Sustainable Management of Scarce
Resources in the Coastal Zone
SMART
ICA3 – 2001-1003
Kick-off Meeting
CEDARE, Cairo, 5-6 January, 2003
Case Study
Jordan
Introduction
•
Jordan has a surface area of (89.544) square kilometers with population of about (5) million
and rate growth of (3.4%).
•
Jordan water resources are scare and are directly depending on the annual rainfall, which
varies from year to year and also varies according to the locality from (50)mm in the eastern
part to (600)mm in the northern and western mountains.
•
Jordan is characterized by a pronounced scarcity of renewable fresh water resources. It is
considered among few countries of the world with limited water resources.
•
Due to the population growth, the available renewable water resources per capita are falling
from around (188)m³/capita/year at present (2000) to (95)m³/cap/year by the year 2025.
•
The water resources of Jordan consist of surface and ground water resources and treated
wastewater used in irrigation.
•
Renewable water resources are estimated at about (940) MCM per annum, (280) MCM per
year ground water and (600) MCM per year surface water. An additional (143) MCM per
year is expected to be available from fossil aquifers and about (75) MCM from brackish
aquifers after desalination. Available treated wastewater from irrigation is about (70) MCM
per year.
•
Population growth, human settlement and socio-economic development will increase the
demand on the limited water resources with priority in water allocation given to the
domestic and industrial sector. Agriculture will suffer the most from water deficiency.
One option to alleviate such suffering is to use non conventional resources like treated
wastewater for irrigation.
•
Wastewater is essentially water that has been fouled by communities through its use in
the various daily activities such as cooking and washing.
•
Domestic sewage is mainly composed of human body wastes and sludge.
•
Industrial sewage comprises numerous and various chemicals including those toxic to
humans and nature.
•
Sewage is extremely hazardous in content mainly because of the number of disease
causing organism and toxic matter that it contains.
Wastewater Treatment.
•
Treated wastewater generated at seventeen existing wastewater treatment plants is
discharged into various water courses and flows to the Jordan Valley where it is reused
for irrigation.
•
About (73) MCM of treated wastewater are effectively discharged into the watercourses
or are used directly in irrigation.
•
Wastewater quantity is increasing with population growth, By the year 2020 when the
population is projected to about (9.9) million and the percentage of sewage service to
population increase from current (50%) to about (65%), about (265.3) MCM per year of
wastewater are expected to be generated.
•Figure (1) shows the distribution of treatment plants in Jordan.
Table (1) shows the expected treated wastewater quantities till 2020
Table (1); Expected Treated wastewater Quantities
WWTP
As-Samra
Aqaba
Ramtha
Mafraq
Madaba
Ma’an
Irbid
Jarash
Kufranjah
Abu-Nusier
Salt
Baqa’a
Karak
Tafielah
Fuheis/Mahes
Wadi Asir
Wadi Hassan
Wadi Mousa
Wadi Al-Arab
South
Amman*
Nau’r*
Ghor 1,2,3*
Wadi AlShallaleh*
Expected quantities in
MCM at Year
1996 2000 2010 2020
46.3
55
110
174
2.1
0.5
0.7
0.8
0.5
2.8
0.6
0.4
0.4
1.3
2.4
0.35
0.3
-
Reuse Site
King Talal dam, Zarqa River Basin,
Around WWTP, As-Samra East, AlHashemiyah University
4
1.9
1.3
2.7
1
4
1
0.7
2
3.5
5.4
0.8
0.7
0.7
1.6
0.6
1.25
6
12
4.5
2.5
1.7
3.6
1.3
4
1.3
1
3
5
7.3
1
1
1
2
0.6
1.8
8.4
1.8
Around WWTP, Airport Highway
Around WWTP
Around WWTP
Around WWTP
Around WWTP
Jordan River and Ghor in near future
Private farm
Around WWTP, Wadi Kufranjah
King Talal Reservoir
Wadi Shuieb and shuieb Dam
King Talal Reservoir
Wadi Karak
Around WWTP and Wadi Tafielah
Around WWTP
Around WWTP
-
3
0.7
1
1.2
0.7
1.6
0.6
0.6
0.6
1.2
3.65
0.5
0.4
0.4
0.4
0.5
2.2
-
-
0.4
-
1.1
10.6
5
1.9
12.4
8
Kafrien Reservoir
Ghor Site
Ghor Site
* WWTP under study and construction
Around WWTP
Around WWTP
Advantage of Wastewater Reuse.
