First Flush Water Diverters – Quality First€¦ · system of 90mm (3”) or 100mm (4”)...

First Flush Water Diverters – Quality First

Rain Harvesting First Flush Water Diverters........................................................................................................................2 How do they work?......................................................................................................................................................2

Help Stop Pollution of Tank Water.............................................................................................................................2 Benefits of First Flush Devices.......................................................................................................................................2

Be confident in your rainwater collection system.........................................................................................................2 Protect pumps .........................................................................................................................................................3

Research.....................................................................................................................................................................3 Selecting the Right Water Diverter ................................................................................................................................4

Downpipe First Flush Water Diverters ........................................................................................................................4 Post/Wall/Stand Mounted First Flush Water Diverters..................................................................................................5 In-Ground First Flush Water Diverters........................................................................................................................6

‘Wet’ and ‘Dry’ systems ................................................................................................................................................8 Depends on the pipework system to the tank.............................................................................................................8 ‘DRY’ SYSTEMS........................................................................................................................................................8 ‘WET’ SYSTEMS .......................................................................................................................................................8 Insect Proofing ‘wet’ systems....................................................................................................................................9 Better water quality .................................................................................................................................................9 Save water..............................................................................................................................................................9 Commercial First Flush Water Diverters.................................................................................................................... 10

How Much Water to Divert? ........................................................................................................................................ 10 Prevent roof contaminants polluting your tank water ................................................................................................ 10

Maintenance.............................................................................................................................................................. 10 Legislative requirements............................................................................................................................................. 11 How to Create a Complete Rain Harvesting System ...................................................................................................... 11 About Rain Harvesting Pty Ltd .................................................................................................................................... 11 Our vision ................................................................................................................................................................. 11 Development of the product range .............................................................................................................................. 12 Contact Us ................................................................................................................................................................ 13

Prepared by Rain Harvesting (Oct 06). For more information, including details of products for collecting good quality rainwater, visit www.rainharvesting.com

Rain Harvesting First Flush Water Diverters

First Flush Water Diverters or 'Roof Washers' capture the first most contaminated rainwater from the roof and gutters, automatically diverting the subsequent cleaner rainwater to the storage tank.


How do they work?

Help Stop Pollution of Tank Water When it rains, water slowly builds up in the roof guttering system before it exits through the downpipe. The first flush of water from the roof can contain amounts of bacteria from decomposed insects, skinks, bird and animal droppings and concentrated tannic acid. It may also contain sediments, water borne heavy metals and chemical residues, all of which are undesirable elements to have in a water storage system.

Instead of flowing to the water tank, these pollutants are diverted with the initial flow of water into the chamber of the water diverter. The water diverters from Rain

Harvesting utilise a dependable ball and seat system - a simple automatic system that does not rely on mechanical parts or manual intervention. As the water level in the diverter chamber rises the ball floats, and once the chamber if full, the ball rests on a seat inside the diverter chamber preventing any further water entering the diverter. The subsequent flow of water is then automatically directed along the pipe system to the tank. For a Water Diverter to work effectively, the contaminated water in the chamber must be sealed off. This prevents the water passing to the storage tank and ensure the water does not "syphon" off the contaminated water in the chamber. The simplest and surest way to do this is with a floating ball and seat. A slow release valve ensures the chamber empties itself after rain and resets automatically. The diverted water need not be wasted water because the drain pipe from the diverter chamber can be fitted to a standard drip irrigation system.

Benefits of First Flush Devices

Be confident in your rainwater collection system First Flush Water Diverters are a critical component of rainwater harvesting systems. By preventing the first, most contaminated water from the roof they: 1. Improve rainwater quality and safety, 2. Help extend the life of pumps (used to distribute

rainwater for use)and internal appliances (such as hot water systems, washing machines, dishwashers, etc),

3. Reduce tank maintenance

The First Flush Water Diverters from Rain Harvesting, are simple to install, operate automatically to help prevent pollution of tank water, and are available in a number of different sizes to suit different requirements.


They operate best when used in conjunction with the Leaf Eater® range of rain heads. When fitted upstream of a First Flush device, the rain heads will direct leaves, debris and other organic matter away from the flow of water. The First Flush Diverter then ensures that heavy sediments and other finer pollutants are captured in the diverter chamber.

