Corporate Responsibility

Pollution prevention activities.

Last reviewed:
We take our responsibility for protecting our environment very seriously, and we’re still working hard to prevent our operations causing environmental damage. We’re responsible for a huge network which includes around 109,000km of sewers, over 4,700 sewage pumping stations and 351 sewage treatment works. In 2017 we saw an overall improvement in our pollution performance compared to 2016. We’re pleased with this improved performance, but our whole business remains focused on continuing to reduce pollution incidents from our operations, and minimise our impact on the environment.

A polluted outfall, before misconnection investigations have been carried out.

Our current performance.

  2015 2016 2017
Serious pollutions (Cat 1 and 2)* 12 10 10
Total pollutions (Cat 1- 3)* 265 357 303
Self-reported pollutions (%)** 61 67 73

* The Environment Agency categorises pollution incidents on a scale of one to four: Cat 1 - major environmental impact, Cat 2 - significant, Cat 3 - minor, Cat 4 - no impact

** Figure represents the percentage of the total pollutions (Cat 1-3) that were self-reported by Thames Water to the Environment Agency.

# The figures included in the Annual Report (SC2 - total pollutions including consented) are pollution numbers according our ODI methodology agreed with OFWAT and do not include pollution from surface water outfalls. This accounts for the differences between the figures in the Annual Report and the table above.

We’ve improved in our overall performance for 2017 (a calendar year measure) with a 15 per cent reduction in the number of pollution incidents compared with 2016. Our performance for serious pollutions has remained the same and we must do better. Sewer abuse was a contributory factor to some of these. We continue to improve on our self-reported pollutions, which increased from 67 per cent in 2016 to 73 per cent in 2017. This brings us closer to meeting our target of 75 per cent of incidents being self-reported by 2020. Our compliance with numeric discharge permits also saw an improvement in 2017 compared with 2016, registering 99.5 per cent (two failures).

Improvements we've made.

We know that performing well with our pollutions performance is a fundamental part of our existence and we’ve learned from the past. Since our pollution incidents between 2012 and 2014, our approach to pollution prevention is now very different, and our long-term aspiration remains to eliminate serious pollution incidents completely. We’ve reviewed how we do things at all levels of our business, and made a number of changes:

  • Increase in investment - in 2017 we invested an extra £40million increase in repairing broken equipment at wastewater sites. This will directly improve our environmental performance, and reduce the risk of pollution incidents.
  • Our Waste Control Team – we’ve continued to expand the resource available within this department, which includes a new team of environmental data technicians. These experts joined us in 2017, and they’re responsible for monitoring data on the quality of final effluent discharges at our sewage treatment works.
  • Increased sewer network monitoring – we installed approximately 450 new monitors in our wastewater network to reduce the risk of flooding and pollution, as well as to meet new regulatory requirements.
  • Increase in sewage treatment personnel – we’re increasing the number of operational staff in our sewage treatment teams, with new roles being created.
  • Pollution response equipment trials – we’ve conducted trials in one of our regions to see how carrying extra equipment (such as booms and spill kits) can help our pollution response teams to react more quickly to incidents.
  • Customer education programme – we’re continuing to invest in our Bin it – don’t block it marketing campaign, particularly in hot spot areas, to highlight the dangers of flushing anything other than the three P’s – pee, poo and (toilet) paper – down the drains. We invested £1.3 million in this campaign during 2017/18.
  • Community open days - we held an open day at Aylesbury sewage works in July 2017 to show local residents and other stakeholders what we’ve been doing since the past pollution incidents in 2012-14, and meet the people who run the sites.