| Haven Garreg Wen Caravan Park | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Heatherdale Holidays (Clarach Bay) Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Install Waste Management Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Interserve Construction Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| J G Hale Construction Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| J H Jones Woodcraft Fencing Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| J W C George & Sons | | | Environmental Violation | 2021 | UK-NRW | £0 |
| JEHU Project Services Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Jolada Hydraroll Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Jonsel Management Black Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Kier Integrated Services Limited | Kier Group PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Knightmovers Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| L J Cook & Sons Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lanes Group Plc | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Leekes Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lelo Metal Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lelo Metal Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| LEM Sporting Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lewis Homes (South Wales) Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lewis Homes (South Wales) Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Llaethdy Plasbach Dairy LTD | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Llanmoor Development Co Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Llanmoor Development Co Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lordan UK | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Lovell Partnerships Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| M D Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| M&M Greene Haulage Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Maes Gwyrdd Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Magnox Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| McCarthy Contractors (Bridgend) Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| McCarthy Contractors (Bridgend) Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Mitie Technical Facilities Management | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Mixit Concrete Services Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Morganstone Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Morrison Water Services Limited | PAI Partners | private equity (including portfolio companies) | Environmental Violation | 2021 | UK-NRW | £0 |
| Morrison Water Services Limited | PAI Partners | private equity (including portfolio companies) | Environmental Violation | 2021 | UK-NRW | £0 |
| N Meakin Contracts Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| NBA Developments Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Newbridge Energy Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Newbridge Energy Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Newbridge Energy Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Newport Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Ni Tri Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Noel Fitzpatrick Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| North Wales Roofing Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Novidon Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| NRW - Mid Wales - Powysland IDD [Redacted] | | | Environmental Violation | 2021 | UK-NRW | £0 |
| P.A.R. HOMES LIMITED | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Panteg Farms Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Perdez Pas Cyf | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Limited | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Limited | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Ltd | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Ltd | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Ltd | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Persimmon Homes Ltd | Persimmon PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Peter Harding & Co ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| PHS ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Pilkington Asbestos Removal Services Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Pryor & Rickett Silviculture Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| PSM Recycling & Hiab Services Ltd. | | | Environmental Violation | 2021 | UK-NRW | £0 |
| R and J Metals Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| RDA Recycling Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| RDA Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| RDS International Refrigeration Disposal Services | | | Environmental Violation | 2021 | UK-NRW | £0 |
| RE Evans Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Reactive Integrated Services Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Recyclan Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Redrow Plc | Redrow PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Redwood Environmental Services Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Rees Building Solutions ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Rees Metals | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Reliance Service Solutions Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Resource Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| SCS (Southwest) Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| SL Recycling Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Slicker Recycling Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Snowdonia National Park Authority | | | Environmental Violation | 2021 | UK-NRW | £0 |
| St Modwen Developments Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Star Pubs & Bars Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Sundorne Products (Llanidloes) Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Sundorne Products (Llanidloes) Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| T D Tyre Recycling Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| T M Wiberg Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Taylor Wimpey PLC | Taylor Wimpey PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| Taylor Wimpey PLC | Taylor Wimpey PLC | construction and engineering | Environmental Violation | 2021 | UK-NRW | £0 |
| The Eurogroup / Europest Environmental Services | | | Environmental Violation | 2021 | UK-NRW | £0 |
| The National Trust | National Trust | miscellaneous services | Environmental Violation | 2021 | UK-NRW | £0 |
| The Pontypridd Golf Club House Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| The Rising Sun (Haverfordwest) LTD | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Thermal Earth Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Thorncliffe Building Supplies Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Ticklock Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Tower Regeneration Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Town & Country Hotels Limited | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Travelodge Hotels Limited | Travelodge Hotels Limited | hotels | Environmental Violation | 2021 | UK-NRW | £0 |
| United World College of The Atlantic | | | Environmental Violation | 2021 | UK-NRW | £0 |
| UPM – Kymmene (UK) Ltd | UPM | paper and packaging | Environmental Violation | 2021 | UK-NRW | £0 |
| V J Thomas & Son Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
| Valero Energy Ltd | Valero Energy | oil and gas | Environmental Violation | 2021 | UK-NRW | £0 |
| VG Recycling Group Ltd | | | Environmental Violation | 2021 | UK-NRW | £0 |
