BHP reported two positive cases this week among rail maintenance workers, sending up to 80 workers into isolation.

BHP Western Australian Iron Ore asset president Brandon Craig confirmed that all of the on-site contacts of the two positive cases at Spinifex Village had returned negative PCR test results.

"There is one outstanding result from a casual contact who has been isolating at home. Their sample has been tested by an external provider who is yet to provide a result," he said.

While 18 close contacts have returned negative results, they are required to serve out the full 14-day isolation period.

"The health and wellbeing of our people is of utmost importance to us and throughout the pandemic, we have had strong controls in place to support our people and the community, while maintaining safe operations," Craig said.

"The highest level of care and support is being provided to our people in isolation, with regular health and welfare checks, and the delivery of all meals, snacks and a range of wellbeing measures including online exercise classes."

Craig said that with active community transmission in WA, further escalation of cases across the mining sector was inevitable.

"Our current controls have been quickly and efficiently implemented to manage the confirmed cases and are continuously reassessed and escalated as required," he said.

"This is vital to maintain our way of working and has allowed BHP to continue business as usual operations here in Western Australia."

Meanwhile, all close contacts of an underground contractor who tested positive to COVID-19 at 29Metals' Golden Grove mine have tested negative and there had been no impact on copper-zinc production.

"There are currently 24 workers in isolation on site, comprising a small number of deemed close contacts of one confirmed case, with the balance being workers identified as attending exposure sites before mobilising to site," the company said.

"Under WA Health requirements, these persons are required to isolate on site for 14 days." 

There have been growing calls for the WA government to adopt new isolation rules amid the closure of three schools just three days into the new term.

On Friday, the WA government announced updated isolation requirements for when the state reaches a "high caseload environment" but did not specify what the trigger would be.

Close contacts will be redefined as a household member or intimate partner of a COVID-19 case or someone who had more than 15 minutes of maskless contact with a positive case or spent more than two hours in a small room.

The isolation period will be cut from 14 days to seven days.

"CME and its member companies would welcome any opportunity to introduce the isolation and close contact protocols announced last week by the WA government sooner rather than later," Chamber of Minerals and Energy of WA chief executive Paul Everingham said.

"As evidenced by current COVID-19 cases on WA mine sites, those protocols will allow operators to respond to positive cases in a way that prioritises the health and safety of our workforce while also providing for continuity of operations."