•
Treated wastewater is now being considered as new source of water that can be used
for different purposes such as agricultural and aquaculture production, industrial uses,
recreational purposes and artificial recharge.
•
Using wastewater for agriculture production will help in alleviating food shortages
and reduce the gap between supply and demand. The interest in the reuse of treated
effluent has accelerated significantly in the world since 1980 for many reasons;
Expansion of sewerage system networks and the increasing number of treatment
plants.
Production of large quantities of wastewater which makes its use of agriculture viable
alternative.
Wastewater is a rich source of nutrient and can reduce the use of fertilizers.
The reuse is a safe disposal of wastewater which will reduce the environment and
health risks.
The treatment of wastewater to be used for irrigation is cheaper than that needed for
production of the environment. Regulation to discharge water into sea and streams or
groundwater recharge are more strict than reuse for irrigation.
1.
2.
3.
4.
5.
Development of Sanitation Services.
•
Until 1969, cesspools, septic tanks and other on-site methods were used for the disposal
of wastewater.
•
This practice coupled with rapid and uncontrolled population growth resulted in major
environmental problems especially surface and groundwater pollution.
•
The government of Jordan has realized the magnitude of the problem and the necessity
to build a safe disposal system for wastewater.
•
In 1969, the municipality of Amman completed a sanitary sewage system to serve the
population of Amman with (500,000) people. This system was associated with a
conventional activated sludge plant with a capacity of (60,000) m³/day and a BOD
loading of (18,000) kg/d. The design effluent standard BOD was (20)mg/L and the
effluent was discharged to the Zerqa river a major tributary of the Jordan river.
•
Due to the high strength of raw sewage (BOD5> 600 mg/L), the effectiveness of the
plant was drastically reduced to the extent that the actual capacity became only (30,000)
m³/d by the year 1980. The operation under high hydraulic and organic loading
conditions resulted in an effluent that could not meet the standard of (BOD5<20mg/L)
and low efficiency in the process of solid processing and disposal. As such, the quality
of surface and groundwater was deteriorated due to the use of low quality water for
irrigation downstream.
•
In the 1980s, the government built a major wastewater stabilization pond (WSP)
system for the Greater Amman Area and other treatment facilities in major cities and
towns in the country totaling (17) treatment plants.
•
By the year 1999, about (50%) of the plants were overloaded including the largest
WSP of Amman. The government has completed a master plan study to upgrade and
expand existing facilities and to build new plants in the country aiming at (90%)
coverage of the population by the year 2010.
•
In Jordan a diverse range of wastewater treatment plants are used in various cities
ranging from conventional treatment methods and wastewater stabilization ponds in
large communities to simple treatment technologies in small communities.
The mostly used conventional methods are:
1.
Stabilization Ponds: This technology is used in the waste treatment plant of AsSamra, Mafraq, Ramtha, Ma`an, Madaba and Aqaba.
2.
Activated Sludge: It is used in the treatment plants of Irbid, Salt, Jarash, Tafilah,
Fuhis and Baqa`a.
3.
Trickling Filters: Used in the wastewater treatment plants of Karak, Kufranja, West
Irbid and Abu Nusair.
4.
Aerated Lagoons: Used only in Wadi Essir wastewater treatment plant.
Table (2a) shows the wastewater treatment plants, daily average effluent (2001) and Table (2b) shows the
treatment method, design parameters, average daily influent and the organic and solids concentration (1999) of the
(17) major wastewater treatment plants.
Table (2a): Wastewater treatment Plants, Daily Average Effluent, 2001
MONTH
WWTP
Jan
M3/day
Feb.
M3/day
Mar.
M3/day
Apr.
M3/day
May
M3/day
June
M3/day
July
M3/day
Aug.
M3/day
Sept.
M3/day
Oct.
M3/day
Nov.
M3/day
Dec.
M3/day
Avg.
