BACKFLOW PREVENTION CONTAINMENT POLICY - Hunter Water

BACKFLOW PREVENTION
CONTAINMENT POLICY
February 2009
www.hunterwater.com.au

QA SUMMARY – Changes to Policy
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TABLE OF CONTENTS
1 INTRODUCTION: 4
1.1 Referenced Documents: 4
1.2 Causes Of Backflow: 5
2 BACKFLOW PREVENTION POLICY 5
2.1 Backflow Prevention Device Installations. 5
2.2 Conditions of Installation 6
2.3 Operational Principles 8
3 DISPUTE RESOLUTION 10
5 DEFINITIONS: 11
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1 INTRODUCTION:
This Backflow Prevention Policy applies to all customers connected to Hunter Water’s water
supply.
Backflow prevention refers to the control of potentially harmful contaminants entering the
Corporation’s potable drinking water supply from cross connections in a customer’s premises
or backflow of contaminants into the water supply system.
The purpose of this policy is to ensure that the Hunter Water Corporation exercises the
required duty of care in the protection of the potable water supply and to safeguard public
health within its area of operation as set out in the Hunter Water Corporation Act, Operating
Licence and Customer Contract. The owners of premises also have a duty of care to prevent
such an occurrence, as well as maintaining responsibility for safe water supply within their
own boundaries.
The objectives of the policy are to:
1. protect the integrity of the water supply; and
2. protect the health and safety of consumers.
The policy details the types of backflow prevention device required for customers’ properties
with low, medium or high hazards as defined in Australian/ New Zealand Standard AS/NZS
3500, Part 1 Water Services (AS/NZS 3500) and the obligations property owners.
The policy details the requirements for containment protection (site protection) at the
property boundary. Protection within individual premises (zone protection) is entirely the
responsibility of property owners and, as such, is not covered in this policy. Customers
should refer to the NSW Code of Practice Plumbing and Drainage and AS/NZS 3500 for
requirements
1.1 Referenced Documents:
The policy is consistent with the aims of The National Plumbing & Drainage reform agenda,
Plumbing Code of Australia, NSW Code of Practice Plumbing & Drainage, National Plumbing
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& Drainage Code Australian/New Zealand Standard 3500 (AS/NZS 3500.1), Hunter Water’s
Operating Licence, Act, regulations and the Customer Contract.
1.2 Causes Of Backflow:
Backflow in this context can be defined as the unintended flow of water from a potentially
polluted source into the potable water supply. Backflow can be caused by either back
pressure from pressurisation equipment on the customer’s premises or siphonage caused
when the pressure in the water supply system falls below atmospheric pressure.
The pressure differential can be affected by a number of circumstances including;
• A break in the water main
• During a fire when water is being pumped from the mains
• A customer using water on site at a higher pressure than the supply pressure (eg
operating a pump)
• Heavy usage from a customer downstream, reducing water pressure upstream.
The problem arises if there is an interconnection between the customer’s water service and a
contaminated source thus providing the possibility of drawing back into the mains system,
pollutants, or contaminants that may provide a risk to public health.
2 BACKFLOW PREVENTION POLICY
All properties with Hunter Water’s area of operation must comply with the requirements of the
NSW Code of Practice Plumbing and Drainage and AS/NZS 3500. All properties with a water
connection that present a high, medium or low hazard rating shall install appropriate
backflow prevention at the boundary for containment protection purposes. Backflow
prevention is necessary to ensure the water supply system is protected from the backflow of
contaminants into the public water supply.
2.1 Backflow Prevention Device Installations.
The type of backflow prevention device is dictated by the potential hazard that may exist in
particular types of businesses or use. The types of devices and the hazard ratings for
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particular uses are set out in AS/NZS 3500. All devices must be installed in accordance with
the NSW Code of Practice Plumbing and Drainage and AS/NZS 3500.
2.1.1 New Developments and Re-developments
All new customers with high or medium hazard installations or processes on their properties
will be identified via an application for hydraulic services approval as detailed in NSW Code
of Practice and an application for a Section 50 certificate. Customers via this application will
be notified with the requirement to comply with the Backflow Prevention Policy before
connection to the water supply being granted. Customers will also be informed by a HWC
representative of the need to comply with the Backflow Prevention Policy upon a plumbing
and drainage inspection identifying a high or medium hazard process being found.
2.1.2 Existing Residential and Non Residential Customers
All existing customers whose properties have high or medium hazards are required to
comply with the Backflow Prevention Policy, as stated in The NSW Code of Practice
Plumbing and Drainage Part B 2.2.9. AS 3500 identifies the industry types and processes
which require testable backflow prevention containment devices. Customers that are
identified by HWC will be issued a Notice of Repair and given a specific period in which
to comply.
2.1.3 Recycled Water Schemes
Where Hunter Water supplies a customer with recycled water, the customer must install
backflow prevention on the recycled water system or standpipe equivalent to the backflow
prevention required for the drinking water supply.
The drinking water supply to this property shall also be compliant with the backflow
prevention requirements for site and zone containment.
2.2 Conditions of Installation
1. Where the hazards are unknown for a commercial, industrial or mixed development, the
hazard rating will default to high, requiring the installation of a device appropriate for that
hazard rating. If the hazard rating varies due to multiple processes or multiple tenants,
the highest hazard rating shall be applied.
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2. All backflow prevention devices must be installed, commissioned and tested by a
licensed plumber with backflow prevention accreditation
3. Only backflow prevention devices manufactured and quality assured to AS/NZS 2845
are to be installed on metered standpipes and properties within Hunter Water’s area of
responsibility.
4. The type of device installed shall be in accordance with the hazard rating of the
processes conducted.
