Boat Harbour: How to clean up a toxic soup

Fifty-two years of toxic sludge — enough to fill 400 Olympic-sized swimming pools to the brim. That’s the cleanup job now in the late planning stages for Boat Harbour.

Boat Harbour is an expanse of stanky brown holding ponds or “lagoons” at an effluent treatment facility located next-door to the Pictou Landing First Nation. “Nova Scotia’s worst example of environmental racism,” to quote former Environment Minister Iain Rankin.

An open house was held at the Pictou Landing Fire hall yesterday, hosted by Nova Scotia Lands. That’s the provincially owned crown corporation that inherited the mess shortly after June 2014, when a pipe owned by Northern Pulp broke and sparked a week-long blockade of the mill by First Nation people and white protesters.

“We’re not going to take it anymore” was the clear message and in May 2015 the McNeil government stepped up to pass legislation decreeing the Boat Harbour facility owned by the province must close down by January 31, 2020.

Amazingly and to Nova Scotians’ chagrin, the Boat Harbour facility has been used and operated since 1967 by a series of mill owners such as Scott Paper, Kimberly Clark, Neenah Paper, and Northern Pulp. These companies were not required by successive governments to pay for cleaning up the pollution their profitable pulp-making left behind.

The current mill owners, Northern Pulp, have asked for a one-year extension of the deadline to close Boat Harbour while they work to comply with guidelines issued by the Nova Scotia Department of Environment. The company has a controversial plan to build a new treatment plant that would pipe hot, treated wastewater into the Northumberland Strait near lucrative lobster grounds.

An employee of Northern Pulp emailed to say “no update is available at this time ” when asked by the Halifax Examiner if the mill will close if the government does not extend the deadline.

But regardless of whether the government grants an extension or not (so far it has not budged), provincial taxpayers are on the hook to clean up the environmental mess which has been blamed for serious health problems among people at Pictou Landing. That work is underway and will proceed.

Here’s what I learned from attending yesterday’s busy open house and from Ken Swain, the project manager for the Boat Harbour cleanup. Swain was also the manager who shepherded the Sydney Tar Ponds:

Cleanup goals: the objective is to clean up a toxic soup of carcinogenic dioxins and furans, cyanide, and metals such as mercury, chromium, and zinc left behind by decades of chemical pulping to make the estuary “safe for human and ecological health.” Christine Skirth, a vice-president with the GHD engineering firm hired by NS Lands, says this means the estuary, known as A’Se’k by the Mi’kmaq, would again be a place where people and animals could swim, although the water will not be fit for drinking.

How long will the cleanup take? It could be 10 years from now before it is completed. Although NS Lands has finished a pilot project on a small amount (14,000 cubic meters) of the total one million cubic meters of contaminated sediments that will be dredged up and remediated, Swain estimates it will be late 2021 before that cleanup can actually begin. Once it gets started — with the building of a new water treatment plant and the expansion of the containment cell (similar to a modern landfill where waste is buried four meters underground before piling above ground) — Swain estimates it will take four to seven years to complete the cleanup. After dealing with the sediments, a new bridge and dam will be built to allow the treated wastewater to flow back into the estuary.

Under federal guidelines, the amount of mercury, dioxins, and furans found in the sediments dumped at Boat Harbour qualify as “hazardous wastes.” The risks posed to human health and the environment (including to wetlands, birds, and fish) by digging up and storing this waste in a facility that will be  more than 50% larger than the current containment cell is what triggered a federal review of the cleanup project by the Canadian Environmental Assessment Agency.

That review process got out of the blocks in April, effectively killing a planned Environmental Assessment process the province had proposed that would have taken much less time. NS Lands is the proponent for the cleanup job; Swain estimates it will be the beginning of 2020 before his agency and GHD, the multinational engineering company hired by NS Lands to do the work, will be able to complete the dozens of studies required by the federal regulator. Then it will take many months before the CEAA can approve (or reject) the remediation plan for Boat Harbour.

Ottawa, by the way, has pledged $100 million to help with the cost which is currently booked by the province as a $230-million liability, a number that “carries a high degree of uncertainty,” according to the notes in this year’s audited financial statements. That’s because the planning and design remains a work-in-progress until the CEAA tells the province what if any changes will be required.

Proposed Solution: NS Lands and GHD have spent many months discussing with representatives of the Pictou Landing First Nation a “proposed solution” to clean up the mess. In short, depending on where the sediments are hauled from and after much of the water has been removed, the volume of sediment left behind to be “contained” or landfilled is predicted to be 30-50% of the original million cubic meters. That’s still a lot of crap. First, though, the sediments have to be removed or dredged from the holding ponds.

“The biggest technical challenge is getting the layer of sludge, which is on average 25-30 centimeters thick,” said Swain. “Underneath that layer of sludge, there is a clay harbour bottom and the sludge hasn’t impacted that clean bottom. There is a very distinct cut line between contamination and clean. Our biggest problem is getting all of that contaminated material dredged off the bottom and taking as little as possible of the harbour bottom so we don’t add to the volume.  We will use a suction dredge mounted on a barge. The dredge will suck that contaminated sludge off the bottom through a pipeline, using appropriate pumping.”

The sludge is about 90% water. Once sucked and piped to the surface, the sediment will be placed inside giant baggies made of treated fabric called “geotubes.” The de-watering process to squeeze out more water will take place inside the porous geotubes and the compacted solids left inside the bags, as well as the bags themselves, will be deposited in the existing containment cell on Boat Harbour property.

“Containment cell” is a fancy term for what is essentially a modern landfill. It currently holds about 225,000 cubic meters of effluent. The plan is to place an additional lining inside to prevent leaks and to expand the cell upwards by about two or three storeys above ground to hold the additional volume of  dredged sludge.

Swain said the completed pilot testing showed that although the water that comes out of the geotubes is clear, it still contains contaminants. A new water treatment plant will be built to do further cleaning before it is eventually released into the tidal estuary. Contaminated wastewater could pose a risk if it leaches into the ground so there is also a plan to truck away an indeterminate amount to an industrial wastewater facility elsewhere in the province.

NS Lands plans to hold a briefing this fall for potential equipment and service providers who might want to bid on part of this massive cleanup project if and when it gets the green light from Ottawa next year. Meanwhile, the public is invited to provide feedback to NS Lands at www.novascotia.com/boatharbour.