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Journal of Environmental Assessment Policy and Management
Vol. 7, No. 4 (December 2005) pp. 735¨C750
. Imperial College Press
OPTIMAL UTILIZATION OF RECLAIMED WASTEWATER
FOR IRRIGATION PURPOSES: CASE OF AS-SAMRA
WASTEWATER TREATMENT PLANT
BASSAM MRAYYAN
Director of Environmental Studies Center
Institute of Land, Water and Environment
The Hashemite University, P. O. Box 150459
Zarqa, Jordan
mrayyan@hu.edu.jo
Received 28 November 2004
Revised 22 September 2005
Accepted 10 October 2005
Due to the rapid population growth and industrial development in Jordan, the demand on
water resources for different purposes, mainly agriculture has been elevated. The shortage
of fresh water resources and the high demand make the reclaimed wastewater a key factor
in the water budget. This paper examines both positive and negative impacts of wastewater
reuse for agriculture. Currently, Jordan has more than 27 wastewater treatment plants all
over the country; the largest is As-Samra treatment plant. The objective of this article is to
set a framework for optimal utilization of the said reclaimed water taking into consideration
the technical, financial, economical and social aspects at the end user demand centers and
the new upgrading project at the study area, in addition to promoting the anticipated findings
for other similar regional cases in terms of knowledge disseminations and setting a pilot
cases for neighboring countries.
Keywords: Jordan; wastewater reuse; As-Samra; irrigations; constraints; recommendations.
Introduction
The scarcity of water resources alongside the rapid population growth and increase
of development activities have increased water consumption. This demand of water
usagemade conventional sources unable to supply the required quantities needed for
irrigation purposes. Decision makers realized the magnitude of problem and started
programs to investigate utilizing non-conventionalwater resources; discharged from
domestic wastewater treatment plants.
735
736 B. Mrayyan
The purpose of this article is to investigate the feasibility of utilizing wastewater,
(reclaimed water), for agricultural purposes. Reuse of TreatedWastewater (TWW),
not only serve the agricultural sector, but also solve the sludge (an inevitable nutrient
rich by-product of wastewater treatment) pollution problems. (Bernard J. et al.,
2000). The use of treated or reclaimed water for agriculture is an international wide
spread concept. Even, countries that have adequate supplies of water resources utilizes
reclaimed water for agriculture. In countries like Denmark, France, Germany,
Italy, United Kingdom and Sweden with 98, 68, 90, 60, 88 and 98 percent of their
populations are served by treated wastewater respectively. Moreover, some middle
eastern countries such as Syria, Egypt, Morocco and the Gulf states use treated
wastewater directly or indirectly where sewage effluent for irrigation is socially
accepted. In Jordan, farmers have been long ago utilizing indirectly sewage water
for agriculture. (EL-Eshbeeli; A.M 1071/1072.)
Wastewater from Amman, Zarqa, Russifa, Sukhnenh, Hashemiyeh and Wadi
Dhuleil municipalities are collected and transported to As-SamraWastewater Treatment
Plant (AWTP). The station consists of natural stabilization ponds covering
200 ha. and treats approximately 80% of the country?ˉs production of TWW. Table 1
represents a comparison between AWTP and others in Jordan with respect to design
features, operation and flow percentages (Al-LafiM., 1996). Figure 1 represents the
increase of wastewater influent within the years of 1997¨C2000.
As-Samra treats both domestic and industrial water, whereas 75% and 44%
of municipal houses and industries are connected consecutively. The effluent of
K. As-Samra wastewater treatment plant is currently being discharged into Zarqa
river causing deterioration to the quality of surface water reaching King Talal
Dam (KTD). The quality of the dam effluents are characterized by high content
of suspended solids (SS) , Biological Oxygen Demand (BOD), nutrients and some
pathogenic species.
Once stored atKing TalalReservoir (KTR), the quality of the treated effluentwill
be enhanced; this is attributed to the run off from the country?ˉs upstream drained to
KTR.Aftermixed water is being settled for severalmonths atKTR, itwill be directly
released for irrigation or down streaming Yarmouk River, where more mixing will
take place resulting in further improvement of the water quality.
Treated wastewater is generated at sixteen wastewater treatment plants located
mainly in populated areas. The quantity of TWW was 46 MCM (million cubic
meters), in 1991 and is expected to reach 270 MCM in 2020. Utilization of
treated reclaimed wastewater for agricultural purpose is essential since the available
water is characterized by scarcity and, thus, considered as a limiting factor
for development. In addition to that, reclaimed water should be controlled due
to environmental considerations. Treated wastewater constitutes an important nonconventional
source in the country. Recently, Jordan plans to construct an additional
Optimal Utilization of Reclaimed Wastewater for Irrigation Purposes 737
Table 1. Major features of the wastewater treatment plants in Jordan.
