The Environmental Impact Assessment is a process for anticipating the likely effects on the environment caused by the development of the dual carriageway. The study contains an analysis of the likely effects of the project (positive or negative) on the environment.

A number of different scenarios were examined when determining likely significant impacts. The “Do nothing” (minimum) scenario which compares the quality of the existing road if the proposed scheme were not to be built. The “Do something scenario”   which compares the quality of the existing road with that of the likely environment should the proposed scheme be built.

The year 2028 is designated as the "horizon" year for design purposes, i.e. 20 years after the road opens.

Environmental Details
This is a brief synopsis of the Environmental Impact Statement. A non technical summary of the project is available online from the Midwestroads.ie.

1. Impact on the Community.
On a regional level the overall impact on the community shall be positive with time saving for most motorists as well as a reduced traffic on the existing N7 by as much as 50%. There will be negative impacts associated with the closing off of local roads at Featherbed Lane (Carrowkeel), Castleconnell Rd. (Mountshannon).  There will also be a negative impact on local resources by the severance of bogland access roads in the Annaholty and Gooig bogland areas.

2. Air Quality.
The findings of the model indicate that for the year of opening (2008), construction of the proposed scheme (“do something” scenario), will lead to lower emissions and pollutant concentrations in the study area and in turn will have a favourable impact on air quality.

3. Noise and Vibration.
Noise predictions were carried out based on traffic flows for the year of opening 2008 and 2028 at a total of 347 identified sensitive locations. Noise barriers and/or noise bunds are recommended and the introduction of these measures will reduce the predicted noise levels to less than the advisory limit along the proposed route. Properties along the existing N7 will experience a decrease in noise levels due to traffic being diverted onto the proposed scheme.

4. Landscape and Visual Impact.
In total, some 105 properties, or groups of properties were identified along the corridor of the proposed route as having some degree of visual impact after the initial construction and short-term operating stages. However, measures are to be put in place to mitigate the nature of these impacts. Visual impact and the appearance of the road will be enhanced through a series of landscape proposals.

5. Terrestrial Environment.
The areas of ecological interest along the scheme that may be affected by the project have been identified and appropriate mitigation measures proposed. Embankments will be replanted with native species of local provenance such as ash, oak, birch, willow, aspen and blackthorn. Wherever there is a requirement for re-vegetation, native tree and shrub species will be used. In stretches along the route, wet grassland off the line of
the route will be protected by fencing during construction and not used for machinery storage or travel.

6. Aquatic Environment and Drainage.
Twenty-two streams/rivers will be potentially impacted by the proposed development. Three of the rivers are rated as being of ”regional” importance, the Nenagh River, the Ballintotty River and the Kilmastulla River. The most effective method of mitigating habitat loss is to minimise it and where this is not possible to create new habitat.

7. Soil, Geology and Hydrology.
The existing environment below ground level including soil, geology and hydrogeology was examined and potential impacts arising from the development were identified including mitigation measures to minimise these impacts..

8. Climate.
The more broad reaching impact of the proposed scheme on the environment was examined including its effects on localised atmospheric conditions. The main impact resulting from the use of motor vehicles is their contribution to greenhouse gases. Government data shows an increase in the use of motor vehicles, which results in an increase in the emission of greenhouse gases. While traffic levels are expected to grow, improvements in road infrastructure leading to free-flowing traffic and increased car efficiencies will reduce the impact from car emissions.

9. Material Assets.
There will be in the order of 130 agricultural landowners significantly impacted by the proposed route, accounting for a total landloss of approximately 320ha/790acres (total landloss includes both agricultural and non-agricultural land). There will be a total of 21 properties (a mixture of agricultural and non-agricultural residences and recreational facilities) fully acquired/demolished as part of the scheme. This includes 17 houses currently inhabited, one scout house used for recreational purposes and three derelict properties. In addition a further 26 non-agricultural residences will suffer some loss of curtilage. Three commercial properties including a B&B will be impacted by acquisition of part of their holding and four nonagricultural landholdings will experience some loss of land. In most of these cases the impact is expected to be minor.