Graywater Reuse in Jordan -- continued --

4.0  Legislating for Graywater in Jordan

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The current legal position regarding the reuse of graywater in Jordan is uncertain. The relevant Jordanian regulation governing household plumbing is the ‘Sanitary Wastewater System Code’, (Ministry of Public Works and Housing 1988). This provides guidelines for internal and external drainage and wastewater systems and includes extensive design guidelines for septic tanks. There is no explicit prohibition of the installation of a separate plumbing system for graywater. On the contrary, it is recommended that the toilet, bidet and urinals should not be connected into the same pipe as the floor drains and sinks, until outside the building. A suggested layout for a domestic wastewater system shows the wastewater from the toilet and bidet being kept separate from the shower and sink until outside the building where they are connected at a manhole. However, the code requires (2/4/2, page 20) that all wastewater should be discharged using a sanitary wastewater system in accordance with the recommendations laid down in the code, and prohibits wastewater discharge according to any other method. This appears to prohibit the on-site reuse of graywater. 

The Ministry of Water and Irrigation has formed a committee to examine the code in light of the potential for graywater reuse, and to propose amendments that would allow the reuse of graywater more easily. CSBE is represented on this committee and has made a number of observations regarding potential legislation, based on experience elsewhere. Committee deliberations are expected to be ongoing into the summer of 2004.

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Many jurisdictions which have drawn up legislation for graywater reuse, have found it beneficial to differentiate between large usage and small usage, since the implications of graywater reuse in each case are very different, and the cost and complexity of solutions are also different.  Customers of a large hotel, which reuses the graywater from its staff and guests, will expect a higher degree of protection than a single household reusing its own graywater, under its own control. One of the main purposes in large usage legislation would be to provide for protection to health and environment, and ensure the responsible design, installation and operation of the graywater system. Since large usage systems will combine graywater from more than one household, additional treatment complexity, and therefore cost will result.  

Low usage systems however, confined to single households, where graywater is reused solely within the property of the household, should be cheap, easy to install and maintain. They should also be cheap and easy to regulate. If the legislation forces the system to be too costly, and graywater reuse is determined by the potential user to be un-economical, then it will not be taken up. Since the potential for cost savings from household water use reduction in Jordan is fairly limited, this will be a key issue in drawing up legislation appropriate to Jordan. Legislation will have failed if; 

• householders consider it too difficult to obtain a permit for a graywater system,

• it requires graywater applications to be complex and expensive,

• it is too costly for the regulatory authority to monitor and oversee. 

Observers of graywater legislation in different countries have noted that the legislation implemented in the US State of California was complex and expensive to comply with, and did not lead to popular reuse of graywater. The legislation introduced in Arizona, however, followed a different philosophy, and has led to successful uptake of graywater reuse in the state.  

A very useful overview of graywater legislation in a number of countries, including a comparative assessment, may be found on the Oasis Design Website, under “Greywater Policy Central” (http://www.oasisdesign.net/greywater/law/index.htm).

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When considering graywater systems, it is important to be realistic about risk. Wastewater professionals instinctively tend to apply existing wastewater standards and principles to graywater.  However, both the quantity and quality of domestic household graywater, and the applications to which it is put, mean that standard wastewater standards which are usually applied to treated wastewater are not necessarily relevant.  

For example, wastewater engineers use BOD as a key indicator of the degree of contamination of the wastewater. This is because ordinary domestic wastewater contains large amounts of sewage – the strength of which can be linked to the BOD level.  However, since graywater contains no sewage, and is to be used to irrigate plants, BOD is not necessarily a useful indicator as the ‘strength’ of the graywater. BOD is a measure of the degree of organic material in the water. Organic material in graywater does not constitute a major problem for either human or plant health, since it does not relate to faecal content. The organic content may be from soaps or detergents, human skin and hair, or particles of food waste. However, provided human contact with the graywater is minimized, BOD from these materials should not constitute a major risk to human health, nor should it cause a problem to plants. Organic material in the graywater will be quickly broken down by the soil. In fact, much organic material will actually be broken down into useful nitrates and phosphates which will act as plant nutrients, and are therefore beneficial to the soil. 

Bacterial content (in particular the faecal coliform count) is also used as an indicator of the strength or degree of treatment of wastewater. However, with graywater, there should be little faecal material to begin with. In addition, bacteria will die soon after coming into contact with the soil, and will cause no harm to the soil or to plants. Provided human (and animal) contact with the graywater is avoided, and safeguards are applied as to the end use of the graywater (for example no irrigation of herbs or root vegetables, or vegetables which are eaten raw), the significance of the bacterial content of graywater is much less than for treated wastewater.  

