Discussion meeting: Mitigating operational impacts

1. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
MITIGATION – POLICYAND CASE LAW
Dr Claire Holman
Brook Cottage Consultants

2. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Contents
1. NPPF
2. Case Law 1: Knight
3. Case Law 2: Gladman
4. Damage costs
5. Conclusions
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3. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
NPPF – Planning conditions and obligations
54. Unacceptable development could be
made acceptable through the use of
conditions or planning obligations.
Planning obligations should only be used
where it is not possible to address
unacceptable impacts through a
planning condition.
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4. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Requirements of Planning Conditions and Obligations
Conditions should be:
a) Necessary,
b) Relevant to planning and to the
development to be permitted,
c) Enforceable
d) Precise
e) Reasonable in all other respects.
Conditions to be discharged before
development commences should be
avoided, unless there is a clear justification.
Obligations must meet all the following tests :
a) necessary to make the development
acceptable in planning terms;
b) directly related to the development; and
c) fairly and reasonably related in scale
and kind to the development.
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5. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Planning obligations (s106 agreements)
• Legal obligations entered into to mitigate the
impacts of development.
• Also known as developer contributions’
(other contributions - highways contributions
and the Community Infrastructure Levy).
• Planning obligations assist in mitigating the
impact of unacceptable development to
make it acceptable in planning terms.
• Planning obligations must meet the tests
• These tests are set out as statutory tests in
the Community Infrastructure Levy
Regulations 2010 and as policy tests in the
National Planning Policy Framework.
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6. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 1 – Wealden Council vs SoS + Knight Developments
• 103 dwellings
• Outskirts Crowborough
• 2.4 km from Ashdown Forest (SAC + SPA)
• Council refused planning consent for serval
reasons including on N deposition on the
Forest
• Planning inspector gave consent.
• Council appealed decision
Photo from visittunbridgewells.com
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7. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 1 – Wealden Council vs SoS + Knight Developments
Council
• Council’s opinion was the proposed
development would have an adverse
impact on the Ashdown Forest.
• No suitable proposals to mitigate this
adverse effect
Planning Inspector
• The impact on its own insignificant
• In-combination, adopting the precautionary
approach, low risk of a significant in-
combination effect.
• This could be mitigated so no need for an
appropriate assessment.
• Contributions towards SAMMS for habitat
management.
Citation: [2016] EWHC 247 (Admin)
17 February 2016 SAMMS = Strategic Access Management and
Monitoring (usually adopted to restrict dog walking
on designated nature conservation sites)
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8. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Mrs Justice Lang’s Judgement
• Financial contribution in the absence of a
scheme, was not a sound basis upon
which to proceed, particularly as Inspector
found that, without mitigation, there would
be a risk of significant effects…and that
mitigation was "necessary" … and "needed“.
• Inspector did not give any proper
consideration to the Council’s concerns
about heathland management as a means
of mitigation.
• Knight had not provided evidence of the
nature and scale of potential impacts upon
the heathland habitats and was therefore
unable to provide evidence that the
proposed mitigation would be sufficient. 8

9. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Mrs Justice Lang’s Conclusions
• There was no evidence that the
contributions would actually be used to
take measures such as cutting and grazing
in a manner that would reduce nitrogen
deposition.
• There was no defined scheme of
mitigation which could be identified as the
means by which any risk of nitrogen
deposition would actually be addressed.
• Planning consent quashed by Court
• Knight Developments appealed to Court but
failed
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10. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 2 – Gladman Developments vs SoS, Swale Borough Council & CPRE
• 330 homes and 60 sheltered
accommodation units, near Newington,
Kent
• Falls between AQMAs in Newington and
Rainham
• Plans for the site, later reduced to 140
homes and 60 ‘extra care’ units
• Refused by Swale Borough Council in 2015
due to impact on air quality
• Gladman appealed
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11. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 2 – Gladman Developments vs SoS, Swale Borough Council & CPRE
• Gladman appealed on grounds of non-
determination
• Planning Inspector concluded that “even
after taking into account the proposed
mitigation measures, the appeal proposals
are likely to have an adverse effect on air
quality particularly on the Newington and
Rainham AQMAs”.
• Panning consent refused.
• Gladman challenged decision in the high
Court.
• AQA predicted with 2020 EFs, “moderate
adverse” impacts at one receptors site, and
two other receptors sites received “slight
adverse” impacts.
• With 2015 EFs “substantial adverse”
impacts at three receptor sites, and
“moderate adverse” and “slight adverse”
impacts of between three and five further
receptor sites
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12. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 2 – Gladman Developments vs SoS, Swale Borough Council & CPRE
• Damage cost calculator used
• Gladman - Inspector should not have
discounted the result on the basis of no
specific evidence of effectiveness because
the principles which underlie the calculation
have been determined by the relevant
Secretary of State.
• Agreeable to a mitigation statement
(planning condition) to contribute towards
mitigation measures which will equal or
exceed the value determined by the damage
cost calculation using the 2020 Emission
Factors (but not the 2105 factors used in
sensitivity test)
[2017]EWHC 2768 (admin) 6 November 2017
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13. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
CASE LAW 2 – Gladman Developments vs SoS, Swale Borough Council & CPRE
Gladman’s case
• Even after proposed mitigation measures,
development likely to have adverse effect
on air quality
• The Inspector presumed that the
“appropriately calculated funding” was not
robust without specific evidence of
effectiveness. He did not explain what was
wrong with the mitigation.
• The undertakings provided precisely what
the Government’s own method required.
More explanation required. It was not the
role of the Inspector to question the agreed
methodology, and none of the parties had
invited him to do so.
• Dispute regarding use of 2015 or 2020
emission factors.
• Difficulty with air quality mitigation “very
difficult to say if we do ‘x’ this will take off ‘x’
micrograms – quantification of effect very
difficult”.
• Number of guidance documents; refer to
planning for air quality guidance which
refers to good practice measures
developers can put in place, for example
charging points, travel plan… Difficult to
specify in detail at this stage and may not
come to fruition if not bus operator.”
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14. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Honourable Mr Justice Supperstone
• Likely effectiveness of the mitigation
measures was issue at the inquiry.
• Contributions not translated into actual
measures.
• Not clear how the mitigation proposal (in line
with the agreed methodology) is to be used
to reduce pollution levels.
• “I consider that … the Inspector reached a
conclusion that on the evidence he was
entitled to reach and that he explained what
was wrong with the mitigation”
• Appeal dismissed by Court
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15. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Damage Costs Calculations
• Damage costs used to assess national
policies, programmes and projects.
• It estimates the cost to society of the
damage caused based on an estimate of the
emissions (£/tonne).
• It does not take account of the spatial
variation in air quality.
• No relationship between damage costs and
the cost of mitigation
Damage costs ≠ cost of mitigation
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Damage costs could be more or less than the cost
of mitigating an air quality impact

16. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Low Emissions Strategies 2010
• “Contributions could be set at a level which
enables full mitigation or offsetting of the
residual transport derived emissions impacts
of a new development. They could, for
example, be derived by estimating the
emission damage costs.”
• Many local authorities have adopted the
damage costs as a way of estimating a
financial contribution
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17. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Air quality damage cost guidance 2019
• “This damage cost guidance is designed for
policy appraisals, to guide in assessing the
air quality impacts of a policy.”
• Various methodologies:
• Damage costs
• Impact-pathway
• Abatement cost approach
• Impact pathways is the best practice
approach to value changes in air quality.
This approach uses atmospheric modelling
to estimate the consequences of changes in
the ambient concentration of air pollutants
for a range of outcomes
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18. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Abatement cost guidance for valuing changes in air quality
• Designed to value changes in air quality
linked to breaches of legally binding
obligations (i.e. EU limit values)
• Again this is for policy appraisal.
• In most cases changes in air quality should
be valued using the impact pathway
approach.
• The best abatement options will often
depend on the local situation. As bespoke
local-level assessments to identify the best
option are resources intensive, standard unit
costs have been developed to inform
decision making.
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19. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Impact pathways approach: guidance for air quality appraisal
• “This document details the methodology
that should be followed by analysts
undertaking bespoke appraisals of air
quality impacts resulting form policies or
projects.”
• …is recommended for use where the air
quality impacts are estimated to be
significant (>£50m) or where changes in air
quality are the principle objective of the
policy or project.”

20. Brook Cottage Consultants Ltd.: Experts in Air Quality Management
Conclusions
• Evidence of the efficacy of mitigation
required
• Mitigation costs are not the same as
damage costs
• The use of damage costs has not been
challenged in the courts.
• Is reliance on damage cost legal?
• Does it mitigate the impact to make an
unacceptable development acceptable?
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