A subsidiary of PTT Global Chemical pcl has reached a settlement with three environmental groups to resolve their appeal of the air permit for the company’s proposed multi-billion dollar ethane cracker in southeast Ohio.

PTTGC America LLC has agreed to strengthen environmental protection measures and public transparency for the project in a settlement signed with Earthworks, the FreshWater Accountability Project and the Sierra Club. Under the deal, PTTGC has agreed to meet requirements not mandated by the state if the facility is ultimately built. No final investment decision has been made.

The company would incorporate optical gas imaging in addition to traditional monitoring in order to enhance its leak detection and repair program. It would also conduct an annual audit of that program and provide the number of confirmed leaks detected and how quickly they were repaired. That information, along with other data, would be published on a special website where the public can access it.

Other stipulations call for an on-site meteorological monitoring station to be installed so the company can more closely track wind speed, wind direction, temperature, humidity and pressure.

The company would also be required to conduct regular flare testing and continuously monitor equipment to ensure it is destroying emitted pollutants. PTTGC would also perform a second set of stack testing on all the facility’s cracking furnaces and boilers within two years of an initial test.

The environmental groups filed their appeal of the air permit, considered a crucial part of the regulatory process, after the Ohio Environmental Protection Agency (OEPA) issued it in December 2018. They argued that OEPA grossly underestimated the amount of pollution to be emitted from the plant and claimed the agency should have required more effective technologies to reduce pollutants.

While they welcomed the settlement, the groups said they plan to continue fighting against the cracker, calling the deal with PTTGC “the best available compromise” for the time being.

“This agreement will help protect local communities from dangerous air pollution should this facility be built, and we’ll continue to fight to ensure that it never comes to that,” said Sierra Club Organizer Cherly Johncox.

The settlement is similar to another signed in 2017 by an affiliate of Royal Dutch Shell plc with the Clean Air Council and the Environmental Integrity Project for a massive ethane cracker under construction in western Pennsylvania. Shell’s facility is designed to consume more than 100,000 b/d of ethane to produce ethylene and polyethylene, both key building blocks for plastics.

The Ohio facility, which would be located in Belmont County along the Ohio River, would be similarly sized. PTTGC and Daelim Industrial Co. continue to explore the feasibility of the project, which has already cleared major regulatory hurdles. PTTGC has also purchased all of the nearly 500 acres it needs to build the plant and selected Bechtel as its engineering, procurement and construction contractor.