Summary Statement: Bioaerosol Assessment

Julia Coulthard

Prepared by: Approved by: Ahlim Hashm

Conrad House Beaufort Square Chepstow Monmouthshire NP16 5EP

Tel 01291 621821 JER3449 Fax 01291 627827 Revision: 0 Email [email protected] November 2006

This report has been produced by RPS within the terms of the contract with the client and taking account of the resources devoted to it by agreement with the client.

We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above.

This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at their own risk

Planning, Transport & Environment Summary Statement : Bioaerosl Assessment

Contents

1 Introduction...... 1

2 Elevated Levels of Bioaerosols Can and Do Cause Problems Despite Lower Levels Occurring Naturally...... 2

2.1 High Concentrations of Bioaerosols from Open Windrow Sites...... 2

2.2 Failure to Recognise the Implications of the Scale of the Operation...... 3

2.3 The Effect of Other Farming Activities...... 3

2.4 In Conclusion...... 4

3 The Health Effects of Bioaerosols...... 5

3.1 The true health Impact of Composting Operations...... 5

3.2 Concern about the nearby Primary School...... 6

4 The Entire Village of Old Sodbury is at Risk Regardless of the 250 m limit...... 7

4.1 Distance to the Receptors...... 7

4.2 The 250m Limit is Guidance Only...... 7

5 Sensitive receptors could be affected 55 days a year or more..8

5.1 Meteorological Data and Temperature Inversion...... 8

5.2 The Commercial Realities of Operating a Composting Site...... 9

6 Conclusions and Recommendations...... 10

6.1 Odour...... 10

RPS Planning, Transport & Environment 1 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment

Appendices

Appendix A Supporting Scientific Evidence for the Summary Statement Reviewing the Quality and Accuracy of the Bioaerosol Assessment Written by Dr John Burden Regarding Southcroft Farm, Old Sodbury

Appendix B Map of Houses Within 250m

Appendix C Number of Houses Within 250m of Compost Farm

Appendix D CV – Ahlim Hashm

RPS Planning, Transport & Environment 2 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 1 Introduction

Our client has asked us to undertake a review of:

. the ‘Desk Top Bioaerosol assessment of the Green Waste Composting Facility for Southcroft Farm’ written by Dr John Burden;

. the additional documentation provided by Gill Pawson (planning agent) and

. the quality of the Environment Agency’s written response

in support of the planning application PK06/1770/k to make permanent an open windrow composting facility at Southcroft Farm, Old Sodbury.

In so doing we have considered whether the information and data provided is suitable to assess the potential impact on human health and whether it complies with the current UK guidance on risk assessment from composting facilities.

The EA’s policy document ‘Agency position on composting and health effect’ states “all permit applications or modifications should be accompanied by a site-specific risk assessment. Where an operation is proposed within 250 metres of a sensitive receptor, there will be a presumption against permitting or exempting unless the site specific risk assessment based on sound, independent, scientific evidence which demonstrates that appropriate levels can be achieved and maintained at any working or dwelling place whose boundary lies within 250 metres of the boundary of the site for which the permit has been applied”.

It is our opinion that the submitted report fails to meet the above risk assessment principles. The report is very generic, extremely vague and occasionally makes contradictory statements.

The only justification provided by the EA for not demanding that the applicant should carry out a site specific risk assessment using the source-pathway-receptor concept is the operator’s lack of knowledge on the source term (the amount and type of bioaerosols which have been and will be produced by the site).

We, however, believe that identifying the source term is the responsibility and duty of the operator (certainly not the residents) and is not a reason for failing to follow the current EA guidance on risk assessment.

In addition the assessment has based its conclusion wholly on four key criteria, which in our opinion are all misleading and fatally flawed.

We take each of these in turn and discuss why it is not appropriate to rely on the argument provided.

RPS Planning, Transport & Environment 1 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 2 Elevated Levels of Bioaerosols Can and Do Cause Problems Despite Lower Levels Occurring Naturally

The assessment recognises that the composting process can result in the production of high concentrations of bioaerosols within the material being composted’ and that ‘in some situations populations as high as 109 with bacteria, 108 with actinomycetes and 106 with fungi per gram can be recorded on materials being composted’.

However, the report then compares these levels with the natural occurrence of bioaerosols in some natural environments. Indeed it states, WITH NO ACCEPTABLE JUSTIFICATION that ‘the background levels of bioaerosols in woodlands and farms are higher than that in a composting yard.’

2.1 High Concentrations of Bioaerosols from Open Windrow Sites

In this document we demonstrate clearly that potential emissions of bioaerosols from composting facilities can be significant particularly from open windrow composting systems. Using general statements on issues related to emissions without reference to the type of composting system (such as those given in Dr Burden’s assessment) can be very misleading.

Our literature review reveals that emissions can be very high and that the open windrow type of composting facility is known and confirmed to have the highest emission levels when compared to partially enclosed and enclosed composting systems. Please make reference to the attached technical review (appendix 1) in relation to published literature levels of emissions from the different types of facilities.

The EA document ‘Agency position on composting and health effects’ states that levels of bacteria and fungi released are significant and in particular, one fungus, Aspergillus Fumigatus, a class 2 pathogen, can be present in sufficient concentrations to give rise to adverse health effects in humans.

A report on ‘Bioaerosol Monitoring and Dispersion from Composting Sites’ by South West Industrial Crops Limited stated that “factors such as the type of system used for composting (e.g. open windrow or enclosed “in-vessel”), the feedstock material being composted and the way that sites are managed, are likely to have an influence on the level of bioaerosol emissions. Lower cost outdoor windrow composting system may, for example, have potential for application on a large number of sites. However, there may be the greatest concern about bioaerosol emissions from these systems. Such sites may well need to be selected with due regard to separation distances from potential sensitive receptors, and they may need to be managed to minimise the impact of bioaerosol emission”.

