Southern Water was fined a record £90m on Friday for deliberately dumping billions of litres of raw sewage into the sea.
The company admitted 6,971 illegal spills from 17 sites in Hampshire, Kent and West Sussex between 2010 and 2015.
A judge said the offences had been “committed deliberately” by Southern Water’s board of directors at the time.
The Environment Agency launched its largest ever criminal probe after shellfish were found to be contaminated with E. coli.
Raw sewage had been secretly diverted away from treatment works in the South East and into the sea and rivers.
What do you think of the punishment? Have your say in the comment section
It meant Southern Water could avoid large financial penalties and the costs of upkeep and upgrades.
During heavy rain water companies are allowed to discharge sewage into the environment to prevent sewers backing up.
But the Environment Agency discovered sewage left Southern Water sites through this route during periods of lower rainfall.
Mr Justice Johnson said the firm “showed a shocking and wholesale disregard for the environment”.
Follow all the latest news by signing up to one of the Mirror's newsletters
The total volume of untreated sewage was between 16 to 21 billion litres, or 7,400 Olympic-sized swimming pools.
Anglers found sanitary towels, condoms and tissues in the water in one small creek in Hampshire.
It is the largest sentence ever issued by a court after an Environment Agency investigation.
Environment Minister Rebecca Pow described the case as “shocking and wholly unacceptable”.
She added: “Water companies should not be letting this happen and those that do will be punished by the full force of the law.”
