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Scottish Court of Session Decisions
You are here: BAILII >> Databases >> Scottish Court of Session Decisions >> WILLIAM MACBEAN AGAINST SCOTTISH WATER [2020] ScotCS CSOH_55 (29 May 2020)
URL: http://www.bailii.org/scot/cases/ScotCS/2020/2020_CSOH_55.html
Cite as: [2020] CSOH 55, 2020 SLT 707, [2020] ScotCS CSOH_55, 2020 GWD 18-259
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OUTER HOUSE, COURT OF SESSION
[2020] CSOH 55
A39/17
OPINION OF LORD WOOLMAN
In the cause
WILLIAM MACBEAN
against
SCOTTISH WATER
Pursuer
Defender
29 May 2020
Pursuer: Smith QC, Young; TC Young LLP
Defender: McBrearty QC, Pugh; BLM
Introduction
[1] William MacBean lives in a large house in Boat of Garten. A waste water treatment
plant (‘WWTP’) sits down an embankment from his property. It discharges into the River
Spey. When it began operating in 2015, Mr MacBean noticed noxious fumes in his garden.
Sometimes they reached his house. He and other residents complained to the WWTP
operator, Scottish Water. As matters did not improve, Mr MacBean raised this action
in 2017. He seeks a declarator of nuisance, together with interdict and damages.
Page 2 ⇓
2
[2] I have now heard evidence on four separate occasions. The proof commenced in
November 2018, was adjourned until January 2019 and adjourned again until March 2020.
Shortly before the last hearing, I took the evidence of three experts on commission.
[3] I adjourned the first two hearings at the joint request of the parties. Each time they
wished to try to find a practical solution. Unfortunately their attempts were unsuccessful.
[4] A significant development occurred at the close of the second hearing. At the
parties’ joint invitation I granted decree of declarator that Scottish Water was causing a
nuisance to Mr MacBean. I did not grant interdict, because the parties also agreed that
Scottish Water should have a further opportunity to remedy matters.
[5] During 2019 Scottish Water carried out remedial works. It also instructed two
independent companies to conduct smell assessments in and around the WWTP. Further it
set up a dedicated complaints helpline.
[6] Fortified by the findings of the smell assessors, Scottish Water believes that it has
now cured the odour problem. Mr MacBean disagrees. He contends that the nuisance
continues. It was on that basis that the proof resumed in March 2020.
[7] Mr MacBean recognises that interdict would have major consequences. The closure
of the WWTP would deprive the community of an important public service. Mr Smith
addressed this point in his closing submissions. He invited me to pronounce a further
declarator of continuing nuisance, rather than interdict. That invitation was subject to
Scottish Water undertaking to remove the nuisance within a reasonable time. Mr Smith
suggested it could do so, either by building a new plant, or by transporting the sewage to
another plant for treatment.
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3
The issue
[8] What constitutes an actionable nuisance? Lord President Cooper formulated the
“The critical question is whether what [the pursuer] was exposed to was plus
quam tolerabile when due weight has been given to all the surrounding
circumstances of the offensive conduct and its effects.”
[9] Here that can be refined into two narrower questions. First, do odours from the
WWTP still come on to Mr MacBean’s land? That is a simple issue of fact. Secondly, would
a reasonable person tolerate them? The answer to this second question involves a more
complex inquiry. It involves an objective evaluation of the nature, intensity and duration of
any such smells having regard to the overall context.
[10] Mr MacBean, supported by friends, neighbours and two experts, maintains that his
property is still subject to objectionable smells from the plant. Scottish Water rejects that
contention. It submits that any smells now emitted by the plant are faint, transient and
localised. It founds on the independent smell assessment records. It also calls attention to
the public utility of the plant and the adverse consequences of requiring it to cease
operation. It argues that, giving due weight to all those factors, any odours are reasonably
tolerable.
[11] I shall flag up at the outset a difficulty that the testimony presents in this case. There
are two conflicting bodies of evidence. Neither side challenges the credibility of the other’s
witnesses. Mr Smith did not challenge the reliability of the defender’s witnesses. By
contrast Mr McBrearty did challenge the reliability of the pursuer’s factual witnesses. I shall
discuss the intertwined concepts of reliability, weight and cogency later in this opinion.
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Background
Mr MacBean
[12] Mr MacBean is now aged 70, does not smoke or drink, and believes that he has a
good sense of smell. He has lived in and around Boat of Garten all of his life. In 1988 he
purchased Tomboyach House (‘Tomboyach’). As well as being his residence, it has been the
centre of his various business operations. He loves his house and would not contemplate a
move.
[13] Mr MacBean has a daily walk around the garden with his dog. He takes a keen
interest in the WWTP and often has friendly chats with Scottish Water employees and others
working at the site. Although he denies that the odour problem dominates his thoughts,
others think differently. Maureen Hendry, who has worked with him since 1975, thinks that
he finds it very stressful. A friend, Ian MacLeod, holds a similar view, “it’s something that is
consuming his life”.
Planning permission
[14] The former sewage works for Boat of Garten were located 50m further away from
Tomboyach. They did not cause Mr MacBean any problems. In 2010 Scottish Water applied
for planning permission to construct a new plant. Its application contained a
misrepresentation. It stated that the new works “will not create any odours and will
therefore not impact on any sensitive receptors”. Scottish Water now concedes that it should
never have made that statement. One expert in the case, Stephen Peirson, said that if he had
been asked about it at the time, he would have said “don’t believe it”. All sewage works
give rise to some odours.
