ONCE, TV’s watershed was that evening horizon before which material unsuitable for young and tender souls was forbidden. Judging by Panorama: The water-pollution cover-up (BBC1, Monday of last week), we need some such rule to exclude programmes that should on no account be watched before supper: its images were so disgusting as to induce not only the moral outrage expected from hard-hitting journalistic exposés, but physical nausea, removing all appetite for the evening meal.

This programme lifted the lid on a social ill that is more and more apparent: the frequency and volume of water companies’ discharges of raw sewage into seas and rivers. Such documentaries usually seek to create a metaphorical stink; this topic required no such subtlety, as the literal stink is already here, and pollution is only too apparent all around us.

Sewage-treatment facilities are permitted by their licences to discharge untreated sewage when “exceptional weather” creates a volume of waste water so great that a plant’s capacity is overwhelmed; “exceptional weather”, however, is nowhere defined. Every twist of the story revealed that the companies set their own rules, and that the Environment Agency, which is supposed to regulate them, is shamefully inadequate and toothless (it said in response to the programme: “We are strengthening our regulation by expanding our specialised workforce, increasing compliance checks and using new data and intelligence tools to inform our work”). Whistle-blowers from both companies and Agency testified how inspections and test results were massaged to give the best possible results — on which the companies were rewarded from the public purse.

One company made a profit of £440 million. Shareholders were the main beneficiaries of what used to be public utilities.

Was this merely another example of the BBC’s Lefty, anti-capitalist bias? The local tweed-clad citizens protesting against a Lake District beck’s pollution, or the 425,000 hours of sewage forcing the closure of Blackpool beach, hardly match that caricature. In this pantomime season, it is as though a wicked fairy had cast a spell over our once beautiful and fruitful land: our seas and rivers are poisoned at our own expense, vastly enriching the few.

Supernatural forces abound in the new US drama series Mayfair Witches (BBC2, from 6 December). Rowan Fielding is a brilliant, gorgeous neurosurgeon, but with a power fortunately rare in doctors of medicine: by concentrating hard enough, she can cause fatal aneurisms in the brains of really horrid people. Where did this power come from? Bit by bit, she will discover that she is heir to a dynasty of witches. The scene-setting is impressively weird and crepuscular; but the story is incoherent, and its spell wears off very quickly indeed.

Presenting herself as a witch — pointy hat, black cloak, bright green face — is Deb’s affectation. Along with her sister, Josie, and their mother, Deb, she makes up the outrageous comedy Such Brave Girls (BBC3, from 22 November). This shameless depiction of desperate, needy, and insecure women (the cast wrote it themselves) breaks every decent taboo. For very strong stomachs, it is excruciatingly funny.