Aquifer recharge in Malta | Natural Water Retention Measures

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.

Light or indepth?

In-depth

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

14.523394

Latitude

35.864492

Site information

Climate zone

warm temperate dry

Type

Actual Test Site

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.

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

Arrangement type	Responsibility	Role	Comments	Name

Design consultation activity

Activity stage	Key issues	Name	Comments

Design land use change

Land use change type

Design authority

Authority type	Role	Responsibility	Name	Comments
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.
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.

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)

Success factor type	Success factor 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

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

Barrier

Barrier type	Barrier 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

Driver type	Driver 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

Financing share

Financing share type	Share	Comments

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 target

Target purpose
Groundwater Recharge
Pollutants Removal

Policy pressure

Pressure directive	Relevant pressure

Policy area

Policy area type	Policy area focus	Name	Comments

Policy impact

Impact directive	Relevant impact

Policy wider plan

Wider plan type	Wider plan focus	Name	Comments

Policy requirement directive

Requirement directive	Specification