Heavy rainfall can cause a decline in water quality due to an increase in run off from the surrounding areas into the River Dee which flows into the estuary.
At this site the Environment Agency makes a daily pollution risk forecast and issues a pollution risk warning when a reduction in bathing water quality is likely. Warnings are posted on the site's bathing water profile.
Pollution risk forecasts are based on the effects of tide, wind and seasonality. These factors affect the levels of bacteria that get washed into the sea from livestock, sewage and urban drainage via rivers and streams and how they disperse.
After a pollution risk warning, levels of bacteria usually return to normal after a day or so, but it's possible to have several warning days in a row. No warnings were issued last season as this site is new to PRF.