Oh dear, what an odour…..

Nantycaws landfill site located near Carmarthen, has been developed as a disposal

facility for domestic, industrial and commercial wastes arising within Carmarthenshire

and neighbouring counties.

The Environment Agency received the first complaints from local residents relating

to odours in the vicinity of the site in July 1998, some time after the first

inputs of sulphate waste. Potential sources of odours identified by the Agency

included:

(i) hydrogen sulphide gas emissions due to the breakdown of the sulphate waste,

(ii) odours from accelerated waste degradation due to elevated rainfall and

leachate re-circulation,

(iii) landfill gas emissions from cells,

(iv) odours due to leachate storage.

The number of complaints increased during November and December 1998, and the

Agency instructed CWM Environmental Ltd, a company wholly owned by Carmarthenshire

County Council, to take immediate action.

Action stations

In December 1998, CWM Environmental Ltd implemented a series of measures to

reduce the potential for odours. These include reduced re-circulation and increased

off-site disposal of leachate, reduced working faces, extra cover materials

for wastes, wells for landfill gas extraction and the installation of a landfill

gas flare.

However, even with these measures, odours might still arise from the leachate

and working faces, and CWM Environmental Ltd needed a liquid product that could

be applied directly to the source of the odour.

In the autumn of 1999, following consultation with Eco Technology Ltd and laboratory

based trials, CWM Environmental decided on a product called Super F SFA PLus

LCH.

The SFA Plus LCH was applied directly to the large 640,000 litre leachate lagoon

next to the landfill. Dispersion was encouraged through use of a bowser and

pumping equipment to agitate and blow air through the lagoon.

A volume of treated leachate was then taken by bowser to the working face of

the landfill and sprayed directly on to the waste and the surrounding perimeter.

In hot weather conditions, the internal working roads are also treated to counter

any malodours.

The SFA Plus LCH was used in three applications; neutralisation of odours in

landfill leachate, on the working face, and internal site use. The product worked

by reacting on a molecular level to bind and neutralise the odourous compounds

in both liquid and air.

The Agency have not pursued CWM Environmental Ltd again since these measures

were taken, and there has been no further action or complaints regarding malodours

from site.

Simone Astins of the Environment Agency commented, ” CWM has conducted

trials with the use of a chemical (Super F) to reduce odours from the leachate.

These trials have proved successful and the product is now being utilised for

larger scale leachate treatment on site.”

Landfill manager, Mike Lewis, was impressed by the product and describes it

as “excellent ……highly effective……we will certainly purchase Super

F again in the future.”