- The performance of seven small commercial greywater treatment systems installed in private gardens was tested and the effluent quality compared against current Israeli standards for irrigation in cities. Additionally, the potential environmental effects of irrigation with insufficiently treated greywater on soils and plants were evaluated in a pot study. The bulk of the small systems currently proposed for greywater treatment fall into one of two categories. Some are filtration systems that provide minimal treatment. The others are small‐scale domestic wastewater‐treatment systems. Neither system is designed to handle the differences in flow or composition that greywater presents. Both are thus unsuitable. Moreover, it was demonstrated that the use of insufficiently treated greywater for irrigation might have detrimental environmental effects. Proper standards, their enforcement and education are necessary to resolve the potential risks currently associated with greywater re‐use.