City's rotten-egg smell blamed on river sediment

A rotten egg-like smell reported by residents in Newport is being caused by tidal sediment in the river, a council has said.

Air quality testing suggested the sulphurous odour was most likley coming from the River Usk and River Ebbw estuary, where sediment can cause the release of hydrogen sulphides.

The gas was found to be at levels that posed no risk to human health but could cause "an annoyance to many people", Newport Council said.

Natural Resources Wales (NRW), which regulates two landfills, a composting facility and a household waste recycling centre in the city, said testing since December had found no evidence of "off-site odour pollution".

A spokesperson said: "We have received a large volume of odour reports from various areas of Newport - mainly concentrated around the level of Mendalgief area.

"We have carried out several off-site odour assessments of the operational landfill and the landfill gas utilisation plant over recent months.

"During these assessments, our officers were unable to substantiate off-site odour pollution.

"We will continue to respond to any further reports of odour from sources within our regulatory remit."

Residents have been urged to contact their GP if they think the odour is affecting their health and to close doors and windows to keep the gas out.

They can also document "unpleasant odours" in the air to an online reporting scheme set up by the council.

Yvonne Forsey, cabinet member for climate change, said: "It is reassuring that [the smell] is caused by 'natural' processes linked with the rivers that run through Newport, rather than an industrial or commercial site.

"Officers will continue the work that is needed to confirm this is indeed the source and rule out any other possibilities."