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From: TSS ()
Subject: Animal safety on radar at DOW site, No spread of chronic wasting disease after study cited concerns (SO FAR)
Date: May 2, 2005 at 12:38 pm PST

-------- Original Message --------
Subject: Animal safety on radar at DOW site, No spread of chronic wasting disease after study cited concerns (SO FAR)
Date: Mon, 02 May 2005 14:43:53 -0500
From: "Terry S. Singeltary Sr."

Animal safety on radar at DOW site
No spread of chronic wasting disease after study cited concerns


Water draining north off the Colorado Division of Wildlife's foothills
research facility was the biggest biosafety concern for an independent
review team that toured the site in 2002.

The team's report, however, did not mention human health but said the
possible cross-contamination of infected and clean dirt in animal pens
at the research site would make it difficult for the DOW to evaluate
experimental results in its animals.

"There is some concern about the cross-contamination of pens," said the
report, provided to the Fort Collins Coloradoan by Colorado State

"Without distinct separations, it will be difficult to form sound
conclusions about the results of various experiments should animals in
'downstream pens' become sick."

But animals in downstream pens have never gotten sick from the practice,
which theoretically could take chronic-wasting-disease-causing prions
from infected pens to pens without the disease.

A CSU biosafety official and DOW's research facility manager say the
lack of sick animals is evidence the prions don't readily move through

A pair of Northern Colorado residents has questioned whether the DOW
site threatens city drinking water at a nearby treatment plant.

The Fort Collins raw water treatment plant, at 4330 W. LaPorte Ave.,
lies just east of the Soldier Canyon Filter Plant, which is below the
Soldier Canyon Dam at Horsetooth Reservoir.

Infected deer and elk as well as healthy cattle, deer, elk and bighorn
sheep live in adjacent outdoor pens at the facility, about 150 feet
northwest and upwind of open ponds at the city's treatment plant, which
produces drinking water for about 200,000 area residents.

The soil in pens with diseased animals also is thought to be infected
with chronic wasting disease.

The city Water Board is investigating whether people could get sick from
drinking city water if infected soil blew into the city's settling ponds
or air intakes at the plant.

The risk seems to be extremely low, according to experts, and city water
managers and the Larimer County Board of Health say the water is safe to
drink because city treatment methods would likely shake out prions,
especially if they're attached to other solids. Still, there is no way
to test water for prions, the mal-formed protein that causes chronic
wasting disease, and little research exists about the way prions move
through water.

The 2002 report says nothing about the potential for wind-blown
particles to find their way east across a road to Fort Collins' raw
water treatment plant.

Water drainage cited in the 2002 report comes from storage ponds at the
Soldier Canyon Filter Plant, a treatment plant south of and adjacent to
the DOW research site that treats water for East Larimer County Water
District, Fort Collins-Loveland Water District and North Weld County
Water District.

When the Soldier Canyon plant staff cleans out solids in the ponds every
couple of months, it drains the ponds, said Bob Reed, Soldier Canyon
plant manager. That water runs north through the outdoor pens at the DOW

Reed said DOW uses the water to irrigate the pens at the research facility.

By comparison, Reed said the amount of water drained into the pens is
less than the runoff expected from snow that fell on the site this week.

Mike Miller, a DOW veterinarian who runs the research facility, said elk
in downstream pens have not gotten sick during their five-year stay. And
bighorn sheep in another downstream pen have not gotten scrapie, chronic
wasting disease's equivalent in sheep.

Researchers believe the prions that cause chronic wasting disease and
other transmissible spongiform encephalopathies tend to cling to bigger
solids, including soil. The drainage water might not be enough to move
bigger clumps of soil, Miller said.

"So far, we haven't seen any crossover," said Bob Ellis, CSU's biosafety

Originally published May 2, 2005

-------- Original Message --------
Subject: CSU - illegal solid waste site?
Date: Fri, 22 Apr 2005 07:59:44 -0600
From: "Jim Woodward"

James B. Woodward
2035 Sherell Drive
Fort Collins, CO 80524

April 21, 2005

Ms. Amy Parsons
Associate Legal Counsel
Office of the General Counsel
Colorado State University
202 Administration Building
Fort Collins, CO 80523

Transmitted via Electronic Mail

Subject: FWRF Certificate of Designation

Dear Ms. Parsons:

In your March 31, 2005 letter, you stated that CSU does not have a Certificate of
Designation as a Solid Waste Disposal Site for the CSU property leased to the Colorado
Division of Wildlife (CDOW) for its Foothills Wildlife Research Facility. The CDOW
operates a composting facility on the CSU property that processes feces and other
materials contaminated with the chronic wasting disease pathogen.

According to statements made by the CDOW's Dr. Michael Miller at the April 15, 2005
meeting of the Fort Collins Water Board's Engineering/Water Supply Committee, CWD-infected
deer and elk carcasses have also been buried on the property.

I have recently confirmed that the CDOW does not have a Certificate of Designation for
this composting facility.

I have copied the Colorado Department of Public Health and Environment's Compliance
Bulletin for solid waste CD's for your review. I understand that CSU may have overlooked
this statutory requirement. When will CSU and/or the CDOW comply with this important
state law?


