An isotopic approach for elucidating the sources of nitrate and chloride contamination in the Mediterranean coastal aquifer: Implementation for the Gaza Strip
Avner Vengosh Groundwater Resources in the Middle East Saline inflows to the Sea of Galilee
salinization
salinization
Fossil brackish groundwater Fossil groundwater 160 BAT YAM
RISHON LEZIYYON 150 Chloride distribution PALMAHIM
REHOVOT in pumping wells from
GIV'AT BRENNER 140 the
Gedera Coastal aquifer ASHDOD
130 Cl (mg/l )
BE'ER TUVEYA 1000
600 120 ASHQELON
400
250 GEVAR'AM 110 150
50 NIR AM
0 100 100 110 120 130 140 150
Figure 1 A large-scale
Nitrate concentration (mg/l) phenomenon: Nitrate pollution of groundwater from the Mediterranean coastal aquifer Coastal Plain aquifer E W Recharge/irrigation Nitrogen leaching of imported water unsaturated Sewage contamination zone dunes Mediterranean Sea
. terrestrial clays (hamra) leakage from adjacent aquifer and aquitrad A flow to the sea Cenomanian/ Turonian Ecocene B1 Sea-water intrusionmarine clays Calcareous sandstone
B2 (Kurkar) 200 m
C marine clays and shales
D IntrusionJaffa Formation of underlyingSayie Group saline 5 groundwater10 15 20 Km from coast
Schematic hydrogeological cross section 160 BAT YAM Sewage recharge RISHON LEZIYYON Oxygen isotope
150 PALMAHIM distribution REHOVOT in ground water from GIV'AT BRENNER 140 pumping wells from the
Gedera ASHDOD Coastal aquifer (n=200)
( ה ) δ18O 130
BE'ER TUVEYA
-2.50
120 ASHQELON -3.00
-4.00
GEVAR'AM Volume of imported 110 -4.50 water ( MCM ) Zohar Lake 0 to 50 50 to 100 -5.00 NIR AM 100 to 200 200 to 400 -6.00 100 100 110 120 130 140 150 Figure 2 Sea of Galilee -1
Yavne -2 waste water Be'er Toviyya Giva't Brener Gedera δ18O (‰) -3 Revadim Hazor
-4
-5 0 200 400 600 800 1000 1200 1400 Chloride (mg/l) 160 BAT YAM
RISHON LEZIYYON Saline plumes in the inner parts 150 PALMAHIM
of the aquifer are not derived REHOVOT
GIV'AT BRENNER from anthropogenic sources 140 Gedera ASHDOD
130 Cl (mg/l )
BE'ER TUVEYA 50 1000
b 600 120 40 ASHQELON sea water ratio 400
250 SRM-951) 30 GEVAR'AM a 110 150 fresh water 50 B ( 20 NIR AM
11 Sea of Galilee 0 c 100 δ 100 110 120 130 140 150 10 sewage-contaminated Figure 1 ground water sewage 0 Be'er Toviyya 0 50 100 150 Giva't Brener 1/Boron (l/mmole) Gedera Hazor Yavne Revadim Binyamina 210 045-85 – 45 mg/l mg/l Hadera
200 450-45 – 85 mg/lmg/l Plume 9
> 85 mg/l Plume 7 Natanya 190 Sampling of 92 wells in the
Plume 6 180 Coastal Plain aquifer
a a 170 e e s S n a n Tel-Aviv e a n e a 160 r n e a it r d r e e Rishon- it 150 dM letzion e M
140
Ashdod Plume 4 130
120 Ashkelon Plume 2
110
Plume 1 100
90
90 100 110 120 130 140 150 Setting a threshold of δ15N=8‰ enabled us to distinguish between nitrate sources: >8‰ - manure and/or sewage <8‰ - natural soil nitrogen 15
Soil N manure and sewage
10 fertilizers
5 (ΝΟ3) Ο
18 0 δ
-5
-10 0 5 10 15 20 δ15Ν (ΝΟ3) Integration of isotopic tools Nitrate pollution
δ18O<-4‰ δ18O<-4‰ δ18O>-4‰ δ15N>8‰ δ15N<8‰ δ15N>8‰ δ11B >20‰; δ11B >20‰; δ11B <20‰; 3H> 10TU 3H< 10TU 3H> 10TU
organic natural nitrogen domestic fertilizers/ (old) animal manure sewage Integration of isotopic tools Salinization
δ18O<-4‰ δ18O~-1‰ δ18O>-4‰ δ11B >40‰; δ11B ~20‰; δ11B <20‰ 87Sr/86Sr < Br/Cl~3x10-3 Br/Cl < 0.7081 1.5x10-3;
intrusion of artificial sewage underlying saline recharge (Sea of groundwater Galilee) The Water Crisis in the Gaza Strip: Integration of Geochemistry, Numerical Modeling, and Policy
Avner Vengosh1, Erika Weinthal2 , Amer Marei3, Alexis Gutierrez 4, and Wolfram Kloppmann4
1. Ben-Gurion University, Beer Sheva, Israel 2. Tel Aviv University, Israel 3. Al-Quds University, West Bank 4. BRGM, Orleans, France
EU Project (EVK1-CT-2000-00046): Boron Contamination of Water Resources in the Mediterranean Region: Distribution, Sources, Social Impact, and Remediation (BOREMED) Statement of the Problem
• The southern Mediterranean Coastal aquifer is a cross- boundary aquifer, shared by the Israelis and Palestinians (Gaza Strip).