2.2 Failure to Recognise the Implications of the Scale of the Operation

In the absence of any significant bioaerosol sources, natural atmospheric conditions in typical suburban areas are reported to be significantly lower than those in areas affected by industrial sources including those affected by composting type of facilities.

We agree that the microbial components of bioaerosols generated during the composting process contain many of the same micro-organisms that are commonly isolated from normal outdoor air.

HOWEVER THE REPORT SEEMS TO IGNORE THE MAIN DIFFERENCE -THE SCALE.

The handling of large quantities of compost potentially can lead to the release into the air of large quantities of the bacteria, fungi and actinomycetes and their components, found in compost as a bioaerosols.

We agree with the first half of Appendix D (extracted from the HSE report) which demonstrates the increased level of bioaerosols in certain farm related activities. However the reported emission from composting facilities in the second half are debatable as the levels of emissions are dependant on the type of facilities, the type of waste they handle and the utilised control measures as discussed above. As stated before, open windrows are the worst in terms of high emission levels and general values relevant to other types of facilities should not be quoted for a comparison purpose.

2.3 The Effect of Other Farming Activities

Dr Burden’s assessment also made reference to the presence of many other faming activities which have the potential to increase the levels of bioaerosols. We agree with the EA position revealed in their letter dated 15th of September, 2006, that the presence of other sources of bioaerosols is not a reason for allowing additional loading from a composting operation. The EA has requested that the risk assessment shows that the additional loading from the composting activities will not raise existing levels above background or the agency’s threshold for acceptable levels. Yet the reply letter provided by Mrs Gill Pawson failed to do this and simply stated that “we are not aware of any agency thresholds “.

The EA has provided commonly recognised “acceptable concentrations of the key components of bioaerosols”. These are:

 1000cfu/m3 total bacteria

 1000cfu/m3 total fungi

 300cfu/m3 gram-negative bacteria

2.4 In Conclusion

In allowing for potential contributions from other farming activities in the area, and using the indicative concentrations provided in appendix D of the report, it is evident that the site is not the best location for permitting an activity that will contribute to the background level of bioaerosols which already, according to the report is significantly loaded with bioaerosols. The overall concentrations will therefore be significantly higher than the EA recommended reference concentrations and certainly above the background concentration in a normal suburban area.

One would assume that in highly impacted area by certain type of pollutants, additional emission from a new facility should be heavily controlled to reduce the level of that pollutant in the area.

In following the examples set for other UK industries regulated by IPPC, when assessing potential impact on air quality from a proposed facility, consideration of the background contribution from other pollution sources should be taken into account and when a release from an installation constitutes a major proportion of an Environmental benchmark, or makes a major contribution to the breach of this benchmark, then this may not be judged to be acceptable. Where the benchmark is already exceeded or may be exceeded as a result of an additional contribution from a proposed installation, consideration of further control measures may be needed to be taken

We are not suggesting that these regulations apply to the proposed installation however, common sense would dictate that this should be the approach adopted rather than trying to dismiss the significance of potential risk by the presence of other sources in the area.

RPS Planning, Transport & Environment 4 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 3 The Health Effects of Bioaerosols.

The submitted bioaerosol assessment recognises that ‘bioaerosols in high numbers for extended periods, can be detrimental to sensitive individuals’; but concludes that ‘composting operations pose no greater threat than other industrial or agricultural activities and that evidence is available to show that only a very small proportion of the population are sensitised by bioaerosols’.

3.1 The true health Impact of Composting Operations

In terms of the potential health impact from exposure to bioaerosols, Section 6 of the HSE review identifies different potential health problems based on a review of a wealth of published data regarding known health effects from organic dust. This report identifies members of the public living in the vicinity of waste composting sites and member of the public passing by the periphery of waste composting sites as some of those potentially at risk to a greater or lesser degree.

Exposure to the micro-organisms found in compost could potentially cause ill-health in the people exposed to them either by infection, allergy or an adverse response to toxins.

Some of the micro-organisms which increase in number during the composting process are toxic and/or allergic.

Even after the microbial cells have ceased metabolic activity and entered a resting or non-culturable but viable stage or for a period after cell death before proteinaceous components have degraded, there is still the potential for microbial cells to be toxic or allergenic.

According to Dr Toni Gladding in a presentation for the sustainable Organic Resources Partnership and many other documents including the HSE report, health effects associated with bioaerosol include:

 Infections: caused by pathogens capable of invading body tissues and growing

 Allergy: immunological response that results in the body becoming “sensitised” following exposure

o Respiratory sensitisers

o Non-specific inflammatory reactions

o Predisposition/atopy

 Gastrointestinal: hygiene issues

 Hyperactive airways: inflammation on exposure (increased susceptibility to other chest illnesses)

 Allergic rhinitis & Asthma: allergy based

 Chronic bronchitis and chronic obstructive pulmonary disease (COPD)

 Extrinsic allergic alveolitis or granulomatous pneumonitis- more applicable to occupational exposure

 Acute Toxic Pneumonitis (organic dust toxic syndrome-ODTS)-Fever and flu like symptoms, headaches, muscle pains, chest tightness 2-6 hrs after exposure (toxic alveolitis- thought to be toxic not allergic) usually occurs during or shortly after, high exposure to airborne dust.

 Chronic ODTS: chronic muscle pains, tiredness, shortness of breath.

 Chronic sinusitis: dizziness, chronic cold etc

It should be noted that some of these ill health effects are associated with short-term exposure. Furthermore sensitisation could be caused by non-viable bioaerosols such as endotoxins (macromolecule with a lipopolysaccharide core, found in the cell walls of all gram-negative bacteria), mycotoxins (non-volatile low molecular weight toxic secondary metabolites produced by some species of fungi during their growth in organic materials) and Glucans (a polyglucose compound in the cell walls of fungi, some bacteria and plants).

3.2 Concern about the nearby Primary School

The site is close to the local primary school where 60+ children attend. It is generally accepted that young children can be particularly susceptible to the effect of environmental pollutants and therefore were identified in the current UK guidance to risk assessment to human health by DEFRA and the EA as the most sensitive receptors. The headmaster has written a letter of objection in which he states” on numerous occasions when the site was in operation the smell was so strong and so unpleasant that it made normal conduct of school life very difficult. It was, on several occasions, impossible to allow children to use the playground at break times and windows, especially those on the mezzanine floor had to remain closed to the great discomfort of the pupils and staff”.

RPS Planning, Transport & Environment 6 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 4 The Entire Village of Old Sodbury is at Risk Regardless of the 250 m limit.

4.1 Distance to the Receptors

The locals, and a firm of Chartered Land Surveyors, Lewis Brown, have undertaken several measurements all of which prove that the distance to the receptors is less than the 250m.

In the professional survey the measurements have erroneously been taken from the edge of the ‘impermeable pad’ and not the composting facility nor even the composting ‘bund’ within which it is clear composting activity has taken place (appendix 2) .

In fact the EA guidance on this is clear; distances should be taken from the boundary of the facility, which in no way limits the distance to the composting pad. The residents of Old Sodbury have photographs which prove that a great deal of the composting activity has taken place immediately behind the bund (outline marked appendix 2) on the western part or Church Lane side of the facility. Indeed officers from the EA have noted on a number of occasions that the activity was not confined to the composting pad (letter from Jim Dadd, 25th May 2005) but still the bund remains.

In summary therefore the 250 metre line is likely to encompass many more than 9 dwellings. The residents have drawn up a list of 36 houses, 1 business and a school within this 250 m circle (appendix 3).

Even on the erroneous map provided the 250 m line encompasses the school field (it has planning permission to turn it to astro) yet this is not listed in the dwellings affected.

4.2 The 250m Limit is Guidance Only.

However and more importantly, this 250 m criterion is a mere guidance and can not be used as an argument for dismissing the need for a proper site specific risk assessment where ill health and nuisance problem were already identified. Furthermore, the HSE Report 2003 stated clearly that “while most published studies indicate that bioaerosols are reduced to background within 250m distance currently prescribed by the EA for risk assessment purposes, some experimental studies and dispersion modelling exercises suggest that bioaerosols sometimes may exceed concentrations chosen as background levels at distances greater than 250m.

Considering that there have been reports of ill health from the residents in the vicinity, this criterion cannot be used to dismiss potential effect, as migration of contaminants is usually site specific and can be affected by the local conditions including metrology and topography.

RPS Planning, Transport & Environment 7 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 5 Sensitive Receptors Could be Affected 55 Days a Year or More

In terms of the fourth criteria, the assessor has presumed that in reporting that the prevailing wind is predominantly away from the nearest sensitive receptor and that the wind only blows in the direction of the village for 15% of the time he is producing adequate evidence to dismiss the significance of potential risk.

Considering that the EA recommended assessment criteria for bacteria, fungi and gram-negative bacteria of 1000 cfu/m3, 1000cfu/m3 and 300cfu/m3 are for the 8-hour and 1-hour averages respectively, having elevated concentrations exceeding the assessment criteria even for only 15% of the year (55 days) is still presenting a serious problem. This is especially important considering that some of the ill effects such as Organic Dust Toxic Syndrome which is associated with short-term exposure to high levels of airborne organic dust.

5.1 Meteorological Data and Temperature Inversion

It should also be noted that the Dr Burden’s bioaerosol assessment only considered wind data in a very simplistic manner, using wind rose data from Filton to establish the prevailing wind conditions.

In our opinion this will not provide a good interpretation of the air movement and consequently the dispersion of pollutants in the vicinity of the site. We cannot stress too highly The meteorological data required should include, in addition to wind speed and wind direction, other surface data such as atmospheric stability and atmospheric temperature.

Temperature is a factor of paramount importance in deciding the dispersion of pollutants.

For instance, at night, with clear skies, cooling occurs as considerable outgoing infrared radiation leaves the earth’s surface. With light winds, the surface and adjacent air layers cool, resulting in a temperature inversion (temperature increasing with height instead of the usual cooling with height). The result is extremely stable conditions with almost no vertical exchange between air layers. Stable conditions inhibit the vertical motions; however, the spreading in the horizontal direction can also be very narrow.

These extremely stable conditions cause the highest ground-level concentrations from surface and near surface releases (such as those from windrows). The light winds that accompany the extreme surface inversion formation also contribute to the high concentration from surface releases (Physics of the atmosphere-Fundamentals of Dispersion modelling-Trinity).

Therefore stable conditions will NOT decrease the concentration of bioaerosols due to deposition, as it is associated with light wind close to the earth surface, that can and will carry the pollutants away from the source with little very limited dilution. In this case therefore such pollutants are likely therefore to be deposited on the nearby receptors including the village of Old Sodbury.

Indeed it ties in with the phenomenon of early morning and evening odour/health problems reported by the residents.

5.2 The Commercial Realities of Operating a Composting Site.

The report suggested that turning windrows will only take place when the wind is away from the properties in the village. In practice, a commercial business, where optimum composting conditions are achieved by regular turning of windrows (employing men for this purpose) cannot cease activity when the weather conditions are unfavourable.

Also it is unlikely that expensive pre-booked screening and shredding equipment will be turned away because the weather conditions dictate they should be.

RPS Planning, Transport & Environment 9 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 6 Conclusions and Recommendations

In conclusion, it is our opinion that the bioaerosol assessment for the subject site has failed to undertake a sound site-specific risk assessment that demonstrates that appropriate levels can be achieved and maintained at any working or dwelling place in the area.

6.1 Odour

It should be noted that, although release of odour from composting facilities is as critical in respect of potential impact on sensitive receptors as bioaerosols, no effort was made to carry out an assessment to this element.

Odour assessment is well established in the UK based on the current UK guidance “Technical Guidance Note- Horizontal guidance for odour“.The aim of an odour assessment, according to this guidance is :

 To predict the exposure of sensitive receptors

 To indicate the amount of abatement

 Improvement or worsening performance over a period of time

 Determine compliance

 Investigate complaints

The guidance states that a qualitative estimation of the risk can be undertaken in terms of whether the release is likely to cause a problem or not. However as the risk of causing annoyance increases, and/or a HISTORY OF ODOUR COMPLAINTS OR ANNOYANCE ALREADY EXISTS, then so will the need for a more in-depth assessment that takes a more quantitative approach.

The EA guidance in part 2 states “where the odour emission rate from a source is known by measurement, or can be estimated, the odour concentration in the vicinity can be predicted by means of dispersion modelling”. To visualise the extent of odour impact it is useful to produce contour plots showing odour concentrations around the source or highlighting where concentrations exceed the appropriate exposure benchmark which relates to acceptability.

Appendix 4 of part 1 of the guidance covers the subject in more detail and proposes a “recommended” approach to odour modelling aimed at bringing about consistency of approach. The guidance states, “There may be circumstances in which there is a valid reason for taking a different approach and the proposed parameters do not exclude this, provided that the methodology is described and justification given. “Benchmarks” are described in Appendix 5 and 6 of part 1 of the guidance”. Indicative odour exposure criteria for ground level concentration of mixture of odorants are set based on the offensiveness of odour. For highly offensive odour such as that from activities involving putrescible waste , the indicative criteria is set to 3 1.5 ouE /m .

On mitigation measures, the guidance states that ”a simple and effective way for the operators of odorous operations to minimise odour complaints has been to locate their process(es) as far as way as possible from inhabited areas”.To demonstrate the importance of the impact of odour, planning permission is required for certain odorous facilities within a distance of 400m from the boundary of any protected buildings (e.g houses and schools) as an incentive for .operators to site any new process at least 400m away from the nearest protected building. The guidance carries on identifying good housekeeping and building design to have significant effects on odour reduction. The guidance dismisses tree planting and earth banking as a solution for dealing with odour problems and states that “ there is no conclusive evidence to show any real and sustained odour removal or dispersion effect resulting from landscaping.”

Considering the facts:

that the released odour is highly offensive, due to the nature of the process;

there is no containment of the operations, being an outdoor windrow facility;

the village of Old Sodbury lies within 400m of the site

the proposed odour management plan, submitted without a proper risk assessment, is not considered adequate or appropriate.

RPS Planning, Transport & Environment 11 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment Appendices

Appendix A

Supporting Scientific Evidence for the Summary Statement Reviewing the Quality and Accuracy of the Bioaerosol Assessment Written by Dr John Burden Regarding Southcroft Farm, Old Sodbury.

RPS Planning, Transport & Environment 13 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment Supporting scientific evidence for the summary statement reviewing the quality and accuracy of the bioaerosol assessment written by Dr John Burden regarding Southcroft Farm, Old Sodbury.

Bioaerosols: UK Recommended Assessment Methodology

The key aim of any environmental impact assessment is to identify and assess potential harms to human and other environmental receptors from any identified sources at the assessed site. The assessment procedure should utilise the source-pathway-receptor concept in constructing a site conceptual model (SCM) and assessing potential impact.

The conceptual model, focussing particularly on site specific characteristics, is usually based on an initial evaluation of available data that characterises the sources of emission and identifies all possible pathways connecting the sources to sensitive receptors both on and beyond the site. As the assessment progresses the conceptual site model is continually refined within the context of the impact linkage.

To present information in a manner consistent with the Source-Pathway-Receptor concept and to assist in evaluating the possible impacts of releases from the site on human wellbeing, the SCM should establish, in a qualitative manner, the sources of emissions, potential pathways of exposure, and potential receptors as follows:

. Principal sources of emissions;

. Substances of primary concern (odour, bioaerosols, etc);

. Behaviour of the emitted substance within the affected media (air);

. All potential receptors;

. Location of potential exposure points;

. Likely migration pathways for the emitted substances to move off-site;

. Plausible pathways connecting sources and sensitive receptors;

. All significant impact linkages associated with the site.

An assessment of releases and dispersion of odour and bioaerosols is usually required where emission sources(s) from a composting facility are located in an area within which sensitive receptors are residing or working. Potential impacts from the releases and dispersion of the pollutants with considerations to the prevailing meteorological conditions for that location, and the proximity of the sensitive locations to the emission sources giving rise to health impact or nuisance are therefore required to be assessed.

