Spiralling costs of another government project have been exposed by Freedom of Information.

The operation to dredge and dispose of 44,000 tonnes of potentially contaminated silt from Peel marina will cost the taxpayer £6.9m, including plans for a new problem waste facility, it’s been revealed.

It joins a growing list of government capital projects that have been dogged by delays and/or ballooning budgets including the new Liverpool landing stage and the Promenades scheme.

Work should have begun on dredging the marina in spring 2019.

But it was only last month that construction began on a lagoon which will take dredged silt contaminated with heavy metals from historic mining activity. Without dredging, a number of marina berths would have to close.

Previously-confidential minutes of Department of Infrastructure marina project board meetings have been released following an FoI request submitted by campaigner Trevor Cowin.

They reveal that Treasury was concerned in May last year about the spiralling costs of the scheme had doubled from £2m to £4m.

The meeting was told that the Chief Minister had expressed concerns about the lack of progress and heightened political risks.

Funding was put on hold until Treasury was convinced there were ’viable options and costings’.

DoI political member and project board chairman Tim Baker told a meeting in November that overall costs now totalled £6.9m, including £5.2m for the Peel marina silt and £1.7m for ’problematic waste’.

At that point £500,000 of costs had already been spent or committed.

Treasury gave funding approval later that month for a budget of £5,233,686 for the marina project.

The minutes released under FoI also show there were concerns about the dredged material being suitable for disposal in Cross Vein Mine, a proposal that has since been abandoned on cost and environmental grounds.

It is now proposed to go to landfill at Turkeylands quarry in Malew with a planning application for the strategic waste facility there due to be submitted early this year.

Questions were asked in July about whether the dredged material was ’fit for purpose’ to go to Cross Vein.

A meeting in August outlined the costs and risks of the various options. Transporting untreated material from Peel and the temporary storage site at Rockmount and then dumping it on the existing surface at the mine, covering it in topsoil and seeding it with grass would cost £1.14m including security fencing.

Creating a lined landfill facility there would cost £2.6m but risked public opposition and there was a risk of leachate into adjacent water courses.

Remediation involving holding and dewatering the silt in a lagoon would take the price to £2.78m.

An option to dredge and cap at sea would cost £3.7m.

A meeting in September heard that if all the material had to go to land the cost to dredge, dewater and stabilise would be £7m-7.5m while if some was going to sea and some to Cross Vein the figure would be £4.7m.

The budget request in 2018 was for £2.47m and in April last year this was increased to £4.3m.

By October, depositing at sea was no longer seen as feasible while Cross Vein was seen as ’costly but still an option’.

But in November, the minutes record that Turkeylands old quarry was the preferred site, with a proposal to link to a problematic waste facility project.

The original plan had been to pipe the silt to the lagoon but the proposal is now for all of it to be transported by lorry.

Minutes of April’s board meeting show there was a discussion about the merits of using lorries to haul the silt to the lagoon.

Mr Baker asked why it was more environmentally friendly to move it by road rather than piping it, and was told it was due to the volume of discharge and content of the contamination, with issues associated with lorry transfer ’easier to overcome’.

Contractor Land and Water Services Limited will start dredging in early March using a long reach excavator on a floating barge.

The silt will be transported 450m in purpose-designed trailers to the lagoon being built behind the power station site.

In 2015, a dredging programme to clear silt accumulated in Peel inner harbour provoked a storm of controversy over its disposal.

On that occasion the silt was dumped at Rockmount in German, near to the Poortown Road quarry.

The move was met with objections from local residents who were against to the passage of lorries transporting the material through the town.