Aquifer recharge in Malta

General

National Id:

Malta_01

Site name:

Bulebel Industrial Estate, Malta Mean Sea Level

Summary:

Aquifer recharge with highly polished treated effluents. With a high population density and almost inexistent surface waters, Malta is in a situation of over abstraction of its groundwater resources and where its total water demand exceeds the sustainable yield of the naturally renewable freshwater resources. Demand comes from the domestic and agricultural sectors alike (the domestic use can even exceed the agricultural use with the arrival of tourists during touristic seasons). From a qualitative point of view, freshwater resources are also under threat resulting from nitrates and salt water intrusions.

The in-depth description of the case study:

cs-mt-01-final_version.pdf

NUTS Code:

Malta

RBD code:

MTMALTA

Transboundary:

Data provider:

Camille Parrod, ACTeon

Source(s):

Assessing the environmental impact of artificial recharge by highly polished treated effluent on an unconfined aquifer system

NWRM(s) implemented in the case study:

Restoration of natural infiltration to groundwater

Longitude:

14.5253

Latitude:

35.8675

Site information

Climate zone:

warm temperate dry

Type:

Actual Test Site

Light or indepth?:

In-depth

Monitoring maintenance

Monitoring impacts effects:

Monitoring location:

Edge of Field/Plot

Monitoring parameters:

Water level (height of water column above probe), salinity, electrical conductivity and groundwater temperature. Organic pollutants (Pharmaceuticals - Carbamezepine, Acetominophen, Diazemam, Diclofenac, Dilantin, Fluoxetine, Gemfibrozil, Hydrocodone, Ibuprofen, Iopromide, Meprobamate, Naproxen, Pentoxifylene, Mefanamic Acid Solvents/Plasticizers/Surfactants - Dibutylphtalate, Glycol Ether, Alkyl Benzene, Dibromochloromethane, Perfluorooctanic Acid, Perfluorooctanesulfonic Acid, BisphenolA Personal Care Products - Caffeine, Galoxolide, Oxybenzone, TCEP and DEET Steroids - Androstenedione, Estradiol, Estriol, Estrone, Ethinylestradiol, Progesterone, Testosterone AntiMicrobial Agents - Trimethoprim, Triclosan, Sulfamedthoxazole, Erythromycin) and conventional pollutants (electrical conductivity, chloride, nitrate and bacterial content).

Performance

Performance impact estimation method:

Catchment outlet

Performance impact estimation information:

Background conditions at the recharge site monitored through two wells located in the immediate vicinity of the recharge well (pre-recharge): use of two multi-parametric groundwater probes; Water level monitoring (post-recharge): use of a water level contact gauge.

Lessons, risks, implications...

Key lessons:

A hydro-geological assessment of the aquifer system must be carried out before any artificial recharge scheme using treated effluents is implemented, in order to assess the prevalence of local and regional groundwater flow should anything go wrong. Effluents should undergo further treatment in order to comply with the EU Directives' requirements concerning recharge of groundwater bodies.

Success factor(s):

Type	Role	Comments
Financing possibilities	main factor	Financing for the treatment of effluents that will be injected into the aquifer
Other	main factor	Location of the recharge facility (close to a wastewater treatment plant)
Existing regulations	secondary factor	Enforcement of control for illegal abstractions

Financing:

Type	Comments
EU-funds: Cohesion and regional development funds	Cofinanced by the European Regional Development Fund

Barrier:

Type	Role	Comments
Other	main barrier	Lack of sufficient treated wastewater resource (quantity of effluents available for recharge)
Lacking financing sources	main barrier	Cost of polishing effluent too high to be sustainable at the moment
Other	secondary barrier	Lack of a dedicated distribution network for the re-use of treated effluent

Driver:

Type	Role	Comments
Legal obligations	main driver	WFD requirements (annual abstraction from the groundwater body does not exceed the long-term annual average rate of overall recharge of the body of groundwater; necessary controls are in place to eliminate the possibility of any degradation in the qualitative status of the receiving body of groundwater)
Other	main driver	Availability of European funding for research projects in this area

Policy, general governance and design targets

Policy description:

Test the hydrogeological response of the aquifer system in the immediate region surrounding an artificial recharge well; test the quality of treated effluents used for artificial recharge of an aquifer

Part of wider plan:

Policy pressure:

Policy requirement directive:

Policy impact:

Policy wider plan:

Policy area:

Policy target:

Target purpose
Groundwater Recharge
Pollutants Removal

Design & implementations

Application scale:

Plot

Installation date:

2010-06

Performance timescale:

< 1 year

Area (ha):

21660

Design capacity description:

±105 mg/l of Nitrate content in the arriving effluent was mitigated, increase of ±1.3m post-artificial recharge over the drawdown levels and 0.6m over the long-term background level

Constraints:

Availability of sufficient treated effluent; quality of the polished effluent; production costs for delivering and polishing the effluent; short- and long-term cyclic behaviour in the water levels.

Favourable preconditions:

Location (next to a wastewater treatment plant); available equipment.

Public consultation:

Contractural arrangements:

Design contractual arrangement:

Design consultation activity:

Design land use change:

Design authority:

Authority type	Role	Responsibility	Name	Comments
Private property owners	Monitoring		Water Services Corporation	The WSC was responsible for assisting MRA from a technical and operational standing point. It owns the purification plant where the experiment took place, and provided the technical expertise and equipment.
National water authority	Implementation		Manuel Sapiano, Malta Resources Authority	The MRA was responsible for leading the Maltese pilot project from the MEDIWAT research project†™s point of view. 'MRA is also responsible for issuing authorizations (after a quality control) for injecting water into the aquifer through boreholes.

Last updated: 18 Jun 2015 | Top

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