Yorkshire Water has been urged to take action over raw sewage spotted in the River Foss near York.
The waste was seen by city councillor Tony Fisher across the August bank holiday weekend at Strensall.
Mr Fisher said he had previously seen condoms, toilet paper and sanitary products in the river, just seven miles from York city centre.
Yorkshire Water said the waste was the result of a storm overflow preventing sewage entering people's homes.
Councillor Fisher, who represents the Strensall ward on City of York Council (CYC), said he had seen the "disgusting" sewage following a period of heavy rain.
"We now need to see urgent action from Yorkshire Water to make sure incidents like this do not happen again," he said.
Councillor Paul Healey, who also represents the Strensall ward on the council, added: "During the periods of heavy rain we saw over the bank holiday weekend we saw that the Victorian combined sewage system couldn't cope with the excess surface water that entered the system and raw sewage pumped out.
"This type of raw sewage discharge is a real danger to the health of not only residents, but also the wildlife and fish that can be seen in the Foss.
"Yorkshire Water continues to ignore calls to improve the sewage network despite recording record profits last year."
A Yorkshire Water spokesperson said: "During periods of heavy rainfall, such as those experienced in Strensall over the bank holiday weekend, when treatment works and pumping stations are working at full capacity, storm overflows act as a relief valve.
"They prevent waste water backing up in the network and causing sewage escapes in people's homes, businesses and gardens.
"These are permitted by the Environment Agency, however, we know there is more to do to reduce overflows into Yorkshire's rivers."
According to the Local Democracy Reporting Service the spokesperson said tackling storm overflows was a "priority" for the utility company, which they said was working on its "largest ever environmental investment as part of our 2025-2030 business plan".
A 2022 House of Commons Committee report on the state of UK rivers showed no rivers in England were free from chemical contamination, with only 14% of UK rivers rated as having good ecological status.