M3/day
AS-SAMRA W.S.P
153386
154327
151018
147713
146863
148901
132215
126702
138555
151970
145751
1155651
146088.1
53.322
AQABA W.S.P
7037
6893
7234
8406
7558
7291
6748
6982
7570
7666
6989
6800
7272.8
2.655
RAMTHA W.S.P
1643
2099
2597
1676
1814
1768
2003
1607
1941
1936
1700
2024
1892.8
0.691
MAFRAQ W.S.P
1215
1380
1460
1562
1432
1520
1200
1250
1300
1120
1580
1620
1386.6
0.506
MADABA W.S.P
3274
3610
4100
2903
4413
4280
3210
4290
3373
3194
3937
3939
3702.8
1.362
MA’AN W.S.P
1444
1298
1751
1725
1621
1457
1524
906
1296
1988
1800
1490
1524.9
0.557
IRBID
4646
4484
5268
4524
4642
4996
5141
5170
4947
4771
5667
9013
4939.0
1.8.3
JERASH
2738
2779
2631
2577
2745
2649
2549
2543
2659
2545
2765
3135
2692.9
0.983
KUFRANJA
1771
1982
1736
1320
1458
1184
906
1418
1408
1320
1933
2811
1603.9
0.565
ABU-NUSIER
1731
1768
1695
1650
1690
1655
1835
1760
1810
1717
1818
1914
1746.9
0.638
SALT
2710
3022
3500
3661
3400
3730
3988
4000
3988
3666
3910
3100
3556.3
1.298
BAQA’
11209
11639
11167
10547
10531
10625
10766
10795
10730
10952
11004
11318
10940.3
3.993
KARAK
1200
1100
1100
1225
1226
1260
1255
1265
1300
1266
1300
1260
1229.8
0.449
TAFILA
793
814
768
694
684
679
680
726
723
766
778
802
742.3
0.271
WADI AL SEER
1232
1229
1064
862
992
1080
1507
1419
1060
1179
1448
1577
1220.7
0.446
FUHIS
1258
1143
1000
1036
1097
950
968
950
1000
933
1100
1100
1044.6
0.381
WADI ARAB
4892
4539
4510
4768
4608
4352
5651
5990
5775
5900
4120
4178
4906.9
1.791
0
0
0
0
0
0.000
WADI HASSAN
WADI MOUSA
Total
MCM/Year
0
0
0
0
0
236
598
699
501
566
260.0
0.040
TOTAL M3/D
202184
204105
202599
196849
196689
198387
182146
177519
190033
203488
196101
208398
196708.0
71.8
TOTAL M.C.M
(PER MONTH)
6.2677
5.7149
6.2806
5.9055
6.0974
5.9516
5.6465
5.5031
5.7010
6.3081
5.9430
6.4603
6.0
71.8
Table( 2b); Treatment methods, total influent , design parameters of wastewater treatment plants in Jordan(1999)
Design Parameters
Plant
As-Samra
Aqaba
Ramtha
Mafraq
Madaba
Ma’an
Irbid
Jarash
Kufranjah
Abu-Nusear
Salt
Baqa’a
Karak
Tafilah
Wadi Al-sear
Fuheis
Wadi Arab
Treatment Method
Stabilization Pond
Stabilization Pond
Stabilization Pond
Stabilization Pond
Stabilization Pond
Stabilization Pond
Activated Sludge and T.F.
Activated Sludge
Trickling Filters
Activated Sludge and R.B.C.
Activated Sludge
Trickling Filters
Trickling Filters
Activated Sludge
Aerated Lagoon
Activated Sludge
Activated Sludge
Flow rate
(m3/d)
68000
9000
1920
1800
2000
1600
11000
3500
1900
4000
7700
6000
785
1600
4000
2400
22000
BOD5
mg/l
Influent
526
900
820
825
850
970
800
119
850
1100
1090
900
1080
1050
780
995
995
Effluent
30
50
50
50
50
50
30
33
30
30
30
30
30
30
30
30
30
Influent characteristics
TSS
mg/l
Influent
550
400
850
850
850
1000
800
943
850
1000
1000
900
1000
1000
850
850
850
Effluent
50
50
50
50
50
50
50
68
30
30
30
30
30
30
30
30
30
Flow rate
(m3/d)
BOD5
mg/l
TSS
mg/l
166844
8774
2174
1933
3609
1738
4612
1603
1734
1411
3166
10284
1146
851
914
1019
5993
760
353
1194
566
1332
549
1179
1119
1331
634
845
1434
729
942
622
677
811
545
266
964
249
1657
715
1139
943
1023
601
828
1720
697
700
565
720
1269
Cost of Treatment.
