In Berkeley, Calif., there is an organization called the Farallones Institute. Those who run the place refer to it as "the Integral Urban House." In simple terms it's an inner-city "farm" that produces much of its food needs through intensive gardening and keeping chickens, fish, and bees.
The key to its remarkable success is the way it recycles waste. Carrot tops feed the chickens, chicken manure feeds the cabbages, and that sort of thing. Even the beehive is situated at one end of the fish pond so that dead bees, regularly removed from the hive by other bees, fall into the pool to feed the fish.
Naturally, the home's gray water is recycled in the garden. And it is this six years of experience in the reuse of waste water that is particularly pertinent in these times of dry-weather forecasts. Already, water restrictions have been imposed in some areas, and the threat of future restrictions faces many more communities.
Gray water is the term used to refer to all water used in a household other than the toilet. It is the water that drains from your bathtub or shower, the kitchen sink or dishwasher, and the washing machine. As a matter of interest, the term given to water from the toilet is black water.
How safe is gray water in your garden? The answer is, fairly safe, particularly in humus-rich soil -- soil in which a good deal or organic matter has been incorporated. But it does have its drawbacks, notably its high-sodium content, derived from the detergents and soap that are used. Sodium tends to break down soil structure, reducing its ability to drain and breathe properly. Sodium buildup in the soil can turn it alkaline, which makes it more of a problem in the West than in the Acid-soil East. gray water can also cause leaf burn if accidentally splashed on leaves.
The Farallones Institute suggests that good garden loam can safely accept up to half a gallon of gray water per square foot each week. Well-drained, sandy soils can accept more; heavier clay-type soils, somewhat less. Do not give gray water to newly transplanted seedlings.
If you plan to use gray water, there are steps to improve its acceptability in your garden:
* Use soap wherever possible, because soaps are generally lower in sodium content than detergents. Gentle soaps are preferred to heavily scented soaps and those that contain lanolin.
* avoid the detergents with "softening power." Water softeners are high in sodium. Bleach should be cut from your washing schedule, and any additive containing boron is unacceptable.
* ammonia is preferred to scouring powders that contain chlorine.
Avoid excessive use of soaps or detergents. More isn't necessarily better for your dishes or clothes, and it certainly isn't better for your garden.
Abby Rockefeller of Cambridge, Mass., whose company markets the Clivus Multrum waterless toilet and a gray-water filtering system, uses Ivory soap and environmentally safe Shaklee-brand cleaning products so that she can safely use all her household's gray water in the garden and in her greenhouse.
Always apply waste water directly to the soil. Overhead sprinkling could damage leaves. On the other hand, some gardeners contend that accidental leaf-scorch problems will be eliminated entirely if gray water is diluted half and half with fresh water.
Water your garden on a rotation basis. This way, one corner won't have to take the whole sodium load. If it is available, follow one gray-water application with a freshwater application the following week. This way many of the unwanted salts are leached out of the soil. A good rain will also help.
Mulch those areas of your garden receiving gray water. A think organic mulch provides the right environment for quick decomposition of any wastes in the gray water.
Avoid using grey water on root crops. Confine its use to aboveground food crops or to your ornamentals. However, do not use gray water on acid-loving plants such as azeleas and rhododendrons.
If consistent use of gray water raises your soil's pH (alkalinity) above acceptable levels, spread gypsum (sodium sulfate) over the soil at a rate of two pounds for every 100 square feet. Thereafter, the Farallones Institute recommends a once- a-month application of gypsum for every 50 gallons of gray water applied daily.
Remember, too, that well-composted soils remain in balance (neither too alkaline nor too acid) far longe r under adverse conditions than do soils low in humus.