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This publication is available at https://www.gov.uk/government/publications/water-and-sewerage-companies-in-england-environmental-performance-report-2021/united-utilities-epa-data-report-2021
This report provides company specific data and information on the Environmental Performance Assessment (EPA) metrics. It contains current year and historic performance data (as published at the time, based on data provided in part by the water companies). For further information on what each EPA metric and performance star ratings mean see our EPA metric guide.
In addition to the EPA metrics, this report contains a section on event duration monitoring (EDM) of storm overflows. For a comparison between water companies and wider regulatory information see the Environmental performance of the water and sewerage companies in 2021 report.
We set targets for each EPA metric. Company performance is then given a red, amber or green (RAG) status:
red - performance significantly below target
amber - performance below target
green - performance better than target
We review and revise thresholds every 5 years.
1. EPA performance star rating
Annual performance star rating after assessment of United Utilities’ performance across all EPA metrics
Year
Overall EPA star rating (out of 4)
Star rating description
2011
3 stars
Above average company
2012
3 stars
Above average company
2013
3 stars
Above average company
2014
3 stars
Above average company
2015
4 stars
Industry leading company
2016
4 stars
Industry leading company
2017
4 stars
Industry leading company
2018
3 stars
Good company
2019
3 stars
Good company
2020
4 stars
Industry leading company
2021
4 stars
Industry leading company
2. Total pollution incidents (sewerage) metric (category 1 to 3)
Main facts
For 2021:
18 sewerage pollution incidents per 10,000km of sewer – this is rated as green
137 actual incidents (needed 181 or fewer to be rated as green)
77,339km sewer length
performance was better than the sector average (32) for sewerage pollution incidents per 10,000km of sewer
best performing for this metric and 1 of 4 companies (out of 9) to be rated green
Annual number of pollution incidents (category 1 to 3) from United Utilities sewerage assets, with EPA status
2011 to 2015 data
Year
2011
2012
2013
2014
2015
EPA status
amber
amber
green
green
green
Incidents per 10,000km sewer
72
74
48
49
40
Actual incident numbers
315
324
208
214
175
2016 to 2020 data
Year
2016
2017
2018
2019
2020
EPA status
green
green
green
amber
green
Incidents per 10,000km sewer
22
23
24
28
19
Actual incident numbers
172
169
181
205
143
2021 to 2025 data
Year
2021
2022
2023
2024
2025
EPA status
green
no data
no data
no data
no data
Incidents per 10,000km sewer
18
no data
no data
no data
no data
Actual incident numbers
137
no data
no data
no data
no data
Annual number of pollution incidents (category 1 to 3) from United Utilities sewerage assets, also showing EPA status and thresholds
Graph note: the EPA RAG status thresholds are set for normalised (per 10,000km sewer) numbers of sewerage incidents (see our EPA metric guide). We review and revise thresholds every 5 years. Equivalent thresholds for actual incident numbers are calculated using water company sewer length data – these are shown in the graph background and the table below.
EPA thresholds for actual number of United Utilities sewerage incidents for the calendar years 2011 to 2025
Calendar year
Red status
Amber status
Green status
2011 to 2015
565 or above
221 to 564
220 or below
2016
386 or above
199 to 385
198 or below
2017 to 2020
368 or above
190 to 367
189 or below
2021
321 or above
182 to 320
181 or below
2022
306 or above
175 to 305
174 or below
2023
291 or above
167 to 290
166 or below
2024
283 or above
159 to 282
158 or below
2025
267 or above
151 to 266
150 or below
Number of pollution incidents (category 1 to 3) from United Utilities sewerage and water supply assets in 2021
Asset type
Number of pollution incidents (category 1 to 3)
Combined sewer overflow
13
Foul sewer
40
Other water industry premises
1
Pumping station
39
Rising main
7
Sewage treatment works
37
Storm tank
0
Surface water outfall
0
Water distribution system (water supply)
7
Water treatment works (water supply)
1
Note: water distribution system and water treatment works (both water supply assets) are not part of the EPA total pollution incidents (sewerage) metric.
