PERCENTAGE OF TREATED WASTEWATER

Update date
Authors

Riccardo Boiocchi, Giancarlo De Gironimo, Massimo Peleggi, Silvana Salvati

The percentage of treated wastewater reflects the amount of biodegradable organic load that reaches urban wastewater treatment plants compared to the total organic load produced by agglomerations (2,000 PE or more) across the national territory. In 2022-2023, this percentage is 93.51%, an increase compared to 2020 (93.3%).

Description

This is a response indicator that expresses the amount of biodegradable organic load reaching urban wastewater treatment plants relative to the total organic load produced by agglomerations (2,000 PE or more) within the national territory. The percentage of biodegradable organic load conveyed to treatment plants equipped with secondary treatment (or more advanced systems for discharges in sensitive areas) represents the level of wastewater treatment system coverage nationally.
Purpose

To verify the percentage of treated wastewater at the national level.
Policy relevance and utility for users
It is of national scope or applicable to environmental issues at the regional level but of national significance.
It is able to describe the trend without necessarily providing an evaluation of it.
It is simple and easy to interpret.
It is sensitive to changes occurring in the environment and/or human activities
It provides a representative overview of environmental conditions, environmental pressures, and societal responses.
Analytical soundness
Be based on international standards and international consensus about its validity;
Be theoretically well founded in technical and scientific terms
Presents reliability and validity of measurement and data collection methods
Temporal comparability
Spatial comparability
Measurability (data)
Adequately documented and of known quality
Updated at regular intervals in accordance with reliable procedures
An “adequate” spatial coverage
An “appropriate” temporal coverage
Main regulatory references and objectives

Directive 91/271/EEC, Legislative Decree No. 152/2006
DPSIR
Response
Indicator type
Descriptive (A)
References

https://cdr.eionet.europa.eu/help/UWWTD/UWWTD_613 

https://ec.europa.eu/environment/water/water-urbanwaste/info/pdf/terms.pdf
Limitations

The national framework could be more comprehensive if agglomerations with fewer than 2,000 population equivalents were also considered.
Further actions

Completion of information useful to the indicator.
Data source

ARPA/APPA (Regional and Autonomous Provincial Environmental Protection Agencies)
Data collection frequency
Two year
Data availabilty

The data were acquired through the Urban Waste Water Treatment Directive 2024 (UWWTD 2024) questionnaire prepared by the European Commission to periodically check the state of implementation of the Directive on the national territory and made available on the SINTAI.
Spatial coverage

National, Regional
Time coverage

2022-2023
Core SET
SDGs Indicators
Strategia Nazionale Sviluppo Sostenibile (SNSvS)
SDG goals
Goal 6: Clean water and sanitation
Processing methodology

The percentage of treated wastewater was obtained by calculating the amount of treated wastewater (in population equivalents) relative to the total load generated by agglomerations of 2,000 PE or more.
Update frequency
Two-year
Data quality

The quality of information is considered adequate to meet the requirements of current regulations. Data are acquired and validated according to homogeneous procedures at the national level, ensuring good temporal and spatial comparability.

Status
Good
Trend
Positive
State assessment/description

In 2023, 93.51% of the total organic load produced by agglomerations was purified in urban wastewater treatment plants (Figure 2).
Trend assessment/description

Compared to 2020, the percentage of treated load relative to the generated load in agglomerations of 2,000 PE or more remains stable (from 93.3% to 93.51%).
Comments

: In 2022, the value of treated organic load amounted to 73,395,222 PE, compared to the total generated load of 78,486,277 PE (Table 1). Regional details show that the percentage of treated organic load exceeds 90% in 16 regions, including the Autonomous Provinces of Trento and Bolzano (Trentino-Alto Adige), while in 3 Regions it reached values above 85%. The lowest percentage is recorded in Sicily (70%) (Figure 1).
Data
Data
Tabella 1 Carico generato e carico depurato nuova DG.xlsx (13.085 KB)
Headline

Table 1: Load generated and load purified by agglomerations greater than or equal to 2,000 pe - regional detail (2022-2023)

Data source

ISPRA processing on ARPA/APPA and regional data (UWWTD 2024 Questionnaire)
 
Headline

Figure 1: Percentage of the adjusted organic load for agglomerations greater than or equal to 2,000 a.e. – regional detail (2022-2023)

Data source

ISPRA processing on ARPA/APPA and regional data
Headline

Figure 2: Total percentage of the treatment of the generated load (2022-2023)

Data source

ISPRA processing on ARPA/APPA and regional data