WATER: Greywater Guerrillas

The Greywater Guerrillas are a collaborative group of educators, designers, builders, and artists who educate and empower people to build sustainable water culture and infrastructure.

According to the New York Times, they are "a team focused on promoting and installing clandestine plumbing systems that recycle gray water — the effluent of sinks, showers and washing machines — to flush toilets or irrigate gardens." with a mission: “It’s about trying to use resources to their full potential and interact with ecosystems in a beneficial way.”
http://www.nytimes.com/2007/05/31/garden/31greywater.html?pagewanted=1&_r=2

This is not just using a hose to spray your garden with shower water, this is a sophisticated recovery system. the picture above shows "A pipe running from the house deposits shower and sink water into an elevated bathtub in the yard that is filled with gravel and reeds, and the roots of plants begin filtering and absorbing contaminants. The water then flows into a second, lower, tub, also containing a reedbed, before flowing into a still-lower tub of floating water hyacinths and small fish."

recently published "Dam Nation: Dispatches from the Water Underground"

Dam Nation is a people's history of water—and the water grid; a detailed accounting of the fallout from a century of Manifest Destiny's attacks on wild rivers. The book traces how—across five continents—beleaguered commoners block the neoliberal makeover of the world and endeavor to restore balance between humans and watersheds. These strategists and innovators blow open the scarcity myth to show how local democratic control coupled with watershed restoration can provide water for everyone.
http://www.greywaterguerrillas.com/index.html

What is graywater ?
Any water that has been used in the home, except water from toilets, is called graywater . Dish, shower, sink, and laundry water comprise 50-80% of residential "waste" water. This may be reused for other purposes, especially landscape irrigation.

Why use graywater ?
It's a waste to irrigate with great quantities of drinking water when plants thrive on used water containing small bits of compost. Unlike a lot of ecological stopgap measures, graywater reuse is a part of the fundamental solution to many ecological problems and will probably remain essentially unchanged in the distant future. The benefits of graywater recycling include:

Lower fresh water use

Less strain on failing septic tank or treatment plant

Graywater treatment in topsoil is highly effective

Ability to build in areas unsuitable for conventional treatment

Less energy and chemical use

Groundwater recharge

Plant growth

Reclamation of otherwise wasted nutrients

Is graywater legal?
In practice, greywater legality is virtually never an issue for residential retrofit systems—everyone just bootlegs them. However, graywater legality is almost always an issue for permitted new construction and remodeling, unless you're in a visionary state such as Arizona or New Mexico. For details see our Grey water policy center and Builder's Graywater Guide (book).