of water supply is to provide adequate water that is suitable and
safe for a variety of uses in the community. Water supply may be
a complex system in a larger town or city or a simple rainwater
tank attached to a house on a remote property. In terms of public
health the common need for satisfactory water supply includes a
source of water that is:
to meet the demands for drinking water and personal and domestic
a good quality that will not impact health.
development and management aspects of water supplies are large subject
areas. Many aspects of engineering and public health protection
are involved. The following is an introduction to core concepts
and factors related to water safety and quality in terms of public
water - healthy people
Water is one
of the few things that we cannot live without. Adequate and safe
drinking water is essential for achieving and maintaining good health.
Worldwide experience shows that protecting and maintaining the water
supply source and distribution systems will reduce the chance of
a range of diseases for the users of water.
Water is used
for many non-drinking uses in our homes and communities. It can
be critical in keeping our living environment cool – through
evaporative cooling, and it can be used for dust control. Many homes
and communities use water to grow shade trees and provide landscaping
around their homes or to grow crops that may otherwise be difficult
to obtain. Consumption of poor quality drinking water is not the
only way water may affect health. Diseases may also be contracted
whilst preparing food or bathing using contaminated or poor quality
water. Our health and the health of our community, particularly
in dry environments where water may be limited, is closely related
to access to adequate and safe water.
one of the driest countries in the world. As a result many remote
communities have significant challenges in acquiring and providing
adequate and safe water supplies. Communities in high rainfall areas
may not have challenges in providing an adequate supply (in terms
of quantity) but they may have challenges in providing safe water.
This is because many other factors affect the safety of a supply
including the types of land use in the catchment; access and maintenance
of infrastructure; and access to finances for capturing, storing,
treating (including disinfection where necessary) and distributing
water to users.
need to be active to ensure adequate and safe water supply. Many
Indigenous communities, especially those in remote localities, face
additional challenges in maintaining adequate and safe water supply.
Factors affecting this include access to personnel and physical
resources needed to maintain and manage a water supply. In many
parts of Australia, meeting total demand for a range of uses can
be an issue. Innovative approaches include integrated water management,
that is, the use of clean fresh water for drinking and bathing plus
reuse and/ or recycling of waste-water for secondary purposes such
as landscape watering or dust control. These may be an option for
maximising the benefit of what water is available.
vary significantly across Australia and corresponding to this, quality
varies as well. Current sources of supply to Indigenous communities
have been identified by ATSIC (2002) as:
water tank (9%)
or reservoir (7%)
or spring (5%)
Water is one
component of the critical health-hardware that has been shown to
be so important to improving functioning of housing in many communities
across Australia. Adequate and safe water supply integrates with
health-hardware and through this the work of Environmental Health
Workers and Officers with their communities.
There are many
uses for water in our community. Not all of them require high quality
water as is required for drinking water supplies. In most cases,
drinking water is but one of the uses required of a water supply.
Unless it is economic to develop a dual water supply, that is two
supply lines with one being for raw water and the other for drinking
water, a supply will need to be designed to treat and distribute
all water to a drinking water standard. Determining intended uses
and the needs for consumers in your community is important when
deciding on the type of supply system to be used. Typical amounts
of water used per house for health related uses in a remote arid
community have been described by Pholeros (1997) as in the following
Use per House Required for Health
clothes and bedding
food, kitchen sink
control, improving nutrition, dust control
and food plants
* a kilolitre is 1,000 litres
** yearly total based on 6 months of use during hotter weather
of water for a community will be dependent on regional characteristics.
In most cases only one of these types of sources will be available
or cost effective for a community. If available, use of two or more
sources could assist a community meet its total water demand.
Water (Lakes, rivers)
If in largely undeveloped catchments, that is there is little or
no urban, industrial or agricultural development, lakes and rivers
can generally provide high-quality water. A weir is often used in
rivers to increase available volume for supply. If used for drinking
water supply, disinfection will be required.
