Waste from the environment segment

[GRI - 103-1], [GRI - 103-3], [GRI - 306-1], [GRI - 306-2], [GRI - 306-3], [GRI - 306-4], [GRI - 306-5],

The streams for the Environment Segment are highly varied, due to the range of types of plants and the broad spectrum of services provided by the Companies. Activities can be grouped in the four macro categories: waste-to-energy, composting, treatment of liquid waste and brokerage/transport. Below are details for the first three, while transport and brokerage are handled under Waste-to-energy, composting, disposal of liquid waste and related services in the Environment Segment section. With the plants of San Vittore del Lazio and Terni, waste-to-energy activity produces the greatest quantity of waste, totalling 92,765 t in 2021. The majority of waste produced is fly-ash, bottom-ash and water from the buffer tank165. In 2021, 43,425 tonnes of ash were recovered (approximately 47% of the total). The Orvieto plant and the three composting plants (Aprilia, Monterotondo Marittimo and Sabaudia) produce leachate as their primary waste in terms of quantity, derived from stabilisation of waste and primarily sent for disposal (98%). As an example, streams of treatment, disposal and recovery for waste-to-energy and composting sites are illustrated in Chart no. 61. Finally, there are the treatment plants handling liquid waste of the Companies Acque Industriali, Berg and the plant of Bio Ecologia166, merged into Acea Ambiente, which primarily produce sludge. The above plants also produce non-process waste, which only represents 1% of the total waste generated by the Environment Segment.

Chart no. 61 – Main waste streams in the Environment Segment (waste-to-energy and compost sites)

Chart 61

Table no. 71 – Waste produced by companies in the Environment Segment (2019-2021)

rifiuti Area Ambiente 2019 2020 2021
environment segment waste (t)
total waste 150.435 154.619 168.024
hazardous 76.437 69.654 65.526
of which ash 68.092 59.509 59.142
non-hazardous 73.998 84.965 102.498
of which liquid waste (leachate and buffer water) 45.767 53.823 57.537
detail by type of processing
entirely recovered waste 55.589 46.503 46.032
of which ash 52.608 42.629 43.425
entirely disposed of waste (*) 94.846 108.116 121.992
of which sent to landfill and subject to other disposal operations 93.123 106.818 121.992

165 Water from buffer tanks or “water for technical purposes”, refers to liquid solutions used as a buffer for acidic components that develop during combustion of waste.
166 The waste from the Bio Ecologia plant derive both from treatment of liquid waste and treatment of wastewater.