The impact of dairy farms on groundwater quality in Israel’s

Coastal AquiferShahar Baram

Zuckerberg Institute for Water ResearchBen Gurion University of the Negev

The presented study is part of the requirementsThe presented study is part of the requirements for the completion of a Ph.D. degree at

The Ben-Gurion University of the NegevThe Ben Gurion University of the NegevIsrael

Supervisors:Ofer Dahan, BGU Zeev Ronen BGUZeev Ronen, BGU

Daniel Kurtzman, The Volcani Center

Funding:Israel Water Authority

700

Degradation in groundwater quality - Israel's Coastal Aquifer

500

(mg/

L)

100

300Cl

60

1966 1975 1984 1993 2002 Possible causes:

1. Mixture with deep

40

60

mg/

L)

brines

2. Industrial activity

20NO

3-(

3. Intensive agricultural activity

01966 1975 1984 1993 2002

Dairy farming in Israel

Number of cows350,000 heads

Haifa

Total slurry generated ~5 million ton / yearTel-Aviv

No waste treatment proceduresDea

d S

ea

Ashdod

Gaza

Cows1-2001-200201-500501-10001001-2500

The reform in Israel’s dairy farming 1999 - 2006

The “detached” dairy farm concept

• Prevention of rain water and local runoff from entering the sheds

• Prevention of effluent overflows from reaching the environment

• Prevention of effluents from infiltrating into the environment

• Providing an end solution to the effluents (waste treatment plants, power plants etc.)

Before After

The objective of the study:

To evaluate the impact that dairy farm waste lagoons h d t lit i I l’ C t l A ifhave on groundwater quality in Israel’s Coastal Aquifer

Research site

HaifaCowshed drainage

Overflow channel

Tel-Aviv

drainage

Dea

d S

ea

Ashdod

Gaza

Waste lagoon

Cows1-200

Waste lagoon

1-200201-500501-10001001-2500

0Methods

Lithological cross sectionXXXX

10

5Lithological cross section

Sediment sampling, aste ater samplingX

X

XXX

10

15

Groundw

a

wastewater sampling, groundwater monitoring

X

X

20

ater observ

Vadose zone monitoringX

30

25ation w

ellX

30

45Sandy loamClay (38% Montmorillonite)Waste water

X

X

50Sandy loamCalcareous sandstone

In-situ monitoring of the vadose zone

Water content measurement using FTDR

Pore-water sampling using vadose zoneusing vadose zone sampling ports (VSP)

Initial results:

Testosterone and Estrogen in the vadose zoneTestosterone and Estrogen in the vadose zone

Testosterone and Estrogen (µg/Kg dry soil)g (µg g dry soil)

0.00 0.05 0.10 0.15 0.20 0.25 0.300

m)

10

20D

epth

(m20

30

40 TestosteroneEstrogenDetection limtGroundwater Table

Modified from Arnon et al., 2008

50

Monitoring set-up

Waste channelWaste channel Waste Lagoon

Changes in the water content across the vadose zoneWaste channel

θ ~55%

Waste channel marginsg

θ ~35%

Changes in the water content across the vadose zone

θ ~40%

Chloride in pore water across the vadose zone

Chloride in pore water across the vadose zoneWaste channelWaste lagoon

%0%

θ~4

5

θ~5

5%

θ~3

0%θ~4

0

θ

Chloride concentrations in the clayey vadose zone increase with depth

Chloride concentrations in the Groundwater ~800 mg/L

Desiccation cracks at the research site

Conceptual model: the effect of the margins on the pore water dissolved salts concentration

Ammonium in pore water across the vadose zone

Groundwater table

Waste channelWaste lagoonNitrate in pore water across the vadose zone

%%

θ~4

5%

~55%

~30%θ~4

0%

θθ

Nitrate concentration in the recharging solutions ~450 mg/L

Nitrate concentrations in the Groundwater ~300 mg/L

Conceptual model: The fate of nitrogen in the vadose zone

Waste lagoon

First stage:

Fast infiltration

Second stage:Partial sealing of the l

Third stage:Substantial decrease in th t t t d Water content = saturationWater content < saturationWater content << saturationFast infiltrationSaturation of the uppermost sediment

lagoonthe water content and formation of desiccation cracks

Water content saturationOxygen concentration = 0Dominant nitrogen form AmmoniumOxygen concentration > 0Ammonium Nitrate DenitrificationDominant nitrogen form Nitrate

Water content saturationOxygen concentration >> 0Dominant nitrogen form Nitrate

Dominant nitrogen form Nitrate

Conclusions:

• Unlined waste lagoons are point sources for nitrate and salts contamination

• The margins of unlined waste lagoon have a majorThe margins of unlined waste lagoon have a major impact on the overall pollution potential of the lagoon

• Preferential flow in seasonal desiccation cracks may transport pollutants directly to the deep vadose zonetransport pollutants directly to the deep vadose zone, bypassing the biogeochemical active zone of the clay sediment

• Nitrification is likely to accrue under all waste lagoons since the vadose zone is unsaturated

• The fate of nitrate in the vadose zone is water contentThe fate of nitrate in the vadose zone is water content dependent

• Drying of waste lagoon in clayey sediments may accelerate the transport of contaminants in to the deepaccelerate the transport of contaminants in to the deep vadose zone and groundwater

Key consequences following this work

• The vadose zone monitoring system is a useful tool for early detection of pollutants in the vadose zoneearly detection of pollutants in the vadose zone

• Drying of waste lagoon in clayey sediments may accelerate the transport of contaminants into the deep

d d d tvadose zone and groundwater• Assessment of the pollution potential of waste lagoons

must take in to account the effects of the margins• Unlined/earth-lined waste lagoons are point sources for

nitrate, salts and hormones

Thanks:Israel's Water Authorityy

Ms Sara Elchanani

Dr Irena PankratovDr. Irena Pankratov

Ben-Gurion University

GDr. Amit Gross

Dr. Shai Arnon

Mr. Yuval Shani

Mr. Michael Kugel

Local runoff

Concentrations in the local runoff:Total nitrogen forms – 139 ± 207 mg/L (n=69)

Chloride – 65 ± 80 mg/L (n=72)