oxygen deficiency may occur, if proper procedures are not followed. Although 
infrequent at any particular location, such accidents are an all too common occurrence in the 
industry. Indeed, in the municipal sector wastewater collection and treatment is the most 
dangerous job next to solid waste collection. These occupational hazards may be largely avoided 
by following safe practices and the use of safety equipment. It is too late to consider safety 



43 



issues after an accident occurs. 

Accident prevention is the result of careful analysis of a situation, the application of a few basic 
principles and knowledge of the hazards involved. It has been said that the "ABC" of accident 
prevention is "Always Be Careful". One must learn how to be careful and what to avoid. 

The overall dangers of accidents are much the same whether in maintenance access points, 
pumping stations or treatment plants. These result from: 

1) body infections, 

2) physical injuries, and 

3) dangerous noxious gases or vapours, oxygen deficiencies and hazardous 
chemicals. 

Workers in wastewater treatment plants are exposed to the hazards of water- bome diseases, 
including Hepatitis, Typhoid Fever, Amoebic Dysentery, Infectious Jaundice and other infections. 
Tetanus and skin infections must also be guarded against. A majority of infections reach the 
body by way of the mouth, nose, eyes and ears. Therefore, washing your hands is a must before 
eating, smoking or using the washroom. It is generally a good policy never to put your hands 
above your collar when working with plant equipment. Wear protective gloves where possible. 

It is important to use safety equipment only as it is meant to be used. Protect eyes and face 
when there is any possibility of injuries from hand tools, power tools, welding equipment, 
chemicals, etc. Feet must be protected with safety shoes to safeguard against injuries while 
breaking pavements, tamping trenches, handling materials, etc. Hard hats are required to prevent 
serious injuries in construction, excavation, electrical work, buildings with low pipes or in other 
work as directed by your supervisor. Gloves should be used whenever handling materials, sharp 
objects, chemicals or electrical equipment. Use SCBA when hazards such as chlorine, painting 
or dusty areas exist. Accidents due to falls can be protected against by using safety belts and 
scaffolds. Spills must be immediately cleaned up to avoid slips. Except for minor injuries, 
wounds should be treated by a doctor and reported for possible Worker's Compensation. All 
injuries on the job must be reported to Worker's Compensation, as required by law. 

Hand tools are the cause of many accidents and injuries when improperly used and in unsafe 
condition. Therefore, use the right tool for the right job in the right way. Use protective safety 
equipment where there is a job hazard. Keep the work area clear of hazards, with plenty of 

44 



working space for solid footing. Tools should be in good condition and used for the purpose 
which they were intended. 

Electrical equipment is a common risk. When examining, working or repairing electrical 
equipment it is essential to lock out the control device. After these precautions have been taken, 
attach lock-out tags such as 'WORKERS ARE WORKING ON LINE.' Lock-out tags shall 
remain on the opened devices until removed by the worker whose name appears on the tag. 

Each operator should have first hand knowledge of fire extinguishers, its ABC rating, point of 
contact and time of operation. 

Sewers pose health risks, are smelly and physically dangerous. A particular problem is the 
accumulation of toxic or explosive gases such as hydrogen sulphide and methane respectively. 
It is illegal to enter a maintenance access point without testing for these gases and to ensure there 
is sufficient oxygen. Workers must also test for the presence of methane gas before removing 
a access cover to avoid any possibility of an explosion. There may also be a requirement to 
force ventilate the maintenance hole to ensure a safe working atmosphere, free of dangerous 
gases and with sufficient oxygen. 

Confined spaces pose a special safety hazard for operational staff. A confined spaces may be 
defined as any space to which exit by an injured person would be difficult. A confined space 
may also be defined as any space which because of its construction, location or contents 
hazardous gases or a deficiency of oxygen may occur. Examples would include a sewers, 
personal access points (manholes), digesters, and below grade lift/pumping stations. Special 
training is provided to workers who must enter maintenance holes or other confined spaces. 
Personnel who have not undertaken this training should not enter into a confined space. 

Chlorine safety is detailed under the general heading of chlorine. 

Safety in the work place is governed by the Ontario Health and Safety Act and its applicable 
regulations. These regulations should be explained to you by your supervisor. It is important 
to note that these regulations place demands on both you, your supervisor and your employer. 
To violate these regulations can lead to heavy fines and/or imprisonment. The Act also gives 
workers the right to refuse to do work if he/she has reasonable grounds that the work is 
dangerous. In such an event the worker must notify the supervisor immediately and remain on 
the job until an investigation is complete. 

45 



I 
I 
I 



APPENDIX A: 

CERTIFICATION FACT SHEET ; Number 2 MARCH 1994 

TOPIC: OPERATOR-IN-TRAINING (OIT) 

What is an operator-in-training licence? 

Operator-in-training (OIT) is a type of operator's licence required by an operator with less than 
one year of operating experience. It is issued after an examination is passed. 

An operator-in-training licence is the minimum requirement for aU existing or new staff before 
they may perform any operational duties. This would include part time and seasonal staff. 

Why does the operator-in-training designation exist? 

Under the law all personnel performing operational duties must be licenced. The operator-in- 
training designation was created to allow new operators to gain the necessary one year 
experience and process knowledge to enable them to obtain a Class I licence. The operator-in- 
training examination encourages the new operator to review basic processes within a facility, 
and tests for basic knowledge of mathematics and applied science. In addition, people seeking 
employment in the water/wastewater field may demonstrate their competence to prospective 
employers by taking the OIT examination. The OIT is also required by all current operators 
who missed the February 1, 1994 grandfathering deadline and are not currently licenced. 

