Welsh Water has admitted illegally spilling untreated sewage at dozens of treatment plants for years.One of their worst performing plants is in Cardigan in west Wales.
During heavy rain, to prevent a plant becoming overwhelmed, it is allowed to discharge untreated sewage. But releasing any before a plant reaches the overflow level stipulated on its permit is an illegal breach. Environmental groups say testing at Poppit Sands only takes place from May to September and there is no regular monitoring of the impact of sewage discharges in the River Teifi. It is designated as a Special Area of Conservation and is home to lamprey, Atlantic salmon and otters. The Teifi flows into Cardigan Bay, home to one of Europe's largest populations of bottlenose dolphins.
Cardigan's problems date back to 2004 when Welsh Water installed a wastewater treatment system which filters sewage through a membrane. That is not how most sewage plants work.