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5
[15] Bob Murdoch is an employee of Highland Council. He has worked in its
environmental health department for many years. He did not accept Scottish Water’s
assertion at the time. He was sufficiently concerned about the proximity of the proposed
plant to housing to ask for an odour management plan during the planning process. The
Cairngorms National Park Authority (‘CNPA’) appears to have taken heed of his view. In
granting permission in February 2011, it imposed this condition:
“3. No development shall commence until an Odour Management Plan has
been submitted to and agreed by the CNPA acting as Planning Authority, in
conjunction with Highland Council Environmental Health. Thereafter the
odour control measures set out in the Odour Management Plan shall be
implemented prior to the [works] becoming operational and adhered to at all
times thereafter.
Reason: In the interest of residential amenity; to ensure the emissions of odours
is controlled.”
[16] Scottish Water did produce an odour management plan, which it has since revised
several times. The original plan contained two errors. It said that Tomboyach was 70m,
rather than the true distance of 17m, away from the WWTP. It also stated that there were
“no significant odour-generating locations at the site”.
Layout & process
[17] Waste water treatment works are essentially about decontamination. The sewage is
treated, the dirty sediment is removed, and the cleaned water discharged. Two main
treatment processes take place within this WWTP.
(1) The sewage enters one of four large septic tanks, where bacteria consume
the raw sewage. This anaerobic process results in (i) the release of gases
and (ii) the settling of solids at the bottom of the tanks. Some of the gases
are contained because a crust forms above the solids.
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(2) An aerobic process takes place in the submerged aerated filter units (‘the
SAF’), which also produces gases and sediment. The latter is pumped back
to the septic tanks.
[18] That description puts matters at their simplest. Other processes take place within the
plant, where extensive piping connects humus tanks, an inlet cover, a splitter chamber and
an intermediate pumping station.
[19] Tanker lorries remove all the sludge from the bottom of the septic tanks and
transport it to Aviemore. This ‘desludging’ takes place every 4 to 6 weeks, each tank in
rotation. The operation lasts between 1 and 4 hours.
Early complaints
[20] When the plant began operating, local residents noticed odours. Mr MacBean
described it as a “stink”. From 15 June 2015 onwards, he kept a diary of smell incidents. He
relayed most of his complaints to Scottish Water. Two neighbours, Elizabeth Mathews and
Alison Grant, also complained. All three gained the impression that Scottish Water brushed
aside their concerns. To a greater or lesser extent, each developed ‘complaints fatigue’. For
example, Mr MacBean’s diary entry on 2 July 2015 states that he was “fed up making
reports, nothing happens”. The Boat of Garten community council carried out a survey to
assess the position, but no evidence was led about its findings.
[21] Miss Mathews was not content to let matters rest. She instructed
Professor Robert Jackson to investigate the problem. In autumn 2015, he produced a
report noting “strong, intense and offensive sewerage odours on the steeply inclined
earth embankment” between the WWTP and Tomboyach. Miss Mathews sent his report
to Highland Council.
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[22] Professor Jackson has scrutinised the operation of the WWTP for the last 5 years on
behalf of different interested parties. In autumn 2016 he provided reports to Scottish Water.
Later he gave evidence as an expert witness for the pursuer.
Summary of the early evidence
[23] In order to put the most recent evidence in context, I shall give ‘thumbnails’ of what
the pursuer and his witnesses said at the first two diets of proof.
William MacBean He experienced frequent “horrible” odours which lasted
most of the day and night. They prevented him from
opening his windows, sitting outside, or working in his
garden (he is a keen gardener). The warm summer
of 2018 was “hellish”.
Pamela Hendry
Sometimes she found it impossible to sit in the garden.
The smell lingered on her clothes. There was a bad smell
most of the time, which was worse in summer. It was
particularly bad during desludging until chemicals were
added in 2016.
Ian MacLeod
The constant smell was sometimes bearable, but on four -
six occasions a year, he felt so nauseous that he and
Mr MacBean chose to eat elsewhere.
William Grant
It was “much worse than the smell of manure being
added to a field”. Once in the summer of 2017 the odour
was “breath-taking”.
Aaron Sneddon
The smell can be “absolutely rank”, like a blocked toilet.
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Anthony Mitchell
Sometimes the smell “almost made me gag”.
Augustine Jones
“The smell can vary from nothing at all to so bad it
makes you want to leave the area. I would not go as far
as to say the smell makes you want to vomit, but it is
almost as bad as that.”
Tessa Jones
“At least on one out of every ten visits the smell is so bad
that I have had to leave the area.”
Kenneth Chrystie
It was unusual for him not to detect smells during the
course of his regular walk past the golf course and over
the Spey bridge. Often on visits to Tomboyach, he could
not sit in the garden, which he regarded as unsellable.
Elizabeth Mathews She first noticed a smell “like rotting rats” on a
desludging day. From time to time since then, she has
noticed a horrible smell. In the summer some of her
B & B guests have remarked on it. The problem has
blighted her life and (she believes) affected the value of
her house.
[24] It was on the basis of this evidence, mostly unchallenged in cross-examination, that
Scottish Water conceded in January 2019 that it had been causing a nuisance.
Chronology - remedial works
[25] The focus therefore shifts to the steps that Scottish Water took afterwards to cure
matters. First, it is necessary to take a backward glance. After becoming aware of the smell
problem in 2015, Scottish Water asked Mott Macdonald Ltd (‘M2’) to investigate. M2
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9
reported that the plant was generating higher odour emissions than expected for a treatment
works of that size.
[26] Scottish Water subsequently sought to reduce the level of noxious odours coming
from the WWTP. At an early stage, it identified desludging as a prime candidate for causing
smells. From 2016 onwards, Taytech Ltd has injected chemicals into the sludge to mask the
smell.
[27] In the course of 2019 and early 2020, Scottish Water carried out these remedial works:
February 2019
Taytech fitted carbon filters to treat any odours escaping
through the air vents on the SAF.
Ross-shire Engineering Ltd replaced the single cover on the
SAF with seals to contain any foul odours within the system.
March 2019
Carbon filters were installed on the septic tank covers.
April 2019
Carbon filters were installed on the covers of other chambers.
September 2019
Odour Control Unit (‘OCU’) was installed on the SAF.
October 2019
All carbon media were replaced.
November 2019
A fixed pump was installed to connect the septic tank to the
lorry tankers.
January 2020
Scottish Water blocked up a hole in the chamber cover for the
chemical dosing hose, and sealed the inlet covers.
[28] Three of these items require fuller discussion: the OCU, the carbon filters and the
fixed pump.
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OCU
[29] Three engineering experts – Professor Jackson, Mr Peirson and Dr McIntyre -
provided guidance on reducing or eliminating the odours. They agreed that, apart from
desludging, the SAF had been the main source. Their preferred solution was an OCU to
prevent fugitive emissions. It sucks the gases from the top of the SAF and blows them
through a carbon filter.
[30] Scottish Water commissioned ERG (Air Pollution Control) Ltd (‘ERG’) to design an
OCU to a high specification. Because of its substantial size, planning permission was
required. Mr MacBean (somewhat surprisingly) was one of the objectors, but permission
was granted. Subsequently, the OCU was installed and it began operating on 19 September
2019.
[31] Since then ERG’s monthly tests show that the OCU has been “very effective” in
eliminating odours. This is not in dispute. The parties have agreed by joint minute “that the
OCU has reduced odour emanating from the SAF by a factor of greater than 10, or
equivalent to more than 1 logarithmic change.” At least one such change is needed to affect
an individual’s perception of a particular smell.
Carbon filters
[32] Carbon absorbs malodours. Scottish Water has fitted carbon filter trays beneath
17 manhole covers at the site. There is conflicting evidence about their effectiveness.
[33] Mr Peirson and Professor Jackson noticed grit present around the lip of some
manhole covers. They query whether they are hermetically sealed, as they detected
offensive smells during a site visit on 13 February 2020.
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[34] By contrast Scottish Water monitors their performance and replaces them at least
every 6 months. Laboratory tests carried out in October 2019 on used carbon media showed
that they had done “a good job” in removing odours. The handful of covers that do not
have carbon filters are lifted monthly for inspection. They are resealed on each such
occasion. Stephen Kirby, senior site engineer for M2, thought that the covers “work
incredibly well.” Karen Dee of Scottish Water examined them in early 2020 and reached a
similar conclusion.
Fixed pump for desludging
[35] Desludging of the four septic tanks takes place in rotation. One tank is cleaned every
4-6 weeks. A fixed pump on the ground now connects the pipework between the septic tank
and the lorry tankers. It is a closed unit that restricts the emissions of smells. Previously,
pumps on the tanker lorries sucked in the effluent, resulting in odours being expelled into
the air.
Expert testimony
[36] In March 2020 I heard the evidence of three skilled witnesses. Professor Jackson and
Mr Peirson (instructed by Mr MacBean), and Professor Philip Longhurst (instructed by
Scottish Water) gave evidence at the commission hearing. Unfortunately, Dr McIntyre (also
instructed by Scottish Water) was indisposed and unable to give oral evidence, but I read his
report along with those provided by the other experts.
[37] Messrs Jackson, Peirson and McIntyre met on three occasions and signed a joint
report, which contained a series of questions and answers. In his closing submissions,
Mr Smith relied on the answer to question 9:
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Do the experts consider that the design of the plant is ‘fit for purpose’? If not, why not?
The agreed answer is:
“No. The plant may be ‘fit for purpose’ in purely terms of having the capability
to treat sewage to the required standards, but it is not fit for purpose in terms of
being able to treat incoming sewage whilst being able to adequately control
odour emissions. Given the defenders’ performance to date, and on the balance
of probabilities, recurring odour nuisance to residents will, from time to time,
prevail during the design lifespan of the treatment works.”
[38] Dr McIntyre added a rider. In his view, no waste water treatment works can be
termed ‘fit for purpose’, because they cannot treat wastewater to the required standard and
at the same time eliminate odour emissions.
Source of any remaining problems
[39] Professor Jackson and Mr Peirson both now attribute at least some of the remaining
odours to the manholes. Professor Jackson suggested that, prior to the installation of the
OCU, the odours from the SAF may have masked every other smell. He has a more general
view about the plant. He believes that, because of its design, the risk of odour nuisance will
remain for the rest of its working life, perhaps 25 - 30 years. In his opinion the problems lie
in and around the septic tanks. He accepts that there may only be one localised incident a
day, but his preferred solution is either “to put a lid on the whole thing”, or to move the
plant elsewhere.
Professor Philip Longhurst
[40] Since 1993 Professor Longhurst has studied the impact of emissions from waste
plants on communities. I highlight three points made by him.
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[41] First, there is no scientific method to determine what smell is acceptable to a
particular individual. We all differ, for example, in our ability to tolerate the smell of human
sewage. Emotions may play a role. Persons exposed to noxious fumes may exhibit feelings
of depression, frustration, and anger. They are more likely to be annoyed if the odour
occurs at unpredictable times.
[42] Second, he studied the number of complaints directed at the Boat of Garten WWTP
and found that they had reduced since the remedial works were carried out, there is a
“marked change” even for such a small sample (report figure 5.3).
[43] Third, when he correlated the complaints with the wind direction, he found that 48%
were made when the wind was blowing in the opposite direction to Mr MacBean’s property
(report table 5.4). That is “unusual and inconsistent with normal patterns of dispersion”.
Professor Longhurst excluded instances of low wind speed, when odours could have
lingered. But that still left 44% of complaints that appear to have occurred with the wind
blowing in the opposite direction. He accepted that he is not a meteorologist and that the
local topography is complex. In his opinion, however, it is highly unlikely that these smells
could have come into Tomboyach from the WWTP.
[44] The expert opinion greatly assisted my understanding of the configuration and
operation of the plant and, more generally, of waste water treatment facilities: Kennedy v
Concordia (Services) LLP [2016] UKSC 6 paragraph 41. On the central question of continuing
nuisance, however, the primary evidence comes from the factual witnesses.
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Third proof hearing - March 2020
Summary of the pursuer’s evidence
[45] The thrust of the pursuer’s evidence was that, although the OCU has slightly
improved matters, when bad smells do occur, they remain offensive. In cross-examination
Mr McBrearty queried the reliability of the pursuer’s witnesses. He suggested to each that
they had given “skewed” evidence because of their friendship with Mr MacBean. Each
witness emphatically denied that suggestion. Mrs Alison Grant misheard the question and
mistakenly believed that her integrity had been impugned. Her reply was “I only know the
truth. I’m sorry I don’t tell lies. I can tell you that if you were up here you would smell this
smell.” Other witnesses stressed that their careers - in the law, the public sector, the
military - had depended on them forming independent judgements.
Excerpts
[46] Again I provide thumbnails of the evidence led on behalf of Mr MacBean.
William MacBean “Although I would say that there has been a marginal
improvement in how strong the odour is, it remains
intolerable to me. I cannot face another summer of foul
odour.”
Maureen Hendry
Overall the odour has not been as bad as when the
WWTP first came into operation, but it is still present and
very unpleasant.
Ian MacLeod
He works off-shore and is very sensitive to smell, as any
whiff of hydrogen sulphide (‘H2S’) on an oil rig calls for
immediate action. “I am pleased that I don’t have to live
Page 15 ⇓
John Dickson
Gerald Dunkley
Gary Coutts
Alison Grant
15
in that house or sit in that garden.” During desludging
on 21 November 2019, the smell was offensive all around
the garden. In 2020, he detected a “noticeable stink”
twice in January, twice in February and once in March,
although not as intense as formerly.
He has had experience of smelly drains as a former civil
engineer. There were foul smells over three days at
New Year 2020. On one of those days the smell along the
river path next to the WWTP was unbearable “to the
point I was almost retching”. He has not detected any
smells in February and March 2020.
The intensity of the smell varies from non-existent to
intolerable, mainly when desludging is taking place.
Over the past few weeks, he has noticed the smell less
often.
On each of his three or four visits since October 2019
there has been an odour of varying strength. At its worst,
it is constant throughout the garden. Sometimes it
reaches inside the house. He would not be able to
tolerate even the milder odours for an extended period.
He would not choose to holiday near the WWTP, far less
purchase Tomboyach House.
Within the last 2 - 3 months, she has noticed an odour at
least once a week at various locations around Boat of
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Jeremy Burr
Richard Eccles
Augustine Jones
16
Garten. There is no clear pattern. It can last for an hour,
go and come back again a couple of hours later. “I don’t
even want to leave my house at times if it smells outside.
I consider the odour to be intolerable and it makes me
worry about my health as I can often feel sick when I
smell it.”
There is a noticeable and unpleasant odour in the
pursuer’s garden. Sometimes it is mild. Sometimes it is
so bad that he is “barely able to stand it”. At least three
times within the last year he and Mr MacBean were
unable to be outside. There is no set pattern. The smell
can last for a couple of minutes, go away and then come
back again. “I would not like to live next to the WWTP
because of this regular intrusion and the disgusting
smell.”
He does not have a good sense of smell, so if he detects
something, it must be odorous. In 2019 he visited the
pursuer two or three times a month, slightly more in
September and October. He detected smells from the
WWTP on at least two out of every three visits. It ranged
from mild to “the really pungent odour that catches the
back of your throat.”
He has not noticed any improvement since last
September. On at least six or seven occasions between
Page 17 ⇓
Tessa Jones
17
November 2019 and January 2020, he noticed a milder
odour. The worst occasions recently have occurred when
desludging has been taking place.
Like her husband, she has not noticed any recent
improvement. At least twice in the last 3 months she has
had to move away from the area because of the smell.
Even slightly milder smells make her want to leave. The
worst smells have occurred during desludging. During
desludging in the week commencing 20 January 2020,
there was a strong sewage and perfume smell.
Evidence led by Scottish Water
General
[47] In early 2019 Scottish Water engaged M2 and Silsoe Odours Ltd (‘SOL’) to monitor
odours at the site. M2 set up a team of graduate engineers (all male) to carry out this task
each weekday and to respond quickly to any complaints. SOL arranged for two employees
(both female) to make monthly visits to the site from July 2019 onwards.
[48] Both teams use Jerome meters, which are hand-held devices that measure the
concentration of H2S in the atmosphere. The anaerobic process in the septic tanks is likely to
generate H2S, but WWTPs may emit other odours which these meters do not measure.
[49] SOL conducts smell sensitivity tests at its laboratory in the south of England in
accordance with European Standard BS EN13725:2003. It has tested all the M2 and SOL
assessors, most more than once. Test candidates have to identify which of two test tubes
contains clean air and which contains n-butanol mixed with air. The test is repeated at
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increasing concentrations to determine sensitivity. Smell assessors are selected to be within
the normal range.
[50] Although M2 and SOL work independently, both employ similar methodology.
Their respective protocols direct the assessors to follow a set route around the site and its
environs. At fixed points, they carry out a sniff test and take a Jerome meter reading. They
record on a pro forma sheet their findings in relation to the nature, intensity, duration, extent
and potential source of any smells.