The EA reported that Bioaerosols assessment is only required where the boundary of the facility is within 250m of sensitive receptors3. The composting association defines sensitive receptors as ‘any building, other structure or installation, in which at least one person

RPS Planning, Transport & Environment 14 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment normally lives or works, other than a building, structure or installation within the same ownership or controls as the operator/owner of the composting facility2.’

It should be noted that the Health and Safety Executive report 20036 stated that ‘while most published studies indicate that bioaerosols are reduced to background within the 250m distance currently prescribed by the environment Agency for risk assessment purposes, some experimental studies and dispersion modelling exercises suggest that bioaerosols sometimes may exceed concentrations chosen as background levels at distances greater that 250m.’

It can be concluded from the above that the submitted report fails to meet the basic requirement of any risk assessment by failing to present the sources, pathways of exposure and receptors in a concise and clear manner. This is especially important considering that a number of receptors are located within less than 250m distance from the installation.

The bioaerosols risk assessment was based mainly on the wind rose for the area. The assessor has presumed, by reporting that the prevailing wind is predominantly away from the nearest sensitive receptors it mainly impinges on open countryside and that the wind only blowing in the direction of the village of Old Sodbury for 15% of the year is adequate evidence to dismiss the significance of potential effect. Considering that the EA recommended assessment criteria for bacteria, fungi and gram-negative bacteria of 1000 cfu/m3, 1000 cfu/m3, and 300 cfu/m3 are for the 8-hour and 1-hour averages respectively, having elevated concentrations exceeding the assessment criteria even for only 15% of the year (55 days) is still presenting a potential health problem.

The bioaerosol risk assessment report stated that ’composting process can result in the production of high concentrations of bioaerosols within the material being composted and that in some situations populations as high as 109 with bacteria, 108 with actinomycetes and 106 with fungi per gram can be recorded on material being composted.’ Nevertheless the report still compared it with the natural occurrence of bioaerosol in some natural environments which totally ignores the scale of production of bioaerosols in open windrow type of facilities.

Schilling et al (1999) compared an enclosed composting plant with biofilter with a partly open plant. The researcher found that fungal spores and Aspergillus fumigatus were up to 500 and 400cfu/m3 at 50m from the enclosed plant in comparison to 6,000 and 7000cfu/m3 of these bioaerosols at a greater distance of 100m from the partially closed plant.

Danneberg et al (1997) has found that the exhaust air emitted from biofilter contained 33 cfu/m3 bacteria and 600cfu/m3 Aspergillus fumigatus (fungi) in comparison to 76,000 cfu/m3 and 2000cfu/m3 of these bioaerosols in the location of the rotating sieve of a box-system composting plant. In comparison, Tovalen et al (1998) reported a thorough investigation of bioaerosols from outdoor composting source separated biowastes in Finland. The compost was processed outdoors. Concentrations of airborne microbes were high especially during crushing of fresh waste and turning of compost. Both bacterial and fungal were higher in the summer when the compost was dry.

Maricou et al (1998) reported that the airborne counts of total bacteria, fungi and yeast at a large indoor composting plant were up to 100 times higher within the inside of the composting halls in comparison to the levels outside.

It can be seen from the above that bioaerosol emissions from open windrow operations such as that proposed for the subject site is significantly higher than those generated at enclosed facilities. Recommended Methods for Assessment of Bioaerosols

A study undertaken by the HSE and the composting Association with the objective of critically reviewing published literature related to studies of air-borne micro—organisms or their constituent parts (bioaerosols) associated with organic waste composting facilities. One of the considerations was that airborne dispersal of bioaerosols from compost facilities could affect neighbouring facilities or residents, leading to health concerns. The report stated that bioaerosols concentrations decline with distance from source due to atmospheric dispersion and dilution and that mathematical and computational models can be used to estimate this dispersion and to examine the effects that different atmospheric stability classes have on reduction of bioaerosol concentrations.

There are few papers that specifically address the modelling of dispersion of bioaerosols from composting.

In some instances, modelling has been used to estimate bioaerosol emission rates based on measurements of bioaerosols made at distance from source. These emission rates have then been used in calculations to examine dispersion under conditions for which no measurements have been undertaken.

Millner et al (1980) describe concentration measurements and dispersion modelling of Aspergillus fumigatus, released from composting sewage sludge when disturbed due to turning. Emission rates were estimated using a Gaussian dispersion model (Pasquill, 1961) by fitting 31 individual concentration measurements, taken at distances from 10 - 620m. The calculated emission rates varied from 2.3x104 to 6.7x1010 Aspergillus fumigatus particles per second. It was assumed that the Aspergillus fumigatus spores were sufficiently small that a Gaussian dispersion model was appropriate and deposition was not modelled.

Also it was assumed that for the times and distances considered viability of Aspergillus fumigatus spores was not an issue. Based on the calculated emission rates, and ‘some judgement’, an effective emission rate of 4.6x106 Aspergillus fumigatus particles per second was then used in calculations examining the effect of different atmospheric conditions on dispersion.

In this modelling the actual release was considered to occur from the bucket of a front end loader above the windrow. A release height representing this was used as being 5m a front end loader bucket mouth area of 2.8m2 was assumed as the source area. They reported that a possible alternative representation of the source would have been an area, or volume, with uniform concentration.

These calculations found that under unstable atmospheric conditions background concentrations were approached 0.5 to 0.6km downwind of the source. The fact that there were variations in emission rates between compost piles containing similar concentrations of Aspergillus fumigatus was mentioned to explain at least some of the range of calculated emission rates.

