In 2017, the Hera Group operated the sewage and purification service in 231 municipalities, 49 of which as Marche Multiservizi and 18 of which as AcegasApsAmga while the coverage of the sewage service for all urban areas is equal to 92% of the needs of the territory (population equivalents).
In 2018, the purification service covered 91% of population equivalents in the areas served by the Group.
These values are very positive if compared with the average of the Italian utilities that were included in the Utilitatis study in 2016, at 90% for the sewage network and 88% for the purification network. Concerning the country-wide values, the latest data available are for 2007, when 85% of Italians was served by the sewage network and 70% by a purification plant. (Source: 2009 Utilitatis Blue Book). Assessing the percentage of wastewater treated compared to the total, the Italian average in 2015 was 89.9%, with negative peaks for the regions of southern Italy such as 68.5% in Sicily or 76.9% in Calabria (Source: ISPRA).
The Hera Group treated over 382 million m3 of wastewater in 2018, compared to 364 million in 2017 as a result of the low rainfall that year and, therefore, of the lower inflow of rainwater. The sewage networks that feed those plants are generally mixed-type systems, and the volumes treated therefore depend on rainfall.
The sewage network Hera Spa operates is approximately 14,800 km long and about 53% of the total (55% in 2014) is a mixed-type system. At Group level, the sewage network operated is 18,626 kilometres long, and 57% of the total is a mixed-type network.
The indicator concerns the plants that serve over 10,000 population equivalents (the volumes treated in these plants are 87% of the total wastewater treated) and expresses the ratio between the measured concentration of BOD5, COD, TSS, ammoniacal nitrogen, phosphorus and total nitrogen, and the corresponding maximum concentrations permitted by Legislative Decree 152/2006.
The efficiency in removing pollutants to comply with the regulatory limits, as expressed by the indicator in the chart, is related to the purification capacity of the plant and the technologies used. Low indicator values indicate higher purified water quality. At Group level, this indicator averages 35% of regulatory limits, taking into account BOD5, COD, TSS, ammoniacal nitrogen, phosphorus and total nitrogen, and 26% excluding phosphorus and total nitrogen. The indicator that expresses the efficiency of removal of the main pollutants improved slightly compared to previous years, also due to the fact that some large upgrade projects started in previous years are nearing completion. In particular, with regard to the Triveneto area, in the first few months of 2018 the new biological section of the Servola purification plant in Trieste was launched, which went into operation in June 2018. This has allowed us to improve significantly the results compared to previous years, when the plant was only primary chemical-physical. A further improvement is expected in 2019, as 2018 was a year of transition with the first half of higher values.