Guest commentary: Alton Gas Storage will help businesses and homeowners in Nova Scotia

Community Online First Opinions

To the Editor:

Thank you for the opportunity to provide readers of the Enfield Weekly Press with information on the Alton Natural Gas Storage Project, in response to recent opinion columns in the News about the project. We understand that there are concerns from some people, and we appreciate that natural gas storage is new to this area. Alton is committed to meeting all environmental obligations and to increasing public confidence in this project.

We welcome discussion as we work to responsibly develop this important energy infrastructure project for Nova Scotia. Our starting point has always been clear: Alton can not cause harm to the Shubenacadie River estuary and the fish that live there.

Alton is an underground natural gas storage facility that is under development near Stewiacke. To make the natural gas storage caverns, water will be drawn from the tidal Shubenacadie River estuary to dissolve underground salt deposits in a process called brining. The water is drawn from a constructed channel built alongside the river and returned as brine to the same channel for release.

The tidal Shubenacadie River estuary has a wide range of salinity depending on the tide and rainfall. Everything living in a tidal river is used to a range of salinity and quick changes in it.

About 55 million cubic metres of salt water enters the Shubenacadie with every tide. Alton proposes to release 5,000 cubic metres of brine with each tide. This volume of brine is .009 per cent of the volume of the river. A brine infographic on the Alton website explains these volumes.

The salt level in the brine will vary, depending on the stage of storage cavern construction. At maximum, during the construction of the two planned storage caverns for Alton, about 1,400 metric tonnes of salt will be released on each tide. That sounds like a lot, but it’s a number that needs perspective. Consider that into the Shubenacadie every day, flows 1.47 million metric tonnes of salt on each tide. The amount of salt being added to the river by brining at Alton is much less than one per cent of the river’s total amount.

Within 5 metres of the brine release point in the channel, the brine will be completely mixed with the river water, aided by fast moving currents, the release through thick layers of rock and the injection of air. The energy and turbulence of the waters in the Shubenacadie contribute to the mixing. Despite what was said in the column on May 1, (“Last of the Fundy Bass”), pockets of unmixed water are not left on the bottom.

As an extra safeguard, in the spring, brining will shut down completely for 24 days when Striped bass are spawning, a further protection for eggs and fish in the Shubenacadie.

For Alton, more than a decade of research and monitoring of the Shubenacadie has been conducted by scientists at Dalhousie University, the most extensive study of the river to date. In contrast to what was suggested in the May 1 column, results of this program including Striped bass data are shared regularly with government and regulators, and information is also posted about it publicly on the Alton website, Furthermore, river research has been expert peer reviewed and published.

With respect to the recent injunction granted for Alton work sites, trespassing at these sites has been an ongoing concern. After Alton attempted to pursue other options, we applied to the Supreme Court of Nova Scotia for an injunction to ensure we have safe, unobstructed access to our work site. Moving forward, access to the work site is open only to approved Alton staff and contractors. For more information please see the Latest News section on the Alton website.

Incorrect information appeared in the June 5 column, (“Written in Stone”), on the geology at Alton. The geology at Alton is well studied with significant analysis showing it is appropriate for storage caverns. Experts from various subsurface disciplines have been involved to ensure that the proposed caverns will be safe. Despite what was said in the column, drill logs, cores and seismic data taken through the proposed cavern area show no dolomite or limestone mixed with the salt. That means there are no rocks that could be pathways for leaks mixed with the salt where the caverns will be located.

Salt cavern development is subject to stringent regulations in Canada and North America. The Alton caverns will be designed and built to exact specifications. In contrast to what was said in the column, the caverns will not be affected by isostatic rebound, which is the term for land slowly rising in the wake of ancient glaciers that once covered much of Nova Scotia. We know this because there are well-established salt mining operations in Nova Scotia and New Brunswick. The underground workings at each of those locations would dwarf the size of the caverns planned for Alton. If isostatic rebound was a concern, the effects would have already been evident at these well-established mining operations.

We are not experts on the proposed storage project in the Canso area in the 1970s, which was referred to in the column. However, you can’t compare Alton to a project from 40 years ago. Information available through the Province of Nova Scotia shows the Canso area caverns were abandoned for commercial, not technical reasons.

Alton will be built to the highest safety standards under the oversight of independent regulators. If readers are interested in learning more about geology and safety at Alton, there are sections in a recent project filing to the Nova Scotia Utility and Review Board that would be helpful. That filing is readily available on the Alton website.

Nova Scotia’s energy mix is changing, and natural gas plays an increasingly important role. It helps power our businesses and warms our homes – all while lowering emissions by displacing higher carbon fuels like fuel oil and coal. In fact, many of the province’s largest employers use natural gas every day to fuel their work, as do industries and public institutions like hospitals and universities plus thousands of homeowners. With Nova Scotia’s remaining supply of offshore natural gas shut down last year, access to a reliable source of natural gas during the winter is important to keep energy costs affordable.

Safe, economical and reliable natural gas stored deep underground at Alton is a part of the solution.

We recognize the Shubenacadie River estuary is at the centre of Nova Scotia’s history, culture and geography. As a member of the river community, we take our duty to operate responsibly very seriously.

We are committed to continuing to work with local Mi’kmaq communities and engage with our neighbours, partners and all levels of government to progress the Alton project.


Lori MacLean

Senior Advisor

Alton Natural Gas Storage Project