I want to recycle my wastewater and harvest my rainwater. Can you help?

Asked by Jonathan
Redwood City, CA

I live in Portola Valley, CA.


Water conservation is a great concept which helps to ease the water shortage and at the same time will lower your utility bill.  Different basic approaches are possible:

Rainwater Harvesting

Collecting water from the roof is most of the time the simplest form especially if you have an existing building with rain gutters – the classical rain barrel.

Today there are a couple of companies out there which offer sophisticated systems. Most of the applications are low-maintenance systems which filter the roof runoff and store the water in tanks (surface or underground). The water can be used for irrigation or flushing toilets (so called “Greywater-Systems”).

Greywater System

Greywater systems use recycled water (roof run-off, showers, sinks,…) to flush toilets. The system requires secondary plumbing besides the existing. For this reason often it becomes unattractive for homeowners unless a remodel is already taking place (code compliance required).

Recently Sloan started offering a micro system which uses the water from the bathroom sink to flush the toilet. The water is getting filtered and stored in a 5.5 gal tank in the sink cabinet. A small pump fills the toilet tank as required. This is an easy retrofit application for existing homes.


Reducing water use is the best conservation. A simple and cheap solution is the installation of “Low Flow Faucet Aerator” for all sinks and showers in the home. Aerators cost from $3.00 to $20.00. The efficiency is measured in gmp (gallon per minute).

Dual Flush Toilet

Dual flush toilets have been used in Germany since a very long time and are now available in the US. The system allows you to determine how big of a flush you need. A new toilet with tank or often a retrofit of your existing is possible.

Read GreenHomeGuide's low flow toilet tips.


This is a very basic overview of systems or approaches which are available.

A review of the special circumstances of your home is necessary to make a determination what will fit best.

Tagged In: water saving, greywater

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