PRUEBAS

Several water reuse guidelines and manuals have been published (Chang et al., 1995, 1998;

Pettygrove and Asano, 1985; UNEP, 1991; USEPA, 1992 and 2004; WHO, 1989 and 2005).

These guidelines have been supporting many countries of the Middle Eastern and North African region to implement or upgrade environmentally sound and safe wastewater reclamation and reuse systems adapted to their own technical, socio-economic and cultural conditions. Some countries have also implemented water reuse strategies and issued standards for pathogens, and organic and inorganic pollutants.

Most of the countries of the region have regulations or guidelines related to water reuse (Table 2.6). The first ones were issued in Kuwait in 1976. The standards vary from country to country, as do their derivation. The main differences are in their enforcement. Wastewater effluent discharge standards have generally been set up but some could not be met as they were too stringent and therefore inappropriate. Countries where reuse is developing on a rational basis, within an organized institutional setting, have elaborated and implemented their own regulations and precise standards. In other countries, reference is just made to health standards. Some of the significant discrepancies in the standards are, in part, due to differences in approaches to public health and environmental protection. For example, some countries have taken the approach of minimizing any risk, and have elaborated regulations close to California’s Title 22 water recycling criteria (1978 and 2000), whereas the approach of other countries is essentially a reasonable anticipation of adverse effects resulting in the adoption of a set of water quality criteria based on the WHO guidelines (1989 and 2005).

Table 2.7 shows significant different physical-chemical and microbial standards for reclaimed water reused for irrigation of food crops for human consumption. Some regulations include both treatment and water quality requirements. Except for some of the Gulf countries such as Kuwait, Saudi Arabia and the UAE, which refer to total coliforms, most of the countries with water reuse regulations have set limits for fecal coliforms or Escherichia coli. None include limits for viruses. Vegetables eaten uncooked are excluded from irrigation with treated effluent in most countries. However, the practice of using raw wastewater is widespread, as vegetables constitute cash crops for farmers. Regulations also differ in the general requirements, management practices, operational standards, frequency of monitoring requirements, etc. A variety of approaches have been taken by different agencies to regulate water quality for water reuse systems. These differences pertain mostly to the existing irrigation practices, local soil conditions, desire to protect public health, choice of irrigation or wastewater treatment technologies and needs to keep costs down.

Countries can, then, be classified into four categories according to the origin of the standards they apply, especially when dealing with reuse for irrigation purposes:

1. Those with no guidelines or standards specific to water reuse: Afghanistan, Iraq, Lebanon, and Libya.

2. Those with no specific regulations dealing with water reuse but with comprehensive guidelines for managing wastewater: Algeria, Egypt, and Syria.

3. Those which are referring to or have adopted a set of public health water quality criteria based on the WHO guidelines (1989): Iran, Morocco, Palestine, Tunisia, and Yemen.

4. Those which elaborated regulations close or equivalent to California’s Title 22 water recycling criteria or the USEPA guidelines: Bahrain, Kuwait, Jordan, Oman, Qatar, Saudi Arabia and the United Arab Emirates.

Table 2.6. Regulations or guidelines related to water reuse in the Middle Eastern and North African region.

Country Legislation / Guidelines

Afghanistan There are no guidelines or standards related to water reuse.

Algeria The Water Law in Algeria prohibits the use of raw and treated wastewater for the irrigation of vegetables to be eaten raw; but allows it for the production of fodder crops, pasture and trees. Authorization is required for the reuse of non-conventional waters. There are no reuse standards.

Bahrain For unrestricted agricultural irrigation and landscape irrigation: tertiary treatment plus disinfection is required. The microbiological criteria are the following: <2.2 coliforms/100 mL, ≤1 helminth egg/L and periodical quality control tests are conducted.

Egypt There are not yet specific regulations dealing with water reuse but comprehensive guidelines for managing reclaimed water, focusing on restricted irrigation, are under development. Water pollution from municipal and industrial effluents is mainly regulated by three laws: Law No. 48/1982 for the protection of the Nile River, Law No. 12/1984 on irrigation and drainage, Law No. 4/1994 on environmental protection. Law No. 48 (1982) requires secondary treatment of effluent prior to discharge into the Nile river and irrigation canals, and specifies limits for maximum allowable fecal coliform of 5,000/100 mL and BOD of 60 mg/L. The 1984 martial law regulation prohibits the use of treated effluent for irrigating vegetables and the use of effluent for crops unless treated to the required standards for agricultural drainage water. There are no reuse standards.

Iran The "Effluent Discharge Standard" developed by the Department of the Environment in 1994 is the only existing wastewater code that sets effluent discharge limits to surface waters, cesspits, and agricultural irrigation. This standard does not define any criteria to use treated effluent for industrial, fisheries and recreational activities.

International guidelines developed by the WHO and by the USEPA are currently used to regulate water reuse.

Iraq Neither guidelines nor a code of practice for the use of wastewater in irrigation have been adopted so far.

