Raw sewage is flowing in from thousands of sites, posing a major potential threat.
A report has found that many rivers in England and Scotland are being impacted, according to The Guardian.
Both wildlife and human life as being put at risk as a result.
A report compiled by WFF, a conversation group unveiled the details.
Their findings suggest that more than half of overflow sites spill sewage into rivers at least once a month and 14% at least once a week, The Guardian reported.
WWF have stated that this is far more frequently than allowed under regulations that permit overflows only at times of unusually heavy periods of precipitation, when treatment work cannot deal with the flow.
The report also found that 40% of the rivers in England and Wales are polluted with sewage.
The number of reported sewage pollution incidents which are inclusive of failures at sewage treatment plans increased in 2016, for the first time in four years.
14% of rivers in England have been granted a “good” ecological status.
It is believed this this figure reflects both sewage and farm pollution and low water levels.
This very same figure sat at 27% in 2010.
WWF belief that the issue is going to deteriorate further if there is no any immediate action undertaken.
The total quantity of sewage entering into rivers on an international level is unknown.