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Graywater re-use for New Homes is simple if the Plumbing Design is changed to Dual Waste prior to pouring the foundation.

It’s really quite simple.  Just have all baths, tubs and laundry waste plumbed to a second waste pipe, looped back into the black waste line, at least 6’ from the foundation — leaving room for the pumping basin for later installation, or install the basin at the same time as foundation plumbing rough-in.

We have found the average additional cost for dual plumbing in a new home ranges from $300—$400; a very small investment for the future landscape potential and protection provided.

Avoid Hand Basins / Lavatories.

Although waste water from these sources is classified as Graywater, our experience is this water is better utilized in the black water line, assisting in washing kitchen and commode solids down the line. 

Plumbing Specifics:

The IrriGRAY basin is 18" diameter x 30" depth. Additional risers can be added in 12" and 6" increments to raise the assembly to ground level from the stub out depth.

The standard IrriGRAY system has a combination 3" DWV (drainage waste & vent) Schedule 40 inlet, and Overflow to waste. 

An additional 2" waste line is required from the filter backwash waste outlet looped back into the black water line, or looped back into the IrriGRAY overflow pipe, downstream of the basin. Pump to waste outlet is also connected to this same waste line.

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Local codes may require a waste backflow prevention valve downstream of the basin overflow.

In most US locations, an RPZ (reduced pressure backflow prevention valve) is required for the potable water connection to the filter and makeup water assembly to prevent possible cross connection. The RPZ is not provided with the system as RPZ code requirements vary across the US.



110v AC supply is required for the IrriGRAY controller box. Total maximum power consumption is 400W, requiring a 5 amp power supply. Most electricians supply a 10 amp connection as standard.

The IrriGRAY controller then provides 110v switched power to the pumping basin, as well as a plug and play valve control cable. An additional control cable, also plug and play, connects the controller to the filter and makeup water assembly.

If the pumping basin is located more than 10' from the IrriGRAY Controller box, we recommend installing an weather proof power socket, supplied by the Controller Box for the pump supply.

The pump power plug should not be cut / hardwired because this will void the pump manufacturer's warranty.