Protect pumps Leading pump manufacturers, such as Davey, recommend the use of First Flush Water Diverters to help extend the life of pumps. Typically pumps utilise a mechanical seal to ensure water does not penetrate into the pump's electric motor. First Flush Devices help prevent sediments and other debris from: 1. Wearing down the seal (which can result in pumps

leaking), 2. Getting caught in the pump impeller, 3. Jamming up other pump components. The Installation and Operating Instructions (as at 29 March 2006) of the Davey Rainbank®, an innovative product that allows the priority sourcing of rainwater, only

using mains water as backup, make the following recommendation: "Your rainwater tank may be required to be installed with a first flush diverter. Installing a first flush device is essential to reduce the introduction to the rainwater tank of sediment and other materials which can pollute the water. Even where it is not a requirement of your local water authority, Davey recommend the use of a suitable first flush diverter and/or rainwater inlet strainers."

Research

Professor Stan Abbott of Massey University in Wellington New Zealand established New Zealand’s most sophisticated Roof Water Research Centre. Prof Abbott has recently released findings from an extensive study commissioned by the New Governments Ministry of Health. The focus of the study was to identify measures that can be taken to improve the water quality from rainwater

harvesting systems. Thousands of samples were taken from a series of different systems, and results from the system featuring Rain Harvesting’s own First Flush Water Diverters (pictured), showed significantly better water quality.

http://www.davey.com.au/rainbank/index.html

Selecting the Right Water Diverter Four types are available – all require minimal maintenance and will improve water quality. The volume of water to be diverted, type of downpipe system and site characteristics will determine the type of diverter required.

Downpipe First Flush Water Diverters Simple and effective first flush devices, they are installed at the downpipe and used when there are a small number of downpipes supplying water to the tank. Require minimal maintenance and can be installed at the gutter downpipe or via a T-junction to a new or existing system of 90mm (3”) or 100mm (4”) diameter PVC downpipes. Add the appropriate length of pipe based on the quantity of water you wish to divert. Consider as a guide that each and each 1m of 100mm PVC pipe holds approximately 8L of water. It is preferable to fit the longest length chamber as possible to ensure better quality water. Install from the roof gutter and after the rain head, to within 150mm above the ground to allow easy access to the end cap.

The diverters are supplied in kit form and come with everything needed to complete installation - just add the length of PVC pipe required to form the diverter chamber.


How are they installed? Downpipe Diverters should be installed at each downpipe that supplies water to the tank system and are ideal diverters for use with under eaves tanks.

Installation options:

Optional Stainless Steel Primary Screens are available - they provide additional filtration to ensure the slow release control valve does not block up. This ensures the diverter automatically resets itself after rainfall.


Post/Wall/Stand Mounted First Flush Water Diverters These are versatile units that divert larger volumes and in many cases one unit is sufficient.

These water diverters can be mounted on a wall, post or stand, to hold larger volumes. They can be adapted to suit a wide range of applications and will manage single or multiple pipes coming from the roof to divert between 20 and 150L.

For mounting to a wall or post: Includes a galvanised steel mounting bracket and saddle. For installing on a stand: A galvanised steel stand is an optional alternative to post or wall mounting.

Add the appropriate length of 300mm pipe based on the quantity of water you wish to divert. For example, a 2m length of 300m diameter PVC pipe is required to hold 150L of diverted water. The kit is easy to freight, and the diverter volume can be made on site to match exact requirements. Where downpipes combine into one pipe section that leads to the tank, one diverter is usually sufficient. It can be easier to maintain one larger unit rather than a series of smaller diverters installed at each downpipe. How are they installed?

1. In-feed from the roof; 2. Tee Junction; 3. To the tank; 4. Pipe Bracket; 5. Chamber Inlet; 6. Ball Seat; 7. Sealing Ball; 8. Diverter Chamber; 9. Filter Screen; 10. Wall/Post Bracket; 11. Chamber Outlet; 12. Screw Cap with O’Ring Seal; 13. Flow Control Valve; 14. Hose Connection; 16. Optional Stand Single or multiple pipes coming from the roof can be connected into a "T" and coupled together so that the first flush from the roof enters the diverter chamber. The pipes are connected from the "T" into the tank

In-Ground First Flush Water Diverters Buried and out of site, an In-Ground Diverter is perfect for sloping allotments. On a site with a minimum 5° slope that also provides the opportunity for the end cap of the diverter to be positioned above ground (to drain out and be accessible for maintenance), these units allow a ‘wet’ system to be converted into a ‘dry’ system. (For information about ‘wet’ and ‘dry’ systems, please see next section).

How are they installed? In-Ground Water Diverters are supplied in kit form - all you need is the 300mm PVC pipe to form the diverter chamber. The length of pipe will depend on the amount of water you wish to divert. The table on the below shows the length of pipe required to capture specific quantities of diverted water in the chamber. Either 90 or 100mm pipes can be connected to the inlet of the diverter chambers. The outlet only requires the use of 90mm pipe.


