Environmental Impact Assessment (EIA) is a procedure which provides the opportunity for identifying, mitigating or enhancing the potential environmental, health and social consequences of a proposed development activity and for generating alternatives or additional options to that activity (Johnstone 1986). It is a process having the ultimate objective of providing decision makers with an indication of the likely consequences of their actions. The greatest contribution of EIA in environmental management may well be in reducing adverse impacts and refining the developmental proposals before they come through. In order to quantify these impacts it is first essential to measure environmental quality parameters before the project has begun. This data on baseline conditions and trends make possible the assessment of changes produced specifically by the developmental project as compared to any natural changes which might occur (Dixon et al., 1983).

2.1 Macro level assessment
The proposed pipeline route was assessed at the macro level by studying the Survey of India and forest maps. The Andhra Pradesh Forest Department was also consulted to check on the status of forest lands and wildlife along the pipeline route. This formed the basis for identifying localities for intensive surveys.

2.2 Rapid Assessment Survey
The macro level assessment was followed by a reconnaissance survey of the proposed pipeline route. The entire pipeline route provided to us in eight maps of 1:50,000 scale by the HPCL authorities was used as the study area. All along the pipeline route, survey points laid by the HPCL were located at random but atleast one for every 15-20 Km interval. For every survey point, details such as point number, general habitat condition, land use category, wildlife values and proximity to forest area were recorded.

2.3 Intensive surveys
In consultation with the Andhra Pradesh Forest Department and the toposheets (1:50,000), the Reserved Forests (RFs) that are were located on the pipeline route or within 500m from the route were intensively surveyed. Vegetation sampling and animal abundance estimation were made in these areas. Ten sample plots of 5m radius each were laid at every 100m in these RFs for the intensive studies. Data on broad vegetation type, plant species presence and their relative abundance was collected. Similarly data on animal (mammals & birds) presence/absence and their relative abundance based on direct and indirect evidences (signs & tracks) was recorded. Secondary information from the A.P Forest Department and local villagers on the status of wildlife was also used as an additional source of information.

2.4 Scaling of biological values and impacts
Data collected from above aspects were summarised and assigned scales. The scales ranged from 0 to 4 for wildlife and forest values, where 0 indicates none or low value and 4 indicates high value. Floral (species richness) and faunal (mammals & birds) values together constituted the biological value that would be assessed in this study. For assessment of disturbance level during construction and post construction activities, the distance form pipeline route of different RFs were given scales between 0 (for the closest) and 3 (for the farthest). The weights for forest and wildlife values are based on their existing status and the impacts would be projected on the probable changes in the existing values. We expect the disturbance resulting from construction phase of the pipeline to be uniform all along and hence only RFs located in close proximity to the pipeline route would be highly impacted. Finally, a comparison of scales for wildlife and forest values (biological value) and the probable disturbance measured through a scale of distance of RF from the pipeline route was done for the impacts on RFs. It is also logical to assume that RFs with high biological values are likely to be impacted upon more by higher levels of disturbance during the pipeline laying process and period.