Oireachtas Joint and Select Committees

Tuesday, 28 January 2014

Joint Oireachtas Committee on Environment, Culture and the Gaeltacht

Management of Sewage Sludge: Cré

2:50 pm

Photo of Denis NaughtenDenis Naughten (Roscommon-South Leitrim, Independent) | Oireachtas source

As I am not a member of this committee, I thank the Chairman for giving me the opportunity. The witnesses are right in pointing out that, as a consistent feed, sewage sludge is a very useful fertiliser for land spreading and the Chairman outlined its numerous uses. I ask the witnesses to comment on residues such as lead, arsenic, etc., that can be found in sludge. How frequently is that happening? I believe Deputy Catherine Murphy asked about chemical discharges from plants into sewage treatment facilities. How can those residues be eradicated?

Deputy Luke 'Ming' Flanagan asked about the processing capacity. There are the issues of aerobic and anaerobic digestion. What direction should we take in that regard? I believe we should choose the anaerobic digestion route because there are problems not only with planning but also with environmental issues regarding aerobic digestion and composting, such as smell and the location of such facilities. Particularly with anaerobic digestion, is there not also an issue with the consistency of the feed going in? When dealing consistently with sewage sludge, a consistent product is coming in thereby making it very easy to have a consistent product going out. If it is operating effectively there should be very little down side or smell. However, when septic tank sludge, which is a completely different product, is going into it, it can cause problems. The same applies when other feed is going in, including belly grass. I ask the witnesses to comment. These are genuine concerns over the industry as it operates at present.

Cré has proposed having no land spreading. Are the witnesses satisfied there is sufficient capacity to treat the existing sludge coming from municipal facilities throughout the country if the land spreading facility disappeared overnight? I have heard estimates of 1 million tonnes of untreated sludge coming from septic tanks every two to three years once the desludging regime comes in. That represents a significant additional loading on the system. Do the local authority facilities have the capacity to cater for the additional loading if land-spreading was not permitted?

I ask Mr. Foster to explain further his comments about the FSAI. Is there not a difference between land-spreading and trailing shoe? There are also different associated risks depending on the production type and whether it is arable, vegetables or livestock on the farm. I ask the witnesses to elaborate on that issue.

The witnesses made a valid point about the removal of solids rather than liquid because the liquid is the feed that can be used to keep a septic tank running effectively. How do we deal with the elephant in the room? Local authorities do not have the capacity to deal with the sludge they have at present never mind septic tank sludge coming in on top of it. That is a very inconsistent feed even if they are only taking the solids because of the nature of it. Considerably more than just sludge is coming into that, including stones and other debris. How can they deal with that inconsistent feed? Local authority systems are not able to cater for that type of feed coming in at the moment unless it is highly diluted. Does taking the solid off it not cause more problems than it solves?

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