I can't remember how long ago it was - maybe 30 years or more - that Southern Water became a by-word amongst local naturalists for "polluters", putting a new spin on the word "scum".
A friend who lives near Thorney Island has challenged them regularly about sewage discharge and they appear as slippery and unpalatable as the stuff they describe as acceptable discharge. They wear you down with the intricacies of law (which is about the only thing they're any good at!) and, if that doesn't work, decide that where you live is ripe for sale to developers.
There's very little that seems to touch them. Court warnings and fines are tossed away with an arrogant "shareholders' will pay" whilst the people at the top seem to be untouched (including by those very shareholders). Without any doubt in my mind, they're run by unprincipled rapers of our natural environment who care for nothing except how to dodge around the flimsy regulations which hold little threat for them.
Until senior managers are sent to prison or have their enormously wealthy lifestyles curtailed financially, there is little likelihood of change.
Peter