Treatment Treatment Operation Design flow Flow 1994 Percent
plant system year (m3/d) (m3/d) overflow
Abu Nusair RBC + AS 1986 4000 1532 ?a
Ma?ˉdba WSP 1988 2000 2077 104
As-Samra WSP 1985 68000 130283 192
Irbid BF + AS 1987 11000 7236 ?a
Jarash AS 1983 1155 1387 120
Ramtha WSP 1987 2335 1462 ?a
Kufrinja BF + MP 1988 1800 689 ?a
Mafraq WSP 1987 1800 1134 ?a
Es-Salt AS 1981 2440 3761 154
Baq?ˉa BF + MP 1988 6000 5214 ?a
Karak BF + MP 1988 786 1077 137
Tafila BF + MP 1988 800 935 117
Aqaba WSP 1987 9000 5448 ?a
Ma?ˉan WSP 1988 1090 1350 124
WSP:Waste Stabilization Ponds
BF: Biological Filter
AS: Activated Sludge
MP: Maturation Pond
RBC: Rotating Biological Contact
Source: Al-Lafi (1996).
150
155
160
165
170
175
1996 1997 1998 1999 2000 2001
Year
M3/d
(
Fig. 1. Wastewater influent with the years (1997¨C2000).
Source: Ministry of Agriculture, Jordan (1998).
738 B. Mrayyan
23 treatment plants to serve 34 towns. In the year 2000, the treatment plants produced
90 MCM, whereas 52 MCM/yr is used currently for restricted irrigation
applications. The major resource of conventional water is ground water. Municipal
uses represent approximately 21% of the total fresh water consumption and
the irrigation sector uses represent approximately 69% of the total consumption
(M.W.I, 1999¨C2002). The portion of irrigation consumption must be decreased
substantially to the benefit of the share of drinking water. This supports the need for
developing alternatives such as non-conventional water in order to meet increasing
demands.
Table 2 shows the projected wastewater demand for agricultural purposes and the
production of wastewater within the years 1991 to 2020. It indicates large increase
in agricultural requirements alongside the increase of wastewater production within
the years 1999 to 2020. However,more effort is required to increase the exploitation
of wastewater in agriculture. If achieved, agricultural dependency on fresh water
will be shifted toward such non-conventional source that will lead to an increase in
the proposed ratio. The ratio of fresh water to TWW in King Talal Dam has been
greatly changed in the last decade. For example, in 1990 the TWW at KTR was
approximately 22.1MCMwhile fresh water was approximately 48.8MCM. In contrast,
in 1999, the fresh water was only 24.8 MCM while TWWwas approximately
42.3MCM. This phenomenon presents adverse impact on aquatic biodiversity and
the quality of irrigation water (Abu Sharar et al., 2001). Moreover, the quality of
TWW is getting worse as for instance, AWTP that was designed to accommodate
68, 000m3/d, whereas, it treats approximately 170, 000m3/d; this hydrological and
biological overloading negatively affects the quality of TWW.
Table 2. Projected water demand for agriculture and wastewater
production within the years (1991¨C2020).
Year Agriculture Wastewater production
requirements
(MCM) MCM (million cubic meters) %
1991 778 46 5.8
1995 889 64 7.2
2000 1051 90 8.6
2005 1224 124 10.1
2010 1419 166 11.7
2015 1637 220 13.4
2020 1879 270 14.4
Source: Abu Sharar et al. (2001).
Optimal Utilization of Reclaimed Wastewater for Irrigation Purposes 739
As mentioned earlier, ground water is considered as the largest contributor to
water supply by 510MCM; of which 445MCMcomes from renewable sources and
the rest from non-renewable ones. Over pumping and over exploitation of ground
water resources are occurring continuously. Studies indicate that 170MCM are
being over pumped. This statement is threatening irrigation unless an alternative
water source is being provided by mainly utilizing non-conventional sources that
will assist reducing over pumping to govern sustainability. As for surface water,
from both, base and flood flow, the main source is the Yarmouk River that contributes
to approximately 45% of the total water budget. While the total estimated
runoff of 686 MCM yearly is not entirely economically achievable, base flow is
derived from ground water drainage through springs. The total actual supplies of
surface water was approximately 372 and 258MCM/year in the years 1997 and
1998 consecutively. (Abu Sharar et al., 2001.)
Due to over pumping and the presence of chloride salts, the quality of ground
water has deteriorated where salinity reached up 3000 ppm in some places that
has proportional effect on surface water quality. Jordan?ˉs water resources; surface
and ground water relies heavily on rainfall that is estimated to be 8532 MCM/year
(M.W.I, 1997¨C2002).Approximately 85% of precipitation is lost due to evaporation,
while 70% of the remaining recharge ground water; that emerges in the form of
wadies and rivers flow; constituting the renewable ground and surfacewater sources.
Depending on precipitations, irrigation water available in the Jordan valley fluctuates
from 198MCM in 1991 to reach up 440MCM in 1992. Irrigation water
available in the country, including reused water has increased from 497MCM in
1985 to reach 612MCM in 1998. Some of this are effluents of the treated industrial
and municipal wastewater.
Moreover, Gazzaz (Gazzaz, N, 1999) has indicated that in the year 2000, the
annual discharge of the TWWat the northern Jordan valley was estimated to be 90
MCM excluding the TWWfrom Wadi Hassan treatment plant. The study expected
this quantity to reach 170 MCM in 2010 and 250 MCM in 2020.
Applying wastewater to agricultural lands is supposed to be more economically
and ecologically sound than the uncontrolled dumping of municipal and industrial
effluents into lakes and streams. However, if not managed properly, the short-term
benefits of wastewater irrigation could be offset by the health and environmental
impacts. For example, the presence of harmful contaminants in wastewater, such
as heavy metals ?a that can occur in soil and crops ?a in addition to the presence
of pathogens (that is source of infection), are the major concerns that must be
addressed when considering reusing wastewater. The high nutrient content exist
in treated wastewater, reduces or even eliminates the need for expensive chemical
fertilizers.
740 B. Mrayyan
Discussion
The rational and constraints to use treated wastewater in Jordan
To successfully utilize treated wastewater, it is required that, institutional frame
work controlling and permitting land applications, social acceptance and support,
land suitability and availability in addition to proper safe measures and allocation of
financial and technical resources must all be present. Moreover, raising the level of
awareness among interested farmers is an important element for achieving success
and acceptability of the idea.
Interest in utilizing treated wastewater has been increased because of: water
scarcity, population growth and its implications, the nutrient rich sewage sludge, the
need for safe disposal of treated wastewater and the outcome of research studies that
proved the safety of utilizing treated wastewater for irrigation. Treated wastewater
has been addressed and examined in Jordan together with their ways of implementation
and consequences. New standards have been proposed for utilization of treated
wastewater for different agricultural applications in the country. The standards have
been reviewed, examined and revised by theministry of water and irrigation through
the national high committee of wastewater discharge. The committee consists of
professors from the national universities, engineers from the Ministry ofWater and
Irrigations and researchers from the Royal Scientific Society (RSS) of Jordan. The
new standards are under revision; the modification includes limitations and speci-
fications for parameters of physical, chemical and biological nature in addition to
guidelines that could be adjusted by the end users according to each application
providing proper justifications. Table 3 shows the proposed specifications of treated
wastewater to be utilized for different applications, (JS 983/2002),where, standards
become more strict as its application becomes directly consumed by human. However,
the social, technical and financial constraints existing in Jordan limit its utilization
for agricultural usage providing restricted legal frame as indicated by the
Jordanian standards JS893/2002 shown in Table 3.
Utilization of treated wastewater in the absence of proper procedures and regulations
will have an adverse impact on both human health and the environments.
Some of which include, soil damage due to salinity and alkalinity, decrease of crop
yield, crop toxicity, potential environmental degradation and risks to public health
due to pathogens.
Studies conducted by Water Authority of Jordan (WAJ) showed that the quality
of surface water produced from As-Samra wastewater treatment plant, exceeds the
limits of the Jordanian standards, especially in BOD, COD, TSS, and bicarbonates.
The effluent of As-Samra wastewater treatment plant is currently discharged into
Zarqa river deteriorating its quality reaching King Talal Dam and affecting the
agricultural sector where most of farming zones are there; provided that irrigation
Optimal Utilization of Reclaimed Wastewater for Irrigation Purposes 741
Table 3. Specifications of standard parameters of treatedwastewater to be employed in irrigating
different crops according to Jordan Standards JS 893/2002.
Parameter Cocked vegetables, parks, Fruit trees, green Field and industrial
play grounds and side areas and sides areas crops, landscaping
walks inside cities of highways trees
BOD5 (mg/I) 30 200 300
COD (mg/I) 100 500 500
DO (mg/I) >2 ?a ?a
TSS (mg/I) 50 150 150
pH 6¨C9 6¨C9 6¨C9
Turbidity (NTU) 10 ?a ?a
NO3 (mg/I) 30 45 45
Total-N (mg/I) 45 70 70
E-Coli (MPN 100 1000 ?a
or CFU/100 ml)
Intestinal ≤ 1 ≤ 1 ≤ 1
helminthes eggs
(egg/I)
BOD: Biochemical oxygen demand
COD: Chemical oxygen demand
DO: Dissolved oxygen
TSS: Total suspended solids
Source: Ministry of Water and Irrigation, Jordan (1999, 2002/2003).
water is scarce. Agricultural sector consumes the largest portion of available water
that the gap between supply and demand is anticipated to increase reaching 515
MCM in the year 2010 (M.W.I, 1997¨C2002) and (Abu Sharar et al., 2001). Table 4
reveals additional studies by the Ministry of Water and Irrigation that indicated
an increase in water consumption and deficit during the period 1995¨C2010. This is
alarming and policymakers started to realize this potential crises that led to planning
of long-term policies and programs to overcome the water deficit.
Industrial water is treated at K. As-Samra wastewater treatment plant (AWTP)
that is located inZarqa goveronratewhere 52%of the country?ˉs industries are located
(2874 industries) (Dallal et al., 1999). Few industries discharge their effluents to the
municipal sewer connected toAWTP. Some studies indicated thatAs-Samra effluent
has high organic Loads, salinity and relatively low in toxic pollutants such as heavy
metals and trace elements (M.W.I, 1999). The calcareous and alkaline nature of
Jordan?ˉs soil inactivated the heavy metals and trace elements by precipitation to
carbonates and hydroxide compounds (M.O.AG, 1998) and (Abu Sharar et al.,
2002).
742 B. Mrayyan
Table 4. Water demand, supply and deficit during the years (1995¨C2010),
in MCM, (million cubic meter) with respect to population growth.
Item 1995 2000 2005 2010
Populations 4.4 5.2 6.1 7.0
(millions)
Resources 832 952 1042 1042
(MCM/Year)
Municipal 216 330 425 497
Irrigation 715 800 900 1000
Industrial 25 40 50 60
Total 1010 1170 1375 1557
(MCH/Year)
Deficit 178 205 333 515
(MCM/Year)
Source: Gesellshaft Fur Technische Zusammenarbeit (GTZ), Agricultural
Water Experts and Water Authority of Jordan (personal communications).
Table 5. Composition of As-Samra maximum influent compared to
the international standards.
Pollutant type Mg/L As-Samra Mg/L International
Wastewater in 2001 Standard
BOD5 798 220
COD 2288 500
TSS 799 220
TDS 1286 500
Source: Ministry of Agriculture, Jordan (1998).
Wastewater effluents form industries led to the surface and ground water pollution.
Owing to greater required quantity of water, unplanned wastewater reuse took
place along the Jordan valley, down stream of the Zarqa river that carries As-Samra
effluents to King Talal Dam.
Table 5 shows that the concentration of organic compounds inAs-Samra influents
for BOD, COD, TSS, and Total Dissolved Solid TDS exceeds the international
standards. This is attributed to the industrial discharge especially those of yeast and
food and also due to the lack and partial operation pretreatment facilities at the
source of generation (Consulting engineers, 2002) and (Dallal et al., 1999). Despite
Optimal Utilization of Reclaimed Wastewater for Irrigation Purposes 743
the increase of organic pollutants in AWTP, the finding results of As-Samra area
indicates its soil is still in acceptable conditions for salinity and heavy metals, and
no clear evidence of threat to As-Samra soil (M.W.I and J.V.A, 1999).
Moving from classical usage of treated water towards integrated
management approach
The classical traditional ways of managing treated effluents is no longer accepted,
especially with the present water deficit and the large increase of sewage sludge
that is accumulated at the premises of the station deteriorating ground and surface
water quality. Some studies by the Ministry of Water and Irrigation indicated that,
approximately 200,000 ton of sludge are accumulated at As-Samra station awaiting
for proper disposal. The citizens of Jordan are constantly questioning the safety
of the unplanned and restricted irrigation of crops at the Jordan valley. This paper
highlights the feasibility of utilizing treated wastewater in the agricultural sector to
meet the rapidly increased irrigation demand, and to constitute a sustainable way
of disposing wastewater. Solving As-Samra treated effluents means solving 80%
of the country?ˉs wastewater problems. A study on the soil of As-Samra effluent
and its effect on soil and plants surrounding the station indicated that heavy metals
may not represent any major health and environmental concerns. Tables 6 and 7
Table 6. The concentrations of heavy metals in (As-Samra soil) as compared
to the accepted level in the soil as reported by WAJ study, 1998.
Element Range in As-Samra soil Acceptable soil
(mg/Kg) contamination (mg/Kg)
Cd 7.8¨C12.6 Up to 8
CO 21.2¨C34.8 ?a
Cr 63¨C95.6 5¨C1500
Cu 17¨C27.4 2¨C250
Fe ?a ?a
Mn ?a ?a
Ni 30