Jim Woodward


Compliance Bulletin
Solid Waste
reviewed/revised August 2002

The siting, permitting and regulation of solid waste
disposal sites is an area of dual jurisdiction between
the Colorado Department of Public Health and
Environment, Hazardous Materials and Waste
Management Division (the Division) and local
governing authorities. Persons proposing a facility in
unincorporated portions of any county must apply to
the commissioners of the county in which the site is
to be located. If the facility is proposed to be within
the corporate boundaries of a municipality, they must
apply to the governing body of the municipality.
Each party has assigned roles and responsibilities.
(6 CCR 1007-2 Section 1.3.1)

What is a certificate of designation (CD)?

A certificate of designation is a document issued by
the local governing body authorizing the use of land
for a solid waste disposal site or facility. The CD is
issued if it has been determined that the technical
standards set out in regulation are met and after local
issues are considered and satisfied.

Who must obtain a CD?

Anyone operating a facility for solid waste disposal
where processing, treatment, or final disposal of solid
waste is performed must obtain a certificate of
designation (6 CCR 1007-2 Section 1.3.3). Examples
of such facilities include municipal solid waste
landfills, certain private solid waste landfills,
composting facilities, and solid waste incinerators.
Exceptions to the requirement to obtain a CD
. those sites at which any person, other than a
governmental unit, disposes of one's own
waste on one's own property, as long as the
Division has determined that the site
complies with state regulations and is not a
public nuisance based on a review of an
engineering design and operations report
prepared and submitted by the operator;
. facilities at which persons are engaged in
mining operations under a permit issued by
the Division of Minerals and Geology of the
Colorado Department of Natural Resources
for mining wastes or other solid waste
generated within the permitted area;
. sites operated for the legitimate purpose of
processing, reclaiming, or recycling
recyclable materials as long as the materials
are not likely to contaminate groundwater or
create off-site odors as a result of these
. sites where sludge is applied for beneficial
purposes (fertilizer, soil conditioner, or
livestock feed) as long as the sludge meets all
State Board of Health and Department of
Agriculture requirements;
. hazardous waste disposal sites issued a CD
under the Colorado Hazardous Waste
regulations; and
. solid waste transfer stations that meet the
requirements of Section 7 of the State solid
waste regulations.
(6 CCR 1007-2 Section 1.4)

Who do you contact to obtain a CD?

Obtaining a certificate of designation begins with the
local governing authorities. Persons interested in
obtaining a CD should contact the county
commissioners, planning department, or municipal
government, based on the location of the proposed
facility. (6 CCR 1007-2 Section 1.6.1)

Is there an application form?

There is no standard application form to fill out.
However, it is strongly recommended that applicants
complete a "Solid Waste Disposal Sites and Facilities
Application Checklist" available from the Division.
This checklist assists the applicant and Division staff
in assuring that all pertinent information is included
in the application packet and where the material is
located. Notations on the checklist direct applicants
to the appropriate sections of the state regulations for
guidance. Copies of the Colorado Solid Waste
Regulations may be obtained from the Division and
are available in downloadable format on the Internet.

What happens after the local governing authority
receives the application?

The local governing body forwards copies of the
application packet to the Division for technical
review and recommendation of approval or
disapproval. The local governing body may also
conduct their own review at this time.

An application completeness determination must be
made by the Division within 30 days of receipt of the
application. The determination of completeness of
the application doesn't imply anything about the
outcome of the review, nor prevent the Division from
seeking clarifications or additional information.
(6 CCR 1007-2 Section 1.6.5)

Once it is determined that the application is complete,
a comprehensive technical review is completed to
determine if the siting, design, and operating criteria
of the proposed facility are protective of human
health and the environment. Any technical
conditions of approval made by the Division in its
final report will be incorporated as requirements in
the Certificate of Designation. (6 CCR 1007-2
Section 1.6.6) A public review and comment period
is included as part of the review. (Title 30 Article 20
Section 104(3)).

Who issues the CD?

The certificate of designation is issued by the local
governing authority. Issuance of the CD is based on
the recommendation of the Division to approve the
application and on local factors. (6 CCR 1007-2
Section 1.6.6) If the Division disapproves the
application, the local governing authority cannot
issue the CD. The local governing authority may
also deny the CD even if it has been approved by the
Division. The local governing authority is required
to conduct a public hearing for new CDs.

What fees are required to obtain a CD?

A non-refundable fee must accompany the
application to the local governing authority. This fee
is based on costs incurred by that body in the
application review and approval process (6 CCR
1007-2 Section 1.6.2). The applicant is also
responsible for costs incurred by the Division during
the comprehensive technical review of the
application, technical review of amendments to
existing certificates of designation, site visits, and
attendance of Division staff at meetings and hearings
concerning the application or amendments. The
applicant must pay all applicable fees prior to
issuance of the final recommendation (6 CCR 1007-
2 Section 1.7.2).

Are there other fees?

Landfill operators are required to collect a user fee
from each person disposing of solid waste at an
attended solid waste disposal site. These monies are
partially used by the Division to fund the ongoing
monitoring and inspection activities of Division Staff
(Title 25 Article 16 Section 104.5 CRS).

