Hello! What recommendations do you have for using grey water to irrigate garden crops? I just read this article from EDN#88, which was very helpful but I still have doubts. We would be using grey water to irrigate small home/kitchen gardens, relying on it primarily in the dry season when there is no other readily accessible source of water. According to the article, because the scale is so small there shouldn’t be too many problems with salt accumulation or pH change in the soil, which is good news, but then we arrive at the uncertainty of the safety of irrigating root crops and leafy vegetables. Considering that the purpose of these home gardens is to improve nutrition and child health, I want to be extra sure that our irrigation methods are not increasing the family’s exposure to pathogens. Furthermore, our roughly estimated irrigation needs will be a minimum of 5 gallons/day, and when the University of Massachusetts rule of thumb is extrapolated to our garden square footage (~32 sq ft) it gets us to about 2.3 gallons/day of grey water which the soil could handle, about half of what the garden needs.
Is this a viable option? Would you advise filtering the water before irrigating? Have you seen/implemented successful examples of household grey water filtration for irrigation? I am particularly interested in low input systems that would be simple to implement and care for. I liked the idea of passing the grey water through the compost pile/pit, but this seems to be an example of a safe way to discharge grey water rather than capturing it to water plants. Is there a low-tech way to pass grey water through compost and capture it on the other end after filtration?
Thanks for your help!
Hola! ¿Me pueden compartir sugerencias para el uso de las aguas grises para el riego de hortalizas? Acabo de leer este artículo que me ayudó mucho pero todavía me quedo con dudas. Usaríamos las aguas grises para regar huertos familiares pequeños, dependiendo de la cual durante la temporada seca cuando no dispone otra fuente buena de agua. Según el artículo, como es a escala pequeña, no esperamos encontrar muchos problemas con la acumulación de sal ni con cambios en el pH del suelo. Que bueno! Pero también hay que considerar la incertidumbre de la seguridad de regar tubérculos y verduras de hojas con aguas grises. Como el propósito de los huertos familiares es mejorar la nutrición y salud de los niños, quiero estar extra segura de que nuestros métodos de regar no aumentan su exposición a agentes patógenos. Además, estimamos que el huerto va a necesitar 5 galones/día, y cuando aplicamos la recomendación de la Universidad de Massachusetts a nuestro huerto (~32 pies cuadrados), nos da 2.3 galones/día de aguas grises que el suelo puede aguantar, solo la mitad de lo que requiere.
¿Es una opción factible? ¿Me aconsejan que filtre el agua antes de regar? ¿Han visto/implementado ejemplos exitosos de filtración de aguas grises para riego a nivel de la casa? Estoy interesada en sistemas de bajo insumo que serían sencillos para implementar y cuidar. Me gusta el idea de pasar el agua a través del compost, pero me parece que es un método seguro de verter el agua gris y no capturarla para regar. ¿Se puede pasar el agua a través del compost pero capturarla después de manera sencilla?
Gracias por su ayuda!
In reviewing the literature, the insoluble debris (which would mostly be found in used dish water) are usually the carrier for most pathogens in grey water. One study (Friedler, 2004) recommended excluding dish water because it only makes up 25-30% of total grey water volume, but contributes half of its COD content. And if the laundry water has been used to clean diapers or soiled bedclothes, it is likely to contain fecal matter. Bath/shower water seems to be the safest option, but hand washing after toilet use and showers can also contribute to the microbial contaminant load…and some studies have found that shower water can even carry the highest coliform count in comparison to other grey water sources (Rose et al. 1991).The high levels of contamination in grey water don’t necessarily correlate with edible crop contamination though as Finely (2008) investigates