In 2022, approximately 63% of the water withdrawn was derived from the industrial aqueduct, in line with the figure for previous years.

The remaining part of the water resource is taken from the well. The total withdrawal during 2022 was 1,220 Megalitres, similar to 2021. Almost 99% of the water collected is non-potable.

Water is the quintessential resource for the tanning industry.

It is used with extreme thrift as it is configured as the bottleneck for the production of tanneries, both in quantitative and qualitative terms. For these reasons, Gruppo Mastrotto has equipped itself with a real-time monitoring system of consumption and, where possible and authorised, tries to reuse process water, in order to optimise the use of water resources.

The graph on the side indicates the amount of wastewater supplied to the purifiers of Arzignano (Vicenza) and Santa Croce sull’Arno (Pisa). Since the water withdrawn is almost all non-potable, in the same way even the discharged water is nonpotable.

The table on the side shows the wastewater supplied to the treatment plants.

To the data relating to 2022, 13.7 megaliters relating exclusively to the District of Santa Croce sull’Arno must be added. In that district the tanneries must recover the tanning baths and send them to the Chromium Recovery Consortium, which treats them to recover the chromium contained in them and return it to the tanneries of the district for reuse.

This management method is characteristic of the institutional structure of the District. From a regulatory point of view these baths represent liquid waste, but from a substantial point of view they represent a waste that is treated and therefore it was considered correct to insert it in that paragraph. In the district of Arzignano tanning baths flow directly into the wastewater sent to the purifier for various purification treatments.

Most of the water discharges are destined for the industrial purification system of Acque del Chiampo, the public company that manages the aqueduct, sewage and purification services for all companies in the tanning district of Arzignano.

Tanning wastewater is treated in an industrial line divided into a series of treatment phases such as:

• fine grating and sandblasting

• homogenisation and odour treatment

• primary sedimentation

• biological active sludge treatment of oxidation-nitrification and denitrification

• separation of activated sludge by dissolved air flotation

• clariflocculation

The sludge from the purification process undergoes a series of treatments of accumulation, thickening, mechanical dehydration and thermal drying, before being disposed of in a controlled landfill.

The purified wastewater is finally subjected to a further disinfection treatment with ultraviolet (UV) rays, in order to prevent the reproduction of pathogenic microorganisms. These flow into the surface water body and can be used for various activities, including agricultural irrigation.

Gruppo Mastrotto is subject to specific qualitative and quantitative limits that the wastewater from tanneries must comply with, parameters that are systematically controlled by technicians and analysts of the treatment plant.

The following graph highlights the systematic ability to remain well below the limits set by the purifier, to confirm an adequate management of the production process.

To reduce water consumption and impacts, Gruppo Mastrotto has made significant investments in recent years in systems for hydraulic regulation of drains, monitoring of environmental parameters and sensors in the finishing phases.