Emissions into the atmosphere

The boundaries  

The boundaries of this section include Acea SpA, Acea Reti e Servizi Energetici, Acea Distribuzione, LaboratoRI, Acea Produzione and A.R.I.A. with the two waste-to-energy plants. With regard to the water sector, Acea Ato 2, Acea Ato 5, Acque, Gori, Acquedotto del Fiora, Publiacqua and Umbra Acque are included.

The monitoring of the emissions into the atmosphere produced by thermoelectric plants and waste-to-energy plants is carried out, where possible, using continuous analyzers periodically checked by internal staff and by qualified outside laboratories.

 Within the context of the environmental Management Systems in force care of all the Group plants which produce atmospheric emissions, annual containment targets are normally set for emissions of micro-pollutants (CO, powders, NOx and SO2) and carbon dioxide (CO2).  

The carbon footprint of the thermoelectric generation process at the two Tor di Valle and Montemartini plants fell considerably as from 2012 in absolute terms - from around 123,000 tons of CO2 in 2010 to roughly 25,400 tons in 2012 (see table No. 93) - even if this is essentially due to a proportionate reduction in production volumes.

Both thermoelectric plants are subject to the Emission Trading Scheme and therefore have the restriction of not emitting quantities of CO2 greater than the quota assigned to them by the National Allocation Plan, at the risk of a deterioration in the profile of the costs due to the need to buy quotas in excess on the market (see table No. 93).

Table No. 93 – CO2 emission allowances as PER THE NAP AND EFFECTIVE EMISSIONS BY PLANT (2010-2012)(2010-2012)

  2010 20112012
plantsCO2 emissions (t)
  assigned by the NAP effective assigned by the NAP effective assigned by the NAP effective
Tor di Valle 235,788 87,989 235,788 26,089 235,788 23,377
Montemartini 1,827 2,902 1,218 4,762 609 1,988

With regard to emissions of CO, SO2 and NOx micropollutants, the same comments made in relation to emissions of CO2 are valid: a sharp decrease was seen with respect to the 2010 values, due to the corresponding reduction in production levels.

With regard to atmospheric emissions produced by the waste-to-energy plant at San Vittore del Lazio, the levels registered by means of on-going monitoring, compared with the reference limits, are shown in table No. 94.


Unit of measurement 2010 2011 2012 
pollutantreference parameter It. Leg. Decree No. 133/2005     Line 2 Line 3 total
HCl 10 mg/Nm3 2.45 1.88 0.16 0.22 0.38
NOx 200  101.49 148.17 23.67 25.58 49.25
SO2 50  6.79 4.18 0.01 0.0017 0.0117
Total powders 10  1.06 1.41 0.0025 0.0042 0.0067
IPA (polycyclic aromatic hydrocarbons) 0.01  0.00013 n.a 0.000012 0.000012 0.000024
Dioxins and furans  (PCDD +PCDF) 0.1 ng/Nm3 0.05 n.a 0.0185 0.02 0.0385
Heavy metals (Sb, As, Pb, Cr, Co, Cu, Mn, Ni, V) 0.5 mg/Nm3 0.00967 n.a 0.0025 0.00375 0.00625
N.B.:Line 1 is not present in the table, because as from March 2011 it was shutdown for revamping work.

CO2 emissions of the San Vittore del Lazio plant came to around 99,700 tons and are mainly due to the combustion of the non-biodegradable component of the WDF treated (around 50% of the total).

 In conclusion, the monitoring carried out on all the plants at risk demonstrated the absence of appreciable quantities of emissions of substances responsible for reducing the ozone layer.

Table No. 95 shows the total emissions of the Group, including those from vehicles and air-conditioning.

Table No. 95 - TOTAL ACEA GROUP EMISSIONS (2010-2012)

(t) emissions 2010 2011 2012
CO2 122,940 35,308 132,123
CO 67.34 34.74 49.62
NOx 226.27 100.59 104.66
SO2 6.70 0.71 0.04

A.R.I.A., which manages the waste-to-energy plants, has taken steps to monitor the quality of the air at the points of greatest fallout of the pollutants emitted by its plants, thereby contributing to the effort to improve the general ecological quality. It also carried out the usual monitoring of the state of the quality of the soil and groundwater surrounding the San Vittore del Lazio plant and carried out studies into the bioaccumulation of heavy metal in the lichen present in the soil surrounding the plant. The campaigns carried out so far have provided results in line with the limits envisaged by current legislation, consistent with the Integrated Pollution Prevention and Control Authorization (A.I.A.), on the basis of which the plant operates.

With regard to the waste-to-energy plant for treating pulper (Terni), a memorandum of intent was entered into with the bodies which control the area which envisages a pollutant monitoring campaign which will go beyond the current regulatory fulfilments in force.

Group vehicle fleet   

For several years the Group has been involved in the reduction of atmospheric emissions; this also led to specific attention to the renewal of the company vehicle fleet, which in 2012 numbered 2,500 vehicles in circulation.

Again in 2012, as in 2011, a lowering of the average age of the vehicles was seen thanks to the acceleration of the natural process for replacing obsolete vehicles with latest generation models. Furthermore, 42 electric vehicles were introduced in 2012, purchased in 2011, which will be joined by another 40, the process for the purchase of which has been launched.