4. Future liability
The question of future liability and the possible requirement to remove the tens of thousands of tonnes of contaminated cuttings already on the sea bed is a major issue. Although this problem is considered as a decommissioning issue, it is important to recognise that current practices may have longer term implications. Although there is little or no evidence to suggest that oil free cuttings pose any serious threat to the sea bed, if clean cuttings are dumped on top of dirty cuttings it would aggravate any future problems in removing the oily waste. Also, if a commitment is made to remove cuttings in place it become less critical to avoid adding to existing piles in the short term. Likewise, whilst cuttings pile removal is a possibility it would be sensible to make extra efforts to avoid dumping any remaining synthetic mud cuttings on virgin sites. In this context, of the options disolids controlussed below, cuttings re-injection and ship to shore disposal have an advantage over cuttings cleaning techniques or the use of water based mud in that they have no impact on the sea bed.