Mae rhaglen sy’n cael ei harwain gan Lywodraeth Cymru i brofi dŵr gwastraff ar gyfer COVID-19 wedi’i hehangu yng Nghymru i gynnwys pob bwrdd iechyd a phob awdurdod lleol ar draws 48 safle.
A Welsh Government-led programme to test wastewater for COVID-19 has been expanded to cover all Welsh health boards and local authorities across 48 sites.