What can an operator-in-training do? 

An operator-in-training is a fully licenced operator. All the duties which a licenced operator 
may perform can be done by an OIT. Operators-in-training may also be designated as an 
operator-in-charge. 

An OIT may not be an operator with overall responsibility or a backup for this person. 

An owner or supervisor must carefully consider what duties an OIT are capable of performing. 
The OIT designation was created as a way for operators to gain experience and knowledge so 
that they may write the Class I examination. It was not designed to by-pass the regular 
Certification process. Owners, supervisors or operators-in-overall responsibility are responsible 
to ensure that a facility is properly staffed with personnel properly trained and experienced to 
perform their duties. 

How do I become an operator-in-training? 

To become an OIT, the operator is required to receive 70% on the operator-in-training 
examination. In addition the operator is required to have completed grade 12 or its equivalent. 

Until August 31 1994 operators who were employed by February 1 1994, will have the grade 
12 requirement waived. 

An OIT licence may also be obtained by passing a Class I Certification examination. However, 
this process is slower and usually cannot be completed at the employee's workplace. 

47 



I 



What about the operator-in-training examination? 

The operator-in- training examination is designed to test a candidates basic knowledge on 
applied water/wastewater technology and basic mathematical skills. It is expected that new 
employees will be able to master the subject material within a week on the job, or through 
review of study materials. 

There is a separate examination for each type of facility (i.e. water treatment, wastewater 
treatment, water distribution, wastewater collection). The examination consists of a core of 43 
multiple choice questions which are the same for each type of examination. The topics include: 
basic and applied mathematics, basic and applied science, basic operating procedures, safety and 
legislation/responsibilities. In addition, 7 questions specific to the type of facility are included. 
If an operator requires a licence for more than one type of facility, they must write the core 
questions once, plus each specific facility questions. 

The operator-m-training examination may be administered by a supervisor at a facility. These 
examinations may also be written on the regular Ministry Certification examination dates, at 
the Brampton Training Centre or other examination locations across the province. Contact the 
Certification Office for further details concerning the exam locations. 

The Ministry of Environment and Energy wiU provide OIT candidates with specifically 
designed study material and examination "need to know" at a minimal cost. Although this 
material is not presently available, it should be ready for distribution by July 1994. 
The operator may write the examination as many times as required to be successful, but no 
more often than once per week. 

What is the cost of an operator-in-training licence? 

There is no cost for the operator-in-training examination or licence. Presently there is no limit 
to the number of years an operator may maintain an OIT licence. It is expected that in the 
future an OIT will be charged a fee if he/she has not obtained a Class I licence after a number 
of years. 

How do I apply for an operator-in-training? 

An owner or operator may apply to write an OIT examination by contacting the Certification 
Office: 

Ontario Environmental Training Consortium 

7510 Farmhouse Court 

Brampton, Ontario 

L6T 5N1 

FAX: 905-456-2246 

PHONE: 905-456-0266 •♦ dial "2" for the Certification Section 

Ministry of 

Environment PLEASE POST AT EACH FACILITY 

and Energy 

Ontario .■-■:■• .■--■■:. 




APPENDIX B: 

Ontario Water and Wastewater Operator Certification Program 

Operator-In-Training Examination 

"Need-To-Know" 

1. Basic and Applied Mathematics (20-25% content on OIT examination) 

1.1 Perform addition, subtraction, multiplication and division of whole numbers, fractions, 
decimals and percentages 

1.2 Express numbers in scientific notation 

1.3 Using conventional formulas, solve for: 

Direct and inverse proportions 

Area of rectangles, triangles, and circles 

Surface area of cylinders 

Volume of rectangular solids, prisms, cylinders, cones and spheres 

Flow/pumping rate 

1.4 Define and use metric prefixes 

1.5 Using conversion references, convert from Imperial to metric measurements and vice- 
versa 

1.6 Interpret graphs and tables 

2. Basic and Applied Science (20-25%) 

2.1 Define concepts in basic chemistry 

2.2 Identify and describe chemicals used in water/wastewater treatment 

2.3 Define and describe the significance of basic water/wastewater treatment chemistry 

2.4 Define and describe the significance of basic concepts in microbiology 

2.5 Define basic electrical concepts 

2.6 Define basic hydraulic concepts 

3. Operating Procedures (30-35%) 

3.1 Describe the purpose of water/wastewater treatment 

3.2 Describe general processes/process control in water treatment/distribution, wastewater 
treatment/collection 

3.3 Identify equipment/materials used in water treatment/distribution, wastewater 
treatment/collection 

4. Safety (15-20%) 

4.1 Identify basic categories of safety hazards and basic safety procedures including: 
Personal hygiene 
Personal safety procedures 
Fire/electrical safety procedures 
WHMIS 

5. Legislation (5-10%) 

5.1 Describe relevant regulations and acts 



49 



APPENDIX C: REFERENCES 

The following references. are among those useful for operators studying for the Operator-in- 
Training and Class 1 Certification Examinations. Telephone numbers for ordering these resources 
are listed. Some of these resources are available through the Certification Office at (905) 456- 
0266 ext 332. In addition the Certification Office produces a document entitled "Education & 
Certification Resource Guide For Water & Wastewater Utility Operators". This booklet lists a 
variety of study guides and training resources available to operators. 

BASIC MATHEMATICS 
Independent Learning Centre: (416) 965-2657 
Secondary School Credit Courses 

Western Canada Water/Wastewater Association: (403) 259-4041 

Alberta Water and Wastewater Operators Level 1 Manual, $60 

WATER AND WASTEWATER OPERATION 

California State University, Sacramento: (916) 278-6142 or 6366 

Water Treatment Plant Operation, Volume 1, $30 US 

Water Distribution System Operation and Maintenance, $20 US 

Operation of Wastewater Treatment Plants, Volume 1, $20 US 

Operation and Maintenance of Wastewater Collection Systems, Volume 1, $20 US 

Western Canada Water/Wastewater Association: (403) 259-4041 

Alberta Water and Wastewater Operators Level 1 Manual, $60 

SAMPLE EXAMINATION QUESTIONS 

American Water Works Association (AWWA): 1-800-926-7337 

Operator Certification Study Guide, Water Treatment/Water Distribution, $40 

Water Environment Federation (WEF): (703) 684-2400 

Certification Study Guide for Wastewater Treatment/Study Guide for Wastewater 
Collection System Personnel, $40 



51 



APPENDIX D: 
CONVERSION FACTORS - CANADIAN ABC EXAMINATION 



To the left are the SI units (Systeme 
International dTJnites) which, when 
multiplied by the conversion factors shown, 
are equal to the Imperial Measure units on the 
right of the table. The arrows next to each 
conversion factor show the direction of the 
conversions. 

Length 



mm 


x 0.039 37 




inches 


4- x 25.4 


mm 


x 3.28xl0- 3 


* 


feet 


4- x 304.8 


cm 


x 0.393 7 




inches 


4- x 2.54 


cm 


x 0.032 8 


•* 


feet 


4- x 30.48 


m 


x 39.37 


-» 


inches 


4- x 0.025 4 


m 


x 3.281 




feet 


4- x 0.304 8 


km 


x 3 280.84 




feet 




4- x 0.3048x IO- 3 




km 


x 1 093.61 


* 


yards 


4- x 9.144x10"* 


km 


x 0.621 4 


-» 


miles 


4- x 1 .609 


Weight/ 


Mass 




g 


x 2.205 x 10-3 




pounds 


4- x 453.59 


g 


x 15.432 3 


* 


grains 


4- x 0.064 799 


g 


x 0.035 27 


■> 


ounces 


4- x 28.349 5 


mg 


x 2.205 xlO- 6 


-» 


pounds 


4- x 453 592.3 


mg 


x 0.015 43 


-* 


grains 


4- x 64.799 


kg 


x 2.204 6 


-» 


pounds 


4» x 0.453 6 



Area & Volume 






m^ 




x 10.763 9 




square 
feet 


4- 


x 0.092 9 




m^ 




x 1.196 


-» 


square 
yards 


4- 


x 0.836 1 




m^ 




x2.471xl0^ 




acres 


4- 


x 4046.9 




ha 




x 2.471 




acres 


4- 


x 0.404 69 




cm- 3 




x 0.061 024 




cubic 
inches 


4- 


x 16.387 




m3 




x 35.315 




cubic 
feet 


4- 


x 0.028 32 




m3 




x 219.9 


-» 


Imperial 
gallons 


4- 


x 4.546x10-3 




L 




x 0.2199 




Imperial 
gallons 


4- 


x 4.546 




mL 




x 219,969.4 




Imperial 
gallons 


4- 


x 0.4346xl0- 5 




m 3 




x 0.2199x10-3 




million 
Imp. gallons 


4- 


x 4.546 




US gallon 




x 0.8327 




Imperial 
gallons 


4- 


x 1.2001 




Work/E 


ner 


gy & Power 




J 




x 0.737 6 




foot 
pounds 


4- 


x 1.356 




kJ 




x 0.947 8 




B. T. U. 


4- 


x 1.055 




kW 




x 1.341 


-» 


hp 

(electric) 


4- 


x 0.745 7 




Pressure 


Pa 




x0.145xl0-3 


-» 


pounds per 
square mcb 


4- 6.895x10-3 


kPa 




x 0.145 


■^ 


pounds per 
square inch 


4- 


x 6.895 




kPa 




X4.0145 


■^ 


inches of 
water column 


4- 


x 0.249 


kPa 




x0.10197 


-» 


inches of 
water column 


4- 


x 9.807 





53 



Flow Rates 


(volume / time) 








Us 






x 13.198 5 


■» 


gallons (Imperial) per minute 


«■ 


x 0.075 84 






L/s 






x 0.035 3 


■» 


cubic feet per second 


«■ 


x 28.3 16 






L/s 






X2.1189 


■> 


cubic feet per minute 


«■ 


x 0.471 9 






L/s 






x 127.134 


■» 


cubic feet per hour 


«■ 


x 7.8650 xlO- J 






L/s 






x 0.019 005 6 


* 


million (Imperial) gallons per dav 


«■ 


x 52.616 






L/d 






x 0.219 975 


■» 


gallons (Imperial) per day 


«■ 


x 4.545 9 






ML/d 






x 0.219 975 


<* 


million gallons (Imperial) per day 


«■ 


x 4.545 9 






m-Vd 






x 219.975 


•* 


gallons (Imperial) per day 


«■ 


x4.545 9xl0* j 






m J /d 






x 0.219 97 xlO" J 


* 


million gallons (Imperial) per day 


«■ 


X4.545 9X10 3 






m J /s 






x 19.005 6 


•» 


million gallons (Imperial) per day- 


«■ 


x 0.052 616 






m J /s 






x2 119 


■» 


cubic feet per minute 


«■ 


x 4.719x10^ 






m J /s 






x 35.315 


■» 


cubic feet per second 


«■ 


x 0.283 2 






10 J -nrVd 






x 490.596 


* 


million gallons (Imperial) per day 


* 


x 4.545 9 






m J /mio 


~¥~ 




x 17.70 


* 


cubic feet per minute 


x 0.028 32 







Rates 



kg/h 






x 2.205 


•» 


pounds f>er hour 


«- 


x 453 6 






kg/d 






x 2.205 


■* 


pounds per day- 


4- 


x 0.453 6 






g/tn^-s 






x 17.70 


■* 


pounds per dav per square foot 


♦ 


x 0.056 51 






kg/m^h 


«- 




x 4.883 


«» 


pounds per hour per square foot 


x 0.204 8 






kg/m 2 -d 






x 0.204 8 


■* 


pounds per square foot per day- 


«- 


x 4.883 






kg/had 






x 0.892 2 


-» 


pounds per acre per dav 


«■ 


x 1.121 






kg/ha -y 






x 0.892 2 


* 


pounds per acre per year 


«■ 


x 1.121 






kg/m-'d 






x 0.062 43 


■» 


pounds per cubic foot per day 


«■ 


x 10.02 






m/h 






x 3.281 


■» 


feet per hour 


«■ 


x 0.304 8 






nr"m 2 -h 






x 3.281 


■» 


gallons (Imperial) per day per square foot 


«■ 


x 2 0385 \ 10° 






ro J/ m z h 






x 20.44 15 


-> 


cubic feet per hour per square foot 


«■ 


x 0.304 8 






m j/ m 2 d 






x 16.02 


■» 


gallons (Imperial) per day per square foot 


«■ 


x 0.048 92 






m J /kg 






x35.315 


■» 


cubic feet pier pound 


«■ 


x 0.062 43 







54 



APPENDIX E: 

FORMULAS - Operator-in-Training Examination 



AREAS 



Triangle 

Aiea = V4 BxH 

B = length of base 

H = height of triangle 

Circle = n R 2 or reD 2 , 
Area 4- 




Rectangle 

Area = L x W 1 

w 
L = length of rectangle i 

W = width of rectangle 



11 


= 3.1416 


R 


■ radius 


D 


- diameter 



VOLUMES 



Jgl 



Rectangular tank 
Volume = area of base x H 
orV = L x W x H * { t— L > 



s 



L ■ length of rectangle 
W = width of rectangle 
H = height of rectangle 



Cylindrical tank 

Volume = area of base x H 
or V = x R 2 x H 
or V = rc_Di x H 
4 



<3 



R = radius of base 
D = diameter of base 
H =height of cylinder 



Cone 

Volume = 1/3 area of base x H 
or V = 1/3jiR 2 x H 

orV =1/371 jgxH- J.jtD*xH 

4 12 ♦ 



*-*' 




R = radius of base 

D = diameter of base 

H = height of cone from base to apex 



Prism 

Volume = Vi area of rectangular base x H 
orV = V* L x W x H 




±S2_ 



L = length of rectangular base 
W = width of rectangular base 
H = heigh tfrom base to apex 



Sphere .(ball) 
Volume ■ 4tcR 3 

3 
orV = 4t: gs 

3 8 



I JtD 3 
6 




R = radius of sphere 
D ■ diameter of sphere 




Lagoon 

Approx. - W x L + (W-2SD) x (L-2SD) xD 

Volume 2 



W - width of lagoon 
L ■ length of lagoon 
S ■ slope (ratio of horizontal to vertical distances on die interior sides of lagoon example 3:1, slope is taken as 

3) 
D = depth of lagoon or depth of liquid in lagoon 



RATE OF FLOW 



Rate of flow 
(m 3 /s) 




W = width of channel (m) 

D = depth of liquid in channel (m) 

V = velocity of the flow (m/s) 



(2) Pipe 
Rate of flow 
(m 3 /s) 



= Ax V 




A ■ cross sectional area (m 2 ) 
V - velocity (m/s) 



APPENDIX F: LIST OF THE ELEMENTS 



Name 


Symbol 


Atomic 


Atomic 


Name 


Symbol 


Atomic 


Atomic 


Name 


Symbol 


Atomic 


Atomic 






Number 


Weight 






Number 


Weight 






Number 


Weight 


Actinium 


Ac 


89 


227 


Gold 


Au 


79 


196.967 


Potassium 


K 


19 


39.102 


Aluminum 


Al 


13 


26.9815 


Hafnium 


Hf 


72 


178.49 


Praseodymium 


Pr 


59 


140.907 


Americium 


Am 


95 


243 


Helium 


He 


2 


4.0026 


Promethium 


Pm 


61 


147 


Antimony 


Sb 


51 


121.75 


Holmium 


Ho 


67 


164.930 


Protactinium 


Pa 


91 • 


231 


Argon 


Ar 


18 


39.948 


Hydrogen 


H 


1 


1.00797 


Radium 


Ra 


88 


226 


Arsenic 


As 


33 


74.9216 


Indium 


In 


49 


114.82 


Radon 


Rn 


86 


222 


Astatine 


At 


85 


210 


Iodine 


I 


53 


126.9044 


Rhenium 


Re 


75 


186.2 


Barium 


Ba 


56 


137.34 


iridium 


lr 


77 


192.2 


Rhodium 


Rh 


45 


102.905 


Berkelium 


Bk 


97 


249 


Iron 


Fe 


26 


55.847 


Rubidium 


Rb 


37 


85.47 


Beryllium 


Be 


4 


9.0122 


Krypton 


Kr 


36 


83.80 


Ruthenium 


Ru 


44 


101.07 


Bismuth 


Bi 


83 


208.980 


Lanthanum 


La 


57 


138.91 


Samarium 


Sm 


62 


150.36 


Boron 


B 


5 


10.811 


Lawrencium 


Lw 


103 


257 


Scandium 


Sc 


21 


44.956 


Bromine 


Br 


35 


79.909 


Lead 


Pb 


82 


207.1 


Selenium 


Sc 


34 


78.96 


Cadmium 


Cd 


48 


112.40 


Lithium 


Li 


3 


6.939 


Silicon 


Si 


14 


28.086 


Calcium 


Ca 


20 


40.08 


Lutetium 


Lu 


71 


174.97 


Silver 


Ag 


47 


107.868 


Californium 


Cf 


98 


251 


Magnesium 


Mg 


12 


24.312 


Sodium 


Na 


11 


22.9898 


Carbon 


c 


6 


12.01115 


Manganese 


Mn 


25 


54.9380 


Strontium 


Sr 


38 


87.62 


Cerium 


Ce 


58 


140.12 


Mendelevium 


Md 


101 


256 


Sulphur 


S 


16 


32.064 


Cesium 


Cs 


55 


132.905 


Mercury 


Hg 


80 


200.59 


Tantalum 


Ta 


73 


180.948 


Chlorine 


CI 


17 


35.453 


Molybdenum 


Mo 


42 


95.94 


Technetium 


Tc 


43 


99 


Chromium 


Cr 


24 


51.996 


Neodymium 


Nd 


60 


144.24 


Tellurium 


Te 


52 


127.60 


Cobalt 


Co 


27 


58.9332 


Neon 


Ne 


10 


20.183 


Terbium 


Tb 


65 


158.924 


Copper 


Cu 


29 


63.546 


Neptunium 


Np 


93 


237 


Thallium 


Tl 


. 81 


204.37 


Curium 


Cm 


96 


247 


Nickel 


Ni 


28 


58.71 


Thorium 


Th 


90 


232.038 


Dysprosium 


Dy 


66 


162.50 


Niobium 


Nb 


41 


92.906 


Thulium 


Tm 


69 


168.934 


Einsteinium 


Es 


99 


254 


Nitrogen 


N 


7 


14.0067 


Tin 


Sn 


50 


118.69 


Erbium 


Er 


68 


167.26 


Nobclium 


No 


102 


253 


Titanium 


Ti 


22 


47.90 


Europium 


Eu 


63 


151.96 


Osmium 


Os 


76 


190.2 


Tungsten 


W 


74 


183.85 


Fermium 


Frn 


100 


253 


Oxygen 


O 


8 


15.9994 


Uranium 


u 


92 


238.03 


Fluorine 


F 


9 


18.9984 


Palladium 


Pd 


46 


106.4 


Vanadium 


V 


23 


50.942 


Francium 


Fr 


87 


223 


Phosphorus 


P 


15 


30.9738 


Xenon 


Xe 


54 


131.30 


Gadolinium 


Gd 


64 


157.25 


Platinum 


Pt 


78 


195.09 


Ytterbium 


Yb 


70 


173.04 


Gallium 


Ga 


31 


69.72 


Plutonium 


Pu 


94 


242 


Yttrium 


Y 


39 


88.905 


Germanium 


Ge 


32 


72.59 


Polonium 


Po 


84. 


210 


Zinc 
Zirconium 


Zn 
Zr 


30 
40 


65.37 
91.22 



APPENDIX G: HELPFUL HINTS FOR STUDYING 

Effective study demands concentration. The ability to concentrate is largely determined by the 
individual's surroundings and physical condition. Being absorbed in study is being oblivious to 
everything else. Learning to concentrate is learning to overcome distractions. 

Many distractions are best dealt with by elimination. The student who wants to do concentrated 
work can best begin by doing away with all unnecessary disturbances. A few important 
suggestions follow: 

FAVOURABLE CONDITIONS FOR CONCENTRATION 

1. Study in a quiet room free of any distractions such as TV, radio, telephone and other 
household members. 

2. Make sure the room is properly lighted, heated (68 - 70'C) and properly ventilated. 

3. Arrange your chair and work to avoid strain and fatigue. Shift your position from time 
to time. Be comfortable, but avoid being too comfortable. It is very difficult to study 
when reclining on a couch or easy chair. 

EFFECTIVE STUDY HABITS 

When studying, as when doing business, it is important to have a plan of action. If the plan is 
consistently followed, study becomes a natural part of your day. A fixed program of study is one 
of the greatest aids to effective and efficient work. 

1. Always study in the same place. Have a particular table and chair which are always used 
for study and intellectual work. Your mind will come to associate this place with 
studying. 