Standards which are applied to the reuse of treated wastewater (for example in Jordanian Standard 893) are often done so with regard to the effect on the groundwater. Nitrate content is a particular parameter of concern in many areas. However these standards are applied to instances where there is large scale reuse of treated wastewater, for example from the output of a large municipal treatment plant. Regarding graywater, since the quantities of single-household domestic graywater will be very small, the risk of any graywater leaching out of the household property into the surrounding environment or water table is very low. The immediate applicability of JS 893 and similar standards to graywater reuse must therefore be assessed on its own merit.  

Minimizing risks to human health and plants is undoubtedly a key factor in the regulation of graywater. Regarding risks to human health, the hazard is low to begin with. It should not be forgotten that minutes before graywater became graywater, it was being used to shower someone, or to clean someone's clothes. Graywater is not sewage, which is why it is easier to use and deal with in the first place. There are 2 main ways to minimize risks to human health; 

1. treatment – i.e. remove potential contaminant material from the graywater  

2. prevention of contact – i.e. design a system where human contact with the graywater during application and afterwards, is minimized.  

Treatment is costly and requires user intervention and high maintenance. However it is relatively simple to design a system which minimizes contact between the householder and the graywater. The average cost of domestic water in Jordan is low, especially for low quantity users, so the direct cost savings to be made from the reuse of graywater are limited. If a system costs too much to install or maintain, then it is simply not worth it to the householder.

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In 2001, the Arizona Department of Environmental Quality published regulations for residential graywater reuse. These regulations are available at www.watercasa.org. These regulations follow a three-tiered approach whereby systems using under 1500 liters per day must meet a list of reasonable conditions, and are covered by a general permit without the need for the householder to apply for anything. Systems producing over 1500 liters per day require a permit, while those over 13,000 liters per day are dealt with on a case by case basis. 

In the legislation, graywater is defined as wastewater collected separately from clothes washers, bathtubs, showers, and sinks. Reuse of wastewater from a kitchen sink, dishwasher, or toilet is specifically prohibited, although a revision of the regulations due in 2003 may permit the use of kitchen sink water under certain conditions.  

The conditions for the private residential reuse of graywater (under 1500 l/day) include; 

• avoidance of human contact between graywater and soil irrigated by graywater,

• containment of graywater from a particular residence within the property boundary,

• graywater usage only for household gardening,

• surface application of graywater may not be used for irrigation of food plants, except for fruit trees,

• surface irrigation by graywater should be restricted to flood or drip irrigation,

• sprinkling is prohibited.

In addition, the graywater should not contain water used to wash diapers or similarly soiled or infectious garments, unless the graywater is disinfected before irrigation. The graywater should not contain hazardous chemicals, for example from cleaning car parts, washing greasy or oily rags, or disposing waste solutions from home photo labs, or similar hobby or home occupational activities. 

The Arizona regulations require that graywater systems should be constructed so that if blockage, plugging, or backup of the system occurs, graywater can be directed into the sewage collection system or an on-site wastewater treatment system. The graywater system can include a means of filtration to reduce plugging and extend the system’s lifetime. Any graywater storage tank should be covered to restrict access and to discourage breeding of mosquitoes or other disease bearing insects. The graywater system should not be sited in a floodway and should be operated to maintain a minimum vertical separation distance of at least 1.5 meters from the point of graywater application to the top of the seasonally high groundwater table. Residences with an on-site wastewater treatment facility for blackwater must not change the design, capacity, or reserve area requirements for this facility if installing a graywater system. Any pressure piping used in a graywater system that may be susceptible to cross connection with a potable water system should clearly indicate that the piping does not carry potable water.  

These regulations are widely regarded as the most progressive anywhere (see detailed discussion on the Oasis Design website www.oasisdesign.net - Oasis Design is a consulting organization with long term and wide experience of graywater systems and legislation). They have been used as the basis for new legislation in New Mexico. The tiered approach makes reuse easy for the ordinary householder and allows for innovation and flexibility of design. They do not prescribe particular design specifics and follow a performance-based approach, while the blanket prohibitions ensure the protection of human and plant health.  

A booklet containing the text of Arizona’s Title 18 Reuse Rules, and some explanatory notes and guidelines, is available for download without charge from www.watercasa.org.