ST. JOHN'S, N.L. -- The $12.7-billion Muskrat Falls hydroelectric dam in Labrador is finally nearing completion, billions of dollars over budget and years behind schedule.

But as the public is offered a final say at inquiry hearings Tuesday night in St. John's and Aug. 8 in Happy Valley-Goose Bay, the province is still answering for a missed deadline on work intended to lessen the impact of methylmercury pollution on crucial food sources for downstream communities.

The Newfoundland and Labrador government's slow response to concerns over methylmercury is the latest in a string of disappointments for those who have been calling for action on the issue for years.

"It's not only a slap in the face, it makes you feel unwelcome in your own home," Roberta Benefiel said of the missed deadline from Happy Valley-Goose Bay last week.

Benefiel has represented the group Grand Riverkeeper Labrador at a provincial inquiry into the dam's cost and schedule overruns. She's one of many Labradorians who resent that the massive hydro dam on the Lower Churchill River, planned by political leaders hundreds of kilometres away, could restrict residents' access to food.

Methylmercury forms as vegetation rots underwater. Research has indicated that flooding the uncleared reservoir near the dam, scheduled to be complete by the fall, could cause an increase in levels of methylmercury in wild food sources used by local Indigenous communities.

After revealing in June that his government had missed a deadline for "capping" to mitigate the effects of methylmercury after flooding, Liberal Premier Dwight Ball announced on July 23 that the $30 million set aside for the work would instead be paid out to three Indigenous governments in Labrador to improve "social and health benefits."

Capping involves covering vegetation and soil with a thick layer of material such as sandy clay to prevent the release of carbon that could contribute to a spike in methylmercury levels.

Innu Nation and the NunatuKavut Community Council, representing about 6,000 southern Inuit in Labrador, recently signed deals with Nalcor Energy, the Crown corporation overseeing the project, to receive $10 million each.

But the Nunatsiavut Government, which represents five Labrador Inuit communities, has not accepted the $10-million offer, maintaining through a spokesperson Monday that "compensation is not a form of mitigation."

Nunatsiavut's firm stance was articulated in a July 22 release from its president, Johannes Lampe, calling on Premier Ball "in the spirit of reconciliation" to halt the flooding or impoundment, currently scheduled to begin Aug. 7, until the issue has been addressed.

"We are extremely disappointed with how the premier has handled the whole Muskrat Falls fiasco," Lampe's statement read. "He has repeatedly betrayed our trust by refusing to address our concerns, opting instead to place the health, culture and way of life of Labrador Inuit at risk."

However, Innu Nation Grand Chief Gregory Rich questioned Nunatsiavut's research.

"Innu Nation has closely examined all the science, including Nunatsiavut Government's own studies," Rich said in a statement. "They have been found lacking and other scientists have proven them wrong -- it's time to accept that."

The NunatuKavut Community Council, which in 2016 had echoed Nunatsiavut's concerns about the methylmercury risk, last week posted a special update on its website along with the text of a July 17 agreement signed with Nalcor executives.

"While this agreement was unexpected, NCC will ensure that the funds are used in a tangible way to address the needs and priorities of our people and communities," the update read.

Long-held fears over methylmercury contamination from Muskrat Falls have sparked protests and more than a dozen arrests. As tensions mounted at the dam site in October 2016, a meeting between Ball and Indigenous leaders ended with the establishment of an independent expert advisory committee to monitor the project.

In April 2018, all four voting members of that committee recommended that Nalcor cap the wetlands before impoundment.

But despite the premier's declared intentions to follow through on capping, it never happened. The public learned during the Muskrat Falls inquiry last month that experts had informed the government last winter that carrying out the work would further delay the project.

Nalcor now says impoundment will begin on Aug. 7, with a target of raising water levels to 39 metres from the current 24.5 metres by the end of September.

Ball, who is also minister for intergovernmental and Indigenous affairs, has maintained that while he wanted the capping done, the process would have had little impact on methylmercury levels. He has also cited regular surveys of water and sediment that indicate methylmercury levels remain safe after the flooding that has happened so far.

Progressive Conservative member Lela Evans of Labrador has criticized Ball for breaking her constituents' trust and putting their food at risk of poisoning.

"A government is supposed to protect its people, its lands and its wildlife," Evans said in the House of Assembly on July 23. "Due to the incompetence of this Liberal government, all three are now at risk."

In response, Minister of Environment Lisa Dempster addressed the "extreme messaging" around methylmercury. Dempster said in the House of Assembly that the idea people will be poisoned is "absolutely false."

Dempster said monitoring of methylmercury levels will continue, suggesting food advisories might be issued if levels become too high.

Ryan Calder, a scholar of human health and resource development at Duke University, co-authored the 2016 Harvard University study that focused attention on the issue of methylmercury at Muskrat Falls.

Calder said in an e-mail to The Canadian Press that the effects of consuming methylmercury, such as hyperactivity and neuro-developmental impairment in children and cardiovascular health risks in adults, are highly individualized, and some people will be more sensitive than others.

A 2018 follow-up study Calder co-authored concluded that reducing consumption of traditional foods rich in nutrients and vitamins could increase other health risks, including cardiovascular mortality. That means there is a "risks tradeoff" if food advisories steer people away from traditional foods like trout and seal because of the methylmercury risk.

"People's responses to these advisories are very unpredictable," he said. "Even focused advisories have resulted in overall reduction of fish consumption."

Benefiel, for her part, questions why the promoters of a project that has seen one delay after another could not budge on the deadline for wetland capping.

"Have you ever seen them meet a hard deadline yet?" she asked.

She said the capping work would have shown Labradorians their health is worth a little extra time.

"If you at least do the capping and take some of the soil out, that means people in Rigolet and people downstream will rest easier," Benefiel said.

"It might repair some of the feelings that people have about these people who run our province."