The amount of leachate generated is collected in the landfill body through gravel drainage network and extraction wells located at the banks (slope riser), conveyed to the storage tanks through dedicated piping, and from there the leachate is sent to authorized treatment plants.

The biogas produced by the landfill is taken by a horizontal and vertical catchment system consisting of drainage wells that, through a specific adduction network (HDPE pipes), conveys it to the intake plant.

The extracted biogas is recovered energetically by two eight-cycle engines with a total installed electric power of 1,250 kWe, and in case of shutdown of one or more plants it is treated in a high-temperature flashlight. The electricity produced is used to power all utilities on the site and the surplus fed into the external distribution network.

From bottom to top, the following waterproofing package was made as required by Legislative Decree 36/2003:

• Bottom barrier made of compacted clay reprofiled in situ;
• HDPE geomembrane 2.5 mm thick;
• Geotextile protection sheet;
• Sand and gravel layer for bottom drainage of leachate.

The final accommodation project, in accordance with Legislative Decree 36/2003, includes on areas 3/4/5 a multilayer cover package consisting, from top to bottom, of the following layers:

• surface cover layer with a thickness of 1 m of topsoil on which the plant species envisaged in the environmental restoration plan are to be planted and with geogrid stabilization on the slope;
• seepage water draining geocomposite;
• HDPE geomembrane 1.5 mm thick;
• bentonite geocomposite 6 mm thick;
• mineral layer made of compacted clay with thickness of approx. 0.4 m;
• biogas drainage layer made of inert material;
• regularization layer in contact with the waste.

To enable the naturalistic recovery of the site, the operator, in agreement with the Local Authorities, has identified a series of mitigation/compensatory interventions to be carried out in and around the landfill, described in the environmental restoration plan. These interventions include, but are not limited to:

• planting of off-site shrub hedges;
• planting of wooded masking strips;
• grassing of the area concerning the first lot;
• creation of a wooded strip on the sides of the service road;
• maintenance work on the Poggio alla Posta grove;
• extraordinary maintenance of the Diaterna riparian vegetation.

The Monitoring Plan takes into account the particular location of the site subject to hydrogeological constraints, flora and fauna impacts and the proximity of natural areas protected by environmental and landscape preservation. The environmental matrices and emissions monitored as environmental surveillance on potential impacts of the landfill are:

• groundwater and drainage;
• water discharges;
• leachate;
• biogas composition;
• emissions piped biogas engines for power generation;
• diffuse emissions from the landfill body;
• air quality;
• noise;
• landfill body morphology and stability;
• meteoclimatic parameters;
• waste produced (amount of leachate disposed and biogas produced);
• electricity production from biogas combustion.