Rainwater Storage (Rainwater tanks)
On-site water storage in small tanks supplied by diversion of downpipes
from a roof or roofs functions as the catchment and collection system
for a rainwater tank. Water can be of good quality but also can
be affected in terms of quantity and quality by climatic seasonal
factors and vegetation surrounding the site. Maintenance of roofs
and gutters is important to ensure quality and efficiency in collection
and to prevent a breeding ground for mosquitoes which can cause
public health issues. Disinfection is important if used for drinking
water supplies. Rainwater tanks are increasingly used in providing
additional capacity alongside town supplies; for example, being
used for non-drinking purposes including flushing toilets, yard
cleaning and watering gardens.
supplies (Bore-water, wells, springs)
act as underground reservoirs for water that may have fallen as
rain and then submerged many hundreds or thousands of kilometres
away. These supplies are very important in arid areas and they need
to be managed well, as overuse can quickly reduce the capacity for
sustaining water quality and quantity of supply. Bore water is the
most common source for supply in remote communities and generally
water quality is adequate for use as drinking water with some treatment
in a water supply
Common to all
systems, whether large community supplies or single site supplies,
are the following elements:
storage to hold water and to meet the fluctuating demands
of users of the system. Typically this may be a weir or dam or
a constructed reservoir or it may be an in-ground or above-ground
tank in the instance of a small community or settlement. A rainwater
tank fulfils this function when used for a single house.
treatment facility where water may be physically and
or chemically treated to improve water characteristics and to
make it suitable and safe for use. At its most basic, treatment
should include disinfection to reduce risk from micro-organisms
that may otherwise cause disease. A storage tank for treated water
is usually required as part of the treatment facility.
distribution system to transport treated and or disinfected
water from the source and or storage to the user. Typically this
will be a network of pipes suitable to delivery of drinking water
to users but it may include water-carting trucks.
quality and safety
The aim of
any water supply is for it to be safe for users; that is, it should
be of good quality with no contamination with any physical matter,
chemical or organism capable of causing disease.
water is generally considered to be water free from contamination
from the following:
borne diseases, pathogens and harmful organisms
dissolved solids, odour, hardness, turbidity
herbicides and weedicides
heavy metals, radioactive material
sources of pollution
Drinking water sources or recreational water are most likely to
be contaminated with human, animal, agricultural and industrial
wastes. The hazards associated with human and animal wastes are
mainly microbiological while those associated with industrial wastes
are generally chemical. Agricultural wastes can be microbiological
(of animal origin) or chemical (fertilisers, pesticides).
pollution can provide the right nutrients and/or conditions for
increased growth of naturally occurring organisms that may affect
water supply treatment or quality. Blue-green algae (cyanobacteria)
blooms and Naegleria fowleri (amoeba) are examples common
to a number of localities in Australia. These naturally occurring
organisms have particular and significant health effects and though
naturally occurring, can be exacerbated by pollution from human
or animal wastes. Each of these also has major implications in regard
to suitability and management of water supplies if they are present
in the locality.
on Blue Green Algae can be found at the following:
Algae Information Sheet (PDF file 4pg)
- Queensland Dept Natural Resources & Mines
Algae: A Guide (PDF file 4pg) - CRC for
Water Quality & Treatment
Information - Australian Academy of Science
on Naegleria fowleri can be found at the following:
Meningitis (PDF file 6pg) - Western Australia
Department of Health
Meningitis - The Meningitis Centre
The Australian Drinking Water Guidelines (ADWG) produced by the
National Health and Medical Research Council has been adopted by
most jurisdictions across Australia. The ADWG provides a series
(PDF file 209 KB) and fact-sheets on acceptable
health and/ or aesthetic criteria for drinking water in terms of
physical, chemical, radiological and microbiological parameters.
The ADWG also provide a framework for how drinking water supplies
should be maintained to ensure water remains safe for consumption.
