From the outside it looks just like any other greenhouse, rising high above the fields in Żejtun.
But the 85-metre-long structure produces some 3,000-cubic-metre worth of natural fertiliser a year, used mainly by local potato exporters.
Frank Fenech, 56, who runs a dairy farm not far away from there, built the greenhouse on a concrete base to store his animals’ manure between October and May.
In this way, he protects the manure from the rain and protects the water table from nitrates that would otherwise seep down to the aquifer.
With high levels of nitrates in the water table, farmers may no longer dump raw manure in a field to let it dry between October 15 and March 15 as this could contaminate the aquifer.
According to EU and local regulations, farmers should store the manure in a sealed clamp and many dump it in cesspits.
Some even dilute it with water and throw it away in the drainage, Mr Fenech said.
“This could not only be illegal, but they would be losing a very good resource, much better than the artificial fertiliser brought from abroad.”
Every day, a truckload of manure from his dairy farm is tipped onto the depot where it is stored for some seven months. The greenhouse is then opened in May, when the fertiliser is separated from other liquids.
It is then mixed with soil and lasts for three to four years as its nutrients, essential to the growth of plants, are released more gradually than in the case of artificial fertilisers.
The final product is used mostly by potato growers and is in demand by produce exporters.
“The process is natural and we do not use any other energy apart from the sun. Another advantage of this system, as opposed to the one where we used to leave it uncovered in fields, is better control of the material,” he noted.
Also, no stench emanates from the greenhouse, notwithstanding the depot’s content.
Mr Fenech was speaking about the manure management system at an EU-funded project organised by the Gal Xlokk Foundation about sustainable irrigation water in the south of Malta.
During the seminar, the permanent secretary at the Ministry for Energy and the Conservation of Water, Mario Rodgers noted that the quality of the water in the south had a high level of salinity and the Government was developing a “polishing programme” for treated water so that it could be used by the agricultural sector.
He said a national plan was also being drawn up to implement a sustainable water programme.
Agriculture Parliamentary Secretary Roderick Galdes said the Government was working on ridding farmers of the bureaucracy keeping them from developing systems to collect water. Another speaker at the seminar, Marco Cremona, from the Malta Water Association, said while Malta used to extract drinkable water through boreholes and pumping stations, now this was not of drinkable quality because of salinity and nitrates.
Malta had to have drinkable aquifer water by 2015 and, although it had applied for a 12-year extension, Dr Cremona expressed doubts whether Malta would manage to meet the targets by 2027.
EU countries with fewer than 2,000 tons of water per capita were considered to have a precarious water situation, he said. Malta only had 40 tons of water per capita. The island consumed 21 times the amount of water it could produce and, while a third was used in homes, 45 per cent was consumed by the agricultural sector.