The specially engineered site at Poortown Quarry provides a safe, practical and controlled solution for the temporary storage of the build-up of silt that is threatening the closure of Peel marina.
Professional advice had warned that dumping large quantities of the dredged silt at sea over a short period could damage the marine environment and potentially result in a risk to public health.
After detailed analysis of several land-based options, the Departments of Infrastructure and Environment, Food and Agriculture have worked in partnership to create a temporary storage facility at Poortown. This approach has been based on compelling human health, economic, reputational and environmental grounds.
Dredging started this week and silt is being transferred from Peel harbour to a bunded pit, which is lined with an impervious membrane. The run-off passes through a bank of settlement lagoons to remove any suspended solids.
Samples taken from the stream adjacent to the site before work started showed existing high concentrations of metal contaminants likely to be a consequence of the local geology and historic mining activity.
The storage site and run-off will be carefully monitored to ensure that the measures taken to control the risk of adverse impact on the surrounding environment are working well.
Infrastructure Minister Phil Gawne MHK said:
'If no action had been taken Peel marina would have lost even more berths, resulting in significant harm to the local and national economy. Boat owners have highlighted the urgent need for dredging to prevent the imminent closure of the marina. Experts advised against dumping 18,000 tonnes of silt at sea over a short timeframe, so we have endeavoured to find the best possible land-based solution. I wish to reiterate that the Poortown site is a temporary measure and we will continue to seek a permanent storage facility.
'I also 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. To put things into perspective, people would be more than 20 times more at risk walking over some of the old mining sites in the Isle of Man than walking over a minor spillage of silt on the Poortown Road.'
Sediment containing naturally occurring metals has been transported by the Island's river systems into the sea for centuries. When the flow of a river slows, as is the case when the River Neb reaches Peel marina, sediments settle to the bottom and over time become more concentrated. Sediment disposed of at sea is ingested by edible marine life such as scallops, crabs and lobsters, which can cause health issues if people consume them in sufficient quantities.
Environment, Food and Agriculture Minister Richard Ronan MHK commented:
'Specialists from the Government Laboratory, Fisheries, Environmental Protection and Biodiversity teams have been involved in this process. The overwhelming conclusion is that the on-land temporary storage option provides substantially better control of any contaminants contained in the silt than offshore dumping until such time as a final management option is identified. I understand the concerns that have been raised, but I want to reassure the public that the engineering works put in place will help to protect the surrounding countryside and water courses.
'Importantly, we will be viewed by our neighbours as a responsible jurisdiction that deals with its own challenges rather than disposing of the dredged silt into a sea that is shared by all.'
Once land-based disposal of the silt was identified as the only practical solution, officers from DoI and DEFA assessed a wide range of potential disposal locations. The Wrights Pit North landfill site at the Point of Ayre, the disused quarry on Peel hillside overlooking Fenella Beach, former mines and mining spoil sites and two privately operated facilities were all ruled out because of issues such as land ownership, legislative restrictions, or environmental considerations. Similarly, supplying the sediment to a smelting facility and reclaiming the heavy metals or filling large textile tubes with silt to protect against coastal erosion were discussed but not considered viable options.
As the imminent closure of Peel's multi-million pound marina and the potential public health issues associated with disposal at sea were considered matters of national importance, DoI sought emergency powers under the Public Health Act 1990 to temporarily store the silt. This allows for a Direction – a form of licence – to be granted by DEFA for projects of this nature, provided the land is in DoI ownership and that appropriate controls are in place.
Two potential DoI storage sites were subsequently identified in mid-March – Stoney Mountain Quarry and Poortown Quarry.
Space within Stoney Mountain Quarry is restricted and its distance from Peel marina would have resulted in high transportation costs.
Poortown Quarry is also limited in terms of available space, but further investigations highlighted the suitability of land owned by DoI immediately adjacent to the quarry at Rockmount. The site is only two miles from Peel, access is already in place and suited to receiving heavy vehicles and the land and its profile can accommodate the engineering measures needed for the project.
DoI engineers have worked closely with DEFA officers to agree a final specification and a Direction was issued on 1 April that gave the go-ahead for the temporary storage site. DoI is also preparing a retrospective planning application.
Minister Gawne said:
'Effectively we have been faced with three options. Do nothing and allow Peel marina to silt up to the extent that it has to close; dump large quantities of silt at sea and put at risk valuable commercial fisheries as well as public health; or progress a properly engineered facility on land owned by DoI. As an environmentally responsible nation, we are confident the correct decision has been taken.'
Minister Ronan added:
'Ideally the silt would be sent to an existing landfill site licensed to accept material of this nature on a permanent basis. That is an outcome we will continue to work towards. In the meantime, we believe the Poortown facility offers the best temporary solution taking into account all the evidence and professional advice. This work will restore Peel marina to its correct depth and is significantly less likely to harm the environment than disposal of large amounts of silt at sea.'