[51] M2 uses a scale of 1 – 5 for odour intensity and extent. By way of illustration, an
odour intensity measurement of 1 would be very faint, 2 would need a bit of effort to smell
it, 3 would be a clear smell, 4 would be offensive, and 5 would make you gag. There is also
a scale for extent - where a measurement of 1 would mean that the odour could only be
detected if standing right at the location or there is a gust or drop of wind.
M2
[52] The M2 assessors carry out their task on weekdays in two shifts (09:00 - 15:00 and
15:00 - 21:00). They take readings every 2 hours at 10 fixed points, 5 within the site
boundary and 5 outside. None are on Mr MacBean’s property.
[53] On arrival an M2 assessor typically follows this pattern. (a) He goes to the main
control room and checks the weather, including the wind direction, the pump speed, and the
flow meter which shows the amount of waste water entering the plant. (b) He takes a
pro forma recording sheet and inserts the date, time and weather information. (c) He slowly
walks clockwise round the site stopping at the 10 points. (d) At each one he puts the Jerome
meter on the ground and while waiting to obtain a reading (15 seconds to 1 minute) sniffs
the air. He note downs his findings for each location on the sheet. If he detects a foul odour,
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he will try to identify its likely source. It takes between 20 - 40 minutes to complete each
survey.
[54] Each week M2 sends copies of all the sheets to Scottish Water, together with a
spread-sheet collating the results. Ten M2 assessors gave evidence at the proof. Their record
sheets were lodged in process. I propose to illustrate the M2 approach by drawing on their
evidence in some detail.
M2 records pre-OCU
[55] I regard 19 September 2019, when the OCU became operational, as a key date in this
case. What really matters is the nature, degree and frequency of odours afterwards. But I
shall begin by looking at excerpts from the records compiled by the M2 assessors before then.
I do so to show their general approach from the outset. This is not a representative sample,
as I have selected records where a smell was detected.
Stephen Kirby
24 May
At 11:10 an odour at the top of the SAF, but no smell
outside the site boundary (intensity 3, extent 3).
David Alexander
4 June
A few faint, local, transient and intermittent odour
readings at the septic tank outlet, at the top of the SAF
and on the river path.
24 June
A couple of 3s - a moderate odour with a localised extent.
Within 2m the odour intensity would have dropped to
a 1 or 2. Also a very faint and very intermittent odour
beside Mr MacBean’s boundary fence.
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20
Andrew Gibson
27 May
16:55 Odours at (a) the splitter chamber (intensity 2,
extent 1). A person had to take a deep breath on the spot
to perceive a smell. There was no smell a couple of steps
away. (b) the SAF unit (intensity 3). You could smell it
when breathing normally but it wasn't overwhelming. It
was a constant smell so he smelled it all the time. It did
not need a bit of a wind to pick it up. At 20:29 at the
septic tank outlet the Jerome meter gave a high reading
but he could not smell anything.
5 August
20:20 A constant mild or stronger intermittent smell at
the SAF (intensity 3 extent 2).
20 August
20:23 on a 20m stretch of the river path (intensity 3).
Andrew Davidson
1 August
20.30 The Jerome meter recorded a high concentration at
the septic tank outlet, so he tested it three more times.
Alexander Bogdanovic
17 August
A faint odour directly above the SAF (intensity 2
extent 1).
Fraser Hogg
11 June
Odours on the way to, and at the top of, the SAF at 16:32
(intensity 2 extent 1) and again at 18:30 (intensity 3
extent 3).
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21
12 June
10:30 Odour at the inlet cover (intensity 3 extent 3). The
smell had a radius of about 5m.
31 July
15:00 At the river path (intensity 3, extent 1). Easily
detectable when there was a gust of wind, or when the
wind dropped.
18:30 at the top of the SAF (intensity 4, extent 3) and also
on the path leading to the SAF and the road towards the
turning circle.
Rhodri Lucas
6 May
09:13 At the splitter chamber (intensity 3 extent 2).
At 11:28 at the inlet cover (intensity 3, extent 3).
26 July
14:47 At the SAF (intensity 3, extent 3).
Donald Morrison
3 June
17:00 At the top of the SAF (intensity 3, extent 2). The
intensity was that of a moderate odour of a sweet sewage
smell but was transient. It could not be detected
about 10m away and did not persist.
1 July
19:10 A predominant smell of grass-cutting towards the
front of the site.
17 July
20:30 Started to pick up a smell when walking up the
steps towards the SAF (intensity 3, extent 3). It was just
in the immediate vicinity but more persistent than
previously.
Page 22 ⇓
20 August
22
12:45 A very faint smell from the septic tank (intensity 2).
No smell at the splitter chamber 10m away, or the
pumping station 4m away.
Readings post-OCU
[56] Turning to the period after the OCU became operational, I will distil the evidence in
a similar manner. Again I have mainly chosen entries where smells were detected.
Andrew Davidson
26 September
A smell from the manhole opposite the site entrance. He
took two readings as he had not smelt anything here
before. Although the readings were high, the smell was
localised, faint and intermittent and did not merit further
investigation.
3 October
Barely detectable and transient odour at the inlet cover.
10 October
18.48 A faint, transient and intermittent smell en route to
the SAF.
11 October
08.55 A faint, transient and intermittent smell at the
manhole opposite the site entrance.
11 December
The smells of a wood fire.
Stephen Kirby
13 November
Sewage had been spilt on the ground, giving rise to an
odour at the splitter chamber and the pumps
(intensity 3.) It might have gone into Mr MacBean’s
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23
garden. It was not offensive and had disappeared
by 20:30.
David Alexander
23 September
09:05 A faint localised odour within 1m of the cover at
the intermediate pumping chamber. It was only
noticeable when bending down to pick up the Jerome
meter.
17 October
17:05 A faint sewage odour at a manhole opposite the site
entrance. There have been a few instances of a very faint
smell there generally only noticeable when bending
down to pick up the meter. It was very faint and very
localised, within 2m of that manhole. “The smell was
pretty much gone by the time you stood up.”
