Before 1967 Boat Harbour was a tidal estuary. The estuary covered about 142 hectares (350 acres) with a narrow entrance that connected it to the Northumberland Strait just east of the Pictou Landing First Nation community.
Boat Harbour was used by people for refuge, recreation, for food and fishing. Pictou Landing First Nation also gathered ceremonial and medicinal plants. Boat Harbour was a salt water habitat similar to other harbours or estuaries along the Northumberland Strait.
1967 to early 1970s
In 1967 Boat Harbour started receiving industry wastewater - the technical name is "effluent" – from the pulp mill at Abercrombie Point, as well as Canso Chemicals. The wastewater was sent through a pipe, under the East River, across land to Boat Harbour. In the first few years, there was no wastewater treatment and Boat Harbour remained a tidal estuary. In 1972, a dam was built at the narrowest point of Boat Harbour. The dam prevents seawater from flowing into Boat Harbour. It lets water flow out into the Northumberland Strait when needed. The dam also keeps the water level in Boat Harbour artificially high. The dam has changed Boat Harbour from a saltwater estuary to a freshwater lake.
Boat Harbour received wastewater - the technical name is "effluent" - from the pulp mill at Abercrombie Point, as well as Canso Chemicals. The wastewater was sent through a pipe from industry, under the East River, across land to Boat Harbour.
Early 1970s to the present
The Boat Harbour Effluent Treatment Facility was built in the early 1970s along with the dam structure, and remains in operation today. Over the years, the facility has undergone modifications and improvements. This is how the treatment plant works:
Wastewater flows from the pipeline into two ponds, each about the size of a football field, where solids fall to the bottom or float. They are then collected and moved to a landfill site at the pulp mill.
Once the solids are removed, the wastewater flows to the aeration stabilization basin, which is about the size of six combined football fields. The water stays there for about five days. In that time it is mixed with air. The air helps tiny organisms digest organic material in the water.
The wastewater released from the aerated stabilization basin into Boat Harbour must meet all federal and provincial regulations. It remains in Boat Harbour for about three more weeks so that contaminants in the water fall to the bottom.
Then the water flows out into the Northumberland Strait, over the dam structure.
The Government of Nova Scotia passed The Boat Harbour Act. This law orders that Boat Harbour will cease to be used for the reception and treatment of effluent by January 31, 2020.
2015 – 2020 and beyond
Clean-up plans are being developed and the plans will be completed by 2020 with implementation planned to begin following the environmental assessment process. The clean-up will likely start in 2021 at the earliest.