WEST LONDON residents were this week threatening to sue Thames Water for compensation for suffering caused by foul smells from its sewage treatment works (STW) in Mogden.
In a letter to Thames Water sent this week, residents threatened to sue the company unless it improves the situation in the next three months.
Mogden is London's third biggest sewage treatment works and serves a population of 1.7M.
Lawyers have told the Mogden Residents Action Group that 'odour nuisance' represents an infringement of human rights, and has hit local house prices.
Mogden resident Simon Fullalove said that residents were becoming increasingly angry because the smell - similar to rotten eggs - has worsened over the past few years.
The situation culminated in six weeks of strong smells combined with intense odour and a plague of mosquitoes in 2001, said Fullalove. 'It was a miserable summer last year, ' he said.
'People couldn't have barbecues and had to shut themselves in.'
The resulting complaints prompted Hounslow Borough Council to slap two abatement orders on Thames Water last July, under the Environmental Protection Act 1990. The notices ordered Thames to get rid of the smell and the mosquitoes respectively. The water company is contesting both notices.
Fullalove claimed that the problem is largely linked to hydrogen sulphide emissions from sewage sitting in stormwater tanks for long periods, awaiting treatment.
He said that this is because the plant - designed to take 810Ml/day combined sewage and stormwater - is unable to cope with high levels of stormwater, leading to the backlog.
Thames Water confirmed this week that the stormwater tanks were the source of the smell. It said they had been used more often in recent years because of higher rainfall.
'Last year, we had four times the amount of rainfall that we would usually expect, which left the groundwater levels very high, ' said a Thames Water spokesman. This was not an undercapacity issue he added, but a temporary problem.
He said that in the short term, the company was ensuring the sewage in the tanks remained fresh, but Modgen STW managers were expected to ask their bosses at Thames to fund a longer term solution.
This could include changing the sewage control system to a cascade system, so that an empty tank will only start to fill when another is at capacity. This will help reduce the total surface area of the sewage.