AGL Energy and Origin Energy will have to come clean on pollution levels from their coal-fired power stations in NSW under new requirements by the Environment Protection Authority that lay the groundwork for the potential introduction of hard limits on greenhouse gas emissions.

EnergyAustralia and privately owned Delta Electricity will also have to comply at their respective plants with the new operating conditions, which arrive as NSW is required to cut CO₂ emissions by 50 per cent by 2030 and 70 per cent by 2035.