Danneberg et al (1997) made concentration measurements and used these to estimate emission rates by modelling dispersion. Concentrations were measured downwind of a composting plant at points on four lines, 45º apart, originating at the plant. Three samples were taken at each point. The emission rate of Aspergillus fumigatus was calculated using

RPS Planning, Transport & Environment 16 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment the mean of the concentrations measured at 150m downwind. The emission rate was then estimated using two models, one a regulatory dispersion model from the German Technical Instructions on Air Quality Control, TA Luft, (1986), the other an expression developed to examine NOx emissions from tall chimneys.

The models were found to give emission rate of 1.25x107 of total bacteria per second. This value was considered to be roughly in the same order of magnitude to those calculated by Millner et al (1980) for Aspergillus fumigatus. Dispersion calculations using the estimated emission rate indicated that concentrations were less than 500 cfu/m3 at 500m; this concentration was assumed to be equivalent to background concentration.

From the above discussed details of the EA work and the HSE review for a number of composting facilities, it can be concluded that although using simplistic dispersion modelling of the Bioaerosol plume was proven not very effective (over-conservative) for bioaerosols, the modelling can be used to predict concentrations in the context of differing atmospheric conditions and the likelihood of different exposure levels and durations. It is a common practice nowadays to use dispersion models to predict the concentrations of bioaerosols at identified receptors within the vicinity of the site. Some assessors use an alternative assessment where analytical models such as the Danneberg et al (1997) models are used to predict concentrations and then insert them into probabilistic models to predict the concurrence of these elevated concentration with worse metrological conditions (from the wind rose data) and assess potential risks accordingly.

The subject bioaerosols risk assessment has not attempted to use any of the above discussed commonly used methodologies and rather used the wind rose data for a subjective assessment in isolation of any site specific data. The use of the wind rose data in such a subjective manner is therefore not considered to be adequate to assess potential impact from the site on the neighbouring properties. We therefore have recommended the use of air dispersion modelling for the assessment of potential impact from the site on the neighbouring sensitive receptors. We have discussed the matter with Dr Martin McVay and he has expressed concerns regarding the applicability of the use of air dispersion modelling stating that “I reiterated that our science projects are still ongoing with regard to quantifying an appropriate source term and appropriate health benchmarks for bioaerosols from composting sites, and that they will hopefully deliver advice on the approach to take with regard to predictive risk assessments in the next year or so. At present, where the source term uncertainty is far greater than the differences between dispersion models, the benefits of using an advanced dispersion model over a simple screening method like H1 are small”.

We agreed with Dr McVay that the source term is essential information that is required for any type of risk assessment for any site with emission that have the potential to pose unacceptable risks to those reside in its vicinity. We however believe that identifying the source term is the responsibility and duty of the operator. Considering that ill health

RPS Planning, Transport & Environment 17 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment complaints have been already reported, we see the necessity to undertake a proper risk assessment. If the operator does not accept the dispersion modelling as an approach to the risk assessment due to the lack of information on his operations, we suggest that he propose an alternative assessment approach that demonstrates that the site is not contributing to the ill health of the residents of the area. Potential nuisance from exposure to odour from the operations will still require proper assessment following the EA guidance.

We have also highlighted to Dr McVay that a number of studies were conducted to identify the source term for different types of composting facilities. These include an EA study that monitored different source terms at different composting facilities with different types of waste input. There is also a literature review undertaken by the HSE within which a large data set regarding emissions from variety of composting facilities was presented. Recently, a project report was published by Viridor and SWICEB. This report presents emission data from variety of sources from operational areas on different sites receiving different types of wastes. We recommend that in the absence of site specific data, literature values for potential ranges of emissions for the different types of operations are collected, statistically presented if possible and used as appropriate with attention given to the uncertainty in the use of non-site specific data. This kind of assessment, though not accurate will at least give an indication on the potential risk.

References

1Environment Agency. 2003. Monitoring of particulate Matter in Ambient Air around Waste Facilities, Technical Guidance Document, R&D project P1-441.

2Environment Agency. 2001. Agency Position on Composting and Health Effects.

3Environment Agency, 2001. Health Effects of composting, A study of three compost sites and review of past data, R&D Technical Report P1-15/TR. ISBN 1 85705 680 9.

4Environment Agency, 2001. Monitoring the Environmental Impact of Waste Composting Plants, R&D Technical Report TR P428. ISBN 1 85705 683 3.

5Environment Agency. 2001. Technical guidance on composting operations (version 3). Draft for external consultation.

6Health & Safety Executive, 2003. Occupational and environmental exposure to bioaerosols from composts and potential health effects- A critical review of published data. Research report 130 prepared by the Composting Association and health and safety laboratory for the HSE.

7Danneberg G, Grueneklee E, Seitz M, Hartung J and Driesel A J Microbial and endotoxin immissions in the neighborhood of a composting plant Annals of Agricultural and Environmental Medicine 1997; 4, 169-173.

Literature referenced in the above documents

Gilbert, E. J., Ward, C. W. Standardised Protocol for the Sampling and Enumeration of Airborne Microorganisms at Composting Facilities. 1999. The Composting Association, Coventry

Lacey J, 1981 The aerobiology of condial fungi. In the biology of condial fungi, Eds. Cole GT and Kendrick WB, Academic press, New york, USA 373-416

Lacey J, Williamson, P. A. M King P and Bardos, RP, 1990 Airbourne microorganisms associated with domestic waste composting, Waren Spring Laboratory Report LR 808.

Lacey J, Dutkiewicz J . Bioaerosols and occupational lung disease J. Aerosol Sci. 1994, 25, 1371-1404

Lacey, J., Williamson, P. A. M. Airborne Microorganisms Associated with RDF Fines at Castle Bromwich, CWM/110/93, Report to UK Department of the Environment Wastes Technical Division, 1995.

