This is the Poly-Mart 12" Post/Wall-Mounted First Flush Water Diverter Kit. A versatile unit that can be mounted on a wall, post or stand, to hold larger volumes. Can be adapted to suit a wide range of applications and will manage single or multiple pipes coming from the roof to divert between 5 and 39 gallons. Includes a galvanized steel mounting bracket and saddle. A galvanized steel stand is an optional alternative to post or wall mounting. Add the appropriate length of 12" pipe based on the quantity of water you wish to divert. For example, a 80" length of 12" diameter PVC pipe is required to hold 39 gallons of diverted water. The kit is easy to freight, and the diverter volume can be made on site to match exact requirements. Instead of flowing to the water tank, pollutants are diverted with the initial flow of water into the chamber of the water diverter. The first flush water diverters utilize a dependable ball and seat system - a simple automatic system that does not rely on mechanical parts or manual intervention. As the water level rises in the diverter chamber 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 top of the "T" to the collection tank.
There is an additional filter supplied with this First Flush Diverter Kit. It sits inside of the standpipe. This mini filter helps keep the line open so that the water in the standpipe may drain out slowly through the bottom. Yes, the speed at which the water leaves the standpipe is adjustable with drip regulators. Attach a drip hose to the bottom fitting and use this water too.
This chamber and filter will need to be cleaned. Unscrew the bottom fitting and everything will fall out of the chamber, including the filter and plastic ball. Carefully clean everything, put the green ball back inside the standpipe and screw bottom fitting into place.
You will need to supply the 12" diameter PVC standpipe; fittings from the downspout to the First Flush Diverter; drain hose for the bottom drain; fitting from the "T" of the First Flush Diverter to the to water containment unit. How do they work?
Fitting an appropriately sized First Flush Water Diverter is critical to achieve good quality water. Water Diverters improve water quality, reduce tank/cistern maintenance and protect pumps by preventing the first flush of water, which may contain contaminants from the roof, from entering the tank/cistern.
When it rains, water slowly builds up in the roof guttering system before it exits through the downspout. 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/cistern, these pollutants are diverted with the initial flow of water into the chamber of the water diverter. The water diverters from Rain Harvesting utilize a dependable ball and seat system - a simple automatic system that does not rely on mechanical parts or manual intervention.
As the water level rises in the diverter chamber the ball floats, and once the chamber is 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/cistern.
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/cistern 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.How much water should you divert?
It is important to prevent heavy sediments and other roof pollutants from entering the rainwater tank/cistern. The amount of water diverted should be a minimum of 12.5 gallons per 1000 square feet of roof area (or 0.0125 gallons per square foot). In calculating the amount of water to divert, consideration can be given to (1) the surface area of the roof, and (2) the 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:Pollution Factor For The Roof
- Minimal Pollution - Divert 0.0125 gallons per square foot of roof area (For example, open field, no trees, no bird droppings, clean environment).
- Substantial Pollution - Divert 0.05 gallons per square foot of roof area (For example, Leaves and debris, bird droppings, various animal matter, dead insects, skinks, etc.)Diversion Volume For A First Flush Water Diverter
Square Foot Roof Area x Pollution Factor = Rainwater to be divertered.
For example a minimal polluted roof of 1000 square feet: 1000 x 0.0125 = 12.5 gallons to be diverted.