Table (3) shows the total cost of wastewater treatment in different wastewater
treatment plants in Jordan, the cost includes depreciation cost, salary, electricity,
operation and maintenance, chemicals, sludge disposal, contracted testing, and
others.
Table(3); Wastewater Treatment Plants Cost of Treatment (Fils/m³) (1999
19400
1500
3000
10000
30000
160000
3000
203000
1000
15000
Chemicals
&
Chlorine
JD
5000
250
0
550
5800
0
2000
8174
37500
71203
23557
7518
60000
6000
6600
2237
26890
9124
6587
1080
13200
10769
20000
1800
377
1000
400
500
600
500
150
650
100
385
743
220
200
120
110
150
150
3500
4790
17800
7500
8000
18500
3000
21500
4000
600
5000
8000
5630
10430
1380
1000
700
420
12000
5100
3537
250
5000
0
5000
9400
2340
120
0
0
0
1386
2400
0
110
23700
14500
2596
0
42000
0
42000
250
4520
0
0
0
0
0
2200
0
2475
5000
1100
740
250
10000
900
10900
2450
1067
1175
3132
1430
3200
2915
2000
50
78800
1600
0
5400
12000
2968
Items
WWTT
Salary
JD
Elect.
JD
Water
JD
As-Samra WSP
E.Zarqa P.ST
W.Zarqa P.ST
Ain.Ghazal
ِ
Total
Aqaba WSP
Aqaba P.ST
Total
Madaba WSP
Irbid
Salt
Jerash
Mafraq
Baqa’a
Ain Basha
Total
Karak
Abu-Nuseir
Tafila
Ramtha
Ma’an
Kufranja
Wadi Essir
Fuhais
Fuhais P.ST
Total
Wadi Arab
116000
22000
54000
66720
258720
33000
24000
420000
50000
204000
4100
678100
9500
18000
7000
1000
11400
33898
113000
38000
49000
51328
77000
20000
97000
45000
49320
48678
26896
37
51320
53242
54000
15000
89600
Spare
Parts
JD
)
Sludge
Disposal
JD
Fuel &
Oil
JD
Pesticide
JD
Others
JD
Total Cost
JD
Annual Influent
M³/year
Cost of
Treatment
Files/m³
0
1000
5000
600
6600
0
0
7500
1000
12000
160
20660
600
600
10000
250
250
0
10500
4000
200
54120
2000
1700
1870
59690
1300
800
1385
1000
500
300
250
2000
500
2500
300
0
130
75
480
1100
1340
160
75
3453
4400
1800
1100
200
5250
150
5400
3842
1265
9398
1755
145
3480
1185
200
400
629620
107500
448350
77000
1262470
50900
63600
114500
56792
202390
150403
88830
68396
220250
30700
250950
67579
86387
74368
46665
46350
82850
72327
82110
18175
100285
202736
60698060
3866587
14346000
42482879
60698060
3202510
2802427
3202510
1317285
1683380
1155590
623436
705545
3753660
412021
3753660
418290
515015
310615
793510
634370
632910
333610
371935
82632
371935
1468285
10.37
27.80
31.25
1.81
20.80
15.89
22.69
35.75
43.11
120.23
130.15
142.48
96.94
58.68
74.51
66.85
161.56
167.74
239.42
58.81
73.06
130.90
216.80
220.76
219.95
269.63
138.08
9200
The cost of treated unit volume of effluent ranges from (0.01) JD/m³ in large
stabilization pond of As-Samra to (0.24) JD/m³ in small activated sludge plant of
Tafilah
Wastewater Reuse In Agriculture.
•
Historically, the concept of using sewage effluents for irrigation can be traced back to
more than 2000 years ago.
•
When crops in Greece were irrigated with such effluent
•
the practice has been prevalent in china for centuries.
•
In Europe, farming with sewage was common practice in Germany as early as the
sixteenth century.
•
The first recorded use of sewage effluent for agriculture in the USA appears to have
been in the late 1870s.
•
In Jordan the indirect reuse of wastewater effluent has been practiced for a number of
years, as it has been discharged into the main wadis and mixed with the surface flow.
