New evidence has been given to the WA Appeals Convenor showing that Texan fracking company Black Mountain Energy’s modelling found proposed fracking wastewater ponds could overflow in above-average rainfall conditions — which are frequently experienced in the area — posing a contamination threat to the Martuwarra Fitzroy River. 

Black Mountain Energy submitted the modelling to the Commonwealth government as part of the federal environmental approval process, but that document was not available to the WA Environmental Protection Authority (EPA) when it recommended approving the project in January. 

The WA EPA’s recommendation to approve the Valhalla project was its most contested decision in history. The Appeals Convenor is currently considering more than 8000 appeals.

Environs Kimberley Executive Director Martin Pritchard said: “An oil and gas wastewater pond has overflowed in the Kimberley before at a well site. We cannot risk this in the catchment of the National Heritage listed Martuwarra Fitzroy River catchment. Potentially radioactive wastewater ladened with heavy metals would be a disaster for the river.

“The 2023 flood in the Kimberley prevented Black Mountain from having heavy vehicle access to well sites. We are extremely concerned that if there was a major problem at a well, the company couldn’t get out there and fix it in a big flood.”

Micklo Corpus, Yawuru man at flooded Buru Energy well pad | Photos - Damian Kelly

Lock the Gate Alliance WA Coordinator Simone van Hattem said: “Lock the Gate has submitted new company documents, not previously considered by the WA EPA, which raise serious questions about whether wastewater ponds can safely contain fracking water full of toxic chemicals.

“Black Mountain Energy’s modelling, which was completed after the state’s environmental watchdog assessed the project, shows that if two wells were fracked in the same year and 70% of fracking water returned to the surface, ponds would overflow in any year with higher-than-average rainfall.”

The modelling only assessed up to a 0.5% AEP (Annual Exceedance Probability) flooding scenario, equivalent to a one in 200 year event, but didn’t model worst-case scenarios, such as what occurred during ex-Tropical Cyclone Ellie in 2023.

“The Kimberley is vulnerable to increasingly frequent extreme rainfall and flooding events. If fracking wastewater ponds overflow, they could release contaminated water into waterways connected to the Martuwarra Fitzroy River. This is far too great a risk for the Traditional Owners and pastoralists that rely on the river for drinking water and for the endangered species that live there,” Ms van Hattem said. 

In its submission to the WA Appeals Convenor, Lock the Gate also submitted data about the quality of fracking water from two wells previously drilled in the area, published by Buru Energy in 2018 and not considered by the WA EPA in its assessment. The data showed extremely high salt concentrations that are toxic to land and aquatic animals, and high levels of the metals boron and barium. 

Ms van Hattem said: “Black Mountain’s own documents show they will use toxic chemicals, including mutagenic chemicals, for fracking. This new evidence demonstrates that the complex and connected waterways, wildlife and culture of the Kimberley will not be safe from contamination by fracking water. 

“The WA Appeals Convenor should walk back the EPA’s decision to approve this reckless project.

“This is the first of many proposals to frack in the Kimberley. If Valhalla is allowed to proceed, it could unleash mass industrialisation of the region. West Australians would be devastated to see the Kimberley sacrificed for the profits of Texan fracking companies.”