For more information:

Colorado Department of
Public Health & Environment
Hazardous Materials and
Waste Management Division
4300 Cherry Creek Drive South
Denver, Colorado 80246-1530
Customer Technical Assistance (303) 692-3320
888-569-1831 ext. 3320 toll-free
Division website

This Compliance Bulletin is intended to provide guidance
on the appropriate siting of non-hazardous solid waste
disposal sites and facilities based on Colorado solid waste
statutes and regulations only. The sites and facilities
described in this guidance may also be regulated under
other statutes and regulations.



-----Original Message-----
> From: Terry S. Singeltary Sr. []
> Sent: Friday, March 11, 2005 12:08 PM
> To: Jim Woodward
> Cc: tom pringle
> Subject: Re: CWD in H20
> hello jim,
> here are a few references;
> The BSE Inquiry / Statement No 19D
> Dr Alan Colchester
> Issued 27/01/2000
> WS493 DATED 09/08/99 BY PAUL GALE
> 1. WS493 by Dr Paul Gale discusses the
> infectivity and environmental
> behaviour of
> the BSE agent, and makes comments on WS18 and WS19.
> 2. The present statement responds to some of the
> points made in WS493.
> 3. In paragraphs 13, 14, and 15 of WS493, Dr Gale
> reviews recent
> evidence relevant
> to the debate about possible minimum or median
> infective dose of
> BSE-infected
> cattle tissue to humans after oral ingestion.
> Evidence from experiments by
> Raymond et al 1997 [J/N/388/285] is reviewed.
> That research contributes
> to our
> gradually increasing understanding of factors
> affecting prion infection,
> but many
> aspects are still not understood. One of the
> apparent implications of
> the Raymond
> et al paper is quoted by Dr Gale [WS493 para 15],
> viz. that sheep scrapie is
> inherently as transmissible to humans as BSE. One
> could draw three
> conclusions
> from this. The first possible conclusion (this is
> the interpretation
> chosen by Dr
> Gale) is that because scrapie is not known to
> cause human illness, so
> the risk of
> BSE causing a human illness is therefore very
> small. A second, alternative
> conclusion is that scrapie may indeed turn out to
> be transmissible to
> man, although
> this has never been demonstrated. Considering the
> strength of the
> evidence that
> BSE is indeed the cause of variant CJD, the
> second interpretation is
> arguably the
> more plausible of the two. A third possible
> conclusion is that the
> information
> provided by Raymond et als experiments about
> transmissibility to man of
> BSE, or
> of scrapie, or both, have to be interpreted with caution.
> 2
> 4. These points underline the fundamental fact
> that our understanding of
> these
> processes is still very limited. We have no
> direct evidence to enable us
> to quantify
> the human oral infective dose of BSE-infected
> bovine material. The
> Government
> naturally has to draw heavily on the advice of
> expert scientific
> committees when
> making decisions about such matters as the
> regulation of rendering.
> However, even
> for an expert scientific committee, uncertainty
> derived from shortage of
> data is
> difficult if not impossible to quantify.
> Conventional risk assessments are
> notoriously bad at coping with such uncertainty.
> The consensus view of a
> committee does not necessarily provide even
> coverage of the true spectrum of
> possibilities. When there is a serious shortage
> of experimental data,
> ten opinions
> about the same single source of experimental data
> may be no more
> valuable than
> one. In such circumstances, Government decision
> making needs to be
> guided much
> more by issues of principle, for example the
> relative prioritisation of
> business and
> health interests.
> 5. In paragraphs 18, 19 and 20 [WS493], Dr Gale
> discusses the expected
> binding of
> prion protein to the particulates. He states
> (paragraph 18) that prion
> molecules,
> which are about 4nm in size, could only pass
> through 400nm filters if
> solubilised in
> highly concentrated detergent which would not
> occur in a natural aquatic
> environment. In my view, we should keep an open
> mind about the possible
> physico-chemical state of the prion protein in
> the water-based products of
> rendering. As I proposed in WS19 paragraphs 21
> and 25, rendering may
> paradoxically increase the total available
> infectivity. The cooking
> processes
> involved in rendering are likely to generate an
> emulsion of lipid
> droplets to which
> the lipid-soluble moiety of the prion protein
> would attach (Planning
> Inquiry APP
> J2210/A/96/2687; Proof of Evidence by ACF
> Colchester, Jan 1997, pages 3 and
> 15), leaving the hydrophilic moiety orientated
> outwards, effectively
> stabilising the
> droplet in solution. This concept was developed
> by John Williams [WS
> 18]. Thus,
> the amphipathic prion protein molecule would
> itself act as a detergent.
> 6. In paragraph 20 [WS493], Dr Gale refers to my
> definition of
> amphipathic as
> slightly misleading. He has slightly
> misinterpreted my definition, and I
> believe I
> have clarified this in the above paragraph.
> 3
> 7. At the end of paragraph 20 [WS493] Dr Gale
> asserts any prions become an
> integral part of the meat and bone meal formed
> during rendering. As I
> have argued
> in WS19, this has not been demonstrated
> experimentally, and in my view
> Dr Gale
> has not justified his assertion. Later, in
> paragraph 25, he repeats one
> of the
> conclusions from one of Taylors 1995
> experiments: the rendering
> process itself
> eliminates 98% of BSE infectivity. Again, these
> were difficult and limited
> experiments carried out on pilot-scale equipment