24 October
Smoke smells from properties across the road.
11 November
A faint odour at the manhole at the site entrance. Jerome
meter gave a high reading at its top, but at waist-height
recorded a faint odour. No odour 10m away.
20 November
A turnip smell at three locations, all within the site
boundary.
Andrew Gibson
14 and 15 October At the septic tank (intensity 2). Only detectable if
standing right on top of it and consciously inhaling.
Page 24 ⇓
20 November
16 December
16 December
Fraser Hogg
19 September
15 October
16 October
24
12:55 At the intermediate pumping station (intensity 2).
Detectable directly on top of its covers if sniffing into the
wind.
15:30 The top of the inlet cover (intensity 2). As soon as
you walked away, it was not noticeable.
17:03 the splitting chamber was being upgraded and
there was not the right connection for desludging. An
open pipe led into an open drain for a couple of days. At
the inlet cover I recorded an odour intensity of 3. If you
stood right on top of it without breathing in deeply you
could detect it. You would basically get it from a
walk-by. I would say a metre away you would not be
able to smell it.
8:55 At the septic tank outlet (intensity 2, extent 1). The
smell was faint, intermittent and localised. At 11:00 he
noted an odour at the inlet cover (intensity 2, extent 1). It
was faint and right on top of the cover.
20:15 An odour intensity 2 at the septic tank outlet.
Although it was constant it was very faint and probably
not detectable on the road.
11:35 A constant odour at the intermediate pumping
station (intensity 3, extent 1), following a desludging
operation a couple of hours earlier. It was not present at
Page 25 ⇓
16 October
13 November
21 November
22 November
Rhodri Lucas
20 September
25
the septic tank outlet, or a couple of metres away on the
opposite side of the road.
13:00 and again on 24 October at 20:25 an intermittent
odour at the septic tank outlet and intermediate pumping
station (intensity 4, extent 1). Although it might have
been offensive, unless there was a gust of wind, only
detectable when directly on top of it. A couple of metres
away you probably could not smell it.
11:30 At the septic tank outlet (intensity 4, extent 3).
Ross-Shire Engineering were carrying out works there
that day and had the manhole covers open for prolonged
periods of time.
17:10 at the splitter chamber and septic tank outlet
(intensity 4) and at the intermediate pumping station
(intensity 3). These three locations are all in close
proximity to each other. He did not detect anything at
the SAF unit or the inlet cover.
13:15 A “very strong whiff” but at the intermediate
pumping station (intensity 4, extent 1).
A faint and intermittent odour (intensity 2, extent 1) at
the intermediate pumping station. He had to stand on
top and make an effort to smell it.
Page 26 ⇓
26
14 October
11.07 A persistent but localised odour (intensity 2,
extent 3) at the inlet cover and splitter chamber.
25 October
15.04 At the manhole opposite the site entry (intensity 3
extent 1). It was a moderate sulphurous odour that he
could smell easily without any effort. Only when
standing right on top of the chamber could he smell it. It
was intermittent. You could not smell it from a couple of
metres away.
21 November
08.56 A moderate odour at the splitter chamber and
septic tank outlet (extent 3) but localised to the area
around the sludge tanker, which was there for
desludging.
Donald Morrison
2 October
A prominent smell of manure.
7 October
17:05 A transient smell at the septic tank (intensity 2,
extent 1).
5 December
In the morning a faint, localised smell at the splitter
chamber and septic tank. At 11.15am the splitter
chamber was open for works to be carried out
(intensity 3, extent 1). At 12:45 at the septic tank and the
intermediate pumping station (intensity 2, extent 1).
Page 27 ⇓
27
Arife Madranefe
1 November
09:00an odour intensity of 2 at the splitter chamber. The
smell was very localised. After 2m there was no smell at
all. It was within the site boundary.
Investigation of complaints by M2
[57] Scottish Water asked M2 to respond quickly to complaints about the WWTP. Most
have been relayed by the helpline. In each case, the M2 assessor will typically try to speak to
the complainant before attempting to detect any odours for himself. Mr MacBean has been
the main source of complaints. Here is a sample of the 2019 investigations undertaken by
M2 in response.
31 July and 1 August Fraser Hogg detected a very faint odour in Mr MacBean’s
garden, something that you might notice as not being fresh air,
but not something strong.
20 May
Rhodri Lucas could not detect any smell in Mr MacBean’s
garden.
26 June
David Alexander spoke to Mr MacBean and Ms Hendry, then
walked around the perimeter of the property without
detecting any smells. Mr Alexander came back and spoke to
them for about 5 minutes in the centre of his garden. There
was a large gust of wind and he got a very faint odour. The
others made out that it was unbearable and Ms Hendry said
that she was almost falling over from the smell. Mr MacBean
was seated on the ground. Mr Alexander took a couple of
Page 28 ⇓
5 June
19 June
5 July
1 August
Arife Madranefe
25 November
28
more readings on the Jerome which disclosed readings
of c 3ppb but the odour was very faint and very intermittent.
He only noticed it on the one gust of wind.
Andrew Davidson recorded a musty odour from the SAF on
the path. He completed a round of odour monitoring, but did
not find any smell in the garden.
Fraser Hogg investigated a complaint of a strong odour
coming from the SAF. He went to Mr MacBean’s house and
asked him to mark on the complaint form map where he could
smell it. Mr Hogg could not detect anything at any of the
locations identified by Mr MacBean.
Andrew Gibson did not detect anything when investigating a
complaint made by Mr MacBean.
Andrew Davidson went to Mr MacBean’s house, but did not
detect a smell at the location he indicated but did detect a faint
smell at the lower boundary of the garden.
