A decision is still pending on what is to be done with tons of sediment that needs to be dredged from Peel inner harbour.

Around 3,500 tonnes of silt and stone is brought down in to the harbour each year by the River Neb, and used to be carried out to sea but, since the flapgate was built, it accumulates, eventually obstructing the berths.

In January, politicians expressed concern at dumping the dredged material at sea because of possible harmful effects on marine life and the fishing industry.

Subsequent analysis of the material has shown contaminants that rule out its disposal at sea.

A government spokesman said: ’The Department of Infrastructure is committed to developing a land-based problematic waste site that would be licensed to accept marina silt.’

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 objected to the passage of lorries transporting the material through the town.

At the time the then DoI Minister Phil Gawne said: ’I want to dispel this myth about the content of the silt being dredged from the marina. It is simply collected river sediment, rather than some form of toxic waste.’

However, the solution remains temporary as the dumping site is subject to a planning condition that the material be removed by August 2020 and the site restored to an acceptable standard.

The government spokesman continued: ’The Department of Infrastructure is continuing to work with Department of Environment, Food and Agriculture, exploring short-term engineering solutions to support the maintenance of the marina.

’Regular maintenance is required to prevent the build-up of silt forcing the closure of vessel berths.’

Some of the silt is contaminated with traces of metal, naturally occurring in the local geology and sometimes released by historic mining activity. This has historically been carried down the island’s rivers into the sea, but now tends to settle in the marina as the water flow slows down.

A government statement said if disposed of at sea and ingested by scallops, crabs or lobsters, silt could potentially cause health problems to people if they ate them in large quantities.

A separate scheme to dredge the outer harbour starts shortly. This will remove and dump at sea beach sand accumulated between the groyne, the lifeboat slipway and the breakwater.