> and without assaying
> all the output
> products [WS19 paras 21-28]. The type of
> rendering processes simulated
> were not
> necessarily the same as those in use in real life
> rendering.
> 8. Gales paragraphs 29 to 43 [WS493] cover
> issues concerning the potential
> minimum size of infective particles. He refers to
> WS19, in which I
> summarised
> two possible scenarios (paragraph 37). These are
> clarified below.
> 9. In Scenario 1, infective particles cannot be
> split i.e. they are
> undilutable. In these
> circumstances, ingestion by an individual of a
> minute mass of material
> carrying the
> infective particle (e.g. a soil particle, a
> droplet of water etc.) could
> transmit the
> entire infective dose. The risk assessment would
> need to estimate the
> probability
> that a specific individual might ingest such a
> particle - and thereby
> acquire a
> significant chance of infection. Risk assessment
> should also estimate the
> probability that the action of releasing a
> certain number of infective
> particles
> would cause any individual(s) to develop the
> disease. This should be
> extended to
> a probability distribution giving the
> probabilities that the actions of
> releasing a
> certain number of infective particles would cause
> different numbers of
> individuals
> to develop the disease (one probability for each
> number of individuals).
> 10. In my Scenario 2, components of infective
> particles were so small
> that they were
> highly dilutable. In such circumstances, minute
> sub-fractions of
> infective doses
> might reach a much larger number of individuals.
> If cumulative dosing
> were not
> possible, this would not imply any risk to those
> individuals. On the
> other hand, if
> cumulative dosing were possible, then the
> probability that a specific
> individual
> 4
> might accumulate one total infective dose from
> multiple ingestions of
> minute subdoses
> would need to be calculated. I agreed that
> Scenario 2 should indeed be
> evaluated, to cover one of the possibilities. The
> risk assessments
> carried out for
> the Environment Agency mainly focused on Scenario
> 2, and used assumptions of
> dilutibility and even mixing within very large
> volumes of water or soil.
> It was
> calculated that it would be necessary to consume
> impossibly large
> volumes of the
> water or soil before accumulating an infective
> dose. For example, Young
> et al in
> WRc Report CO4268, published in Jan 97 as EA14 at
> the Public Planning
> Inquiry,
> estimated that 8.3 litres of contaminated soil
> from the discharge zone
> would have to
> be consumed to transmit one human oral infection
> dose. (This was based
> on a socalled
> worst case situation  see below). It seems
> inconceivable that any human
> would ever ingest 8.3 litres of soil. However,
> under scenario 1, local
> aggregations
> of one or more infectious doses could certainly
> be ingested as a result of
> contamination of e.g. hands by trivial amounts of
> soil. As an aside, I
> do not accept
> that Youngs so-called worst case assumptions for
> the above example were
> really
> worst case. One of the assumptions was a species
> barrier. In fact, it
> assumed a
> species barrier of 1000 which is certainly not
> worst case. Professor
> Almond
> considered that a species barrier of 1 would be a
> reasonable worst-case
> assumption and this would have implied a human
> oral infectious dose could be
> carried in 8.3ml of soil  a volume which might
> easily be ingested. For
> scenario 2
> (as for scenario 1), the probability that the
> action of releasing a
> certain dose of
> infectivity would cause any individual(s) to
> develop the disease should
> also be
> calculated. This second probability may be quite
> different in the different
> scenarios.
> 11. To recap, I argued that the risk assessments
> should fully evaluate
> both scenarios. In
> addition, the risk assessments should not only
> calculate the probability
> of a specific
> individual acquiring infection, but the
> probability that the action of
> discharging
> infective material would lead to one or more
> infections. I do not think
> Dr Gales
> responses [WS493] have answered these points.
> 5
> 12. In my discussions about the potential risks
> associated with
> rendering, and the whole
> approach to its regulation, I have repeatedly
> stressed that there is a
> spectrum of
> possible risks, associated with various
> environmental pathways and various
> possible portals of entry into the body. Once
> again, the Environment
> Agency has
> focused specifically on the issue of the
> possibility of transmission by
> the water
> supply. I regard the water supply pathway as
> representing only a very
> small risk,
> but one which is very hard to quantify and one
> which would potentially
> affect a
> large number of people. The debate about water
> supply should not detract
> attention
> from the existence of several other potential
> pathways which need to be
> considered
> and evaluated.
> Issued on behalf of the witness by:
> The BSE Inquiry Press Office
> 6th Floor Hercules House
> Hercules Road
> London SE1 7DU
> Fax: 0171 803 0893
> Website:
> email:
> The BSE Inquiry / Statement No 19C
> Dr Alan Colchester
> Issued 27/01/2000
> WS490 DATED 09/08/99 BY MR C P YOUNG
> 1. Statement WS490 by Mr C. P. Young, Principal
> Hydrogeologist, Soil
> Waste and
> Ground Water Group, WRc, Medmenham, Bucks,
> concerned geological and
> hydrogeological factors which may control the
> movement and attenuation
> of BSE
> infectivity in water in the environment, and
> referred to specific points
> raised in
> WS18 and WS19 of March 1998.
