Ms Harper has written to the Secretary of State for Scotland and the Defence Secretary following speculation that through committing to upgrading the A75 and building a new nuclear power station, that the Government will once again use Beaufort’s Dyke as dumping site.
Previously Ms Harper has also raised concerns over the noted increase in the amount of unexploded ordnance which has washed up on beaches across south west Scotland over recent years.
Beaufort's Dyke became the United Kingdom's largest offshore dumpsite for surplus conventional and chemical munitions after the Second World War.
Nuclear waste from UK power stations, including Hinckley Point A, has also been disposed of in Beaufort’s Dyke over the years.
Ms Harper said: “The UK Government has in the past used Beaufort’s Dyke as its dumping ground for surplus chemical and biological weapons, as well as encased nuclear waste.
"It is a concern that these weapons have been washing ashore our beaches in increased numbers over recent years, and I have raised this on a number of occasions.
"I have recently been contacted by constituents who are concerned that the UK Government, through committing to upgrading of the A75, and through committing to open a new nuclear power station, are intending on again using Beaufort’s Dyke as a location for the disposal of nuclear and radioactive waste.
“Given these concerns, I have written to the Secretaries of State for Scotland and Defence, to seek a commitment from them that Beaufort’s Dyke will not be used for future disposal of nuclear waste, as has been the case previously.
"I have also asked whether the UK Government have carried out a current risk assessment of the stability of the area, so constituents across the region can be assured of its safety and that there are no plans to use the site as a dumpsite for UK nuclear and radioactive waste.
“I look forward to hearing the response from the UK Government soon.”