5: Ecological Impacts in all Stages of a Project

Case study on a Wind Farm

A project from EIA’s point of view, has multiple effects that are grouped according to the stage of the project. Various impacts are covered in the EIA baseline study including the effect a project has on the physical, chemical, biological, and human environment. The physical and chemical scope includes air pollution ( as well as noise, and vibration), water ( effects on surface water and groundwater), and land ( terrain, rock, and soil). On biological and human scope, major effects are seen on biodiversity and social environment as well for humans. A survey is generally done on project sites (detailed data is taken for the primary location), immediate surroundings, and farther surroundings ( for which primary, as well as secondary data, is taken)^[9].

The impacts are best explained by an example of a wind farm. A wind farm, which is a renewable energy project, is considered environment friendly, though it has associated impacts that are discussed below:
The life phases of a wind farm project are:

1. Pre-construction Phase
2. Construction Phase
3. Operation Phase
4. De-commissioning phase

1. Environmental Impacts in the Pre-construction phase:

• Impacts due to Land clearing- Land clearing means removal of vegetation ( trees, shrubs, herbs, climbers) from the project land. This results in loss of habitat ( e.g. Forest, Grassland) and the habitat features ( such as feeding grounds, nesting sites, and tools) and also results in loss of ground cover, soil fertility, and soil moisture. This all contributes to the degradation of habitat and ecosystem services.
• Land Levelling- This step includes digging and filling. The primary impacts are alteration of natural drainage patterns, therefore drying of existing wetlands or water bodies or water logging in drylands. These impacts result in the loss of terrestrial habitats ( mounds, knolls), aquatic habitats ( ponds, pool) and other related habitat features like spawning sites, mounds, nests, burrows.
• Access Roads- Access roads for the movement of material and equipment fragment the otherwise continuous, unaltered habitat as well as introduces alien species. Such species compete for food, shelter, territory and other resources as well as decrease the reproductive capacity and population.

2. Environmental Impacts in Construction phase

• Transport and storage of raw materials- Break and tear related incidents during transportation causes spillage or blow-off of raw material, as well as leaching of hazardous chemicals or materials into air, soil and water contributing to pollution of natural resources and ecological degradation.
• Movement of heavy vehicles/ machinery- Heavy vehicles cause primary impacts of emissions and compaction of soil, which degrades the ecosystem.
• Functioning of labour camp- Ingress of humans and activities like washing, cooking, defecating contribute to extraction and pollution of natural resources and degradation of habitats and ecosystem services.

3. Environmental Impacts in Operation phase

• Impact of presence of the wind turbines- Wind turbines being a large infrastructure, occupies large pieces of land obstructing land and aerial passage of various birds, reptiles etc. The moving blades of a turbine cause visual and sensory disturbances to animals, birds and reptiles and even death ( for birds by accidental collisions.)
• Impacts of wind turbine operations- Primary impacts include noise, shadow flicker (flickering effect caused when rotating wind turbine blades periodically cast shadows), accidental blade throw, fires etc. Such incidents disrupt biodiversity, habitats ,movements, and sometimes cause death by collision with rotors especially for migratory birds.
• Impact of presence of the project staff- Staff present in the location for operation purpose alters the local ecosystem through use of resources, entertainment, recreation and movement.

4. Environmental Impacts in Decommissioning phase

• Dismantling and disposal of wind turbines- After the project machinery is decommissioned, the dismantling and disposal of the components are a major concern. The heavy-duty parts take up space, contributing to waste which is generally left on disposal sites for a long time. A major portion of which is hazardous and therefore acts as a threat to animals, birds, etc.