https://www.gov.wales/sites/default/files/publications/2023-10/water-resources-control-agricultural-pollution-wales-regulations-2021-guidance-farmers-and-land.pdf
https://www.llyw.cymru/sites/default/files/publications/2023-10/rheoliadau-adnoddau-dwr-rheoli-llygredd-amaethyddol-cymru-2021-canllawiau-ar-gyfer-ffermwyr.pdf