Thames Water was sentenced on 26 February 2021 to a fine of £2.3m and ordered to pay costs of almost £90,000. The case is noteworthy both because of the level of the fine imposed and because the Environment Agency (“EA”) uses criminal prosecutions as a means of enforcement relatively rarely.

Between 21 and 24 April 2016, untreated sewage leaked into a stream that led to the River Thames at Henley and the high ammonia content in the sewage caused over 1,100 fish to die. Friday’s sentence followed a guilty plea by the company.

This is Thames Water’s second multi-million pound fine in as many years having been sentenced to a fine of £1.8m in 2019 for a sewage pollution incident in the Cotswolds. This followed the company’s 2017 record breaking fine of £20m, when it was found liable for spilling 1.9bn litres of untreated sewage into the Thames. This was the largest water pollution case brought by the EA since it was established over 20 years ago.

Substantial sentences such as these make headlines, however the EA also uses undertakings – an enforceable promise to do certain things – as an effective means of enforcement. Whilst these undertakings may represent a better outcome for offending water companies than a criminal prosecution, they frequently require significant remedial action and an agreement to make reparations amounting to hundreds of thousands of pounds. For example, a recent EA report shows that £225,000 was paid by Wessex Water and £300,000 by Yorkshire Water as terms of undertakings agreed by them.

In addition to enforcement action, as exemplified in the EA’s October 2020 publication of its environmental performance report on the nine companies who provide clean and waste water services, the EA also uses adverse publicity as a means to highlight and challenge performance that it deems to be poor.

Though fines like those imposed on Thames Water represent the likely outcome in egregious cases, the EA continues to use a range of other tools in its mission to improve environmental standards.