John Mangion

Reference is made to public statements from various quarters claiming that groundwater is in danger of vanishing within 15 years or less. While recognising the significant pressures on Malta’s limited groundwater resources, the Malta Resources Authority feels that such claims warrant clarification.

In compliance with the requirements of the EU Water Framework Directive, in 2005 the Authority published a status report, known as the Article 5 report, where information was presented on the qualitative and quantitative status of all groundwater bodies in Malta and Gozo. This report explained in detail the status of all the aquifers at that point in time based on observed trends physically recorded through a groundwater-monitoring network covering the whole territory. It also included results of analytical modelling performed by several water experts. These reports were made available for public consultation and comment on the Authority’s website. To date however, no comment or response has been received by the Authority refuting, challenging or questioning the methodology adopted, the estimates made, and the information and results submitted on the status of groundwater bodies.

The Authority points out that it is continuously monitoring groundwater levels and groundwater quality across the islands in line with the EU Water Framework Directive’s (WFD) requirements. An analysis of data obtained from these groundwater monitoring networks indicates that in spite of the estimated significant over-abstraction from these water bodies, water levels in gauging boreholes (height of the water table above mean sea level) still remain either relatively stable or show mildly declining trends (refer Figures on the right).

This observation appears to confirm that the mean sea level aquifers are characterised as relatively slow-response systems, mainly due to their large storage capacity as compared to the mean annual recharge. In fact, while the mean annual recharge of both the mean sea-level aquifers (Malta and Gozo) is estimated to be of the order of 40 million m3, their storage capacity is estimated to be of the order of two billion m3.

From a qualitative point of view, it should also be noted that the main issue is that of high nitrate levels which has already led to several groundwater bodies (perched aquifers) being decommissioned from the public water supply, thus indirectly putting more pressure on the sea level aquifer systems.

In line with WFD requirements, Malta is required to submit a programme of measures by March 2010 where the results of the monitoring of groundwater are taken into account. This programme of measures entails identification and estimates the costs of implementation of a series of measures that would need to be implemented to attain the Water Framework Directive’s objectives by 2015.

Therefore in this scenario Malta cannot and is not adopting a status quo approach. On the contrary, both the government and the Authority recognise the importance of groundwater to the local economy and are therefore seeking to strike a balance between environmental and socio-economic considerations.

At the same time, it is noted that certain practices cannot be expected to be changed overnight without the introduction of sustainable and feasible alternatives which deliver the desired results, and without inducing social hardships to sectors of the economy, such as agriculture. Sustainable groundwater abstraction may be implemented more effectively when alternative supply options, such as treated sewage effluent, become available together with further implementation of demand management measures. Such measures are generally associated with significant capital investment in infrastructure, parts of which have already been made or allocated by the government. More investment will be required in the coming years to deliver these alternative sources of supply to the point of use. Careful consideration is needed to ensure that such infrastructural projects do not levy disproportionate economic costs with overall negative consequence to the national economy.

The Authority therefore considers the claim that groundwater will vanish in 15 years or less to merit caution and diligence, prior to it being published in the media. The Authority further recommends that similar claims should be clearly supported by scientific studies and high quality field data gathered over a long period of time. This is key to the correct interpretation of hydrological phenomena.

To conclude, the Authority invites authors of such statements to provide further scientific evidence to support this claim and perhaps they will kindly oblige to indicate:

a) to which groundwater bodies they are referring (i.e. whether if any specific groundwater body or bodies or all groundwater bodies in Malta and Gozo risk vanishing within 15 years or less);

b) how they arrived at such a figure and the models and data used to compute the 15-year timeframe for exhaustion of Malta’s aquifers, as well as details of the associated assumptions and methodology adopted;

c) scientific observations and data available to support their estimates and conclusions.

Dr Mangion is Director of Water at the Malta Resources Authority