Investigated complaints made on 10 June, 29 July, 8 and
9 August. He was able to detect faint localised orders, but
nothing to support a problem.
This complaint related to odours both that morning and
throughout the preceding weekend. Shortly after receiving
word of it at 11.45am, David Alexander carried out Jerome
meter measurements. They registered zero at three locations
adjacent to the boundary fence with Mr MacBean’s property,
Page 29 ⇓
29
one along the access path to the SAF unit and two along the
river path. The Jerome meter registered zero at all these
locations. Mr Alexander detected no smells using a sniff test,
other than (a) an intermittent faint odour of cabbage on the
river path (intensity 2 extent 1), and (b) a similar odour coming
from the manhole covers at the splitter chamber. He also
carried out a meter reading and sniff tests beside the area of
the loading pump which is close to the entrance to the
treatments works. There was a zero Jerome meter reading at
that location and no detectable odour. Mr Alexander went to
visit Mr MacBean at his house, who made it clear that he had
experienced smells in his property and in the vicinity of the
treatment works since the previous Thursday (21 November),
when the newly installed pump was used for desludging of
the septic tanks for the first time.
[58] I recognise that some of the complaints were made hours or even days before M2 had
an opportunity to carry out investigations. But it is striking that in some cases, their
investigators had very different perceptions to those of Mr MacBean.
M2 summary
[59] All the M2 witnesses said that they had never smelt anything intolerable or offensive
at the site. Any odours had been faint, localised and intermittent. The only exception was
desludging. They accepted that during that operation, there had occasionally been more
Page 30 ⇓
30
persistent smells of higher intensity. Smells had also come from elsewhere - a small bonfire
in a neighbour’s garden and a local farmer fertilising his fields with manure.
[60] Here are some excerpts that give the flavour of their evidence.
Fraser Hogg
“Barring the odd anomaly… had you not known that you were
on a [WWTP], any odours detected would be comparable to if
you were out for a walk in the countryside.”
Arife Madranefe
Any smells have been localised, faint and within the site
boundaries. He has only rarely recorded an odour intensity
of 3.
Alexander Bogdanovic The OCU had “totally eradicated” the slightly sweet smell
there before.
Andrew Gibson
There has been a “100% difference” since the installation of the
OCU. Other than the manure from the fields, I have not smelt
anything which I would consider to be intolerable or offensive.
The SAF Unit did have a detectible smell but it was a sweet
smell and not offensive.
SOL
[61] Sarah Bevan and Maureen Goodwin of SOL have visited the site once a month since
July 2019 to carry out odour assessments. The only exception was November 2019. Most
visits have lasted 2 days. None has taken place on a desludging day. Only Mrs Bevan gave
evidence at the proof, but Ms Goodwin’s affidavit supports her account in all material
respects.
Page 31 ⇓
31
[62] SOL takes its measurements at 18 fixed points, which are located (i) at the site, (ii) on
the Spey Bridge, (iii) across the river near to Miss Mathews’ establishment, and (iv) at
4 points in Mr MacBean’s garden. At each point they sniff the air every 10 seconds. The
assessors primarily focus on sewage odours, but they record any other smells that they come
across, such as manure from local fields and from the wood burner at the local golf club.
Each SOL survey takes about 90 minutes to complete.
[63] The evidence of Mrs Bevan and Ms Goodwin supports the M2 testimony. On their
first site visit in July they detected the smell of sewage, which they followed into
Mr MacBean’s garden. That is when they first met him and he gave them permission to
carry out part of their regular surveys on his property.
[64] Since then, they have hardly ever detected sewage smells outside the site itself.
Mrs Bevan said:
“So rare are these occasions that I have at times annotated my sheets or the map
marker app if I feel there are circumstances that might account for the odours
and warrant further explanation.”
“I have noticed a difference at the site since I visited in July. The last few times
I have been there, apart from the one occasion with the heavy rain, or when I
have been close to where samples are being collected, I haven’t recorded any
odour.”
[65] An exception occurred during their visit on 10 and 11 December 2019, when they
detected a strong sewage odour coming from the top of the septic tanks. On the morning of
6 January 2020 she noted a very faint sewage odour.
Page 32 ⇓
32
Other evidence relied on by Scottish Water
Miss Rachel Smith
[66] Miss Smith has lived opposite the plant since May 2017. Although her house is
across the river, it is closer to the site entrance than Tomboyach. She is not troubled by
smells and says there are fewer instances this year than before. She works as a shop
assistant in the village and says that smells are not a topic of conversation. She gave the
following hearsay evidence: “everyone tells me that there were issues but they have been
rectified”.
Highland Council
[67] Mr MacBean contacted Mr Murdoch in mid-2015. In his reply Mr Murdoch asked
Mr MacBean to provide details of each odour incident as it occurred. He enclosed forms for
that purpose. They called for information about: (a) the date and time of each incident,
(b) the weather conditions, (c) the nature, location, duration and extent of any smell, and
(d) its likely source.
[68] Despite reminders, Mr MacBean did not always complete the forms. That frustrated
Mr Murdoch’s ability to assess the impact of any smells. He did, however, investigate
whenever he was in the area. In the course of several visits, Mr Murdoch twice smelled
odours. One occurred during desludging. The second time he briefly detected a very faint
smell when he was standing beside Mr MacBean at the top of the embankment between the
garden and the site.
[69] Mr Murdoch had two students on placement with him for a 6 month period in 2016.
He enlisted their help with this matter. He encouraged them to check the position if they
Page 33 ⇓
33
were in the vicinity. They did not notice any smells that compromised the amenity of the
neighbourhood.