Farmers along the banks of these wadis used to pump water or direct the flow of the
wadis and reuse it for unrestricted irrigation. Natural recharge to aquifers takes place
through wadis beds.
•
•
•
•
In Jordan the direct and controlled reuse of treated effluent has been increasing
since 1985.
At the national level, the total production of the treated wastewater is about
(73) MCM as of 1999. Nearly all these amounts are being reused mainly for
agriculture (95%), about (3%) for groundwater recharge and (2%) for
industrial uses.
This practice is a result of the government policy so as to conserve water as a
scarce and valuable resource.
The government of Jordan has introduced new legislation on effluent quality to
control its use considering public health issues and protection of the
environment.
•
It is mandatory that all treatment plant projects must include a fully designed and
feasible reuse scheme. Below is a brief description of reuse schemes that are currently in
operation
•
.
Zarqa River Basin Scheme
Is the largest reuse system in operation in Jordan.
•
There are four treatment plants located in the basin that discharge its treated effluent to
Zarqa River where it is collected downstream at King Talal Dam and used for restricted
irrigation in the southern section of the Jordan Valley.
•
The largest treatment plant is As-Samra waste stabilization pond treating about (60)
MCM where most of it joins the flow of Zarqa River. A small portion (2%) of this
effluent is used for on-site irrigation of about (300) hectares planted with olive trees,
fodder crops and forest trees.
•
The other plants (Jarash, Abu Nusair, and Baqa’a) discharge about (4.0) MCM to the
same river.
•
King Talal Reservoir with a capacity of (85) MCM collects surface runoff and treated
sewage effluent which results in quality variation from summer to winter. The total
irrigated area by the reservoir water release is about (10,000) hectares.
•
•
•
AqabaWSP
The volume of domestic treated wastewater from Aqaba WSP reached (3.2)
MCM in 1999. About (1.5) MCM is used for irrigating palm trees and the rest
is used for artificial recharge using infiltration basins.
Ramtha, Ma’an, and Madaba WSP
These three plants are served with three WSP producing about (3.5) MCM
(1999) where it is used for irrigating fodder crops and trees around the WWTP.
Salt, Tafielah, Karak, Irbid and Kufranja
These plants are treated about (6) MCM. Where their effluents join the stream
of wadis. This water is also used by downstream users for irrigation or
collected in small dams, which are built on the wadis for later use in irrigation.
Table (4) shows direct reuse areas and crop patterns in Jordan.
Table (4); Direct Reuse Area in Jordan
As-Samra
Aqaba
Planted area
(ha)
300
150
Ramtha
50
Mafraq
25
Madaba
60
Ma’an
7
Irbid
Jarash
0.5
-
Kufranja
Abu-Nusair
Salt
Baqa'a
Karak
Tafielah
Fuhais/Mahas
Wadi Essir
Wadi Al- Arab
Wadi Musa
Wadi Hassan
South Amman
Nau'r
Ghor 1,2,3
7
0.5
3.5
1
24
15
-
Crop's
Olive, forest, fodder
Forest, some olive trees
Forest, barely, sudan
grass, alfalfa
Forest, fodder crop
Forest, olive, fodder,
flowers
Forest, olive, ornamental
trees
Forest, ornamental trees
Forest, olive, sudan
grass, alfalfa.
Forest, olive.
Olive, ornamental trees
Olive, fruit trees
Forest, fruit trees
Forest, fruit trees
-
Excess Effluent
Flow
King Talal Dam
None
None
None
None
None
Jordan River
KTD
Wadi Kufranja
KTD
Wadi Shuieb
KTD
Wadi Karak
Ghor Fifa
None
None
Jordan River
None
None
Wastewater treatment plants under study and construction
•There are about 6 small domestic treatment plants serving the residential areas of the
employees of major industries (Cement, Phosphate, and Potash) providing about (1.5)
MCM of water. Some of this water is used for on-site irrigation and the rest is reused in
industries for cooling purposes.
•Industrial water from the two major industrial cities (Sahab and Al Hassan) is treated
separately and is used for on-site irrigation.
•Scattered industries, whose influent could not join the domestic wastewater, are using their
industrial effluent for on-site irrigation like the yeast and paper factories.
•The effluent of hazardous industries like paint, batteries, chemicals and pharmaceutical are
disposed through evaporation or incineration.