How much space do you need?


‘Wet’ and ‘Dry’ systems

Depends on the pipework system to the tank Rain Harvesting systems require rainwater from the roof to be directed to the water storage vessel through gutters and pipes. These pipework systems will be different at every location, however are classified as either ‘wet’ or ‘dry’ systems. Both systems have strengths and weaknesses, and with a little planning, you can optimise your water quality and install a system that looks good.

‘DRY’ SYSTEMS Are systems where the pipe system is designed to run direct from the gutter into the tank. The pipes drain out after rain and do not hold water when the rain stops. “Dry” systems are best because water sitting idle in pipes can become stagnant and provide a potential breeding ground for mosquitoes.

A typical ‘dry’ system (left) – slimline metal tank with rainwater directed to the tank directly from two downpipes, fitted with Leaf Eater® rain heads to screen leaves and debris, and a First Flush Water Diverter at each downpipe to screen finer pollutants before the tank.

‘WET’ SYSTEMS Are systems where the pipes from the gutter go down the wall and underground and then up into the tank. Many systems are “wet” because the size of buildings and the placement of tanks away from the buildings mean that there are long runs of pipe underground leading to a riser at the tank. Because the pipes are underground and below the entry point to the


tank, even during periods without rainfall water remains in the pipes. "Wet" systems can be converted to ‘dry’ using In-Ground Water Diverters, improving water quality and saving water in the process "Wet" systems are also referred to as "charged" or “flooded” systems.

Insect Proofing ‘wet’ systems Because the water that sits in underground pipes has a tendency to become stagnant and provides a potential breeding habitat for mosquitoes, it is critical to insect proof the pipes in a 'wet' system. Legislation broadly says that where pipes hold water they must be screened with a non-corrosive screen of not more than 1mm aperture to prevent the entry of mosquitoes and vermin. Mosquitoes are known to be responsible for many diseases including Dengue Fever and Ross River Fever. Rain Harvesting has developed a range of products to insect proof water tanks and these have been designed to meet all legislative guidelines. Products include rain heads, insect proof screens and flap valves, tank screens and vent cowls.

Better water quality The water that sits in underground pipes has a tendency to become stagnant and provides a potential breeding habitat for mosquitoes. When it rains a "head" of pressure will force this poor quality water towards the tank. Not only can an In-Ground Water Diverter prevent this water from polluting the tank, it will also ensure that after rainfall the water in the pipes drains out through the diverter chamber.

Save water By draining the water normally held in pipes after rain, an In-Ground Diverter SAVES WATER, because the next time it rains, the only water that has to be diverted is the amount of water required to flush the roof.


Commercial First Flush Water Diverters Large units used where there are significant catchment areas or because of a high degree of contamination on the roof and gutters.

Generally divert between 500 and 1000L. Individually designed and manufactured to specific requirements. Can be ground mounted next to the holding tank, and even installed in-ground. Made with single, or up to quadruple inlet pipes, ranging in size from 90, 100 or 150mm. These are water diverters not rubbish diverters. The water entering the diverter must be screened upstream by a either a Filter Pit rain head.

How Much Water to Divert?

Prevent roof contaminants polluting your tank water


It is important to prevent heavy sediments and other roof pollutants from entering the rainwater tank. The amount of water diverted should be a minimum of 20 litres per 100 square metres of roof area (or 0.2L per m ). In calculating the amount of water to divert, consideration can be given to the:

2

1. surface area of the roof, and 2. amount of pollutants on the roof and gutters. The following factors can be used as a guide in determining the volume of water to be diverted.

As a rule of thumb, the more water that is diverted the better the quality of water in the tank. The Diverters are sold in kit form and incorporate standard 90, 100 or 300mm PVC pipes as the diverter chamber section. The length of pipe used will vary depending on the volume to be diverted. Diverters with a variable volume chamber are better than fixed volume diverters because the volume of diverted water can be customised to the specific requirements of each roof.

Maintenance

A well maintained water diverter will not only improve water quality and reduce tank maintenance, it will protect pumps and internal household appliances. By installing a Leaf Eater® or Leaf Beater® screened downpipe rain heads ‘upstream’ of the Water Diverter you will reduce the maintenance required of your system. (Leaf Beater® shown right, installed in conjunction with a Downpipe Water Diverter). If leaves and debris are allowed to build up in the Diverter Chamber, it will block up more frequently. Ensure the outlet of the diverter is clear of any debris. If the outlet is blocked, the chamber will not empty and the first flush of water when it rains will not be

http://www.rainharvesting.com.au/commercial_diverter.asp

http://www.rainharvesting.com.au/system_maintenance.asp

http://www.rainharvesting.com.au/commercial_diverter.asp

diverted. Instead it will flow to the tank and pollute the water.