> 2. WS490 referred particularly to the potential
> impact of the discharges
> from Thruxted
> Mill on the ground water, particularly because of
> its proximity to
> drinking water
> extraction bore holes. However, it did not
> consider the other risks
> arising from
> material delivered to or discharged from this factory.
> 3. In paragraph 18 [WS490], Mr Young described
> his conclusions about the
> probable
> rate of flow of water through the unsaturated
> zone. This would be slow,
> with the
> result that it would take from a few to several
> tens of years for
> material to travel
> from the surface to the water table. It is likely
> that such slow
> transmission applies
> at many parts of the discharge zone around
> Thruxted Mill. This is true
> whether or
> not there are also locations where transit
> through to the water table is
> faster. It is
> therefore clear that some of the material
> discharged many years ago may
> only now
> be beginning to reach the aquifer. This is one of
> several reasons why
> the past
> history of discharges at Thruxted Mill continues
> to be important.
> 4. Mr Young gave a very clear review of the
> potential behaviour of water and
> dissolved or particulate materials when soaking
> through a medium such as
> chalk
> 2
> which may contain variable numbers of large
> fissures. The presence of
> significant
> numbers of fissures, or the use of a borehole or
> old well for discharge
> purposes,
> would provide a rapid route to the water table
> through which a variety of
> particulate substances could pass. Mr Young
> referred to the absence of
> persuasive
> evidence of rapid movement via fissures of water
> and dissolved or
> particulate
> materials from the surface to the water table at
> Thruxted Mill [WS490
> para 20].
> In my view, it should be borne in mind that
> absence of persuasive
> evidence is not
> persuasive evidence of absence. The physical
> existence of potential routes
> allowing rapid transit is one type of evidence;
> evidence from water
> samples (tested
> for conventional pathogens, ionic substances etc)
> is another.
> 5. My Young also provided a clear review of the
> potential mechanisms of
> removal of
> particulate matter from liquid passing through
> intact chalk [WS490] (ie.
> not through
> large fissures or boreholes). He discussed the
> potential for filtration and
> adsorption of particles carrying BSE prions. In
> my view, the problem
> about this is
> that prions can exist in several physico-chemical
> forms. The range of
> types of
> particles which might exist in the inputs and
> outputs of a rendering
> factory and
> which might carry BSE prions is simply not known
> with confidence. In
> particular,
> the rendering process itself will alter the
> properties of lipid and
> protein particles.
> We do not know enough to quantify the possibility
> that particles may
> exist in a form
> that could pass through the chalk matrix. We
> certainly know that, in
> laboratory
> conditions, preparations of infective material
> are often passed through a
> microporous filter, with pore sizes of less that
> 0.5 micron. This does
> not generally
> attenuate prion infectivity but does remove most
> other pathogens.
> 6. In paragraph 26, final bullet point, Mr Young
> referred to pore sizes
> used in the
> laboratory of 500 micrometers [WS490] (one
> micrometer is one millionth
> of a
> metre or one micron). I presume this is a
> typographical error, because
> he should
> have referred to nanometers (a nanometer is one
> thousand millionth of a
> meter).
> 7. Considering what is now known about the
> potential infectivity of
> rendering factory
> output, there would seem to be an overwhelming
> case for its
> classification as toxic
> waste. However, in the historical context,
> rendering factory outputs
> appear to have
> 3
> been classified with strong organic and
> biodegradable effluents. The
> Environment Agency emphasise the consistency of
> their approach, as if
> this were to
> be commended, an attitude which seems dangerously
> inflexible in the
> light of the
> new information about the risks to human health
> of the products of
> rendering.
> Within the historically accepted class of strong
> organic and biodegradable
> effluents, the categorisation should clearly be
> low nutrient/ industrial
> effluent
> (Policy and Practice for the Protection of
> Groundwater, National Rivers
> Authority,
> 1992). When the discharge area is near a water
> supply borehole, the
> ground above
> is graded into three Source Protection Zones: the
> Inner Protection Zone
> (based on
> a 50 day travel time from any point below the
> water table to the
> source); the Outer
> Protection Zone (400 days); and the Source
> Catchment Zone (the remaining
> catchment area of the ground water source). The
> approach to regulation of
> discharge, according to the type of effluent and
> the travel times to the
> water
> extraction point, is shown as a matrix (table) on
> page 36 of the NRA booklet
> (Appendix 1 [YB92/00.00/10.1]). Appendix 1 shows
> that there is an important
> threshold between the Outer Protection Zone and
> the Source Catchment Zone,
> because, in the former (areas closer then 400
> days transit time to the
> water supply
> extraction point), discharges of low nutrient
> content or industrial
> effluent should be
> automatically prohibited.
> 8. In paragraph 21 of WS490, Mr Young referred to
> Thruxted Mills
> location as being
> in an area in which time for flow in a saturated
> zone to the boreholes
> is about 400
> days, or greater. In the light of the historical
