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Misinformation
Other websites claim, essentially, that pumps and dripperlines are not worth the effort. How do you counter this?
Cleaning an internal filter can result in graywater solid matter reaching the pump, and care is required to wash and drain the system before re-inserting the cleaned filter and switching on the power.
To be fair to many other US websites, they are based on US experiences over the last 10 years. Until recently most US states did not have the need to save water. However, within the next 10 years 35 States will suffer from water shortages.
Australia, already the driest continent, entered a 15 year drought period, commencing in the mid 1990's. Cities and rural areas alike have suffered from severe water shortages, with garden watering either banned or heavily reduced. This forced the rapid development of graywater technology.
The Australian experience with tens of thousands of installations over 10 years has proven the worth of pumped (pressurized) graywater irrigation systems.
Technological improvements in the past 5 years have produced systems where minimal maintenance is required (certainly less than gravity based systems), while maximizing the use of water you have already paid for.
Amongst many astounding claims that have been made, the following need to be discussed:
Dirty water submersible pumps are designed for ...dirty water. They use an impeller to create a whirpool in the pump and force the water out with little contact with the impeller.
They are designed to pump soft solids up to 1 1/2" or more in size.
About 10 years ago there was a common perception in Australia that graywater had to be filtered before the pump, to preserve the pump. This has since been proven false - in over 5,000 systems manufactured and sold in Australia by Just Water Savers (Australia), not one pump has been bound by hair or lint, and this is with filtration after the pump.
A 660 Watt pump, providing more than enough power for residential graywater applications, will typically run for 1/2 hour per day, in total, with 4 people living at the house. Although rated at 660W, the pump will actually run at 450 watts.
Therefore the total daily power usage is 0..23 kilowatt hours. At say, 11 cents per kilowatt hour, this comes to a cost of 2.53 cents per day, or $9.23 per year.
As comparison, this is about the same amount of power consumed by a dvd player, hardly in the top 5 energy consumers in the home.
Overall the power usage represents 1.1% of the average home power consumption (based on 2001 USA household electricity statistics.
This calculation is based on a graywater system connected to all shower / bath and laundry waste.
If the system is properly designed with a traditional float, the float switch will not hang.
However care should taken choosing systems that use electronic sensors or floats riding on a shaft, both methods can suffer from sensors being gummed up by graywater.
10 years ago, filtration was a hassle. Screen or mesh filters did need to be cleaned very often, because the only dripperlines commercially available required 125 micron or finer).
5 years ago, with the introduction of 'Tiran' dripperline by Netafim Australia, filtration became much easier. Titan is now manufactured in the US and available as 'IrriGRAY'.
'Tiran' dripperline only requires 400 Micron filtration, which is much coarser. Combined with new generation filters, filter cleaning in a residential graywater system should take no more than 1 hour over a year.
This is simply a matter of inexcusably poor design. Also, plumbing regulations in both Australia and the US require overflow of graywater into the sewer / septic before it can possibly back up the waste pipes.
Graywater systems that use internal filters - before the pump - generally consist of three chambers;
We do not favor internal filtration. Apart from being difficult to clean, internal filters can cause large amounts of graywater to overflow to the sewer / septic. In such systems, water is only moving through the filter by gravity, and the filter can not process water quickly enough as it starts to store graywater solids.
Filtration after the pump, instead of before, is far more efficient, as water is forced through the filter.
Also, external filtration after the pump ensures graywater solids cannot enter the irrigation dripperline system.
We agree! Instead use a system that has a easily accessible external filter, such as the IrriGRAY pumping systems.
At around 66 cents per foot, the Irrigray dripperline might appear to cost more than regular dripperline, but actually costs less.
70% less dripperline and fittings are required than with traditional dripperline covering the same area. 300' of dripperline costing $198 is normally sufficient for all the garden beds on a 7,000 sqft residential property.
With tens of thousands of installation in Australia, Irrigray is proven to virtually eliminate clogging (if the graywater is filtered to 40 mesh / 400 micron levels.)
Historically packaged systems have been expensive (especially in the US). Substantial product development and competition in Australia has driven down prices significantly.
This price drop has now transferred to the US, where a high quality pump driven graywater diversion system, together with a complete residential graywater irrigation kit can be found for approximately $800.
Every house is different, and some systems are difficult to adapt. The IrriGRAY pumping system is an example of system where the installer can customize the system to suit the house, with as many inlets as required.
For square shaped houses it is often easiest (and therefore cheaper) to create multiple graywater pipe inlets into the pumping unit, while other long houses may be easier to plumb with one long graywater waste pipe.