Periodically unscrew the End Cap of the water diverter to allow debris to fall out. Hose or wash the Filter Screen if required and clean the Flow Control Valve.


Fine sediments and pollutants captured in the End Cap of Water Diverter (see left). Two screens installed to provide double protection of the Slow Release

Control Valve.

Legislative requirements Many Local Councils have developed guidelines for the installation of rainwater tanks, and in some states of Australia it is law that rain heads, first flush devices and insect proof screens are fitted when rainwater is captured and stored in tanks. Before installing a rainwater tank, you should check whether your Local Council has such guidelines in place. Health Officers will confirm that it is most important to keep the catchment system free of bacteria at all times to harvest good quality water. Mosquitoes must be kept out of pipe systems and the tank to prevent breeding and the spread of disease. Ensure that all plumbing work that is carried out complies with all regulations. If in doubt, seek professional advice.

How to Create a Complete Rain Harvesting System

1. Check ROOF SURFACE is suitable for collecting quality rainwater.

2. Install GUTTER MESH (such as Blue Mountain

Mesh™) to prevent leaves and debris from blocking gutters.

3. Fit GUTTER OUTLETS from the underside of the

gutter to prevent obstruction of water flow. 4. Fit Leaf Eater® or Leaf Beater® RAIN HEADS to

downpipes to stop gutters blocking. Rain heads deflect leaves and debris & keep mosquitoes out of pipes that hold water (“wet” systems).

5. Install WATER DIVERTER/S to prevent the first

flush of most contaminated rainwater from entering the tank.

6. Ensure the TANK SCREEN is installed at tank

entry point to filter water and keep mosquitoes and pests out.

7. Choose a WATER TANK. Consider annual rainfall,

roof catchment area and water usage when determining its size.

8. Attach INSECT PROOF SCREENS or FLAP

VALVES to the end of all pipes to the tank screen (for ‘wet’ systems) and to TANK OVERFLOW OUTLETS to keep mosquitoes and pests out and ensure tank is vented properly.

9. Utilise a TANK TOP UP system (if required) to

automatically top-up the tank with mains water when water levels fall to a designated minimum level.

10. Select a PUMP SYSTEM (if required) to distribute

water for use inside or outside the home.

About Rain Harvesting Pty Ltd

Our vision Rain Harvesting Pty Ltd is a new company, established in March 2005 following the acquisition of a portfolio of unique products that form a complete water catchment and storage system. Rain Harvesting is a manufacturer and wholesaler of sustainable water products intent on helping people build sustainable futures. Our specialty is water catchment, storage, insect/pest control, and leaf and debris removal systems used in both rainwater

harvesting and home protection. Our vision is to be a leader in sustainable water systems, not only providing complete rainwater solutions, but to develop new sustainable water markets, both in Australia and internationally. We are committed to driving innovation and aim to provide a complete system – a one-stop for sustainable water products. We value our stockists as strategic partners in our business. Whether it is product training for store staff, our comprehensive product brochures or retail point-of sale materials, we make it easy for our stockists to sell the benefits of rainwater harvesting to the end-user. When you need us, we’ll deliver. 98% of our orders are delivered to our stockists within 3-5 days. We’re easy to deal with because we believe in building relationships for mutual benefit. We’re driven by your success and are active partners in fuelling category growth.

Development of the product range The Leaf Eater® gutter downpipe rain head was first manufactured in 1992 to prevent the build up of leaves and debris in roof gutters which is the most frequent cause of poor quality tank water. It was the first multiple screen rain head developed, working as both an insect proof water catchment device and a hassle free leaf and debris exclusion system for roof gutters.


After three years of development trials, production began in 1997 of an all steel gutter mesh system now known as Blue Mountain Mesh™.

A complete range of insect proof screens and flap valves, tank overflow outlets and other accessories were added to the range through the 1990’s, prior to the invention of the range of First Flush Water Diverters.

In 2006, the Rain Alert™ was the first wireless tank level monitor launched into the Australian and New Zealand markets.

Contact Us

Rain Harvesting Pty Ltd 28-34 Reginald Street, Rocklea, Brisbane QLD 4106, Australia PO Box 311, Archerfield QLD 4108, AustraliaTel: +61 7 3248 9600 Fax: +61 7 3248 9699 Website: www.rainharvesting.com.auEmail: [email protected]


http://www.rainharvesting.com.au/

mailto:[email protected]

First Flush Water Diverters – Quality First€¦ · system of 90mm (3”) or 100mm (4”)...

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