Allington Quarry Waste Management Facility

Community Liaison Committee

Minutes (amended)

Meeting16 November, 6-8pm

AttendingFiona MacIntosh (minutes)Jim Wiegner

Paul AndrewsPeter Dyer

Bob NapthineKCC

KCCKCC

Geoff RoweJabbar Neseyif

Brian White (chair)Nicola Perryman

John TurnerDavid Porter

Steve Bruce-JonesMyra Farrer

Prof. Jim Bridges (speaker)Tom Jerral (speaker)

Mark WalshEA

Malcolm Robertson

ApologiesNicola BarkerTony Harwood

No apologiesRoss Knowles(received later)Tom Cook

Action points are noted in bold

INTRODUCTIONS

All attending introduced themselves.

APOLOGIES/SUBSTITUTES

As above.

PREVIOUS MINUTES

Minutes of the meeting of 8 September 2004 were accepted as accurate.

UPDATES

Mark Walsh gave a brief update of work on site:

Diaphragm walls are completed
Preparation for piling/construction is ongoing
The waste bunkers are being prepared/constructed
Building work will be above ground level in the next 1 to 2 months
There are currently c. 120 staff working on site
Orders have been placed for all mechanical equipment, which will be installed during 2005
Engineering design work is going on in tandem with construction.

Jim Wiegner explained that Steve Bruce-Jones is leaving Kent Enviropower and introduced Paul Andrews as the new MD. Paul will take Steve/Jim’s place on the liaison committee. The committee wished Steve well.

Mike Clifton informed the committee that the application to extend working hours had been approved by KCC.

The committee agreed that there had been no complaints to date about work on site.

Malcolm Robertson said that Maidstone Borough Council has written tothe EA asking for their full input in monitoring the project.

PROFESSOR JIM BRIDGES

Prof. Bridges gave a presentation on health issues. (Copy attached.)

Malcolm Robertson commented that he had no particular concerns about operation of the plant in ordinary circumstances and within the regulatory limits, but that he was worried about what would happen in the event of a malfunction or mismanagement. He referred to a plant in Dundee which had experienced problems. He asked how small particulate matter (PM10s) was to be dealt with adequately.

Prof. Bridges commented that any error at the plant would have to be massive for it to result in events causing health concerns. He commented that the plant would have on line monitoring and results would be linked to the EA. (The plant will also have on line monitoring available for local people to see.) He commented that there could be more concern about health impacts from particulate matter resulting from walking next to a main road than from operation of the facility. He commented that short terms peaks in dioxins, for example as the result of some error in the plant, were not a health concern since concern arises from the concentration of chemicals over time.

Tom Jeral referred to the gas clean up systems to be used and the monitoring regime agreed with the EA.

Jim Wiegner said that to override any mechanical warnings of malfunction manually would not be in anyone (including the company’s) best interest.

Prof. Bridges talked about emissions standards. Emissions from the stack are regulated by the Waste Incineration Directive and are based on what the technology being used can achieve. Health concerns, by contrast, look at the ground level concentrate of emissions and are set with health impacts in mind: for acute (short term) impacts and cumulative impacts. He commented that the operation of the facility should no get anywhere near approaching the limits for emissions, but that its operation must always be considered in context.

Malcolm Robertson asked whether the EA could require improvements in emissions from the plant.

Kevin Thaw said that the EA could, subject to a Best Available Techniques assessment.

There was some discussion about the ingestion of chemicals (particularly dioxins) and Prof. Bridges commented that it was extremely rare to find a person 20% of whose food came from local sources. In most cases it was closer to1% he said.

Geoff Rowe asked whether Prof. Bridges could quantify the scale of risk to health posed by the facility in lay terms. Prof. Bridges commented that there were so many risks present in every day life it would be difficult to do this realistically without the facility’s contribution getting lost.

Malcolm Robertson commented that an Air Quality Management Area is being instituted along the M20 corridor.

Bob Napthine talked about the dispersal of emissions under very low/no wind. (An answer to his question on this point from Apsinwalls is attached.)

Mike Clifton commented that the location of monitoring stations to consider operation of the plant was agreed under the S106 agreement which accompanied the planning permission.

The committee thanked Prof. Bridges for his presentation.

NEXT MEETING

The next meeting will be Tuesday 18 January. A site tour will be held at 17.30. The meeting will run from 18.00 to 20.00. The meeting will address water issues.

The following meeting will be Tuesday 22 February. A site tour will be held at 17.30. The meeting will run from 18.00 to 20.00. Kevin Thaw will give a presentation on permitting and monitoring.

The following meeting will be Tuesday 12 April. A site tour will be held at 17.30. The meeting will run from 18.00 to 20.00. The meeting will address security issues.

ANY OTHER BUSINESS

MBC’s The Big Debate was raised as a possible forum for discussing waste issues. Malcolm Robertson has since confirmed that the meeting will not focus on waste.