•Phosphate mining and processing is considered one of the main industries in Jordan, which
consumes about (20) MCM of water. Recently, the processed water has been recycled after
settling and filtration.
• The effluent of the treatment plants of Amman Airport and Al-Hussein Medical City
are used for irrigation of grasses, green areas and forest trees in the vicinity of the two sites.
Regulations and Legislations.
•
Concerned agencies have issued regulations and standards that are used to implement
their wastewater management policies.
•
These regulation cover agencies in charge of, collection of sewage, treatment process
and disposal and discharge.
•
The discharge of industrial and commercial wastewater into the sewerage system is
strictly prohibited unless such effluent comply with standards of domestic wastewater.
•
If these regulation are violated, the concerned agencies have the full right to take
immediate actions including imposing penalties.
•
All house owners or leaseholders residing in an estate, which is served by a sewerage
system network, are encouraged to connect.
•
The discharge of surface runoff water or storm water into the sewerage system networks
is strictly prohibited.
•
Sometimes, tertiary treatment of wastewater including ozonation or chlorination is
needed before the effluent is discharged.
•
Lately, regulations and guidelines to direct the reuse of reclaimed water have been
given the necessary importance with regard to the associated health and
environmental impact. In 1982 and after thirteen years of uncontrolled use, Jordan
issued standards through a by-law, which allows irrigation by wastewater only for
trees and fodder crops. Jordanian standards and regulations were updated in 1995 with
the following general criteria:
1.
The treated wastewater must meet the specified standards that vary according to the
planned use.
When treated effluent is used for irrigation of fruit trees, cooked vegetables and
fodder crops, irrigation must be ceased two weeks before collecting the products.
Fallen fruit should be discarded.
The adverse effect of certain effluent quality parameters on the soil characteristics and
on certain crops should be considered.
Use of sprinkler systems for irrigation is prohibited.
Use of treated effluent in the irrigation of crops that can be eaten raw such as
tomatoes, cucumber, carrots, lettuce, radish, mint, or parsley is prohibited.
Closed conduits or lined channels must be used for transmission of treated effluent in
areas where the permeability is high, which can affect underground and surface water
that could be used for potable purposes.
Dilution of treated water effluent by mixing at the treatment site with clean water in
order to achieve the requirements of this standard is prohibited.
Use of treated effluent to recharge an aquifer, which is used for potable water supply
purposes, is prohibited.
2.
3.
4.
5.
6.
7.
8.
• Tables (5&6) presents the Jordanian standards for wastewater
discharge and reuse (893/95).
• The major features of these tables are not to permit application of
treated sewage water in irrigation of fresh vegetables.
• In addition, restriction on the utilization of treated wastewater
increases with switching the destiny of grown plants from animal to
human food.
Table 13: Maximum Concentration of Reclamied water Targete for Reuse in Agriculture
according to Joradn Standards
Quality
Paramet
er mg/L
BOD5
COD
DO
TDS
TSS
PH
Veget
ables
eaten
Cook
ed
150
500
>2
2000
200
6.09.0
150
500
>2
2000
200
Discharge
to
Streams
and
Water
Body
50
200
>2
2000
50
6.0-9.0
6.0-9.0
6.0-9.0
6.0-9.0
Fruit
Trees
Cereal
Crops
Artifical
Groundwate
r Recharge
Fish and
Aquacultur
e
Pupli
c
Parks
Fodder
and
Pastures
50
200
>2
2000
50
<5
2000
25
50
200
>2
2000
50
6.09.0
250
700
>1
2000
250
6.0-9.0
Color
(PCU)
FOG
Phenol
MBAS
NO3-N
NH4-N
T-N
PO4-p
Cl
SO4
CO3
HCO3
Na
Mg
Ca
SAR
Al
As
Be
Cu
F
Fe
Li
Mn
-
-
75
75
-
75
-
8
0.002
50
50
100
350
1000
6
520
230
60
400
9
5
0.1
0.1
0.2
1.0
5.0
2.5
0.2
8
0.002
50
50
100
350
1000
6
520
230
60
400
9
5
0.1
0.1
0.2
1.0
5.0
5.0
0.2
8
0.002
25
25
15
50
15
350
1000
6
520
230
60
400
9
5
0.05
