The capital's sewers were built 150 years ago and are in perfect working condition but they're struggling to cope with a population twice the size as the one they were built for.
Up to 50 tons of untreated sewage can be pumped straight into the Thames every second. Now Thames Water want to build a tunnel for the sewage which will see around £70 put on every customer's bill.
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It is the fourth time in five years that the London borough has topped the rankings, according to data from the ONS.
Catherine Burke's body was discovered at a house in a quiet street in Muswell Hill last Thursday evening.
Residents said living next to the 40 foot high stinking mound was a 'living nightmare'.