• In the Gaza Strip (30x12 km) groundwater is the only source of water for over a million people. Degradation of the water quality has created an ecological disaster. Chloride distribution in groundwater of the southern coastal aquifer (summer 2000).
115 Sources: this study, PA water authority, Velder 2002
110
105
100
95 1500
1000 90 600 Israel 85 400
250 80 EU, WHO 150
75 Chloride (mg/L) 50
0 70 70 75 80 85 90 95 100 105 110 115 120 125 The Water Crises in the Gaza Strip
Population over 1.2 million Israel pumping 3.43%
Domestic 50 MCM 34.5% Agriculture 90 MCM
62%
Total annual consumption - 145 MCM
Data from UNEP The Water Crises in the Gaza Strip
150 Water deficit 140 Natural replenishment Domestic
100
52
Anthropogenic Agriculture MCM/year 50
33 Lateral flow from east
0 Recharge Consumption 122 145 Data from UNEP The Crises after the Storm
4.5 Estimate rate 70,000/year 4
3.5
3
2.5 Current water deficit is ~23 MCM/y 2 A major component of the recharge is
Population (in millions) 1.5 water with low quality: high salinity and high nitrate pollution
1 1990 2000 2010 2020 2030 2040 2050 Year A joint Israeli-Palestinian-French project • Field work • Inorganic constituents (Ca, Mg, Na, K, Sr, Cl,
SO4, HCO3, NO3, Br, B @BGU and Al-Quds) • Strontium, boron, oxygen isotopes (@BRGM) • Nitrogen isotopes (University of Calgary, Canada) • Numerical modeling • Policy analysis slope=5.6 -12 The δ18O-δ2H slope of LMWL groundwater in the -14 Israeli side and Gaza
-16 Strip is identical to that of the slope in )
groundwater from the -18 ה
H ( adjacent Eocene 2 δ -20 aquitard.
-22
-24 GMWL
-5.5 -5 -4.5 -4 -3.5 -3 (ה) δ18O Loess water extractions (batch)
. Loess leaching
0.70840
87Sr/86Sr 0.70830
0.70820 3 2 1 0
0.70810 Eocene
0.70800
0.70790 0 0.02 0.04 0.06 0.08 0.1 Sr Nitrate pollution of the Gaza Strip 115
GEVAR'AM 11 0 YAD MORDEKHAY
Brur Hail
10 5 NIR AM
Gaza 10 0 Kfar Aza NAHAL OZ
95
90 KEFAR DAROM 90
85 70
80
45
75
0 70 70 75 80 85 90 95 100 105 110 115 120 125 Gaza Strip
15
14
13 (NO3)
N 12 15 δ
11
10 0 100 200 300 400 500
Nitrate (mg/l) . . Gaza Strip 20 Nitrate fertilizers
15
NH4 fertilizer manure and septic waste 10 Soil N (NO3) O 5 18 δ
0
-5 -5 0 5 10 15 20 15 δ N (NO3) Nitrate pollution by septic waste The Geochemistry data • Saline groundwater in Israeli territory originates from a mixture of saline groundwater flowing from the adjacent (Eocene) aquifer and leaching of overlying loess. This is a natural (geogenic) long- term process. • Sources of salinization within the Gaza Strip include seawater intrusion and anthropogenic (nitrate) pollution, but the major source of salinity is the flow of the saline natural groundwater from Israel to the Gaza Strip. • The salinization rate in the Gaza Strip has increased due to over pumping, lowering groundwater level, and intensification of the water gradients between Israel and Gaza Strip. Sources of salinity in the Gaza Strip • Sea water intrusion • Saline groundwater from the eastern part of the aquifer (Israel)
•Anthropogenic sources (sewage effluents within the Gaza Strip)
NW SE
PA Israel
Loess cover
Mediterranean Sea
0
-40 Eocene aquitard -80 Jaffa Formation (Sayie Group) -120
meters ~ 20 km MARTHE -A mono- layer hydrodynamic two-dimension model
Grid: square meshes of 500 m Applying the MARTHE model in the Gaza Strip
Simu l at e d Chlo rid e pat t ern (MARTHE software)
Water salinity components: Water balance: 1. Northern, Cl=0 to 50 mg/l; 1. Natural and induced recharge (within the 2. South-eastern, Cl=1500 mg/l; Gaza Strip only) = 55 MCM/y 3. Atmospheric, Cl=20 mg/l; 2. Pumping = 90 MCM/y 4. Ag return flow, Cl=300 mg/l Management model
1. Reduce salinization by increasing pumping (x3~12 MCM/y) in the eastern side. 2. Decrease pumping within the Gaza Strip at the same magnitude (81 instead of 90 MCM/y). 3. Desalination of the pumped saline groundwater and supply to the Gaza Strip. Water quality remediation upon increasing pumping along the border Long-term implications 1. Improve the quality of water that is utilized the Gaza Strip (health aspects) 2. Remediation of the salinity problem in the Gaza Strip 3. Establish a mechanism of cooperation between Israel and the PA for mitigating the water crisis and lessen the political tension. In contrast to the classic “upstream” versus “downstream” situation, increasing pumping in the upstream (Israel, or along the border) will improve the water quality downstream (Gaza Strip). 4. Lack of cooperation will lead to ecological and social disaster in the Gaza Strip.