0.1
0.2
1.0
2.0
0.1
0.2
N.D
0.002
15
25
15
50
15
350
1000
6
520
230
60
400
9
1
0.05
0.1
0.2
1.0
1.0
0.1
0.2
8
0.001
0.2
0.5
0.05
0.1
0.04
1.5
0.5
1.0
8
0.002
15
25
50
100
15
350
1000
6
520
230
60
400
12
5
0.1
0.1
0.2
1.0
5.0
3.0
0.2
12
0.002
50
50
350
1000
6
520
230
60
400
9
5
0.1
0.1
0.2
1.0
5.0
5.0
0.2
Ni
Pb
Se
Cd
Zn
Cn
Cr
0.2
5.0
0.02
0.01
2.0
0.1
0.1
0.2
5.0
0.02
0.01
2.0
0.1
0.1
0.2
0.1
0.02
0.01
15
0.1
0.05
0.2
0.1
0.02
0.01
15
0.1
0.05
0.4
0.15
0.05
0.015
0.6
0.0005
0.1
0.2
0.1
0.02
0.01
2.0
0.1
0.1
0.2
5.0
0.02
0.01
2.0
0.1
0.1
Table 14: Recommended microbiological quality guidelines for wastewater use in agriculture
Category
Reuse
condition
Exposed
group
Intestinal nematodes b
(arithmetic mean no. of
eggs per liter c )
Fecal coliform
(geometric mean
no. per 100 ml c )
Wastewater treatment
expected to achieve the
required microbiological
quality
A
Irrigation of
crops likely to
be eaten
uncooked,
sports fields,
public parks d
Workers
consumers
public
1
1000 d
A series of stabilization
ponds designed to achieve
the microbiological quality
indicated, or equivalent
treatment.
B
Irrigation of
cereal crops,
industrial,
crops, fodder
crops, pasture
and trees e
Workers
1
No standard
recommended
Retention in stabilization
ponds for 8-10 days or
equivalent helminthes and
fecal coliform removal
C
Localized
irrigation of
crops in
category B if
exposure of
workers and
the public does
not occur
None
Not applicable
Not applicable
Pretreatment as required by
the irrigation technology,
but not less than primary
sedimentation
a)
In specific cases, local epidemiological, socio cultural and environmental factors should be taken into account, and the guidelines modified
accordingly.
b)
Ascars and Trichuris species and hookworms.
c)
During the irrigation period.
d)
A more stringent guideline (<200 fecal coliform per 100 ml) is appropriate for public lawns, such as hotel lawns, with which the public may
come into direct contact.
e)
In the case of fruit trees, irrigation should cease two weeks before fruit is picked, and no fruit should be picked of the ground. Sprinkler
irrigation should not be used.
Source: WHO, 1989.
Government Policy
On
•
June, 1998 the government established the latest policy for wastewater
management and reuse, it’s main features on reuse of treated effluent is as follows:
Treated wastewater effluent is considered a water resource and is added to the water
stock for reuse. This warranted and deemed feasible in light of the semi arid climate, the
modest per capita share of freshwater resources, the high demand for municipal water,
the per capita share of the deficit in the trade of food commodities, and of the marginal
cost of resource development.
•
Priority shall be given to agricultural reuse of treated effluent for unresticted irrigation.
Blending of treated wastewater with fresh water shall be made to improve quality where
possible. Crops to be irrigated by the treated effluent of blend thereof with freshwater
resources shall be selected to suit the irrigation water, soil type and chemisty, and the
economics of the reuse operations.
•
Crop nutrients requirement shall be determined taking into consideration the prevailing
effluent quality. Overuse of nutrients shall be avoided.
Government Policy continued
•
•
•
•
•
Accumulation of heavy metals and salinity shall be monitored, managed and
mitigated.
Farmers shall be encouraged to determine the rate of water application needed
for different crops, taking into consideration the value of nutrients in the
treated water and other parameters.
Farmers shall be encouraged to use modern and efficient irrigation
technologies. Protection of on farm workers and of crops against pollution
with wastewater shall be ensured.
Treated effluent quality should be monitored and users be alerted to any
emergency causing deterioration of the quality so that they will not use such
water unless corrective measures are taken.
Studies should be conducted and projects designed and implemented to store
the excess treated wastewater in surface reservoirs or in groundwater
reservoirs through artificial recharge technique.