Lacey, J., Williamson, P. A. M., Crook, B. Microbial emissions from composts and associated risks In Aerobiology (Muilenberg, M. and Burge, H., eds.), 1996, 1-17, CRC Press, Boca Raton, Florida

Malmberg P, Rask-Anderson A, Palmgren U, Hoglund S, Kolmodin-Hedman B and Guernsey J R, 1988 Incidence of organic dust toxic syndrome and allergic alveolitis in Swedish farmers. International Archives Allergy Applied Immunology, 87,47-53

Malmros P. Problems with the working environment in solid waste treatment. The National Labour Inspectorate of Denmark report 1990.

Millner P D, Bassett D A and Marsh P B. Dispersal of Aspergillus fumigatus from sewage sludge compost piles subjected to mechanical agitation in open air. Applied and Environmental Microbiology 1980: 39, 1000-1009

Millner, P. D., Olenchock, S. A., Epstein, E., Rylander, R., Haines, J., Walker, J., Ooi, B. L., Horne, E., Maritato, M. Bioaerosols Associated with Composting Facilities Compost Science and Utilization 1994, 2, 6-57

Haas DU, Reinthaler FF, Wust G, Skofitsch G, Degenkolb T, Schumann P, Marth E. Emission of thermophilic actinomycetes in composting facilities, their immediate surroundings and in an urban area. Centr. Eur. J. Publ. Health 1999; 2: 94-99.

Lavoie J, Alie R. Determining the characteristics to be considered from a worker health and safety standpoint in household waste sorting and composting plants. Ann Agric Environ Med, 1997, 4, 123 - 128.

Palchak R B, Cohen R and Jaugstetter J. 1990 A threshold for airborne endotoxin associated with industrial scale production of proteins in Gram-negative bacteria. Developments in Industrial Microbiology, 31, 199-203

Rylander R, Lundholm M and Clark C S, 1983 Exposure to arosols of micro-organisms and toxins during handling of sewage sludge. In Wallis P M and Lehmann D L (eds) Biological health risks of sludge disposal to land in cold climate.

Rylander R, 1986 Lung diseases caused by organic dusts in the farm environment. American Journal of Industrial Medicine, 10, 221-227

Rylander R. Organic Dusts and Lung Disease: The Role of Inflammation Ann. Agric. Environ. Med.1994, 1, 7-10.

Rylander R. Evaluations of the risks in endotoxin exposures Int. J. Occ. Environ. Health. 1997, 3, S32-S36.

Rylander R, Bake B, Fischer JJ, Helander IM. Pulmonary function and symptoms after inhalation of endotoxin Am. Rev. Resp. Dis. 1989, 140, 981-986.

Sigsgaard T, Back B and Malmros P, 1990 Respiratory impairment among workers in a garbage handling plant. American Journal of Industrial Medicine, 17, 92-93.

Sigsgaard T, Malmros P, Nersting L, Pedersen C. Work related symptoms and lung function among Danish refuse workers. Am. Rev. Respir. Dis. 1994, 149, 1407-1412.

Sigsgaard T, Hansen JC, Malmros P. Biomonitoring and work related symptoms among garbage handling workers Ann. Agric. Environ. Med. 1997, 4, 107-112.

Tolvalen O, Veijanen A, Villberg K. Occupational hygiene in biowaste composting. Waste Management and Research, 1998, 16, 525 - 540.

Tuomela, M., Vikman, M., Hatakka, A., Itävaara, M. Biodegradation of Lignin in a Compost Environment: A Review Bioresource Technology 2000, 72, 169-183

Appendix B

RPS Planning, Transport & Environment 20 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment Map of Houses Within 250m

RPS Planning, Transport & Environment 22 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment Appendix C

Number of Houses Within 250m of Compost Farm

Number of houses within 250m of compost farm

Dwellings within 250 metres of the composting pad. (Taking measurement to boundary of dwelling not the actual dwelling.)

RPS Planning, Transport & Environment 23 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment 1. Old Sodbury Primary School 2. School House 3. Sunnymeade 4. 19 Church Lane 5. 17 Church Lane 6/7. 15 Church Lane (Includes dwelling of a family of 4 and a business which employs 5 South Glos residents.) 8. 22 Church Lane: The Gate House 9. 20 Church Lane: The Cottage 10. Weylode 11. Plough Farm (Home and an operational farm)

Additional properties within 250 metres of the composting operation itself.

12. Oxleaze 13. Hayes Farm Cottage 14. The Coach House 15. 25 Church Lane 16. 23 Church Lane 17. 21 Church Lane 18. 13 Church Lane 19. 11 Church Lane 20. Woodbridge (18 Church Lane) 21. 16 Upper Church Lane 22. 16 Lower Church Lane 23. 14 Church Lane 24. 12 Church Lane 25 10 Church Lane 26. 8 Church Lane 27 6 Church Lane 28 4 Church Lane 29 2 Church Lane 30 9 Church Lane 31 7 Church Lane 32 5 Church Lane 33 3 Church Lane 34 1 Church Lane (Raisdale) 35 Vale View 36 Hill Crest 37 Next door to Hill Crest (name of property unknown) 38 Southcroft Farm

Appendix D

RPS Planning, Transport & Environment 24 Southcroft Farm, Old Sodbury November 2006 JER3449 Summary Statement : Bioaerosl Assessment CV – Ahlim Hashm

RPS Planning, Transport & Environment 25 Southcroft Farm, Old Sodbury November 2006 JER3449 Name: Ahlim Hashm

Office: Chepstow

Position in Company: Principal Consultant

Qualifications / Memberships: PhD Environmental Geotechnics, BEng Engineering, B.Sc. soil sciences, The Lloyds prize, The David Lenczner prize, The John Barrett prize and The Norman Thomas design prize.

