Wales is the most under-represented country in the UK – the Senedd has the least Members of any devolved Parliament in the country, and our UK Parliamentary seats are being reduced.
Olew yw un o’r prif gyfryngau llygru dŵr yng Nghymru ac yn aml daw’r llygredd o olew sy’n gollwng o gyfleusterau storio annigonol.