3. Serious pollution incidents (sewerage and water supply) metric (category 1 and 2)
Main facts
For 2021:
1 serious incident – this is rated as green (needed 3 or fewer to be rated as green)
1 serious incident from sewerage assets
0 serious incidents from water supply assets
1 of 2 companies (out of 9) to be rated green
Annual number of serious pollution incidents (category 1 and 2) from United Utilities assets (sewerage and from 2021 including water supply), with EPA status
2011 to 2015 data
Year
2011
2012
2013
2014
2015
EPA status
green
green
green
green
green
Serious incidents per 10,000km sewer
0.7
1.1
1.1
0.5
1.2
Actual serious incident numbers - sewerage
3
5
5
2
5
2016 to 2020 data
Year
2016
2017
2018
2019
2020
EPA status
green
green
green
green
green
Serious incidents per 10,000km sewer
0.4
0.1
0.1
0
0
Actual serious incident numbers - sewerage
3
1
1
0
0
2021 to 2025 data
Year
2021
2022
2023
2024
2025
EPA status
green
no data
no data
no data
no data
Serious incident numbers - all assets
1
no data
no data
no data
no data
Serious incident numbers - sewerage
1
no data
no data
no data
no data
Serious incident numbers - water supply
0
no data
no data
no data
no data
Annual number of serious pollution incidents (category 1 and 2) from United Utilities assets (sewerage and from 2021 including water supply), also showing EPA status and thresholds
Graph note: for 2011 to 2020 EPA RAG status thresholds were set for normalised (per 10,000km sewer) numbers of serious sewerage incidents (see our EPA metric guide). Equivalent thresholds for actual serious sewerage incident numbers were calculated using water company sewer length data. We review and revise thresholds every 5 years. For 2021 to 2025 water companies are in one of two groups with different thresholds set for actual serious sewerage and water supply incident numbers. The thresholds for actual serious incident numbers are shown in the graph background and the table below.
EPA thresholds for number of serious incidents from United Utilities assets (sewerage and from 2021 including water supply) for the calendar years 2011 to 2025
Calendar year
Red status
Amber status
Green status
2011 to 2015
18 or above
7 to 17
6 or below
2016
12 or above
5 to 11
4 or below
2017 to 2020
11 or above
5 to 10
4 or below
2021 and 2022
6 or above
4 or 5
3 or below
2023 and 2024
5 or above
3 or 4
2 or below
2025
4 or above
2 or 3
1 or 0
Number of serious pollution incidents (category 1 and 2) from United Utilities sewerage and water supply assets in 2021
Asset type
Number of serious pollution incidents (category 1 and 2)
Combined sewer overflow
0
Foul sewer
0
Other water industry premises
0
Pumping station
0
Rising main
0
Sewage treatment works
1
Storm tank
0
Surface water outfall
0
Water distribution system (water supply)
0
Water treatment works (water supply)
0
4. Self-reporting of pollution incidents (sewerage and water supply) metric
Main facts
For 2021:
81% of all incidents self-reported, 87% from just pumping stations (PS) and sewage treatment works (STW) combined – this is rated as amber
118 self-reported incidents, 27 incidents reported by others
needed 80% or higher self-reporting and 90% from just PS and STW combined to be rated as green
performance was better than the sector average (77%) for self-reporting of all pollution incidents
performance was worse than the sector average (88%) for self-reporting of just PS and STW pollution incidents combined
1 of 5 companies (out of 9) not to be rated green
Annual self-reporting of pollution incidents (category 1 to 3) from United Utilities sewerage and water supply assets, with EPA rating
2011 to 2015 data
Year
2011
2012
2013
2014
2015
EPA status
green
green
green
green
green
Percentage of incidents self-reported
71
76
69
75
81
Number of incidents self-reported
229
253
155
175
163
2016 to 2020 data
Year
2016
2017
2018
2019
2020
EPA status
green
green
green
green
green
Percentage of incidents self-reported
75
82
79
90
82
Number of incidents self-reported
144
151
154
194
119
2021 to 2025 data
Year
2021
2022
2023
2024
2025
EPA status
amber
no data
no data
no data
no data
Percentage of incidents self-reported
81
no data
no data
no data
no data
Number of incidents self-reported
118
no data
no data
no data
no data
Percentage of PS and STW incidents self-reported
87
no data
no data
no data
no data
Number of PS and STW incidents self-reported
66
no data
no data
no data
no data
Annual self-reporting of pollution incidents (category 1 to 3) from United Utilities sewerage and water supply assets, also showing EPA status and thresholds
Graph note: the EPA RAG status thresholds (for all sewerage and water supply assets) are shown in the graph background and in the EPA metric guide. We review and revise thresholds every 5 years. From 2021 the additional number in brackets is the self-reporting percentage for just PS and STW incidents combined. To achieve green status self-reporting for all assets must be 80% or above and for just STW and PS combined must be 90% or above.
