DRAFT Sustainability Appraisal Report for the Emerging Local Plan ...

Table 10 – Additive and interactive effects (Adapted from James E, et al. (2003)
Action Type Additive Process Interactive / Synergistic Process
Single Action
Multiple Actions
Repeated effects from a
single proposal e.g. affect
of emissions a power plant
on terrestrial eco-systems.
Repeated effects from
multiple sources e.g.
Effects of various emitters
from different locations
into the same catchment
Effects from a single action that interact with the resource in a
complex manner e.g. bio-accumulation of nitrates from various
sources within the airshed catchment.
Effects from multiple sources affecting resources in a non-linear
manner, e.g. increase of nutrients from point discharges
(sewage works) and non point discharges leading to algal
blooms and lowering of dissolved oxygen or providing a more
suitable habitat for a competing species.
3.36 In general the significance of all adverse and beneficial impacts will be assessed for each identified
policy of the Local Plan in relation to the specific receptors of the SEA: ER01‐ Natural Environment and
Biodiversity, ER04 – Water Resources & Management, ER05 – Air Quality, and ER06 – Climate Change.
3.37 Present baselines for each ER have already been characterised in ‘The State of the Environment’
chapters of Sections 7 ‐ 16 of this SAR. Indicators presented in individual sections were determined for
individual receptors to monitor any changes to the state of the receptor prior to implementation of the
Local Plan. This data was enhanced where it become apparent that further information was needed to
assess the significance of cumulative effects – transportation and air quality. Adverse affects as
determined by the SEA assessment process for the individual impact pathways/mechanisms for effect
were used as thresholds – that is limits beyond which cumulative change becomes an important
concern.
3.38 Pathways of impacts between the sources and receptors have been identified as shown in Table 11 –
Cumulative effects assessment of Policies in the Local Plan. Linkages between the impacts were
determined in the process of a network analysis of impacts and cause‐effect pathways – as shown by
way of example in Figure 5. Causes of impact are presented on the left of the diagram. The directness
of impact of the Local Plan is decreasing towards the right. Lower order impacts, when combined, can
result in higher order effects – for example, climate and ecosystems.
3.39 The significance of combined impacts of multiple policies and projects (inter‐policy impacts) (last
column of Table 11) is assessed against the established benchmark.
Table 11 – Cumulative effects assessment of Policies in the Local Plan
Potential
Receptor
Policies within
the Local Plan
with potential
to impact
Receptor
Other plans &
projects with
potential to
impact
Receptor
Pathway
Potential
Cumulative
Effects
Significance
ER01‐ Natural Environment
and Biodiversity;
ER02 ‐ Welfare, Health and
Well‐being.
ER03‐ Land and Soil
Resources;
ER04 Water Resources and
Management;
ER05 ‐ Air Quality;
ER06 ‐ Climate Change;
ER07 ‐ Materials Efficiency
and Waste;
ER08 ‐ Built Environment;
ER09 ‐ Historic Environment
and Archaeology;
ER10 ‐ Landscape and Visual
Amenity;
Individual
programmes of
the Local Plan
likely to impact
the receptor
refer to Figure 5.
Individual
programmes of
other plans and
projects likely to
impact the
receptor refer to
Figure 5.
Impact
pathways
relevant
to
receptor
refer to
Figure 5.
All negative and
positive effects that
may arise through
the specified
pathways as a result
of the plans and
projects being
implemented refer
to Figure 5.
Overall significance of
impacts assessed
against the thresholds
as described in text
above.
The significance will be
assessed as:
Significant
Beneficial
Beneficial
Mixed
/
Neutral 0
Uncertain ?
Adverse
Significant
Adverse
Page | 43 Runnymede BC FINAL Sustainability Appraisal Report – Feb 2013