> importance of this 400
> day threshold,
> I examined the situation of Thruxted Mill in
> relation to the 400 day
> transit time to
> the nearest borehole (Godmersham). Maps included
> in the Environment Agencys
> studies confirm that the Mill in fact must lie
> extremely close to that
> threshold. Two
> such maps are reproduced here for ease of
> comparison: Appendix 2 is p
> 16, fig 2.3
> (Hydrogeological features of the area around
> Thruxted Mill), from C.P.
> Young et
> al Assessment of the Potential Impact of Past
> and Present Disposal of
> Effluent
> from Thruxted Mill on Ground Water Quality,
> March 1997 [M70 Tab 9].
> Appendix 3 is fig 1 (Location map) from WS490
> itself. The 400 day
> threshold
> line has clearly been drawn freehand (compare the
> two maps in the
> Appendices),
> and indeed small differences in drawing could
> lead to the Mill lying
> inside or
> 4
> outside the Outer Protection Zone. The transit
> time from Thruxted Mill
> to the
> aquifer in the saturated zone appears only to
> have been estimated very
> approximately. More accurate measurement might
> well indicate a shorter
> transit
> time. If this were to be the case, the
> Environment Agency should have
> prohibited
> discharge long ago, even assuming that no new,
> more stringent,
> regulation was
> applied to take account of the recent discovery
> of serious risks to
> humans of BSEcontaminated
> material. It is accepted that the NRA document is
> not prescriptive
> and while it seeks to control activities within
> certain travel time
> zones around
> public water supply sources, it allows for
> individual site specific
> assessment
> (Canterbury Planning Inquiry, EA Proof of
> Evidence, section EA 1, Pages
> 7 & 8,
> Groundwater Protection Policies). However, in the
> case of Thruxted Mill, the
> heightened concern about the safety of discharges
> should clearly have
> led to a more,
> rather than a less, stringent interpretation of
> the Policies.
> 9. In paragraph 22, Mr Young referred to the
> February 1997 Public
> Planning Inquiry in
> Canterbury [WS490]. Concerning the old well on
> the site of the Mill, he
> says that
> its potential impact on groundwater quality was
> not assessed. However,
> as my
> second statement to the BSE Inquiry [WS19B]
> showed, the EA were fully
> informed
> about the recent allegations of discharges into
> the well as early as
> June 1996. The
> EA have also admitted that the NRA/ EA had been
> fully aware of the
> presence of
> the well on the site for some years previously,
> and that the well had
> only been
> partially backfilled with sand in 1978, which
> would of course have
> allowed its
> continuing use as a discharge route. The EA were
> requested, at the
> pre-Planning
> Inquiry meeting in Canterbury in December 1996,
> to take full account of
> the well,
> although Counsel acting for the EA argued that it
> was irrelevant (cf
> WS19B para
> 59). Furthermore, Mr Youngs report, which was
> dated March 1997 [M70 Tab 9],
> contained extensive data obtained before the
> Planning Inquiry. It is
> quite clear from
> that report that many of the analyses contained
> in it must have been
> completed well
> before the publication date of the report, in
> other words well before
> the Planning
> Inquiry. In summary, while I agree that the
> potential impact on groundwater
> quality of the well was not assessed in the
> context of the Planning
> Inquiry, the
> relevant data and analyses were available at the
> time of the Inquiry. In
> my opinion,
> 5
> these data should have been discussed at the
> Planning Inquiry, and my
> reasons were
> made very clear before and during that Inquiry itself.
> 10. In paragraph 24 [WS490], Mr Young refers to
> readings quoted by the
> EA showing
> that the rate of fall of the water level in the
> well during late 1996
> was low. This
> implied that the well had become blinded.
> However, the data about the
> rate of
> soaking away obtained in late 1996 do not provide
> any information about
> the time
> when the blinding may have taken place. In the
> risk assessments
> referred to by
> Young in his report dated March 1997 [M79 Tab 9]
> it was assumed that the
> rate of
> leakage from the well had smoothly reduced from
> 1988 to 1996. This is
> complete
> speculation. The arbitrary assumption of a
> gradual reduction over many years
> generated predictions which appeared to
> contradict one of the
> allegations by a
> former contractor who worked on the site (who had
> stated that he had
> seen flexible
> hoses dragged to the top of the well and effluent
> being discharged
> through them).
> These apparent contradictions were used by the EA
> and by solicitors
> acting for
> Canterbury Mills Ltd to argue that the former
> contractors evidence was
> unreliable.
> In my view, exactly the opposite conclusions were
> more logical. That is, the
> possibility that the blinding was a recent event
> was not only plausible
> a priori, but
> such an interpretation was supported by the
> observations alleged by the
> former
> contractor of the use of the well as a route of discharge.
> 11. In paragraph 26 [WS490], final bullet point,
> Mr Young refers to the
> precautionary
> principle. He quotes PPG 23, where the
> precautionary principle is set
> out. PPG
> 23 requires that the precautionary principal
> should be applied when
> there is
> perceived to be an unacceptable risk, even if it
> cannot be scientifically
> quantified. Youngs argument is circular. He
> merely states that because
> the EA, or
> the scientific consultants acting for the EA, did
> not themselves
> perceive there to be