2. Only study for two hours at a time. Research has shown that little benefit results from 
extended study time. If you want to study more than 2 hours in one day, take a break 
first. Go for a walk, exercise or just relax between study periods. 



59 



3. Try to study at the same time every day. Make sure it is a time when you can study 
uninterrupted. Everyone has their own preference, however try to follow some basic 
guidelines, such as: pick a time of day when you feel mentally alert and avoid times 
when there is a lot of activity around you. 

EFFECTIVE READING METHODS 

In order to gain the most out of your study time you must learn how to read quickly and 
effectively. Usually an assignment is best mastered by combining an initial rapid survey with 
a more careful and thoughtful second reading. 

- 

1 . Think about the topic of study before beginning to read. Prepare your mind. Retire to 
your area of study and sit quietly and concentrate on the topic at hand. 

2. Be acquainted with the reading at the onset. Gain a first impression of the book by 
noting the title, section headings and manner of presentation. Decide what you expect 
to achieve. 

3. Read through rapidly at first. This technique will give you a good background 
understanding without bogging you down with too many of the details. 

4. Read through a second time. This time read more slowly, thoroughly and thoughtfully 
paying attention to more detail. Really concentrate on the meaning of what you are 
reading. 

5. Make note of important points in your reading; highlight your book or make summary 
notes to use for your review. 

6. Review the examination objectives (need-to-know). At the completion of a section, make 
sure you can answer all the questions related to the objectives of that section. 

7. Complete each section thoroughly. Before moving on to the section be sure you have 
fully understood all the material covered in the previous section. Sections often build on 
each other, making it difficult to move forward without a thorough understanding. 



60 



CRAMMING AND EXAMINATIONS 

Cramming may be good or bad, depending on what is meant by it. If it refers to feverish last 
minute efforts to memorize masses of previously unstudied material, it is harmful. It only serves 
to introduce fragments of knowledge that are quickly forgotten. 

If cramming is interpreted as meaning a strenuous review at the end of intensive study, it is 
highly recommended. You can refresh your memory by running over the main ideas that you 
covered. If you have summary notes, use these for review. 

1. Review the main points, getting a skeleton view of the subject. You should avoid 
memorizing scattered details. Focus on the main ideas and how the details are organized 
within this context. 

2. Give yourself plenty of time for reviewing to avoid last minute pressures. Begin at least 
a week or two before the examination. Leave only a few finishing touches for the day 
before the examination. 

3. Review the objectives (need-to-know) for the examination. Think over the kinds of 
questions which will probably be asked, and plan how to answer them. 

4. When the examination period comes, be well rested, and remain as calm and self- 
confident as possible. 

ANSWERING MULTIPLE CHOICE QUESTIONS 

Multiple choice questions consist of a statement and several options for the answer. Only one 
answer is correct. The other, incorrect, options are called distracters or decoys. The following 
techniques will increase your chances of doing well on a multiple choice examination. 

1. Listen to the examination administrator's instructions and read the directions carefully. 

2. Read each question all the way through before answering. Often times an individual may 
feel overly confident and jump to answer the question without completely understanding 
what is being asked. One word could make the difference to the whole meaning of the 
question. 

61 



3. Read the options all the way through. 

4. Mark only one best answer. Often times more than one answer may seem appropriate, 
however mark the most appropriate. 

5. After you read the questions and the options, spend no more than a few seconds puzzling 
over the question (unless it is a calculation). 

6. If the answer does not come to you right away, mark the question and move on to the 
next. 

7. When you have worked your way through the test, go back to the questions you have 
marked for reconsideration. 

8. The second time, mark one option and move on. 

9. Make sure to answer every question. There is no penalty for guessing. 

10. Reserve time to go over you answers and make necessary changes. 

11. Watch out for negative and extreme words. Whenever you find negative words such as 
"not" or "except" in the question, circle them so they will stand out. Make sure you take 
them into consideration when you choose your answer. 

12. Foolish options are usually incorrect. They are often simply distractions. 

13. Check for look alike answers. Test makers occasionally list two options that are alike 
except for one word. It is likely that one of the pair is correct — however read the 
options carefully. 

CALCULATION PROBLEMS 

Calculation problems are an important, and often challenging, part of all Operator Certification 
Examinations. The following suggestions will help you to solve calculation questions. 

1. Make a drawing or sketch to help visualize the problem. 

62 



2. Break complex problems down into sections that you may solve separately. Simplify 
questions whenever possible. 

3. Convert to the units required in the answer. 

4. Round all answers to the nearest significant figure. For example, 68.575122 kg can be 
rounded to 69 kg if your measurements are only accurate to the nearest kg. 

5. Check that your decimal place is in the proper position. 

6. Make sure- that your answer makes sense. For example, if you determine the annual cost 
for coagulant in a 10 mgd plant is $800,000,000,000, something is obviously wrong. 



63 



APPENDIX H: 
WATER/WASTEWATER FACILITY OPERATORS GLOSSARY 

(Source - Glossary Water and Wastewater Control Engineering, Ingram et al, Published by AWWA 
et al, 1969) 

As an Operator-In-Training you will be placed in an "environment" which has a language unto its own. 
It is important that you quickly become familiar with the terms which your more senior colleagues use. 
Listed below are some of the terms which are commonly used in your new career field. 