Date of Birth: 22nd March 1962

Key Clients: Worcester County Council Gleeson Group Simsmetal

Furlong Homes Aylsford Newsprint Limited Alcan,

St James Homes Waste Recycling Group Federal Mogul

NPL Estates

Areas of Expertise:

Ahlim has over 10 years experience working in environmental assessment and waste management particularly human health, air quality and waste assessment. Specialist technical expertise in modelling exposure, transport, retention and migration of contaminants in soil, water and air. Extensive experience in the use of the more prominent protocols and software packages for assessing risks to human health and the environment.

Experience Includes:

Ahlim is a human health risk assessment, air quality and waste management specialist responsible for the human health risk assessment and air quality team. She has extensive experience in environmental assessment and project management gained through working in the public and private sectors. Prior to joining RPS, Ahlim was the project manager of the ERDF-funded programme “Regional Centre for the Treatment of Contaminated land” and the technical supervisor of the ERDF funded project “Development of commercial software tools for assessment of contaminated land” within Cardiff University

Ahlim has applied her expertise to the assessment of risks to human health from exposure to a wide variety of naturally occurring and artificial toxins and carcinogens via a range of pathways and for a variety of land use scenarios. She has been directly involved in the assessment of potential risk and nuisance impacts from gaseous and odorous emissions and bioaerosols from a number of waste management/treatment facilities on the local air quality. She used her extensive experience in the classification of waste and development of waste acceptance procedure to a range of waste streams generated by various industrial activities

l Key Experience

Human Health Risk Assessment . Has undertaken a large number of human health risk assessments for a wide variety of sites ranging from small residential properties with naturally occurring or commonly found determinands to complex industrial premises affected by a wide range of contaminants.

. She used a number of human health risk assessment models including, CLEA, SNIFFER, RBCA, smartRisk, and other internationally recognised models and databases such as the USEPA PRG on-line model. She has also developed a number of non-standard risk assessments for “special case” sites.

. Within the context of the latest UK guidance on human health risk assessment that requires the derivation of guideline values for chemicals of potential impact on human health, Ahlim is the leader of the team responsible for deriving guideline values from first principles. This involves extensive reviews of toxicological data for a large number of chemical substances, evaluating the data to derive tolerable intakes and index doses, identify all potential routes of exposure and utilise the derived values in assessing risks from human exposure to these substances through relevant pathways of exposure.

Air Quality Assessment Carried out a number of tier 1 air quality assessment in accordance with the IPPC horizontal guidance and the screening method for emissions to air from landfill sites provided by the Air Quality Modelling and Assessment Unit of the Environment Agency for a number of waste management/treatment facilities. As part of her responsibility as the leader for the air quality team, Ahlim was responsible for the development of the in-house package of the tier 1 assessment based on the regulatory guidance.

Carried out a number of detailed air dispersion modelling for a variety of waste treatments/disposal installations such as gasification/pyrolysis and MBT plants, engines and flares using the new generation dispersion model Aermod.

Carried out aerosol and odour assessments for a number of composting facilities using air dispersion models. Ahlim has also involved in providing technical advice in respect of identifying the location and height of the venting sources giving considerations to the local meteorological regime and the location of sensitive receptors.

Landfill Gas Assessment

. Carried out landfill gas assessment as part of the PPC permit application for a number of landfills accepting various waste streams using GasSim. Considerations were given in all of these assessments to accidents and failure scenarios in order to quantify the impact of given events and assess the reliability of landfill gas control system and site engineering. She also involved in the development of the gas management plan for these sites.

l . Annually produced and electronically submitted Pollution Inventory Forms for a large number of landfills.

. Involved in advising landfill operators on the sizing of flares of engines based on the waste input and predicted methane emissions

Waste Assessment Undertaken a waste classification based on the Hazardous Waste Directive and the Environment Agency guidance WM2 and in accordance with the revised European Waste Catalogue for a number of waste streams to identify appropriate type of treatment and disposal options.

Developed a number of waste acceptance procedures in compliance with the requirement of the Landfill Regulations (England and Wales) 2002 and amendments 2004 for a number of landfills. Ahlim has also involved in giving technical advice with regards to the specific acceptance criteria as per the European Council relevant Directives and Decisions for underground Storage disposal facilities

Other Experience

Carried out a number of risk assessment and ventilation requirements for the ingress of methane and other gases from the ground into buildings. The assessments are carried out in accordance with the CIRIA 152 methodology and various BRE Publications. The ventilation requirements are estimated in accordance with the British standard ventilation principles and other methodologies such as the Johnson Attinger model.

Undertaken a number of ecotoxicological assessments for a number of sites of ecological significance. Ahlim previous experience in research and modelling within the field of fate and transport of contaminants gave her the ability to undertake site specific, non-conventional risk assessment where required and in the absence of UK standards and guideline values.

Managed a number of large-scale projects involved the design and management of site investigation, risk assessment and remediation for a variety of industrial and waste management sites. These include site specific risk assessment to controlled water and sensitive ecological receptors from contamination in soil, water and air. This involved the use of a number of models such as Consim, R&D 20, RBCA and bioplume.

Prepared a number of occupational health and safety strategies for remediation and construction workers on heavily contaminated sites.

Undertaken site auditing and environmental due diligence for a large number of sites in the UK on behalf of Lloyds TSB and other clients.