SEWAGE EFFLUENT DISCHARGE REGULATIONS

FOR IRRIGATION DEVELOPMENT IN THE MIDDLE EAST REGION

By T. Sammis, B. Stewart, W. Zachritz

Water Resources in the Middle East

• Water has been a scarce resource in the Middle East since early civilizations

• Water shortage in the Middle East has forced countries to reuse treated wastewater for agriculture, industry, recreation and to recharge aquifers

Wastewater lagoon in Ramallah

Wastewater Health Risks

• The primary problem associated with using treated wastewater for agriculture is the inherent health risks from wastewater containing bacteria, viruses, and a wide range of parasitic organisms

• Indicator organisms are used to reflect the sanitary quality and suitability of particular water reuse or consumption.

• Typical indicators are fecal coliform content measured as CFU/100mL (colony forming units) and the number of helminth eggs or ova

• Waste water can also contains large amounts of dissolved and suspended organic matter that has the potential to clog soil pores and irrigation equipment emitters

Drip system in Hawaii using wastewater from a lagoon

Wastewater flush Line for a drip system in Hawaii

Wastewater Application to Agriculture Crops

• Treated wastewater has been applied mainly to field crop but Gideon Oron in Israel demonstrated that sweet corn (zea maize), and sweet pepper (paprika) could be irrigated using treated wastewater through subsurface drip irrigation systems without detection of fecal coliform in plant parts and with minimal bacteria concentrations in the soil surface

Agencies responsible for wastewater regulations

Country Federal Agency Jurisdiction

Jordan Ministry of Water and Irrigation

Regulates wastewater treatment plants and Wastewater management

Palestinian Authority

Ministry of Environmental Affairs

Wastewater management

Israel Ministry of Health

Wastewater management

Egypt Ministry of Agriculture

Regulates the application of wastewater

Wastewater reuse standards in the Middle East

• Wastewater reuse rules for agricultural lands either follow the rules developed by the World Health Organization or they follow more stringent rules developed in the United States by the State of California

• WHO standards for the use of wastewater in agricultural production for export generally require a level of treatment that ensures that the fecal coliform content of the wastewater is less than 103 cfu per 100 ml

Helminth Eggs and Intestinal nematodes

• WHO standards are that the effluent should contain less than 1 heliminth egg per liter.

• The WHO recommended treatment methodology to achieve this standard using a series of stabilization ponds (aerobic, facultative, and polishing lagoons) with a hydraulic retention time of not less than 8-10 days.

• This health problem only exists where intestinal nematodes are prevalent

Treatment Levels

• Currently in the Middle East, wastewater treatment levels for application to agricultural land range from zero—discharge of raw sewage—to highly treated water produced from newly constructed wastewater treatment plants

• The long-term goal of all Middle East countries is to treat wastewater used in agriculture to minimum WHO standards

Table 2. The World Health Organization's criteria for effluent application for irrigation agriculturalcrops.

Constituents(Mg/1)

Group AIrrigation ofcrops to beeaten uncooked

Group BCereal crops,industrial crops,fodder crops,pasture and trees

Group CLocalized irrigation ofcrops in Category B ifexposure of workersand the public does notoccur

Effluent quality

Intestinal nematodes(arithmetic mean no. of

eggs per liter)<1 <1 N/A

Coliform Counts/100 ml<1000 No Standard N/A

Mandatory treatment

Stabilization pondRequired Required

8-10 days retentiontime

N/R

Equivalent watertreatment plant Required N/R N/R

Pretreatment needed byirrigation technology orprimary sedimentation

*N/R means not recommended

WHO Standards

• Wastewater can be applied to the land using flood irrigation but this method of irrigation should not be used for producing vegetables.

• Sprinkler irrigation should not be used on vegetables and fruit unless the effluent meets the guideline for “Group A” conditions

• Subsurface or localized irrigation, with the surface covered with plastic mulch, gives the greatest degree of health protection when using treated wastewater.

Middle East Transfer of Technology

• Appropriate Technology Consortium (ATC) was formed to develop low-cost, efficient, and replicable wastewater treatment and reuse systems in rural areas of the Middle East.

• The consortium consists of: The Galilee Society (Israel), The Palestinian Hydrology Group (West Bank), The Egyptian Center of Organic Agriculture (Egypt), The Technion, Israel Institute of Technology (Israel)

Web site- Middle East Wastewater Use Clearinghouse

• Purpose is to present wastewater information on

an internet site that has standards for reuse of wastewater to agriculture lands in the Middle east

• To present design and operation internet tools for wastewater management

Design Criteria Equation based on Nitrogen loading to the ground water

• Lw = [Cp (Pr - ET) + (100 (a+ b ET) Cc)] / (Cn (1-F)-Cp) • Lw = allowable irrigation amount (mm/yr)• Cp = total nitrogen allowed in percolating water (mg/L)• Cn = total nitrogen in applied wastewater (mg/L)• Cc = nitrogen concentration in plant tissues (%): • ET = ET rate (mm/yr) Pr = precipitation rate (mm/yr)• a and b constants of the Evapotanspiration production

function • F = fraction of applied total nitrogen removed by

denitrification and volatilization.  

Alfalfa irrigated with wastewater having a yield of 17 t/ha

0

10

20

30

40

50

60

70

80

0 2 4 6 8 10

Nitrogen in Drainage water ppm

Irri

gati

on

eff

icie

ncy %

wastewater N 40ppm

Wastewater N60ppm

Irrigation efficiency

• Seasonal Irrigation efficiency= seasonal evapotranspiration/irrigation amount

• IE= Et/Lw

• Use a water balance –crop coefficient-climate based spreadsheet to operate the irrigation system to match the design criteria.

Temperature sensor and radiation shield

Conclusions

• Wastewater regulations and standards of use vary among the Middle East countries. These regulations are based on scientific information and also on public perceptions about wastewater.

• The information on the use of wastewater in agriculture covers a range of health issues, production issues related to crop/water requirements and the type of irrigation system to use for each crop.

• This information is not found on any centralized database available on the web but use of the web is the most efficiency method of transferring knowledge.