Letters. Recycling laundry wash water

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waste papers, blending various types to produce just the right paper the customer calls for. Most of the waste papers we use come from waste paper dealers who carefully sort the paper before it is sent to us. We, in turn, sort it a second time to make sure that the paper we introduce into our de-inking mill will flow smoothly through our reclaiming system. We recognize that this is a small point in Spofford’s article-which was very well done-but we just want to “set the record straight.”

Henry Bickerstaff Communication Coordinator Bergstrom Paper Co. Neenah, Wis. 54956 Recycling laundry wash water

DEAR SIR: One way to fight the present problem of accelerated eutrophication of bodies of water is to use the soil as a resource renovator and to adopt the principle of “Land Disposal.” This can be done, for example, by draining laundry wash water onto a lawn rather than into the sewer. Unlike municipal sewage effluent, which needs expensive treatment for medical and esthetic reasons, laundry wash water-a solution rich in plant nutrients-is free from pathogens and can be recycled and used directly for lawn irrigation. The wash water does not emit unpleasant odors and contains valuable plant food rich in nitrogen and phosphorus. The phosphates are absorbed by actively growing vegetation such as grasses, and are metabolized to organic phosphate. Under aerobic conditions, the nitrogen content of the detergent in the laundry water, when drained onto the yard of the house, is soon mineralized by the soil microbes and appears as nitrates. These, in turn, are also taken u p by growing vegetation to be metabolized as organic compounds. In the fall of 1970, my curiosity led me to study the effect of laundry wash

water on the lawn grass and a few ornamental bushes in my yard. W e drained the water onto the yard of the house for the irrigation of grass, camellia (c. japonica), azalea, chrysanthemum (c. indicum), etc. T h e soil is well-drained, loamy sand; the natural vegetation is coniferous. Soil p H is slightly on the acidic side. In our laundrying, we used Gain laundry detergent, The wash water, when drained onto the lawn, is at 40°C. Since then, we have not noticed any unwanted o r undesirable symptoms on these plants. Rather, the lawn area and ornamental plants which have been receiving laundry wash water from time to time show a better stand and healthy, vigorous green growth as compared with a surrounding area of the lawn where tap water is used for irrigation. Further research on these lines is, of course, needed. The washing machine does not need any major modification except that the drain hose should be long enough to reach the desired area in the yard. Ordinary water hose with an appropriate diameter can meet this need. T h e idea is primitive-based on the old concept of “back to nature’’-but seems t o work well in solving the problem of eutrophication. I cannot foresee any problem that this method will create when used for aerobic sandy soils, especially if the laundry wash water is kept cool. Some housewives, who d o not wish to pay ever-increasing municipal bills and taxes, may prefer to exert just a little effort to recycle the laundry waste for its profitable use in lawn irrigation. Land disposal of laundry wash water not only reduces the labor and cost of lawn fertilization and irrigation, but it also decreases water consumptionsaving on water bills and municipal taxes,

S. S. Sandhu Professor of Chemistry ClafEin University Orangeburg, S.C. 29115

Closing the gap in waste management

Walter 0. Spofford, Jr., author of the feature article in our December 1970 issue, has brought to our attention that the article ES&T published was based on a version which had been considerably edited by ES&T and not on the final version submitted to us by him. Spofford believes that some of ES&T’S editing significantly distorted economic concepts. While we, and he, agree that the general conclusions contained in the published article are correct, he feels that some of the detailed statements and reasoning leading to the conclusions are misleading to the general reader as well as to the economist. Any question one might have regarding Spofford’s article may be addressed to him at Resources for the Future, Inc., 1755 Massachusetts Ave., N.W., Washington, D.C. 20036.

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Volume 5, Number 2, February 1971 95