Water and Sewerage Companies (WASC) Environmental Reporting – Transparency around pollution

At RPS we understand the need for Water Companies to manage the perception of how overflows are performing. But with regulatory annual environmental reporting data available to the public, how can this be done, without the pressure of constant public and governmental scrutiny?

10 Nov 2021

At a time of ever increasing public and government pressure on Water and Sewerage Companies (WASC) in relation to pollution and overflow performance, the requirement for publicly accessible Annual Reporting including the Environmental Performance Assessment (EPA) potentially lays open the challenges that companies are facing to the public. And with star ratings, bad performance can have considerable impact on public, regulator and government perception of how WASCs are operating.

Environmental Performance Assessment

The EPA was introduced by the Environment Agency (EA) in 2011 to enable a yearly performance comparison between water companies. A number of metrics were developed to enable this, aligned to the 5 year Asset Management Plan (AMP) investment cycles which water companies operate in. Each metric has targets set and are normalised to allow comparison across companies with Red/Amber/Green performance thresholds for annual figures created to allow for comparison.

There are three metrics for pollution covering all aspects of pollution incident categorisation and reporting. These metrics are normalised against sewer length (incidents per 10,000km sewer) to allow suitable comparisons and threshold setting across all WASCs. These metrics are:

  • Total Pollution Incidents – A count of all recorded pollution incidents – Red ≥50, Amber 50-25, Green ≤25+
  • Serious Pollution Incidents (Category 1 and 2 incidents)– Red ≥1.5, Amber - 1.5-0.5, Green ≤0.5
  • Self-Reported Pollution Incidents – Red ≤55%, Amber 55-75%, Green ≥ 75%

Self-reporting is when a WASC informs the EA of an incident before others do and is set to emphasise the importance of internal procedures and response to an incident. This is a critical step in pollution management and also allows pro-active management of incidents without the need for regulator involvement.

Delivering messages to customers

So how did our WASCs perform? The EPA produces a simple graphic to highlight performance across all metrics and gives the overall performance star rating. This allows customers to easily see how companies performed in 2020, with the associated reporting allowing a more detailed assessment.

EPA infographic.png

A full version of this diagram is available here

Total Pollution Performance and Serious Pollution Incidents

As you can see, performance against pollution has been variable, with both Southern Water and South West Water experiencing challenging Total Pollution Performance results, with a further three WASCs performing worse than target. This picture for Serious Pollution Incidents is similar with only four water companies meeting targets. These performance figures contributed to Southern Water and South West Water achieving only two stars in the overall performance rating, highlighting the significant improvements required in 2021. On closer examination this score is, in part, related to ‘consistently unacceptable’ performance during the last five years.

Improved Environmental Performance

Environmental Performance however has improved generally since 2019, with five WASCs showing at least a one star improvement in overall performance - this includes Southern Water which improved from one star in 2019.

Between 2019 and 2020, Northumbrian Water achieved a two star improvement - from two stars to four in 2020. This suggests that there is a degree of improvement, however WASCs are still some way off eliminating pollutions and there is an emphasis on accelerating the drive to zero serious pollution incidents.

Increased pressure from the public and media

With the increased outcry from the public and the media around pollution performance, the government is under pressure to tighten requirements in the Environment Bill, and with the House of Lords recently demanding stronger action and adding an amendment to place a duty of “Sewerage undertakers to take all reasonable steps to ensure untreated sewage is not discharged from storm overflows into inland and coastal waters” this pressure is likely to realise tighter performance assessment. The EPA will continue to reflect overall performance, but we can expect the pollution metrics to be under close scrutiny moving forward.

In summary, all of this pressure serves to underline that a deep understanding of overflow performance and how associated data is reviewed, is absolutely critical to future urban drainage management. RPS will continue to support our clients drive towards zero pollution through strategic performance modelling, monitoring, assessment and intervention to better understand how and why overflows operate and how this operation can be reduced.


If you would like to discuss this topic further and understand how RPS can support you, please contact me anytime.

Howard Cutts

Regional Director, Water Consultancy


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