Greywater Recycling in Israel

In Israel, greywater recycling remains at an early stage. This may appear ironic at first, as Israel is a global leader of water solutions in general and wastewater treatment in particular, utilizing some 80% of its treated water primarily for agricultural irrigation.

In years past, the value and need for greywater recycling as a long term water conservation measure was not understood or appreciated by Israeli authorities. Expert findings presented to the Treasury in 2012, maintain that as Israel’s population grows to an anticipated 10 million people by 2025 and 15 million by 2050, were a conservative 30% of Israeli households to recycle greywater, this could translate to an annual savings of some 40 million cubic meters (MCM) of water by 2025 and 140MCM by 2050 (Adel, Bass, Friedler, Shmueli). The cumulative savings to the economy (direct costs) by way of reduced water and energy consumption, carbon emissions and eliminating the need for 2 water desalination plants is estimated to be between 13-17 billion NIS.

At present, Israel does not have regulation in place regarding greywater recycling. Over the years, the Israeli government has been unwilling to authorize greywater recycling within urban environments, the facilities of which would be installed and maintained in a decentralized fashion. This issue still poses a problem for the Ministry of Health, the authority responsible for authorization of water treatment facilities and the public health. In 2008 the Ministry of Health published guidelines, in accordance with the water quality levels recommended by the Halperin Committee of 2003, regarding greywater recycling that would be permitted for watering public gardens and flushing toilets. Since that time, several greywater systems have been authorized to operate, primarily in country clubs and on campuses and the Ministry of Health is furthering a proactive stance on regulatory measures.

Barriers to Recycling Greywater in Israel

In spite of the government’s new willingness to examine the possibility of decentralized water recycling, there remain a number of barriers that must be addressed:

  •   Ministry of Health concerns fear of endangering the public health by using greywater in the urban sector, as is strongly expressed by the Ministry of Health, a fundamental objection to the decentralization of water treatment facilities, and a preference for transport of sewage to centralized facilities.
  • A lack of clear regulations regarding greywater and reliance on the personal views of district engineers, with no uniformity of opinion on the part of the Ministry of Health.
  • The conservative nature of construction entrepreneurs and contractors, and the abstention from promoting environmental causes due to regulation, financial uncertainty, as well as the obscurity regarding the image and marketing value of greywater recycling.
  • Claims that the greywater recycling on a national level would be undesirable due to the fact that it reduces sewage water, the recycling of which is used for agricultural irrigation; these claims may cause the agricultural lobby to raise objections as well.
  • An engineering fear that greywater recycling will cause a lowering of the fluid ratio sewage pipes, causing the ratio of solids to rise and resulting in obstructions and transport problems. However, should this fear be realized, it would only come to pass after a major implementation of greywater recycling systems into new construction and over time. By the time this would happen, studies on the subject that are currently in progress will have likely produced information that would facilitate   the design and adaptation of  piping systems in new neighborhoods  to prevent the problem for occurring.

The field of greywater is beginning to develop in Israel, and requires institutional involvement in order to maximize its conservation potential while managing threats to environmental and public health.