Pollution is defined by the Environment Protection Act of 2001 (Chap 435 of the Laws of Malta) as "the direct or indirect introduction by man into the environment of substances, organisms, genetic material or energy that cause or are likely to cause hazard to human health, harm to living resources or to ecosystems, or damage to amenities, or interfere with other legitimate uses of the environment".
If we consider the local scenario, the sources of water pollution are numerous, and their effects vary depending on the severity of the pollution source and its location. Following is a list of pollutants of relevance to the local environment and a short description of their effects:
| Activity | Resulting Pollutants | Potential Impacts |
| Agriculture | Nutrients
Pesticides
Suspended matter | • Decrease in light and oxygen availability to aquatic life.
• Nutrient enrichment and eutrophication.
• Increased stress to aquatic life. |
| Sewage discharge | Biological Oxygen Demand
Nutrients
Organics
Bacteria and viruses
Turbidity
Heavy metals
Pesticides
Other synthetic chemicals | • Decrease in light and oxygen availability.
• Nutrient enrichment and eutrophication.
• Alteration of habitats and communities.
• Increased stress to aquatic life. |
Discharges from industry | Heavy metals
Organics
Synthetic chemicals
Thermal pollution | • Increased stress to aquatic life.
• Possible increased mortality in aquatic organisms. |
| Aquaculture | Nutrients
Suspended matter
Organics | • Nutrient enrichment.
• Reduced oxygen levels.
• Accumulation of particulate wastes.
• Alteration of habitats. |
| Oil and fuel terminals | Petroleum Hydrocarbons | • Increased stress to aquatic life. |
| Shipping, including bunkering and harbour dredging | Anti-fouling chemicals
Petroleum Hydrocarbons
Suspended matter
Heavy metals | • Alteration of habitats.
• Decrease in light and oxygen availability |
Agriculture
Legislation
Protection of Waters against Pollution Caused by Nitrates from Agricultural Sources Regulations, 2001 - L.N. 343 of 2001
This legal notice transposes the European Nitrates Directive (CD91/676/EEC), which has the objectives of reducing water pollution caused or induced by nitrates from agricultural sources and preventing further such pollution. Nitrates are a health hazard in waters which are used as sources of drinking water. Nitrates are also nutrients which, when found in excess concentration, contribute to eutrophication. The Directive requires:
• the establishment of a code of good agricultural practice, to be implemented on a voluntary basis by farmers, to protect waters from pollution by nitrates;
• the identification of waters polluted by nitrates from agricultural sources;
• the identification of the land areas contributing to the nitrate pollution and the designation of these lands as Nitrate Vulnerable Zones (NVZs);
• the establishment and implementation of action programmes in relation to designated NVZs.
All of Malta was designated as a nitrate vulnerable zone under L.N. 233 of 2004.
Urban Waste Water
Urban Waste Water Treatment Regulations, 2001- L.N. 340 of 2001
This legal notice transposes CD91/271/EEC on Urban Wastewater Treatment. The objective of this legal notice is to protect the aquatic environment from the adverse effects of discharges of untreated or improperly treated urban waste water and of waste water from certain industrial sectors.
This legal notice:
Requires the provision of urban waste water collecting systems (sewerage) and treatment plants for all agglomerations above 2,000 population equivalents;
Provides a legal framework for specific authorization for all discharges of urban waste water and industrial waste water from particular sectors, as well as for all discharges of industrial waste water into urban waste water systems;
Requires the phase out of any dumping or discharge of sewage sludge into surface waters;
Requests that the treated urban waste water discharges and their effects are adequately monitored;
The legal notice requires the Competent Authority to designate sensitive areas and these have been designated through LN120 of 2005.
Malta has been granted a transition period until March 2007 to be fully compliant with this legal notice, through the construction of three new sewage treatment plants, two in Malta and one in Gozo.