Greywater System: A Way to Save Water at Home

Design and install a water-recycling system to make your wash water do double duty.


| July/August 1984



Greywater System Water-Reuse System Schematic

Fig. 1. Water-reuse system schematic.


ILLUSTRATION: MOTHER EARTH NEWS STAFF

I like rural living; it really has its pluses. But five-second showers, trekking eight miles to the nearest Laundromat to do the family wash, and flushing only once a day are not on my list of ten reasons why I chose the country life. So two years ago, when the experts at a nearby university predicted a decade of drought, and the water level in our well failed to recover with the winter snows and spring rains, my engineer husband and I started looking for ways to painlessly cut down on our water usage.

We really didn't have to look very far. Both of us remembered reading about a water-reuse system when we were planning and designing our energy-efficient home two years earlier. At the time, we decided not to design our house around that setup, but it did strike us as a very practical way to save water.

The report we recalled was by the National Aeronautics and Space Administration (NASA) on its Technology Utilization House constructed at Langley Research Center in Hampton, Virginia. (The publication's title is Technical Support Package for Tech Brief LAR-12134.) The NASA engineers had come up with a way of recycling greywater —waste water from the shower, bathtub, bathroom sinks, and laundry—and using it to flush toilets. Instead of letting the water from these fixtures run down the drainpipes into the septic tank or sewer system, the NASA staffers collected it in a tank, chlorinated and filtered it, and then pumped the recycled water back to the toilets. The engineers figured that this system used in combination with water-saving toilets and shower heads would reduce a family of four's water consumption by 50%.

Greywater System Decisions

With the basic system requirements from the NASA paper in mind, we set out to design an economical water-recycling system for our home. Our dwelling is unique, but to help you visualize the interior I'll call it a raised ranch house. On the lower level are the garage and a semifinished living area that includes a bedroom, a half bath, the family room, and the utility room. Upstairs, in our main living quarters, we have two bedrooms, the kitchen, the living/dining room, and a combination bath and laundry. I call the downstairs semifinished because our family room doesn't have a finished ceiling—all the pipes and wires are exposed. This, we knew, would make plumbing changes much easier.

We were determined to build a system that would be both inexpensive to install and easy to maintain. To those ends, we decided that all drains should gravity-feed into the recycling tank. Otherwise, we might have had to add expensive pumps that would have boosted our electric bill. Of course, the gravity-feed requirement ruled out using water from the first-floor bathroom sink, since there was no practical way to locate the storage system below the ground floor.

A survey of the drain lines showed that they all run between ceiling joists over the family room to the family-room/garage common wall, where they make a right-angle turn and converge into an exposed, vertical pipe. This main drain travels under the floor of the house and garage to the septic system. The upstairs bathroom sink is adjacent to the toilet, and the drains from those two fixtures are connected. Only a small amount of water goes down that sink (compared to the washing machine or tub), so it didn't make sense to go to the trouble of cutting and rerouting its drain. But it certainly did make sense to tap the tub and washer drains, and we had plenty of room at the garage wall to tie them together into a new pipe that would carry their water into a storage tank.

atians
6/23/2015 7:46:24 AM

You are missing 2 figures (drawings). If they were added they'd make that "5th" page a little more legitimate.


victoria001
12/29/2013 11:02:02 PM

This is really good automatic system to stop water wastage. With the usage of this system we can conserve water which is wastage by full of tank. This system auto stop water filling process when tank was became full. So this is really nice system. I like to fix it in my water tank.. http://uslifed.com






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