> an unacceptable risk, the precautionary
> principle automatically did not
> apply. Any
> serious debate about this issue should address
> the question of how to
> define an
> unacceptable risk which cannot be scientifically
> quantified.
> 12. Once again, the Environment Agency has
> focused specifically on the
> issue of the
> possibility of transmission by the water supply.
> I regard the water
> supply pathway
> 6
> as representing only a very small risk, but one
> which is very hard to
> quantify and
> one which would potentially affect a large number
> of people. The debate
> about
> water supply should not divert attention from the
> existence of several other
> potential pathways which need to be considered
> and evaluated. In my
> discussions
> about the potential risks associated with
> rendering, and the whole
> approach to its
> regulation, I have repeatedly stressed that there
> is a spectrum of
> possible risks,
> associated with various environmental pathways
> and various possible
> portals of
> entry into the body. In my opinion, the recent
> statements by the
> Environment Agency
> and its contractors have not invalidated the very
> strong case to support
> the view that
> the precautionary principle should be applied to
> the disposal of liquid
> effluent and
> sludge from rendering factories. In particular,
> it should be applied to
> the proposed
> new subsoil drainage method, as well as to the
> existing discharge method
> in use at
> Thruxted Mill.
> Issued on behalf of the witness by:
> The BSE Inquiry Press Office
> 6th Floor Hercules House
> Hercules Road
> London SE1 7DU
> Fax: 0171 803 0893
> Website:
> email:
> Rendering practices and inactivation of
> transmissible spongiform ...
> File Format: PDF/Adobe Acrobat
> ... The UK BSE Inquiry. concluded that the
> disease was bovine derived
> (1) but the
> Horn ... recombinant prion protein in water,
> lipid and lipid-water ...
> -
> Health Stream Article- Issue 10 June 1998
> Water supplies at risk from BSE?
> A leading neurologist has warned the British
> Government's Inquiry into
> BSE (bovine spongioform encephalopathy or "mad
> cow disease") that
> drinking water supplies may be at risk of
> contamination. Dr Alan
> Colchester from Guy's Hospital in London gave
> evidence that the practice
> of allowing the spreading of sludge and liquid
> effluent from carcass
> rendering plants onto land could allow the
> infectious agent to enter
> underground aquifiers. The infectious agent of
> BSE is believed to be an
> extremely stable protein molecule (prion) which
> Dr Colchester believes
> may be able to survive the rendering process.
> Dr Colchester is one of over 100 scientists and
> 300 civil servants
> expected to testify before the Inquiry which
> began in March this year.
> The terms of reference of the enquiry are "to
> establish and review the
> history of the emergence and identification of
> BSE and nvCJD (new
> variant Creutzfeld-Jakob Disease) in the United
> Kingdom, and of the
> action taken in response to it up to 20th March
> 1996; to reach
> conclusions on the adequacy of that response,
> taking into account the
> state of knowledge at the time".
> The proceedings of the Inquiry have been made
> available on a World Wide
> Web site including detailed submissions by
> witnesses, descriptions of
> the roles of key people, and a chronology of events
> ( The scientific evidence
> now appears conclusive
> that the 26 cases of nvCJD diagnosed in the UK
> since 1995 represent a
> distinct and new form of the disease, and that
> the characteristics of
> the nvCJD agent in animal infection experiments
> closely match those of
> the BSE agent.
> However the possibility of transmission of BSE
> via water supplies would
> appear to be remote if the assumptions used in a
> recent paper by Gale et
> al. are accurate (1). The authors assessed the
> risks associated with a
> rendering plant processing BSE infected cattle
> and disposing of
> carcasses in the catchment of a chalk aquifier.
> The exercise was
> difficult because specific data on several
> aspects are lacking - there
> is no dose-reponse data for humans, no
> information on the behaviour of
> the BSE prion in water, no information on the
> effectiveness of barriers
> that may reduce movement of the prion into water,
> and limited data on
> the decay of infectivity in the environment.
> To overcome these problems, the authors assessed
> the available data on
> the BSE agent and extrapolated using a series of
> worst case assumptions.
> Infectivity to humans
> Infectivity is expressed as the 50% infectious
> dose (ID50) - the dose
> which would infect 50% of exposed individuals.
> Animal experiments have
> shown that infectivity is concentrated in the
> brain and spinal column of
> cattle, and a partial barrier to transmission
> exists between species so
> that about 1000 times the dose is needed to
> consitute an ID50 in a
> different species.
> Infectivity via oral or gastric exposure is
> reduced about 100,000 fold
> compared to the intracerebral and intraperitoneal
> routes. Mice
> experiments have shown an oral ID50 of 6.3 g for
> BSE infected cattle
> brain, and the human ID50 is likely to be
> similar. For risk assessment,
> it is assumed the oral ID50 in humans is 1g, and
> each infected cow
> contains 1000 infectious doses (in the brain and
> spinal tissue). It is
> estimated that the oral ID50 in humans is
> equivalent to about 1013 prion
> molecules.
> BSE in the aquatic environment
> The BSE prion protein is known to contain both
> hydrophobic and
> hydrophilic regions, and to be associated with
