Plan to reduce excessive nitrate levels in water - di-ve

An action plan tackling excess nitrate levels in Maltese groundwater has been put up for consultation, and government hopes to have a final plan by September, Resources Minister George Pullicino said on Friday.

The EU Nitrates Directive sets a limit of 50mg/l for nitrate concentration. However, a monitoring programme showed that just 3 groundwater bodies were within the limit. The figure for the Marfa coastal groundwater body is not known, but expected to be in excess of the standard, while in 3 cases – Pwales coastal aquifer, Mellieħa coastal aquifer and the Żebbuġ (Gozo) perched aquifer – the level exceeds 300mg/l.

High concentrations of nitrates can be harmful to people and nature, although Mr Pullicino stressed that drinking water posed no such problem: it is mixed with reverse osmosis-derived water to keep nitrate levels under control.

The excessive nitrate concentrations are due to the use of organic and chemical fertilisers in agriculture, as nitrogen is vital for plant growth. Improper storage of manure also increases nitrate concentrations. The action plan, therefore, aims to introduce better practices in agriculture to reduce them.

One measure would prohibit the use of fertiliser – organic and inorganic – between October 15 and March 15, with an exception for inorganic fertiliser in the event of a demonstrable crop requirement. The use of slurry manure would be banned outright. Further restrictions would be in place based on the land’s location, while the amount of total nitrogen applied from livestock manure should not exceed 170kg/hectare annually.

Records on the use, sale and movement of fertilisers would need to be kept.

In livestock farms, facilities for manure storage should provide enough space for the storage of all the manure produced between October 15 and March 15. Manure is to be stored in a leak-proof, covered storage clamp which is connected to a cesspit. 

Farmers would be required to attend a compulsory course on the use of fertilisers, with Mr Pullicino noting that due to lack of knowledge, farmers often used excessive amounts.

Mr Pullicino stressed that this did not mean that Maltese crops were in any way unfit for consumption, but noted that farmers were needlessly overspending on fertiliser.

He noted that although the plan is set to be finalised by September, it would be years before nitrate levels drop significantly – the groundwater cycle is around 40 years long.

John Paul Cordina
di-ve
07 May 2010