By Lewis Brown

Gaining a better understanding

Southern Water is a company in transformation and achieving zero pollutions by 2030 is one of the many ambitious targets underpinning that journey.

We’re delving deeper and gaining a better understanding of why incidents happen, as well as a forensic understanding of all our wastewater treatment works, pumping stations and network, how we monitor and analyse flows.

This means we have the data to be able to target investment to those sites most likely to fail and anticipate failure before it happens – prevention rather than cure.

Zero pollutions

Is our zero pollutions target achievable? Absolutely.

That’s why Dr Nick Mills, head of asset performance for wastewater operations at Southern Water, organised the country’s first Zero Pollutions Conference in London during the summer. In combination with Isle Utilities, the focus was to drive challenging conversations and to discuss how wastewater pollution comes from multiple sources, the legacy of pre-1960s combined drains and sewers, failure of utility equipment and customer behaviour.

Global experts shared their knowledge on cutting pollution and Dr Mills emphasised that reaching zero pollutions in a decade can only be achieved if everyone works together.

At Southern Water we’ve been working hard over the past couple of years to better understand the problems our sites face. We’re also auditing the top 10% of our sites which we know have the biggest impact on the environment and tested and checked all our equipment. We’ve carried out health tests of around 236 of our pumping stations (there are 350) to check that we know where the spill points are and what could cause an issue.

We’ve all been through rigorous compliance training and we are finding and reporting more issues than ever before. This has an impact on our reporting figures but it also means we are demonstrably finding and fixing issues earlier. It also means fewer incidents that can potentially impact the environment.

Prevention and detection

The focus on causal analysis and detailed understanding of issues on our sites means that we are learning faster and reporting issues quicker as evidenced in our dramatic increase in self-reporting.

We are putting in place a 24/7 wastewater desk which will work alongside our duty managers to ensure we respond swiftly and with dedicated resource. This is coupled with a resilient approach out of hours and redoubled preparedness for weekends.

Our developing resilience matrix will enable us to report resilience dynamically looking at actions from the pollutions database and reporting on improvements that are being made.

We are on a journey to being more compliant. The increase in pollution numbers is expected as we investigate more, we understand the root causes and with better measurement, we have seen an upward trend in reported incidents – but this is because we’re better at spotting asset performance.

Root cause analysis

Pollutions this year have increased. Our evidence and analysis of the events shows that weather and more specifically abnormal weather from climate change has very little bearing on the incidents we have seen. Rainfall does impact assets but has not caused significant issues for treatment works.

However foul sewers, pumping stations and combined sewers are affected by rainfall and this has an impact on surface water flooding, which we work closely with local authorities to solve. Dry weather can impact the severity of an incident if flows have not been running it can lead to bigger blockages.

The increase in pollutions has been driven by an increased awareness and reporting improvements. However, underlying causes relate to asset issues which is why increased investigations and health checks are being carried out at 400 treatment works and pumping stations. This work will be complete by early next year.

The biggest impact currently on our sites and cause of incidents is power outage and blips.

Power and measuring spill times

The site health checks enable us to create a targeted maintenance schedule for all sites. However the biggest issue we have found is the resilience of the power supply on sites. We’re working with other companies in the area to establish if there is a network issue in the south east and how we can solve this.

We are also investigating our own on site power resilience, this includes checking and maintenance of all back-up generators and ensuring our processes are in place for health checks on all pumps and the control philosophy is suitable for the site.

We have also carried out checks across all sites to ensure we have accurate time to spill understanding which gives us a priority roster of sites which have a repeated history of failure and which sites have a high consequence if they do spill.

We’ve found there is a strong correlation and 10% of our sites with the highest environmental consequence were responsible for 45% of pollutions in 2019.

Investing in the future and our Pollution Reduction Plan

On top of investing £100 million in bringing our IT team in-house, we’ve invested £442 million improving our sites and network in 2018-19, including our monitoring and analysis capabilities and also telemetry. Our investments in our Bathing Water Enhancement Programme has also been recognised especially recently, with more bathing waters in the south east recording some of their best ever results.

This improved performance was the result of the assiduous work carried out under the SWS Bathing Water Enhancement Programme, and our improved coastal modelling, the ‘Beachbouy’ initiative, our ‘Beauty of the Beach campaign’. We’re currently piloting our Beachbuoy scheme at two harbours in our region, as well as a small selection of bathing waters. Langstone and Chichester Harbour were chosen for the pilot as they are also used as recreational waters. Along with the bathing waters at Hill Head, Ventnor, Bexhill and Joss Bay. We plan to provide similar information for other bathing waters in the near future. During this pilot, we’ll add updates between 9am and 5pm but we’re aiming for 24/7 updates in the future.

The funding of wastewater sites, such as the £100 million redevelopment of our Woolston treatment works, Southampton, and replacing Thanet’s old sewer network in Kent to help protect the environment are also bigger examples of how we’re transforming as a company, improving assets and allowing for better monitoring of wastewater flows.

We have also put in place (and resourced) a Pollution Reduction Plan which allows us to prioritise improvement activity and response resources at sites which have the highest potential environmental impact (and which has been shared with the Environment Agency).

A final word on improving environmental performance

We’ve created an Environment+  programme which looks at all aspects of environmental compliance and performance. Alongside wastewater treatment works compliance, it also focuses on improving river quality, reducing pollution incidents and flooding and enhancing bathing water quality.

Details of the work being carried out by the Environment+ programme can be found in our Annual Report (which was published on our website). We have recruited a team of environmental compliance advisors and created environmental champions within the business to increase awareness and introduce cultural change.