Ross Knowles has not attended the last 2 meetings and not sent apologies. In line with the committees terms of reference FM was asked to write to him and offer his place to the next person on the list interested in joining. (Apologies have subsequently been received from Mr Knowles and thus no action will be taken.)

David Alexander told the committee he was retiring from KCC. His place on the committee will be taken by a colleague. The committee wished David well.

Malcolm Robertson commented that he was pleased to learn that an alternative route to the A20 for the power cables from the site had been found. The cables will be laid from Jan-Jul 2005.

Action Points

EA to provide speakers for next two committees
FM to book Mid Kent Water speaker for next committee
FM to post Prof. Bridges’ presentation on web site
FM to write to non attendees (No action now required.)
DA to confirm to FM KCC member to replace him
DP to provide FM with links to Lurgi web sites for inclusion in web site

Allington Quarry Waste Management Facility – Community Liaison Committee
Kent Enviropower response (by Enviros) to question raised by Mr Bob Napthine, August 2004

Re: Dispersion modelling – proposed Allington waste to energy facility

“Is there an updated EIA available which should include an analysis for the zero wind to light breeze (say up to 5 Knots). I had a quick look in the Library's copy but I think that is still the original. You might remember I pointed this out as an omission at the meeting on site 2 years ago. The range of winds analysed then for emission spread did not include this significant proportion as shown at the centre of the wind Rose.”

The general point raised by the questioner is a relevant consideration, because Gaussian dispersion models cannot directly take into account dispersion under zero or low wind speed conditions.

However, it is not quite correct to suggest that the study excludes an analysis for wind speeds up to 5 knots. In fact, the model produces results for wind speeds down to 0.5 metres per second, equivalent to approximately 1 knot, as measured at 10 metres above ground level. At ground level, this would be equivalent to a wind speed of approximately 0.25 knots. So it is only the very lowest wind speeds which are not included in the modelling study. For example, looking at the meteorological data for Gatwick, 1997, which was one of the datasets used in the dispersion model, only 3.0% of the hourly data recorded a windspeed less than 0.5m/s.

For the very lowest wind speeds, Gaussian dispersion models are not appropriate, because at these wind speeds, the contribution of other physical processes to dispersion is significant. This issue is a more significant concern for ground-level sources of pollution than for elevated sources. This is because the very slow dispersion of pollutants from an elevated source under these conditions will in general take place at some distance above ground level, with no potential for adverse effects on local people. Conversely, the slow dispersion of pollutants from ground level sources such as road traffic under low wind speed conditions could give rise to relatively high levels of airborne pollutants close to the source.

In order to ensure that uncertainties such as the absence of model forecasts for the lowest wind speeds did not result in air quality impacts being underestimated, a worst case approach was adopted to the assessment of the potential impact of emissions from the Allington plant. This was designed to ensure that air quality impacts were more likely to be overestimated rather than underestimated. The worst case approach included the following aspects:

The plant is assumed to operate continually at maximum capacity throughout the year with no downtime. In reality, some limited downtime will occur;
Emissions of NOx are assumed to occur as 100% NO2for short term calculations and 50% NO2 for long term calculations, whereas the actual proportion is more likely to be in the region of 5-10% NO2.
Emissions were assumed to be at the limits set out in the Waste Incineration Directive (2000/76). In practice, emissions will be lower than these limits;
The dispersion modelling study was carried out using a number of years of meteorological data, and the highest modelled value for any year used in the interpretation of results.
The ADMS model is verified against field monitoring studies and has been found to be more likely to overestimate than underestimate impacts, by comparison to AERMOD, the main alternative system.

Even following this worst-case approach, there was a considerable “margin of safety” between the modelled air concentration levels, and the air quality standards and guidelines. For example, the highest modelled levels relative to the air quality standard was for PM10. In this case, the process was forecast to contribute 0.6% of the air quality standard, with a combined process contribution and background level of 83% of the air quality standard. Similarly, for nitrogen dioxide, the process was forecast to contribute 4.4% of the air quality standard, with a combined process and baseline level of 82% of the air quality standard. Minor changes in the process contribution values would not have a significant effect on overall air quality, and would not affect the interpretation of the model results.

Our own experience of measurement to verify dispersion model forecasts confirms that modelled levels of airborne pollutants from elevated point sources are in general over-estimates of the levels which arise in practice. It should also be noted that the use of a Gaussian dispersion model in the manner used for the proposed Allington facility is widely established best practice, and is carried out by industrial process operators, by regulators such as the Environment Agency, by consultants such as ourselves, and in academic research.

In view of these considerations, we conclude that the exclusion of periods of zero or very low wind speed does not have a significant effect on the conclusions of the air quality study.

Committee Secretariat: Fiona MacIntosh, Tel: 0845 601 5432, Email: