ABN 49 546 344 356 Cnr Elizabeth St & Kirkham St, Moss Vale NSW 2577 P O Box 141, Moss Vale NSW 2577 DX4961 Bowral Ph: 48680888 Fax: 48691203 Email: wscmail@wsc.nsw.gov.au
Fact Sheet – Water Tanks and required Backflow Prevention for Dwelling Houses
Why backflow protection? Backflow is the flow of a liquid in a direction contrary to the normal or intended direction of flow. Backflow may occur from properties connected to Council’s mains water supply when water pressure in the mains is less than that present inside the property (eg; when there is a sudden high water demand for fire fighting purposes from Council’s mains supply or by a mains break). Backflow protection ensures Council’s potable water supply is not contaminated by backflow. When installing a rainwater tank, you need to ensure that appropriate backflow protection is in place to prevent rainwater from mixing with the potable (drinking water) supply in Council’s mains. Backflow protection needs to be at the connection to the mains and, in instances where a mixing risk can occur, will also be needed on the house water plumbing service. Main Connection Metering It is your responsibility to check with Council to determine whether the existing meter is adequate to achieve the required level of backflow prevention at the main connection. Council regularly replaces water meters both through breakdown and through a scheduled meter replacement programme, where new meters installed have a dual check valve within the meter. Older Council meters may not have dual check valves within the meter, depending on their type. If a working existing meter does not have a dual check valve within the meter, Council will replace that meter free of charge as part of its meter replacement programme. What applications do I need to make to Council? You may need to make a development application, especially if you are installing a larger tank (capacity of greater than 10 000 litres in a residential area and 12 000 litres in a rural area) and if it is not with a development application for a house or additions. You will require plans and Council has reduced its fees for water tank applications. There are also requirements for tanks up to 10 000 litre in capacity - see Schedule One. You must make an application (under Section 68 of the Local Government Act 1993) to Council for water plumbing alterations if you are choosing either option 2 or 3 below. Again, if the water tank is happening with the approval and construction of a house or additions, you should apply for it all at the same time. You will need a plan and pay fees for this application. Council will issue you with an approval if all the details are satisfactory and an inspection will be required throughout and at the completion of the installation. NOTE – If you are applying for a rebate from the State Government for the water tank, they will check with the local Council. If an application to Council was required and has not been made, this will result in Council advising that its requirements have not been met. This may delay any rebates due for your water tank.
Fact Sheet produced 22nd October 2008
More Information? For general enquiries concerning installation of water tanks and water meters contact Councils Customer Services staff on 48 680 888 from 8.30 am – 4.30 pm Monday to Friday. For Technical advice concerning Water Plumbing requirements in the installation of water tanks and plumbing , contact Councils Building Surveyors between 8.30 – 10am Monday to Friday on 48 680 888. There are also helpful sources of information available from the following: Sydney Water information on rainwater tank selection http://www.sydneywater.com.au/SavingWater/InYourGarden/RainwaterTanks/ NSW Department of health , public health information http://www.health.nsw.gov.au/publichealth/environment/water/rainwater.asp NSW Department of Environment and Climate Change – rebate program http://www.environment.nsw.gov.au/rebates/ccfrtw.htm Various options can be adopted when installing rainwater tanks and these require different types of backflow prevention as follows: Option 1: No Connection between Rainwater Tank and Councils Main Supply (Figure 1)
Protection at meter for 20 or 25mm service Rainwater Tank Backflow Prevention required Above Ground Water meter with Dual check valve in the meter Fully or Partially buried Water meter with Dual check valve in the meter
Fact Sheet produced 22nd October 2008
Option 2: tank
Indirect Connection (i.e.: Topping up of tank) – Figure 2 showing above ground
Protection at meter for 20mm or 25mm size services Rainwater Tank Above Ground Fully or Partially buried Backflow Prevention required Water meter with Dual check valve in the meter Vented Dual check valve or a testable backflow prevention device
Protection for house service Rainwater Tank Above Ground Fully or Partially buried) Backflow Prevention required Air gap or Dual check valve (non-testable) installed. Air gap or Dual check valve (non-testable) installed
Fact Sheet produced 22nd October 2008
Option 3: Direct Connection between Rainwater Tank and Council’s Main Supply (Figure 3 – above ground tank)
Protection at meter for 20mm or 25mm service Rainwater Tank Above Ground Fully or Partially buried) Backflow Prevention Required Water meter with Dual check valve in the meter Vented Dual check valve or a testable backflow prevention device
Protection at connection to house service Rainwater Tank Above Ground Fully or Partially buried Backflow Prevention Required Dual Check Valve (non-testable device) Dual Check Valve (non-testable device) NOTES 1. All works and fixtures installed are to comply with the NSW Code for Plumbing and Drainage 2006 and AS3500. Works relating to water plumbing must be carried out by a Licensed plumber and Drainer 2. A partially buried water tank includes where any sides are buried. 3. Council’s Customer Services Staff are able to check if your meter has the required Dual check valve and, if not, can arrange for meter replacement at no cost to you. 4. For properties where the size of the boundary water meter is more than 25mm the owner will be responsible for the installation of the appropriate backflow prevention device at the water meter. A licensed plumber is required to fit the device in accordance with AS/NZS 3500 and provide evidence of this to Council.
Fact Sheet produced 22nd October 2008
Schedule One - When rainwater tanks do not need a development application
(1) For a rainwater tank to be exempt development, it must comply with the following requirements: (a) the capacity of the tank, or the combined capacity of tanks, on a lot must not exceed the 10 000 litres, (b) the tank must be designed to capture and store roof water from gutters or downpipes on a building, (c) the tank must not collect water from a source other than gutters or downpipes on a building or a water supply service pipe, (d) the tank must be fitted with a first-flush device, being a device that causes the initial run-off of any rain to bypass the tank to reduce pollutants entering the tank, (e) the tank must be structurally sound, (f) the tank must be prefabricated, or be constructed from prefabricated elements that were designed and manufactured for the purpose of the construction of a rainwater tank, (g) the tank must be assembled and installed in accordance with the instructions of the manufacturer or designer of the tank, (h) the tank, and any stand for the tank, must be installed and maintained in accordance with any requirements of the public authority that has responsibility for the supply of water to the premises on which the tank is installed, (i) the installation of the tank must not involve the excavation of more than 1 metre from the existing ground level, or the filling of more than 1 metre above the existing ground level, (j) the tank must not be installed over or immediately adjacent to a water main or a sewer main, unless it is installed in accordance with any requirements of Wingecarribee Shire Councils Water and Sewer Branch, (k) the tank must not be installed over any structure or fittings used by a public authority to maintain a water or sewer main, (l) no part of the tank or any stand for the tank may rest on a footing of any building or other structure, including a retaining wall, (m) the tank must be located behind the front alignment to the street of the building to which the tank is connected (or, in the case of a building on a corner block, the tank must be located behind both the street front and street side alignments of the building), (n) the tank must not exceed 3 metres in height above ground level, including any stand for the tank, (o) the tank must be located at least 450 millimetres from any property boundary, (p) a sign must be affixed to the tank clearly stating that the water in the tank is rainwater, Note. If water in rainwater tanks is intended for human consumption, the tank should maintained to ensure that the water is fit for human consumption—see the Rainwater Tanks brochure produced by NSW Health and the publication titled Guidance on the use of rainwater tanks, Water Series No 3, 1998, published by the National Environmental Health Forum. (q) any overflow from the tank must be directed into an existing stormwater system, (r) the tank must be enclosed, and any inlet to the tank must be screened or filtered, to prevent the entry of foreign matter or creatures, (s) the tank must be maintained at all times so as not to cause a nuisance with respect to mosquito breeding or overland flow of water, (t) any plumbing work undertaken on or for the tank that affects a water supply service pipe or a water main must be undertaken: (i) with the consent of Wingecarribee Shire Council and (ii) in accordance with any requirements of Council, and (iii) by a licensed plumber in accordance with the New South Wales Code of Practice—Plumbing and Drainage produced by the Committee on Uniformity of Plumbing and Drainage Regulations in New South Wales, (u) any motorised or electric pump used to draw water from the tank or to transfer water between tanks: (i) must not create an offensive noise, and (ii) in the case of a permanent electric pump, must be installed by a licensed electrician.
Fact Sheet produced 22nd October 2008
(2) Despite subclause (1) (a), a rainwater tank with a capacity exceeding the maximum capacity may be exempt development if another environmental planning instrument applying to the land concerned provides for such a rainwater tank to be exempt development. (3) This clause does not apply to land that is a lot within the meaning of the Strata Schemes (Freehold Development) Act 1973 or the Strata Schemes (Leasehold Development) Act 1986. (3A) This clause does not apply to development carried out by or on behalf of a public authority. Note. See State Environmental Planning Policy (Infrastructure) 2007, which provides that certain development for the purpose of a rainwater tank carried out by or on behalf of a public authority is exempt development. :
Fact Sheet produced 22nd October 2008