The new powers would allow the Environment Protection Agency to punish polluters where there was a potential or threat of harm to the environment.

That would strengthen the existing arrangements, which only allowed for penalties to be meted out after pollution had occurred.

The changes would allow the EPA to issue on-the-spot fines, and take potential polluters to court to face penalties of up to $30,000 for an individual, or $150,000 for a corporation.

Environment Minister Simon Corbell said the changes to the Environmental Protection Act would strengthen the ACT's regulatory system to help prevent the discharge of pollutants into the air, land and water.

The new powers were informed by a review of existing laws, extensive consultation, and an analysis of other state and territory environmental protection regimes.

They also come after revelations about the pollution of groundwater at a block of land in Hume by Koppers Wood Products, which operated a timber processing plant at the site from the late 1980s to the early 2000s.

That pollution left groundwater contaminated with hexavalent chromium, a potentially carcinogenic toxin.

Tests have since found the pollution was contained to groundwater beneath the former plant, and Koppers was cleared of paying the hefty clean-up bill by the ACT Supreme Court after the multinational sold the block to a local company.

Greens MLA Shane Rattenbury said the new powers appeared to address problems raised in that case.

"I am pleased that the EPA bill addresses many issues that were identified through the investigation of the Koppers Log contamination issues," he said.

"However, I will be examining the bill more closely over the next few weeks to evaluate whether it sufficiently covers off the many issues raised in the EPA review."

Mr Corbell said the reforms were necessary to ensure the Environmental Protection Act stayed current and took into account technological advancements and current industry practice.

"Protecting our local environment is a challenging task and the legislation will provide the EPA with increased ability to take action against polluters," Mr Corbell said in s statement

"This approach will bring the ACT in line with contemporary environment protection legislation throughout Australia, particularly NSW within which the ACT is a key regional partner."

The reforms were introduced on Thursday morning. They are likely to be debated next month.

Opposition environment spokeswoman Nicole Lawder said the Canberra Liberals would review the details of the bill but early indications showed some measures were appropriate.

"The introduction of strict liability clauses could be appropriate," she said.

"I welcome the removal of government immunity; the government shouldn't be treated differently to other landholders or leaseholders. I think every member of the ACT public would agree with that."