State of wastewater purification in Italy

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Freshwater scarcity is a crucial global problem, originating from multiple causes, including contemporary lifestyle, pollution, demographic pressure. The picture of suffering is also complicated by the same climate change that is taking place. In Italy, for example, hydrogeological failure, lack of infrastructure or maintenance also affect them. In addition to affecting the protection of the resource, the decisive factor is the recovery of water within an integrated cycle that falls within the canon of the circular economy. And in this water cycle a key role is played by the system of purification, in which public bodies, water managers, companies in the sector operate.

The closed water cycle

The integrated water cycle goes through the phases of picking, use, purification, reuse. Wastewater in this perspective becomes a valuable resource, as highlighted in 2017 by the Unesco Report: “Wastewater. The unexplored resource.”

The report highlights the great worldwide exploitation of water resources where 44% is consumed in agriculture by evaporation from irrigation, 56% return to the environment from civil, industrial and agricultural waste drains. While high-income countries purify the water by 70%, as incomes fall, so does the proportion of sewage wastewater. Overall, it is estimated that 80% of the world’s water is returned to the environment without adequate purification. In addition to potential environmental and sanitation emergencies, we can see the great potential of reusing water purified in agriculture, industry and drinking water as a source of raw materials.

The centrality of the data

Setting goals for protecting water resources and reusing waste to combat water scarcity, in line with current European environmental and health policies, necessarily means first of all having an up-to-date, clear, comprehensive statistical picture on water resources. Only from the data can appropriate strategies be established.

In Italy, in this direction, it is the ISTAT itselfthat declares the difficulty in obtaining national data organized in an overall framework, largely due to the fragmentation of management.

The state of the sewage treatment in Italy

But what is the state of the art of purification in Italy? The ISTAT makes a three-year census, the next step is the year 2018 of which the data were collected in the current year. The data available are therefore those of 2015, as also reported in a recent ISTAT report: “Use and quality of water resource in Italy”.

There are 17,897 operating plants. The North is the territory with the most plants: in order in Piedmont, Emilia-Romagna, Lombardy, Veneto. 46.8% are Imhoff tanks, 44.2% secondary or advanced plants, 9% primary plants. Lombardy and Veneto have many advanced plants. Although – proportionally – the South and Islands also have high rates of advanced treatments. However, advanced plants, although not majority, deal with more than half (66.7%) polluting loads.

By estimating potential waste on the basis of the urban total equivalent inhabitants and comparing them with what is actually purified, there is still a gap. The demand for sewage is about 98 million equivalent inhabitants, compared to 75 million served.

Civilian-type polluting loads are treated at least secondary to the extent of 59.6% of their potential. The percentage is 64.6% in the North-West, lower the percentages in other areas of Italy with differences from Region to Region.

Large plants, mainly in the North-West, purify 61.4% of the purified load in terms of equivalent inhabitants and are predominantly tertiary/advanced. As for discharges, they occur at sea (16.7%) surface water (80.3%).

Also interesting are the specific data of the coastal municipalities. The quality of bathing water is excellent for 91.9% of the total monitored, but 42 municipalities lack public sewage treatment plant, almost all in the South.

Demands and sanctions from Europe

Since 1991, through a specific EEC Directive, Europe has been calling on member states to adapt wastewater treatment plants and sewage systems. This year Italy was sanctioned with 25 million euros for non-adjustment of 74 urban areas. And other infringement procedures are ongoing.

If you look at these figures and look at the disparities between North and South, it is clear that the situation in Italy is complex and needs integrated, cohesive, coherent actions, not only to ensure purification standards throughout the territory. A concrete policy of the integrated water cycle is needed, with adequate investment from both the public and private sectors.