Raw sewage has been spewing out for more than 20 days despite no rain for more than a week.
An interactive map produced by Thames Water shows that sewage has been released from Standlake sewage treatment works for 24 days continuously and from Clanfield for 23 days.
Discharges are allowed in exceptional circumstances such as during heavy rainfall to stop effluent backing up into properties.
But dry spills, which take place when excessive rain has stopped, are not permitted under the Environment Agency rules.
A Thames Water spokesperson said: “Our monitors can only tell us when a discharge is occurring, and for how long.
"They do not provide information about the cause of any discharge, nor whether a particular discharge event is compliant with permit conditions for that site."
The water company said it does carry out some analysis of the data from its sites to assess whether a discharge was in line with permit conditions.
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"Where we conclude that a discharge was non-compliant this is reported to the Environment Agency.
“Additional meters which will provide water companies and their regulators with information to better assess the compliance of discharges are currently being rolled out across the industry.
"Separately we are undertaking a comprehensive review of our sites and implementing changes to support long term compliance in relation to storm sewage discharges.”
Public consciousness about the scale of Thames Water’s raw sewage discharges via storm overflows has risen sharply since the company launched its digital map earlier this month identifying discharges as they take place.
The map was a response to pressure from campaigners such as Ash Smith, a water activist from the group Windrush Against Sewage Pollution in West Oxfordshire, and latterly to the Environment Act, which has imposed a new duty on water companies to publish near real-time information on the operation of storm overflows.
Mr Smith said the problem was a long running one and was down to a lack of investment by Thames Water over many years.
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He said: "Water companies will tell you that sewage is dumped to stop it from backing up into homes but the stark reality is that it is really dumped as a consequence of companies failing to spend bill payers' money on infrastructure and instead taking it as dividends (or interest payments) and bonuses.
"Claims that Thames Water shareholders have not taken anything from the company for five years have been shown to be false according to WASP's communications with Ofwat, the economic regulator and this was admitted by Catherine Ross of Thames Water in a You and Your interview featuring WASP a few weeks ago."
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This story was written by Miranda Norris, she joined the team in 2021 and covers news across Oxfordshire as well as news from Witney.
Get in touch with her by emailing: Miranda.Norris@newsquest.co.uk. Or find her on Twitter: @Mirandajnorris
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