Northern Ireland Environment Agency (NIEA) resource efficiency and regulation chief Mark Livingstone has confirmed that no mobile oils or tars have been encountered during surveys of the Mobuoy illegal waste site.
Briefing members of Derry City and Strabane District Council's Environment and Regeneration Committee in Strabane on Wednesday, Mr. Livingstone also said there was a low risk of contamination to waters at the Cloghole abstraction point downstream of the dump, which meets over 50 per cent of Derry's drinking water needs by sucking water into NI Water's Carmoney plant.
Mr. Livingstone said the NIEA was working towards completion of a costed remediation strategy and implementation plan, which must then be signed off by whichever future environment minister is in office in May 2017.
He said several options will be on the table, including removal or containment of some of the waste on the site.
"We may have to take the most noxious waste out," he said.
He said containing waste by capping and sealing is also an option with the protection of the Faughan and Derry's drinking water paramount whatever happens.
"Sometimes, if you're putting in a new bathroom, you might want to go for the most extravagant bathroom, but ultimately you have to go with the one that fits and that you can afford," said Mr. Livingstone.
The NIEA chief also reiterated his, and the agency's view, that drought, even more so than heavy rainfall or flooding, which effectively flushes, diffuses and dilutes whatever contaminants are present in surface water, run-off lagoons, ditches or streams at Mobuoy, is a pollution concern.
This is not considered a significant risk given our consistent rainfall.
Mr. Livingstone agreed to appear before the committee on a more or less quarterly basis to regularly update members on progress at Mobuoy, provided he has relevant updates to report.
More on this story later.