ABS 



Customary abbreviation of sodium alkyl benzene sulphonate. It is used to make 
Pipe- 



absorption 



The taking up of one substance into the body of another. 



acidic - 
acidity - 



A solution with a pH less than seven (7). 

The quantitative capacity of aqueous solutions to react with hydroxy ions. It is 
measured by titration with a standard solution of a base to a specified end point. 
Usually expressed as milligrams per litre as calcium carbonate. 



activated 
sludge - 



Sludge floe produced in raw or settled wastewater by the growth of zoogloeal bacteria 
and other organisms in the presence of dissolved oxygen and accumulated in 
sufficient concentration by returning floe previously formed. 



adsorption - The taking up of one substance at the surface of another. 

aerobic - Requiring, or not destroyed by, the presence of free elemental oxygen. 

algae - Comparatively simple plants, one- or many-celled, usually aquatic, and capable of 

by obtaining energy through photosynthesis. 



65 



alkaline 



The condition of water, wastewater, or soil which contains a sufficient amount of 
alkali substances to raise the pH above 7.0. 



anaerobic - 



Requiring, or not destroyed by, the absence of air or free (elemental) oxygen. 



appurtenances 



Machinery, appliances, or auxiliary structures attached to a main structure to enable 
it to function, but not considered an integral part of it. 



autotrophic 
organisms - 

backflow - 



Bacteria which thrive by using inorganic materials for energy and growth. 



A flow condition, induced by a differential in pressure, that causes the flow of water 
or other liquid into the distribution pipes of a potable water supply from any source 
or sources other than its intended source. 



backflow - 
preventer 

basic data 



BOD 



buffer - 



bypass 



Certificate of 
Approval - 



A device for a water supply pipe to prevent the backflow of water into the water 
supply system from the connections on its outlet end. 

Records of observations and measurements of physical facts, occurrences, and 
conditions, as they have occurred, excluding any material or information developed 
by means of computation or estimate. In the strictest sense, basic data include only 
the recorded notes of observations and measurements, although in general use it is 
taken to include computations or estimates necessary to present a clear statement of 
facts, occurrences, and conditions. 

Biochemical oxygen demand. The quantity of oxygen used in the biochemical 
oxidation of organic matter in a specified time, at a specified temperature, and under 
specified conditions. It is a standard test used in assessing wastewater organic 
strength. 

A solution containing a weak acid and its conjugate weak base whose pH changes 
only slightly on the addition of an acid or alkali. 

An arrangement of pipes, conduits, gates and valves whereby the flow may be passed 
around a hydraulic structure or appurtenance. 

A document issued by the Ministry of Environment and Energy which approves an 
undertaking (such as the construction of alteration of a water or wastewater treatment 
facility). The C of A's purpose is to ensure the quality of the environment and 
human health are protected. 



check valve - A valve which permits flow in one direction only. 



66 



chlorine 
residual - 

COD- 

coliform - 
concentration 



confined 
space - 

cross 
connection 



crown - 
curb cock 

facility - 
flushing - 



flume 



force main - 



gage 

(or gauge) - 



The chlorine measured in water or wastewater, after application of chlorine. 

Chemical oxygen demand, (see BOD above) 

A non pathogenic bacteria which indicates the possibility of pathogens. 

(1) The amount of a given substance dissolved in a unit volume of solution. (2) The 
process of increasing the dissolved solids per unit volume of solution, usually by 
evaporation of the liquid. 

A work area which has difficult egress and which may have toxic explosive gases 
or limited amounts of oxygen. 

(1) A physical connection through which a supply of potable water could be 
contaminated or polluted. (2) A connection between a supervised potable water 
supply and an unsupervised supply of unknown potability. 

The inside top of a sewer. 

A shut off valve attached to a water service pipe from a water main to a building, 
installed near the curb, which may be operated by a valve key to start or stop flow 
in the water-supply lines of a building. Also called a curb stop. 

Something designed, built, or installed to serve a specific function. 

(1) The removing of deposits of material which have lodged in conduits, sewers, or 
tanks because of inadequate velocity of flow. Water or wastewater is discharged into 
the conduits at such rates that the larger flow and higher velocity are sufficient to 
remove the material. (2) The release of water from hydrants to remove deposits 
from water pipes leading to the hydrant. 

An open conduit of wood, masonry, or metal constructed on a grade and sometimes 
elevated. Sometimes called aqueduct. 

A pressure pipe joining the pump discharge at a water or wastewater pumping station 
with a point of gravity flow. 

(1) A device for indicating the magnitude or position of an element in specific units 
when such magnitude or position undergoes change; examples of such elements are 
the elevation of a water surface, the velocity of flowing water, the pressure of water, 
the amount of intensity of precipitation, and the depth of snowfall. (2) The act or 
operation of registering or measuring the magnitude or position of a thing when these 
characteristic are undergoing change. (3) The operation of determining the discharge 
in a waterway by using both discharge measurements and a record of stage. 



67 



hazardous work A room or area in which hazardous materials are stored, such as the room in which 
area - chlorine cylinders are stored. 



head 



hydrant 



hydrogen 
sulphide (H 2 S) 

infiltration - 



invert 



isotopes 



The height of the free surface of fluid above any point in a hydraulic system; a 
measure of the pressure or force exerted by the fluid. (2) The energy, either kinetic 
or potential, possessed by each unit weight of a liquid, expressed as the vertical 
height through which a unit weight would have to fall to release the average energy 
possessed. It is used in various compound terms such as pressure head, velocity 
head, and loss of head. (3) The upper end of anything, as headworks. (4) The 
source of anything, as head water. (5) A comparatively high promontory with either 
a cliff or steep face extending into a large body of water, such as a sea or lake. An 
unnamed head is usually called a headland. 

