A provincial plan is slowly being unveiled for Nova Scotia’s largest contaminated site, known as Boat Harbour, where a 140-hectare collection of settling ponds, basins and coves receive tens of millions of litres of toxic wastewater, piped daily from nearby Northern Pulp mill at Abercrombie Point.
Nova Scotia Environment Minister Iain Rankin announced on April 27 that the massive remediation project for contaminants like zinc, cadmium, mercury and small amounts of organic pollutants like dioxins and furans, will undergo a Class 2 environmental assessment, which typically takes 275 days, compared to the 50-day review period for Class 1 assessments.
The latest figure for the cleanup of an estimated 350,000 cubic metres of contaminated material is $132 million. The goal of the cleanup is to return Boat Harbour to its original state as a tidal estuary. It first received industrial wastewater in 1967 and was sealed off from the ocean in 1972.
In 2015, the Liberals passed the Boat Harbour Act, mandating the closure of the facility. The act allows time to plan and build a new wastewater treatment plant, as well as to plan the cleanup of Boat Harbour. Paper Excellence Canada Holdings Corp. has a lease to use Boat Harbour under until 2030, which it pays $25,000 a month to the province and covers the treatment facility’s operating costs.
The actual cleanup of Boat Harbour won’t occur until 2020, and is expected to take four years at that point. But, there is plenty to keep the remediation team busy in the meantime. In July 2018, a team under the guidance of consultant GHD will construct infrastructure necessary to carry out pilot testing, which is set to begin in August and conclude in winter 2019. This includes construction of a treatment laydown pad and dredging work compound. The treatment pad is comprised of a gated access area, a containment berm, lined sludge dewatering pad and supporting pipelines. A chain link fence will also be installed to separate the area from the operational effluent treatment plant, according to a project fact guide.
The pilot project work will help project officials determine the most effective technologies to use in the cleanup phase of the project. Part of the process will include examining sediment behaviour, management, treatment, and its transport and eventual containment.
The third and final stage will be the actual pilot testing of methods recommended by the design engineer, based on studies over the past number of months.
The project is in the planning phase until 2020. The current phase is focused on scientific and technical planning studies, including:
- Phase 1 and 2 environmental site assessments
- Environmental baseline studies
- Geotechnical investigations
- Mi’kmaq ecological knowledge study
- Bench and pilot scale testing
- Remedial action plan
- Environmental impact assessment
- Remedial design options, including detailed design