Self-reporting of pollution incidents (category 1 to 3) from United Utilities sewerage and water supply assets in 2021
Asset type
Number of pollution incidents self-reported (category 1 to 3)
Number of pollution incidents not self-reported (category 1 to 3)
Combined sewer overflow
11
2
Foul sewer
27
13
Other water industry premises
1
0
Pumping station
32
7
Rising main
6
1
Sewage treatment works
34
3
Storm tank
0
0
Surface water outfall
0
0
Water distribution system (water supply)
6
1
Water treatment works (water supply)
1
0
5. Discharge permit compliance (numeric) metric
Main facts
For 2021:
99.0% numeric discharge permit compliance - this is rated as green
16 permitted discharge outlets from water treatment works (WTW) – 93.8% compliance (1 non-compliant WTW)
needed 4 or fewer non-compliant treatment works to be rated as green
performance was better than the sector average (98.7%) for numeric discharge permit compliance
1 of 5 companies (out of 9) to be rated green
Annual discharge permit compliance (numeric) for United Utilities (STW and from 2016 includes WTW), with EPA status
2011 to 2015 data
Year
2011
2012
2013
2014
2015
EPA status
amber
green
amber
amber
amber
Percentage permit compliance
98.6
99.2
98.6
98.3
97.2
Number of permitted discharge outlets from STW
360
359
359
360
358
Number of non-compliant STW
5
3
5
6
10
2016 to 2020 data
Year
2016
2017
2018
2019
2020
EPA status
amber
amber
amber
amber
green
Percentage permit compliance
97.4
98.8
98.7
98.5
99.7
Number of permitted discharge outlets from STW
369
374
370
372
377
Number of permitted discharge outlets from WTW
50
30
26
20
20
Number of non-compliant STW
7
4
4
6
0
Number of non-compliant WTW
4
1
1
0
1
2021 to 2025 data
Year
2021
2022
2023
2024
2025
EPA status
green
no data
no data
no data
no data
Percentage permit compliance
99.0
no data
no data
no data
no data
Number of permitted discharge outlets from STW
375
no data
no data
no data
no data
Number of permitted discharge outlets from WTW
16
no data
no data
no data
no data
Number of non-compliant STW
3
no data
no data
no data
no data
Number of non-compliant WTW
1
no data
no data
no data
no data
Annual discharge permit compliance (numeric) for United Utilities (STW and from 2016 includes WTW), also showing EPA status and thresholds
Graph note: the EPA RAG status thresholds are shown in the graph background and in the EPA metric guide. We review and revise thresholds every 5 years.