If water is
supplied to users to meet the ADWG for drinking water, the water
will also be suitable in terms of public health for other household
uses including bathing and cooking. Water meeting the ADWG will
also be generally suitable for other community uses. However if
a particular need has to be met as part of a community supply e.g.
special irrigation purposes, then other guidelines may need to be
met. Contact should be made within the relevant environmental protection
agency in your State or Territory.
supply protection and management principles
barrier approach is recognised as the best-practice method for reducing
contamination and health risks associated with water supply.
of barriers to the transmission of pathogens and contaminants is
important in reducing health risks associated with water. The multiple
barrier approach is promoted in the ADWG and relies on using more
than one type of protection or treatment and undertaking numerous
actions from the water catchment through to a user’s tap.
Examples include the following:
of source water from contamination with active catchment protection
- Long detention
times (weeks or months if possible) within off-line storages e.g.
- Water treatment
e.g. coagulation, settling, and filtrations
of treated water
of residual chlorine throughout the distribution system.
microbiological status of water supply should be regarded as a check
that the barriers are working.
barrier approach applies to all types of water supply, from small
to large. The scope of the activities at different scales of systems
will, however, need to increase in complexity as the scale of a
system increases. An example of how this would work is shown in
the following table.
tanks, small in or off-stream storage supplies
sanitary surveys of catchment/ system
of in-line carbon filters if organic or chemical contaminants
are a concern
cleaning and maintenance of gutters, roofing, channels,
disinfection (especially if birds or animals present)
sized/ simple systems
bores and surface water supplies
of catchment - fencing, animal exclusion
soiled runoff/ stabilise or rehabilitate catchment areas
and/or chemical treatment (as necessary)
regular infrastructure maintenance programm
regular water quality monitoring including physical, chemical
and biological parameters
enclosure (e.g. roofing tanks and storages and capping viaducts)
of storages and implement infrastructure maintenance programme
and maintain residual chlorine levels within system continuously
Scale/ Complex systems
bores and surface water supplies
regular monitoring and maintenance activities in catchment
plus consider restricting development and access to water
physical and chemical treatment to ensure public health
frequent infrastructure maintenance and replacement programmes
and implement frequent water quality monitoring including
physical, chemical and biological parameters
and maintain residual chlorine levels within system continuously
Sanitary surveys are an important tool for Environmental Health
Workers when planning and making assessments of water supplies.
A sanitary survey
involves inspections to check for any direct or potential sources
of contamination of a water supply. They are particularly important
where treatment of the water source is minimal or when there are
concerns with water quality raised by the community or if there
has been illness in the community that was likely to have been water-borne.
(1996). Fact Sheets on Environmental Sanitation. WHO/EOS/96.4 World
Health Organisation. Geneva
of sanitary inspections of a catchment will depend on the characteristics
of the locality, the type of source of raw water (e.g. river, rainwater
or bore), the time the water remains in storage (the longer the
better as this would allow natural die-off of pathogens to occur),
and the subsequent treatment that is provided. As well as regular
inspections in the immediate vicinity of the off-take site, every
catchment where habitation or public access exists should be thoroughly
inspected at least once a year for potential sources of pollution.
assist EHWs design their own sanitary inspection are provided in
the Tools section at the end of this document.
Disinfection of water
drinking water is of paramount importance to protect public health.
Without disinfection an unacceptable risk would exist from exposure
to harmful organisms that could cause widespread illness in the
using chlorine gas or hypochlorite is the most common method of
disinfection used worldwide. Effective chlorination is achieved
by adding chlorine at an amount that ensures some remains as ‘free’
chlorine. The level at which free 'chlorine residual is held within
any water supply will vary depending upon location-specific factors,
but in major Australian water supplies typical ranges are held at
between 0.1 mg/L to 4 mg/L. A recognised target value for reticulated
supplies is 0.5mg/L of residual chlorine throughout the system.
Water may also
be disinfected by physical (boiling) or other chemical (ozone, iodine)
means. By far the most popular disinfection however is chlorination.
