Research by has found that Cornwall saw the highest number of counted spills from storm overflows during 2022.

Cornwall saw a total of 11,285 spills last year out of the 389,000 discharges of untreated sewage entering rivers in the UK in 2022 .

Storm overflows are designed to prevent sewer flooding by discharging wastewater into rivers which can be detrimental to both the environment and wildlife.

To find which areas are contributing the most to water pollution, Utility Bidder analysed data on the duration and number of counted spills across the UK over the last year.

Storm overflows are praised for helping to protect streets and houses from flooding during heavy rain, but in doing so they pollute the water of rivers.

Below is the top three UK areas which have seen the highest number of counted spills in 2022 with Cornwall at the top with what Utility Bidder says about them.

Falmouth Packet: Number of counted spillsNumber of counted spills (Image: Utility Bidder)

1. Cornwall With 11,285 counted spills during 2022, Cornwall has more recorded storm overflow spills than any other area in the UK. This area is known for its stunning beaches - which are popular tourist hotspots during the warmer months - but Cornwall’s position on this ranking may make people think twice before taking a swim.

2. Carmarthenshire The next local authority on our list is Carmarthenshire which has seen 11,195 counted spills throughout last year. Carmarthenshire is nicknamed the ‘Garden of Wales’ as a result of its agriculture and land, but unfortunately, the pesticides used in farming have been known to contribute to water pollution.

3. County Durham Completing the top three list of UK areas with the most counted spills in 2022 is County Durham - totalling 9,940. This area has had some run-ins with the Environment Agency over the last year, with some water-related incidents resulting in penalties for the parties who have breached regulations.

Utility Bidder used Catchment Based Approach Data Hub to find the number of counted spills and the total duration of spills in each local authority across England and Wales in 2022.

They divided the total duration of spills by the number of counted spills to calculate the average spill duration for each local authority.