6. Delivery of the Water Industry National Environment Programme (WINEP) metric
Main facts
For the financial year ending 2022 (cumulative year 1 and year 2 of the WINEP):
100% schemes completed within planned deadlines - this is rated as green
208 schemes completed (all completed within planned deadlines)
performance was better than the sector average (99.5%)
1 of 6 companies (out of 9) to be rated green
Annual delivery of the NEP (WINEP from April 2020) by United Utilities, with EPA rating
Data for financial years ending 2012 to 2016
Financial year ending
2012
2013
2014
2015
2016
Asset Management Plan (AMP)
AMP5
AMP5
AMP5
AMP5
AMP6
EPA status
green
green
green
amber
green
Percentage of NEP complete to date (cumulative)
101
101
104
97
100
Cumulative number of schemes completed during AMP period
93
150
193
256
8
Data for financial years ending 2017 to 2021
Financial year ending
2017
2018
2019
2020
2021
Asset Management Plan (AMP)
AMP6
AMP6
AMP6
AMP6
AMP7
EPA status
green
green
amber
green
green
Percentage of NEP complete to date (cumulative)
100
100
98.6
99.7
100
Cumulative number of schemes completed during AMP period
63
106
162
290
5
Data for financial years ending 2022 to 2026
Financial year ending
2022
2023
2024
2025
2026
Asset Management Plan (AMP)
AMP7
AMP7
AMP7
AMP7
AMP8
EPA status
green
no data
no data
no data
no data
Percentage of WINEP complete within deadlines (to date)
100
no data
no data
no data
no data
Cumulative number of schemes completed during AMP period
208
no data
no data
no data
no data
Cumulative number of water quality schemes completed during AMP period
190
no data
no data
no data
no data
Cumulative number of water resources schemes completed during AMP period
10
no data
no data
no data
no data
Cumulative number of fisheries, biodiversity and geomorphology schemes completed during AMP period
8
no data
no data
no data
no data
Table note: AMP5 schemes that were completed early before their planned year were included in the cumulative delivery percentage (in some cases resulting in percentages over 100%). AMP6 and AMP7 schemes that were completed early before their planned year are not included in the cumulative delivery percentage until their planned year (cannot report over 100%). The EPA RAG status thresholds are in the EPA metric guide. We review and revise thresholds every 5 years.
7. Sludge disposal and use metric
Main facts
For 2021:
99,609t (tonnes dry solid) total volume dispatched
17,541ha (hectares) land used for spreading
97% of sludge produced was used in agriculture
Annual compliance with sludge disposal and use metric by United Utilities, with EPA ratings
2011 to 2015 data
Year
2011
2012
2013
2014
2015
EPA status
amber
amber
amber
green
green
Percentage of sludge compliant
99.1
99.2
99.9
100
100
Total volume of sludge dispatched (t thousands dry solid)
191.9
145.6
111.1
106.1
99.1
2016 to 2020 data
Year
2016
2017
2018
2019
2020
EPA status
green
green
no data
no data
no data
Percentage of sludge compliant
100
100
no data
no data
no data
Total volume of sludge dispatched (t thousands dry solid)
98.2
112.7
112.1
113.0
116.8
2021 to 2025 data
Year
2021
2022
2023
2024
2025
EPA status
no data
no data
no data
no data
no data
Percentage of sludge compliant
no data
no data
no data
no data
no data
Total volume of sludge dispatched (t thousands dry solid)
99.6
no data
no data
no data
no data
Table note: from the 2018 calendar year, we suspended the metric from the EPA whilst we reviewed our regulatory regime for sludge. The EPA RAG status thresholds are in the EPA metric guide.
Annual summary of sewage sludge disposal and use (dry matter) by United Utilities
1,826 megalitres per day water distributed to the network
1 of 7 companies (out of 9) to be rated green
Annual compliance with SDBI by United Utilities, with EPA ratings
Financial year ending
2022
2023
2024
2025
2026
EPA status
green
no data
no data
no data
no data
SDBI score
100
no data
no data
no data
no data
Table note: the EPA RAG status thresholds are in the EPA metric guide.
9. Event Duration Monitoring (EDM) delivery
All water companies have investment in place to monitor all storm overflows by December 2023. We have published the EDM storm overflow annual return dataset received from water companies. This shows how often and how long the monitored storm overflows operated during 2021. The 2021 dataset also includes water company reasons for performance issues with monitors and reasons for high spill counts.
United Utilities storm overflows
Year
2021
Total number of storm overflows listed in the annual return
2,192
Total number of storm overflows with EDM commissioned
2,006
Percentage of storm overflows listed with EDM commissioned
91.5
Total number of storm overflows with spill data
1,954
Percentage of storm overflows listed with spill data
89.1
Average number of spills per storm overflow with spill data
41.8
Average duration (hours) per monitored spill event
