550,000 cubic metres of pig waste produced annually

This vast amount of waste contributes both to the high level of nitrates in the aquifer and inland waters as well as to added costs for the Water Service Corporation which has to dispose of this material.

Pig slurry and washing water is presently collected in cesspits on the farm and disposed of in the public sewerage network, either through a direct connection to the cesspit or by bowser.

The WCMP report also denounces the illegal disposal of slurries in valleys..

Manure and slurries in agriculture are identified in the WCMP as one of the main sources of contamination of groundwater and inland surface waters. Pollution can occur both from application of manure and slurries as fertiliser on fields as well as from livestock farms with inadequate manure collection and storage systems.

The direct discharge to the sewage networks linked to the Gozo and Malta North plants has been prohibited following the start of operation of these plants. The illegal disposal of this waste in public sewers in 2009 resulted in a temporary breakdown of the sewage treatment plant.

Discharge of slurries and farmyard wastewaters into the sewerage system has to be completely prohibited by the WSC once the third urban wastewater treatment plant comes on line, since treating this waste would result in excessive operating costs due to the high nitrogen load of the slurry.

The draft Agricultural Waste Management Plan for the Maltese Island recommended the construction of 3 or 4 treatment plants to treat manure, pig slurry and waste waters through anaerobic digestion to  produce electricity and heat and stable soil conditioner that can be applied to the fields in the dry season.

How waste is collected

In the case of cattle, solid waste (which includes manure and used bedding) is collected daily from the yards and stored to dry naturally until the summer when it is used as fertiliser by crop farmers, while the liquid fraction runs off to a cesspit from where it is transported by bowser for discharge into the public sewerage system via designated manholes or into the ground in the case of unsurfaced yards. In farms with uncovered yards, the volumes of this liquid increase  significantly by the addition of rainwater.

In the case of poultry, manure from broilers is mixed with bedding which covers the broiler house floor and is collected when the shed in cleaned out. Manure from layers falls onto manure belts below the stacked battery cages in which the hens are kept, from which it is collected every few days.

Since 2005 a number of livestock farms have upgraded, their  infrastructure for the collection and containment of manure in accordance with the Maltese Code of Good Agricultural Practice (CoGAP) to abide with requirements of the Nitrates Directive. This  involves the construction of leak-proof and covered clamps for the storage of manure during the closed period (15th October – 15th March) and the construction of cesspits for collection of urine and washings and storage capacity for 15 days. However, a number of farms are unable to become compliant due to space or other constraints while others appear to have no  intention of becoming compliant.

But despite these precautions slurry still ends up in the public sewers.

An inter-ministerial committee is presently discussing proposals on codes of good practice for the storage, treatment and disposal of waste, including that from pig, cow and other livestock farms.