Preventing Pollution – progress towards a better environment

In March, Thames Water was fined for pollution incidents at six sites in the Thames Valley during 2012-14.  A combination of equipment and management failures meant the sites weren’t able to treat the volumes they were designed to, and discharged untreated wastewater to the environment.

We take full responsibility for what happened. We didn’t protect the environment we rely on – and it is up to us to put that right.

So what are we doing to make good what happened – and to reduce the risk of problems recurring?

First of all, we have paid £400,000 in compensation to organisations directly affected.  And we have added £1.5 million to our Community Investment Fund, ring-fenced for projects to help the rivers, wildlife and local environment in the vicinity of the incidents.

We’ve also strengthened the team looking after the region in which the incidents took place, so there are more staff, each with fewer sites to deal with.

Of course, people want to know what we’re doing to avoid similar problems elsewhere.  The answer lies partly in investment, with £26 million spent since the incidents to help ensure we meet sewage treatment standards, and reduce the risk of pollution from all our sites.

Severe weather and the devastating impact of wet wipes and other ‘unflushables’, were common factors across the incidents.  It is up to us to insulate our customers and the environment from these pressures, so, much of our focus has been to ensure we are more resilient to their effects.

This includes an £18 million programme to refurbish the screens that protect our treatment works from items including wet wipes, which have a crippling impact when they ball together, clogging pipes and breaking pumps.

But arguably the most significant changes we’ve made have been in our Wastewater Operational Control Room. In addition to doubling staffing levels, we’ve transformed the way we work, harnessing technology to take a much more proactive approach to managing our sewage works, pumping stations and sewer network.

This includes a new system for visualising near-live data so we can pre-empt potential problems.  We know, for example, from analysing previous incidents that sewage pumping stations can show unusual patterns of energy use before failing.

By tracking their energy use we can see where this is happening, and have intervened on up to 15 different occasions within a single month – in some cases averting potentially serious pollution incidents. By capitalising on the insights data can offer, we are shifting our focus from reacting to alarms, to intervening to prevent assets failing, flooding and pollution.

On the sewer network, our storm chasing project is perhaps the most innovative and influential change we’ve made.

Historically, we’ve used weather forecasts covering periods of hours, and large parts of our region – helpful in preparing for slow-moving weather fronts, but not the short, sharp storms that can quickly overwhelm our sewers.

We’re now using advanced weather radar, forecasting several hours ahead and showing changes at 15 minute increments, on a 2km grid, to pinpoint when and where a storm will hit. This makes it easier for us to proactively pre-position the teams and equipment we’ll need to deal with the potential impacts. It’s not so much chasing storms as getting ahead of them.

At the same time, a new Logistics Management Centre and ten distribution hubs with stocks of the kit we need to respond to events, means we can despatch crews to proactively manage the risk of potential incidents at a local level.

Taken together, these improvements have supported a significant reduction in pollution incidents from their peak in 2013.

The Blueprint for PR19 challenges companies to aim for zero category one, two and three pollution incidents and 100% self-reporting – and these are mirrored in our own aspirations. There’s much more we need to do to get there, including making our operations more resilient to the effect of storms – but we believe we’re making real progress.

Please don’t take my word for it. We are holding open days later this year at all the sites where incidents took place so you can see for yourself what we’ve done, and meet the teams who are doing everything they can to protect the environment on which we all rely.

Lawrence Gosden
Managing Director, Wholesale Wastewater – Thames Water