Chlorination is popular as it is relatively easy and safe (with
some worker safety protections) to use and dose into supplies and
because the ability to provide a residual amount of chlorine in
the water after its addition (dosing) provides an ongoing level
of protection that other types of disinfectants can not.
disinfectant is important as it can minimise bacterial re-growth
and the effects of recontamination that may occur during distribution
of water to the user from the storage or treatment plant.
Technical Cards on Environmental Sanitation (WHO, 1997)
with chlorine is most efficient in clean water. Highly turbid or
muddy water will be hard to disinfect using chlorine. For this reason
chlorine is best added after primary treatment or at least after
settling and basic filtration.
disinfection is an important tool for protection of public health.
Chlorinating (disinfecting) a water supply is a relatively simple
and cheap method for reducing risk of exposure to pathogens in the
community. The Tools section below provides a series of extracts
about low-technology methods for disinfection. These are sourced
from the World Health Organization. Environmental Health Workers
and community people can easily employ these methods in managing
water supply hardware, e.g. community supply storages and rainwater
on the use of rainwater tanks (PDF 29pg)
provides comprehensive information on rainwater tank uses, including
- Water quality
- Sizing of
maintenance and repairs
and mosquito control
- Use of supplementary
water (from bores dams, rivers, creeks etc) with rainwater tanks
for Working on Public Health and Water Supply
- WHO (1997).
cards on environmental sanitation. (PDF file
46pg) World Health Organisation.
water samples - (PDF file 130 KB) methods
- methods for taking samples to test for chlorine
for chlorine (PDF file 82 KB) includes
methods to determine chlorine levels and amounts required for
of storage tanks, tanker trucks and pipelines (PDF
file 94 KB) includes information on making disinfectant
Inspections - (PDF file 551KB) provides
overview of role and activities in sanitary inspection
Inspection Resources - (PDF file 487 KB)
provides model forms and inspection sheets that can be used when
doing sanitary inspections
disinfection of water supply guidelines - US EPA website outlining
what to do to provide emergency disinfection
Kit / Test Kit - Palintest commercial website
Atlas of Health Related Infrastructure in Discrete Indigenous
Communities. Aboriginal and Torres Strait Islander Commission.
National Housing and Infrastructure Centre. Melbourne.
HealthHabitat. (1993). Housing for Health: Towards a Healthy
Living Environment for Aboriginal. Australia. PO Box 495 Newport
Beach NSW 2106. Phone: (02) 9973 1316.
NEHF. (1998). Guidance
on Use of Rainwater Tanks. (PDF file 46pg)National
Environmental Health Forum Monographs. Water Series No. 3. South
Australian Health Commission. Adelaide.
NHMRC (1991) Australian Drinking Water Guidelines.
Pholeros, P (1997)." Energy and water required for health in
housing on the AP lands" reported in Environmental
Health Handbook: A Practical Manual for Remote Communities
(PDF file 230pg), G. Harris (ed), Menzies
School of Health Research. Northern Territory.
Territory Health Services, Public Health Strategy Unit. (1999) The
Public Health Bush Book. (html for Table of Contents)
Facts and approaches to three key public health issues. Department
of Health and Community Services. Darwin.
WHO (1997). Guidelines
for drinking-water quality. Surveillance and control of community
supplies. 2nd Edition. Vol. 3. World Health Organization.
WHO (1997). Technical
cards on environmental sanitation. (PDF
file 46pg) World Health Organization. Geneva.
for Water and Government Departments
and Water Advisory Service Dept. of Infrastructure, Planning
Health Programme Dept. Health & Community Services
for Water Resources Dept. Water, Land and Biodiversity Conservation
Health SA, Dept. Human Services
Resource Management NSW, Dept. Infrastructure, Planning
& Natural Resource Management
Unit - Environmental Health Branch, NSW Health Dept.
Water Resources Data Warehouse
Health Group, Dept. Human Services
of Narural Resources
Queensland Health, Indigenous
of Primary Industries, Water
Public and Environmental
Health Service, Department of Health and Human Services
& Rivers Commission, West Australian Government
Health Division, Health Department of WA