Plans to dump tonnes of 'laxatives' in St Ives Bay 'not harmful'

Plans by a Canadian company to dump tonnes of minerals into the sea as a way to fight climate change would not harm the environment much, an independent review has concluded. Planetary Technologies and South West Water want to carry out a carbon sequestration trial by dropping tonnes of magnesium hydroxide in St Ives Bay. According to the controversial project they hope to remove carbon dioxide from the atmosphere by locking it in the sea by adding the alkaline mineral.

Magnesium hydroxide is probably better known as the compound Milk of Magnesia, which is used as a laxative. The scheme has attracted opposition from local residents, environmentalists and animal charities alike who fear changing the alkalinity of the ocean could have an impact on the local flora and fauna.

As part of the proposal, the Canadian company and South West Water submitted their plans to the Environment Agency (EA) which commissioned the Water Research Centre (WRc) to carry out a risk analysis during a first phase of small scale trials. The EA has yet to decide whether a full scale trial will go ahead.

If given the green light, the larger scale trial would involve magnesium hydroxide being added into the treated wastewater outlet pipe at Hayle Waste Water Treatment Works. The wastewater pipe would transport the magnesium hydroxide 1.5 miles (2.4km) into the sea outside St Ives Bay.

Planetary Technologies said adding the alkaline compound to the sea would help counter ocean acidity caused by climate change.

Last April about 300 concerned people took place in a protest on Gwithian Towans beach in Hayle to show their opposition to the scheme. Organised by members of the group ‘Keep our Sea Chemical Free – Save St Ives Bay’, opponents to Planetary Technologies’ scheme said they are “passionate about protecting our environment and helping to reach net zero. But not at the expense of our precious marine ecosystem”.

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The protesters said the proposal would be akin to a massive “dangerous chemical dump” in the area. More than 60 surfers also took to the water on the day for a paddle out at Godrevy, forming a huge circle in the sea in front of the lighthouse to show their solidarity for the cause.

The WRc review has now come back and concluded the proposed trial was a “very low risk”. A spokesperson for the Canadian firm said: “Magnesium hydroxide – our source of alkalinity – is safe for use in the marine environment without adverse effects in the ecosystem from the proposed trial. This new report confirms that this naturally occurring antacid is ‘of low acute toxicity to aquatic organisms and of low chronic toxicity to microalgae’, and that the risk to marine organisms from the trial is considered ‘very low’.

“This confirms Planetary and others’ work showing minimal likely effects on the most sensitive marine life even in areas that would see the highest concentration of magnesium hydroxide, which would be in the immediate vicinity of the diffused dispersal site, during the trial.

“We are also extremely pleased that WRc recognises that our technology has the potential for ‘significant net carbon removal’. This is in strong agreement with studies on the potential scale of carbon removal through ocean alkalinity enhancement, with conservative estimates indicating the potential for 44 billion tons of CO2 removal. This report reinforces the value and importance of our mission to fight climate change and restore the world’s oceans.”

Hundreds of people take part in a protest at Gwithian Towans on Sunday, April 16, against a proposed chemical dump in St Ives Bay. Following speeches, more than 60 surfers took to the water for a paddle out, forming a huge circle in the bay.

However the report was not a blank cheque but also recommended that changes are made to Planetary Technologies’ submission. The WRc asked that additional sampling of the source material, the magnesium hydroxide, are made along with extra monitoring to detect any impact and help to confirm the rates of dissolution in water.

They have also asked that the Canadian company refines its calculations of the suitable concentration of magnesium hydroxide to use, using long-term data on multiple appropriate marine species. The firm said it has already taken onboard the recommendations.

However, opponents to the project remain sceptical of its proclaimed benefits and worry about its impact on wildlife. The Seal Research Trust has called for a closed water test of magnesium hydroxide in St Ives Bay to get a definitive understanding of its impact, before open sea trials take place.

Charity founder Sue Sayer said it supports the EA requiring Planetary Technologies to do some additional monitoring to detect long-term impacts on multiple species of animals.

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She said: “The conclusion that there is a low risk to marine organisms from MH in this trial is worrying, as no testing has been done on St Ives Bay sea water and species (such as brown crabs and lobsters), let alone the long term testing on ‘multiple appropriate marine species’ recommended by the EA.

“This is why SRT have called for closed water and air lock system testing of MH on St Ives Bay seawater and species, to get a clear and definitive understanding of impacts and measurable carbon dioxide removal (CDR), before doing open sea trials where everything is so much riskier and more complicated.

“Of even greater concern to us is the WRc’s assessment, that the formation of calcium carbonate sediment is a medium risk, as this will cover sea bed species with knock on effects for the food chain including being ingested by seabed feeders such as seals.”

Following the report, the EA said: “We will need to assess the changes before we can make a decision.”

A spokesperson for South West Water said: “We continue to work with the Environment Agency as it makes its decision on whether to allow Planetary to carry out the proposed trial. We will not support any initiative that presents a significant risk to our local environment and our priority is always to protect our natural environment.”