5. All High Hazard installations shall be fitted with either a Reduced Pressure Zone Device
(RPZD) or Registered Break Tank (RBT) or Registered Air Gap.
6. Medium hazards require the installation of a Testable Double Check Valve as a
minimum.
7. Metered standpipes require a Non Testable Double Check Valve. The device shall be
integrated into the design of the standpipe. All water carts and fill stations shall have a
registered air gap or reduced pressure zone device at the fill point
8. Separate hydrant and sprinkler fire services require the installation of a Testable Double
Check Detector Check assembly. The device shall be installed close to where the water
service crosses the property boundary, prior to any suction on booster assembly.
9. On a drinking water service, the device shall be installed on the customer’s side of the
water meter with no connections between the water meter and the device.
10. All property services shall have a water meter affixed including a detector check bypass
for fire services.
11. Where a 20mm or 25mm meter is used for the connection of a property, considered to
be a Low Hazard risk, the property shall be fitted with an approved meter, supplied by
Hunter Water at the time of connection, which incorporates an integral Dual Check
valve. The property owner is responsible for applying to Hunter Water for an Integral
Dual Check Valve water meter. The owner shall provide access to the water meter at all
times.
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12. Owners of new residential premises connected using a meter larger than 25mm shall fit
an appropriate BPD as required in the NSW Code of Practice Plumbing & Drainage and
as specified in AS/NZS 3500.
13. If the usage, and hence the hazard rating, of a premises changes, the owner shall be
required to install the appropriate Backflow Prevention Device.
14. Conditions apply for other uses of Hunter Water’s drinking water supply i.e. water
tankers and standpipes. These shall be registered, be inspected annually and must have
an air gap or approved backflow protection device.
15. The water meter set shall not be altered (eg; removal of the meter spacer and dirt box
are not permitted).
2.3 Operational Principles
1. Backflow Prevention Devices are required to be installed, inspected and maintained in
accordance with the NSW Code of Practice Plumbing & Drainage and AS/NZS 3500.
Customers are required to register the device with Hunter Water upon commissioning.
2. The cost of the backflow prevention device, installation, testing, inspection and ongoing
maintenance will be the responsibility of the owner of the property for all devices other
than Low Hazard 20mm and 25mm meter installations.
3. The property owner is responsible for ensuring that an annual test of any Testable
backflow prevention device is carried out in accordance with the NSW Code of Practice
and AS/NZS 3500.
4. The registration of tests and inspection shall be carried out by Hunter Water upon
payment of the prescribed fee. Hunter Water may choose to audit the test report and
inspection. Backflow Prevention Device Inspection and Maintenance Report forms are
available for purchase from Hunter Water Corporation Offices.
5. If Hunter Water determines that the backflow prevention device is unsatisfactory and
issues a notice requiring the customer to repair, maintain, test, replace or install a
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ackflow prevention device, the customer shall, at the customer’s expense, comply
with the notice within the time specified in the notice.
6. If the customer fails to install, repair, maintain, replace or test a backflow prevention
device as required by a notice issued by Hunter Water, Hunter Water may disconnect
in the case of a non-residential property or restrict in the case of a residential property
or mixed development the water supply system until such time as the customer has
complied with the notice to carry out works, as may be necessary to prevent
contamination of the water supply.
7. If the customer does not comply with the notice, Hunter Water may undertake to
remedy the defective work. The customer may be charged the cost incurred in
undertaking this work.
8. Existing customers connected to the water supply must install a backflow prevention
device within the timeframe specified on a notice issued by Hunter Water.
9. Where a Testable BPD is installed, it shall be installed by a licensed plumber but must
be commissioned and tested by a plumber with the appropriate backflow prevention
training and accreditation.
10. Installation and test certificates must be received by Hunter Water within five working
days of the completion of the property service.
11. A person must be authorised to draw water or connect to the Hunter Water’s water
supply system and must not introduce a contaminant to the system. The connection
point shall be a suitable backflow prevention device installed inline and immediately at
the utilities connection point.
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3 Penalties for Non-compliance
If the customer fails to install, repair, maintain, replace or test a backflow prevention device
(as per AS3500 and NSW Code of Practice) as required by a notice issued by Hunter Water,
Hunter Water may utilise the provisions of the Customer Contract, Clause 6.3 (Disconnection
or restriction) and Clause 8.5 (Defective work) until such time as the customer has complied
with the notice.
4 Dispute Resolution
Any disputes which arise from the operation of this policy will be dealt with using Hunter
Water’s customer dispute resolution procedures.
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5 DEFINITIONS:
Backflow Prevention device (BPD) is defined in AS/NZS 3500- as a device which will
prevent reverse flow of water from a potentially polluted source into the water supply system.
Containment Protection (Site protection) is the installation of a backflow prevention device
on the water service at the property boundary between the distribution system and the
owner’s property.
Zone Protection is the installation of backflow prevention devices within sections of the
owner’s property.
Individual Protection is the installation of a backflow prevention device at the water
connection to an individual apparatus.
Cross Connection is any connection or arrangements between the drinking water supply
system connected to the water main or any fixture, which may under certain conditions
enable non-drinking water or other substances to enter the drinking water supply system.
High Hazard Rating (AS/NZS 3500) - any condition, device or practice which in connection
with the potable water supply system has the potential to cause death.
Medium Hazard Rating (AS/NZS 3500) - any condition, device or practice which in
connection with the potable water supply system has the potential to endanger health.
Low Hazard Rating (AS/NZS 3500) - any condition, device or practice which in connection
with the potable water supply system would constitute a nuisance but not endanger health or
cause injury.
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