Thames Water expects its performance around pollution incidents to get worse before improving after incidents rose by almost 20% in the six months to 30 September. The company said regulatory changes to definitions of pollution are likely to increase the overall number of incidents it reports, regardless of any changes it makes to mitigate impact. The environmental figures are contained within Thames’ interim financial results for the six months to 30 September, which show profits have halved while debts rose by £780 million to £14.7 billion.