A device, connected to a water main and provided with the necessary valves and 
outiets, to which a fire hose may be attached for discharging water at a high rate for 
the purpose of extinguishing fires, washing down streets, or flushing out the water 
main. Also called fire plug. It is normally designed to drain itself when not in use. 

(1) Gas resulting from the decomposition of organic matter in waste water. (2) Gas 
produced during the digestion of sludge. 

(1) The flow or movement of water through the interstices or pores of a soil or other 
porous medium. (2) The quantity of groundwater that leaks into a pipe through 
joints, porous walls, or breaks. (3) The absorption of liquid by the soil, wither as 
it falls as precipitation or from a stream flowing over the surface. 

The floor, bottom, or lowest portion of the internal cross section of a closed conduit. 
Used particularly with reference to aqueducts, sewers, tunnels, and drains. 
Originally, it referred to the inverted arch which was used to form the bottom of a 
masonry-lined sewer. 

Atoms with the same atomic number (same chemical element) but different atomic 
weights. Atoms of which the nuclei have the same number of protons but different 
numbers of neutrons. 



jar test - A laboratory procedure to determine the optimum coagulant dosage. 

lateral - A sewer that discharges into a branch or other sewer and has no other common 

sewer sewer tributary to it. 

lift station - A wastewater pumping station that lifts the wastewater to a higher elevation when 

the continuance of the sewer at reasonable slopes would involve excessive depths of 
trench, or that raises wastewater from area too low to drain into available sewers. 



log 



A written record of events. 



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neutral - 

nutrient - 

open switch - 

packing - 
gland 

pathogens - 

pH- 

precipitate - 
priming - 
PVC- 

sedimentation 



slope 



sludge 



pH of 7. 

Phosphorus or nitrogen which promotes plant growth. 

An electric switch in the "off position so that there is no electrical connectivity. 

A device which retains packing around a rotating axle or shaft, this packing 
separates a fluid from the atmosphere -ie. it holds it within a pump 

Pathogenic or disease-producing organisms. 

The reciprocal of the logarithm of the hydrogen-ion concentration. The concentration 
is the weight of hydrogen ions, in grams, per litre of solution. Neutral water, for 
example, has a pH value of 7 and a hydrogen ion concentration of 10" 7 . 

Insoluble settleable substance which is a product of a chemical reaction within a 
liquid. 

(1) The First filling with water of a canal, reservoir, or other structure built to contain 
water. (2) The action of starting the flow in a pump or siphon. 

Polyvinyl chloride - A white water insoluble thermoplastic resin, used for making 
pipes. 

The process of subsidence and deposition of suspended matter carried by water, 
wastewater, or other liquids, by gravity. It is usually accomplished by reducing the 
velocity of the liquid below the point at which it can transport the suspended 
material. Also called settling. 

The inclination of gradient from the horizontal of a line or surface. The degree of 
inclination is usually expressed as a ration, such as 1:25, indication 1 unit rise in 25 
units of horizontal distance; or in a decimal fraction (0.04); degrees (2 deg 18 min); 
or percent (4 percent). (2) In water supply and wastewater hydraulics, the inclination 
of the invert of a conduit expressed as a decimal, or as metres per stated length 
measured horizontally in metres. 

(1) The accumulated solids separated from liquids, such as water or wastewater, 
during processing, or deposits on bottoms of streams or other bodies of water. (2) 
The precipitate resulting from chemical treatment, coagulation, or sedimentation of 
water or wastewater. 



spring line - The centre line of a sewer. 

supernatant - The liquid standing above a sediment or precipitate. 



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suspended (1) Solids that either float on the surface of, or are in suspension in, water, 

solids - wastewater, or other liquids, and which are largely removable by laboratory filtering. 

(2) The quantity of material removed from wastewater in a laboratory test, as 
prescribed in "Standard Methods for the Examination of Water and Wastewater" and 
referred to as nonfilterable residue. 



tertiary - 
treatment 



Treatment to remove nutrients from sewage before discharge to the environment 



thrust block - A restraint to prevent separation of pressurized pipe systems at bends or ends. 

trench - (1) An excavation made for installing pipes, masonry walls, and for other purposes. 

A trench is distinguished from a ditch in that the opening is temporary and is 
eventually backfilled. (2) A relatively long but narrow structural or erosional feature 
of the earth's surface or the floor of the ocean. 



trunk - 
sewer 



A system of major sewers serving as transporting lines and not as local or lateral 
sewers. 



turbidity 



weir 



(1) A condition in water or wastewater caused by the presence of suspended matter, 
resulting in the scattering and absorption of light rays. (2) A measure of fine 
suspended matter in liquids. (3) An analytical quantity usually reported in arbitrary 
turbidity units determined by measurement of light diffraction. 

(1) A diversion dam. (2) A device that has a crest and some side containment of 
known geometric shape, such as a V, trapezoid, or rectangle, and is used to measure 
flow of liquid. The liquid surface is exposed to the atmosphere. Flow is related to 
upstream height of water above the crest, to position of crest with respect to 
downstream water surface, and to geometry of the weir opening. 



70 



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