Jordan The previous Jordanian quality standard on reuse, JS893/1995, prohibited irrigation of vegetables eaten raw. It listed 47 specific constituents and prescribes quality standards on discharge to streams and catchment areas and on water reuse for each of the six following uses: irrigation of vegetables eaten cooked, irrigation of fruit trees, forests, industrial crops, and grains, artificial recharge of groundwater, use in aquaculture (fish hatcheries), irrigation of public parks, and irrigation of fodder. Fecal coliforms for irrigation of cooked vegetables had to be <1000 MPN/100 mL, BOD5

<150 mg/L, and helminth egg ≤1/L. Necessary presence of residual chlorine in treated effluent was required.

New standards have recently been approved and were enacted in 2003 under the title JS893/2003, in which the irrigation of vegetables eaten raw with reclaimed water remains prohibited whatever treatment is applied. E. coli should not exceed 100 count/100 mL for cooked vegetables. Groundwater recharge is not allowed where aquifers are used for drinking purposes. The helminth egg criterion has been maintained for all uses.

Kuwait Effluent quality standards for water reuse require advanced level treatment with effluent’s total coliforms count not exceeding 100/100 mL, and BOD and TSS <10 mg/L.

Lebanon There are currently no guidelines or regulations for water reuse. However, Lebanese regulations prohibit the reuse of treated effluents for irrigation of fruits and vegetables. National environmental standards for discharge of treated effluents into surface water and sea have been established.

Libya Under preparation.

Morocco There are not yet any specific water reuse regulations. Reference is usually made to the WHO recommendations. Reuse standards are under preparation. Relevant regulations are Decree No 2-97-875/ 1998 and Water Law Nº 10-95.

Quality standards for water to be used for irrigation have been issued: No 1276-01 of October 17, 2002.

Oman There is a General Water Resources Law - Royal Degree No. 83/88.

Treatment is required and two main rules regulate water reuse: (1) water reuse, discharge and sludge disposal that include physical-chemical parameters, and (2) wastewater standards related to biological characteristics. Two categories of water reuse are distinguished:

For Category A (which includes irrigation of vegetables and fruit to be eaten raw, landscape areas with public access, controlled aquifer recharge, and spray irrigation), effluent quality should be such that fecal coliforms are less than 200/100 mL, and helminth eggs less than 1/L.

For Category B (which includes irrigation of cooked vegetables, fodder, cereals, and areas with no public access), the standard is <1000 fecal coliforms/100 mL, and

<1 helminth egg/L.

Palestine The draft Water Law and reuse standards are based on the WHO guidelines.

Qatar Advanced treatment is required as well as strict standards.

Saudi Arabia The Royal Order No. M/34 issued in 1980 forms the legislative framework for the protection of water resources including wastewater.

National wastewater quality standards have since been approved. Advanced wastewater treatment is requested for unrestricted irrigation. Concentrations in the effluent should not exceed 2.2 count/100 mL for total coliforms, 10 mg/L for BOD and TSS, and 1 NTU for turbidity. Irrigation of any kind of vegetable is forbidden.

Syria There are currently no guidelines or regulations for water reuse.

Resolution No. 2823, dated 29/8/1990, issued by the Ministry of Agriculture excludes vegetable farming from irrigation with polluted water sources of all origins. Use of wastewater is restricted to fodder and industrial crops and fruit trees on small areas.

Tunisia Water reuse is regulated by (1) the 1975 Water Law, (2) the 1989 decree (Decree no. 89-1047), and other standards:

• Reclaimed water quality standards for reuse (Tunisian standard 106.03, 1989);

• Wastewater disposal standards (Tunisian standard 106.002, 1989);

• Code for crop selection and agricultural practices.

Reclaimed water quality criteria for agricultural reuse were developed using the guidelines of FAO (1985) and WHO (1989) for restricted irrigation (less than 1 nematode egg/l), and other Tunisian standards related to irrigation or water supply.

United Arab Emirates

Advanced treatment is required as well as strict effluent standards, which are as follows: BOD5 <10 mg/L, TSS <10 mg/L, Total coliforms <100/100 mL. Complete nitrification is requested. In Sharjah: total coliforms <23/100 mL and 1 mg/L residual chlorine as Cl2.

Yemen There are draft national water reuse standards proposing a uniform standard for all crops.

Table 2.7 Overview of some national standards for selected chemical and microbial parameters for reclaimed water reused for irrigation of food crop for human consumption. Parameter Unit Kuwait Jordan** Oman Saudi Arabia Tunisia UAE California USEPA WHO 2003 A* B* 1989 pH - 6–9 6–9 6–9 6.0–8.1 6.5–8.5 - - 6–9 - BOD5mg/L 10 30 15 20 10 30 10 - 10 - COD mg/L 40 100 - - - 90 - - - - TSS mg/L 10 50 15 30 10 30 10 - - - Turbidity NTU - - - - <1- - - - - Chlorine residualmg/L 1 0.5-1.0 - - - - - Present 1 - Total coliforms MPN/100mL <100 - - - <2.2- <100 <2.2- - Fecal coliforms MPN/100mL - <100 <200 <1000 - - - - <200<1000 Nematodes eggs/L - - - - - < 1- - - ≤ 1 Helminths eggs/L - ≤ 1 < 1< 1- - - - - - **: cooked vegetables. A*: irrigation of vegetables and fruit to be eaten raw, landscape areas with public access, controlled aquifer recharge, and spray irrigation. B*: irrigation of cooked vegetables, fodder, cereals, and areas with no public access.