Standing in Bryngarw Country Park near Bridgend you are in a wildlife haven. With meadows, mature woodland and gardens it feels like a privilege just to stand there and take it in. One of the most lovely parts is the river Garw where you will see dippers and kingfishers diving for their supper.
You would never know that just two miles up river, on 325 out the 365 days in a year, everything households flush into their toilets and tip down their sinks is allowed to flow untreated for thousands of hours a year into this idyllic waterway. That is because two of Wales' most overused combined sewer overflows are less than a park run away upstream of this popular spot for walkers and families.
These outlets are among hundreds around Wales that are a regrettable legacy of the UK's largely Victorian sewer network. When the system can't cope because of high rainfall or other reasons, the excess simply tips out into waterways, rivers and seas around Wales through the overflows.