[70] At the pursuer’s request, Mr Murdoch attended a desludging operation on
28 February 2019. He went with his manager Gregor McCormack. When they arrived at
Mr MacBean’s front door, he said that he could smell odours. Neither of them could detect a
smell. All three then walked through the garden. About half way to the WWTP,
Mr Murdoch and Mr McCormack picked up faint odours. They also noticed a faint smell at
the fence, which is the highest point of the garden. Mr Murdoch said words to the effect that
it did not amount to a statutory nuisance, as that requires a severe smell for a protracted
period. Mr MacBean was unhappy with this response. He remarked that the two men
“were in cahoots with Scottish Water.”
[71] Mr Murdoch gave evidence on two further points. First, he said that Scottish Water
is operating the plant in accordance with its updated odour management plan. Secondly,
the council has received complaints from fewer than five other residents about smells in the
area. All bar one were one-off complaints. Nuisance recording sheets sent to them by
Mr Murdoch were either not returned or returned saying there was no longer an odour.
SEPA
[72] The Scottish Environmental Protection Agency (‘SEPA’) has a particular
responsibility to ensure that the quality of the water discharged back into the environment
from WWTPs meets certain standards. It has no responsibility for odours.
[73] In an affidavit dated 7 August 2019 Lisa Forsyth, a senior SEPA employee, makes
four points. First, over the years Mr MacBean has mentioned to SEPA that bad odours come
from the WWTP, as well as complaining about discharge from the sewer overflow.
Page 34 ⇓
34
Ms Forsyth says that only one other individual has made complaints about both issues. She
added, “Since the site was upgraded in 2015 and after we received a number of complaints
about the site which have reduced significantly since 2017.” Second, the WWTP complies
with its SEPA licence conditions. Third, she has not noticed any odours when she has been
on site. Fourth, compared to the old plant, the new plant has materially improved the
effluent quality of the discharged water.
A replacement plant?
[74] Scottish Water says that it would be prudent to allow 5-6 years for a replacement
plant to be operational. That is because there are variables outside its control. They include
identifying a suitable site, acquiring the land, obtaining planning permission and
constructing the works. It has no cost estimate, other than using as a yardstick the £5.4m
cost of the present works. Interdict (whether granted now or at some later stage) would
have significant consequences. A convoy of tanker lorries would be required to transport
the effluent away on a daily basis. Other plants would have to check whether the extra
volume would affect their SEPA licence conditions.
Is there a continuing nuisance?
[75] I accept that the WWTP continues to emit odours that come on to Mr MacBean’s
property. But the key question is whether they amount to a continuing actionable nuisance.
[76] As to the nature, frequency, and intensity of the smells, I prefer the evidence of the
M2 and SOL assessors to those of the pursuer’s witnesses. I do so because of the weight and
cogency of their evidence. I found it to be more accurate because (a) they were independent,
(b) the methodology itself was systematic and exacting, (c) they all carried out their task in a
Page 35 ⇓
35
meticulous way, (d) they had detailed records of their findings, (e) it took place several
times of day over many months, and (f) they were all clear that there had been a marked fall
in odours since the OCU began operating. Their evidence provided a detailed and complete
mosaic.
[77] I would add this observation. My impression was that the assessors were actively
pleased to find smells. It relieved some of the monotony of their task. In other words, there
was no attempt to ameliorate the figures.
[78] By contrast, the evidence led by the pursuer was largely anecdotal. Some came from
persons who visited the village from time to time, rather than residents. They had limited
opportunities to detect smells. Some detected no change pre and post OCU. That seemed
odd, given the agreement that it materially altered matters. They were not reliable about the
big picture. Their evidence provided an unfinished jigsaw.
[79] I therefore hold that while the WWTP continues to emit offensive odours, they are
irregular, faint, transient and only occasionally go on to Mr MacBean’s property.
[80] Next I must give “due weight to all the surrounding circumstances of the offensive
conduct and its effects”. In this regard I consider the following factors to be relevant. First,
Scottish Water did not intend to cause a nuisance and has taken careful steps to try to cure
the problem. Secondly, there are few complaints from persons other than Mr MacBean.
Thirdly, the WWTP performs an important public service which would create major
disruption if it had to move elsewhere or cease operations. There are three further points. It
appears that many complaints relate to desludging. I am not satisfied that they cause a
nuisance on every occasion, but even if they do, I hold that they are reasonably tolerable,
having regard to the degree to which they invade Mr MacBean’s property and disturb his
amenity: Stair Memorial Encyclopaedia, Nuisance (Reissue) (paragraph 51).
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36
[81] Second, I have taken into account the regrettable misstatements made by Scottish
Water at the outset. They form part of the overall context, but do not determine my
decision.
[82] Third, I do not accept the experts’ statement in their joint report that the plant is “not
fit for purpose”. That finding usurps the function of the court and in any event must be seen
in the context of Dr McIntyre’s rider.
Defence of implied statutory authority
[83] Mr McBrearty advanced a fall-back submission of implied statutory authority. He
founded on Lord Blackburn’s statement that:
“… no action will lie for doing that which the legislature has authorized, if it be done
without negligence, although it does occasion damage to anyone; but an action does
lie for doing that which the legislature has authorized, if it be done negligently”:
[84] This argument only emerged in his closing submissions. It was not mentioned in the
pleadings until February 2020, when the defender added one opaque sentence to Answer 7.
Mr Smith said that the submission had taken him by surprise. He indicated that he would
have presented the case in a different manner, founding on the misrepresentations made
during the planning process as amounting to negligence.
[85] In view of my decision on the merits, Mr Smith’s difficulty, and standing that
Scottish Water does not have a relevant plea-in-law, I decline to reach a view on this point.
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37
Conclusion
[86] I hold that the pursuer has not established a continuing nuisance. I shall fix a By
Order hearing to hear submissions on the order I should now pronounce, given the decree of
declarator I have already pronounced.