> cell membranes. It binds
> strongly to surfaces and is unlikely to exist in
> free solution in
> aqueous media. The authors conclude that as
> cattle carcasses decay the
> BSE agent would be released from cell membranes
> but would immediately
> bind to other particles.
> While aggregates of BSE prion have been observed
> in some infected
> animals the maximum number of molecules in an
> aggregate is about 10 5
> molecules, or about 108 fold less than the
> estimated human ID50.
> Therefore such aggregates are not likely to pose
> an infection risk and
> significant net dilution is likely to occur in
> aqueous environments.
> Risks from ingestion
> As the considerations above show that it would
> not be possible to ingest
> an entire infectious dose in a single esposure
> (eg a glass of water),
> the risks associated with small fractions of an
> ID50 were considered.
> Using the conventional linear low dose
> extrapolation commonly applied to
> microbial infections, it is calculated that
> ingestion of 108 prion
> molecules (the largest aggregate observed in
> infected animals) would
> correspond to a risk of 0.5 x 10-5, or 1
> infection per 200 million
> people ingesting this dose.
> The authors also discuss experimental evidence
> that a threshold may
> exist for infection - this would have the effect
> of further reducing the
> risk.
> Environmental input of BSE
> The sources of BSE input are described and it is
> noted that rendering is
> known to destroy 98% of infectivity. Residual
> infectivity has been
> demonstrated for MBM (meat and bone meal) but not
> tallow (fats).
> Environmental barriers
> The prion protein is resistent to proteolysis and
> heat degradation, but
> there is evidence that infectivity declines in
> buried carcasses. There
> are no data on the effect of conventional water
> chlorination on the BSE
> prion, but given the molecule's resistance to
> other chemical treatments
> it is unlikely that chlorination would reduce infectivity.
> Quantitative risk assessment
> The above considerations are factored into a risk
> assessment with the
> following assumptions:
> * the rendering plant processes 2000 BSE
> infected carcasses per week.
> * all infectivity is associated with MBM particles
> * effluent is treated by dissolved air
> flotation and sand filtration
> before discharge to chalk substrata, 80 m
> above an aquifier.
> By modelling the removal of suspended solids (and
> attached BSE prion) it
> is concluded that only 0.004 human oral ID50
> would be discharged from
> the plant each day.
> It is assumed that the discharge from the plant
> would take at least 2
> years to reach the aquifier layer and that
> infectivity would decline by
> 93% in this time. No allowance was made for
> removal of the BSE prion by
> filtration or binding to the chalk, although the
> authors believe this
> would be a major effect. A dilution factor of
> 83-fold is assumed for the
> borehole fed by the aquifier (ratio of plant
> discharge volume to water
> extraction volume).
> On this basis the estimated concentration in the
> extracted water would
> be 3.0 x 10-11 of a human ID50 per litre of
> water. Assuming that
> consumers drink up to 2 litres of water per day,
> the daily risk of
> infection would be less than 10-10. An individual
> would require 45
> million years of exposure to reach a cumulative
> exposure of one ID50.
> The application of worst case assumptions at each
> step means that even
> this risk estimate may be grossly over inflated.
> The authors note that for quantitative risk
> assessment to be of
> practical use, there must be confidence that the
> outcome has a
> reasonable degree of accuracy. In this case the
> many unknowns in the
> data and the adoption of extreme worst case
> assumptions means that this
> is not the case. However the systematic
> consideration of each step in
> the process illustrate that even if some
> assumptions are incorrect (eg
> if there is no species barrier) the risk of
> transmission of BSE by
> drinking water is still remote.
> While the incidence of diagnosed new cases of BSE
> in cattle in the UK
> and other European countries appears to be
> declining, researchers in
> Switzerland have found evidence that many cattle
> may be infected without
> displaying symptoms. A report in the 13th June
> issue of New Scientist
> described the development of a sensitive test to
> detect the abnormal
> protein which causes BSE.
> Application of this test to brain tissue samples
> from 1761 apparently
> healthy cows slaughtered because they came from
> herds where cases of BSE
> had occurred, found 8 which tested positive. This
> suggests that BSE
> infection is present at a rate of 4.5 per 1,000
> cows, yet the rate of
> symptomatic BSE in Switzerland is 100 times less
> than this. The Swiss
> government will now test cows from herds where
> BSE has not been
> reported, to determine whether they too may be infected.
> (1) Gale P, Young R, Stanfield G and Oakes D.
> Development of a risk
> assessment for BSE in the aquatic environment. J
> Applied Microbiology
> (1998) 84 p467-477.
> More than 90 burial sites were used to dispose of
> all the cattle
> slaughtered due to foot and mouth disease. The
> burials included cattle
> over five years old, which should have been
> incinerated under the
> governments own BSE regulations. The government
> has now ordered the
> carcasses to be dug up to protect water supplies
> from infection with the
> BSE agenta rather belated attempt because most
> body fluids will have
> leaked out after two months.


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