Facilitating cumulative impact assessment in the EIA process

Abstract

For almost two decades prepared environmental impact statements (EISs) and environmental assessments (EAs) in the United States have been required to address cumulative impacts (CIs). However, the current overall level of attention given to CI considerations in these documents is lacking and inconsistent. This paper presents the highlights from a study on the current state‐of‐practice of cumulative impact assessment (CIA) in the environmental impact assessment (EIA) process. The study consisted of six components: (1) reviewing published literature related to CI fundamentals (e.g., definitions and generic frameworks); (2) reviewing 14 EISs from the United States; (3) reviewing 30 EAs from the United States; (4) reviewing international regulations from 8 different countries/groups of countries; (5) reviewing 40 court cases related to CIA issues; and (6) analyzing the results from a questionnaire sent to EIA practitioners in both the United States and internationally to ascertain professional viewpoints and experiences on CIA issues. The study results yielded 13 needs and recommendations for improvements to current CIA considerations organized according to the following topical categories: the need for standardization of a CI definition; the need for increased attention to CIA in EAs; the need for better utilization of scoping in the CIA process; the necessity for an appropriate land management framework if CIA is integrated into this context; the need to appropriately define spatial and temporal boundaries; the necessity for monitoring CI predictions to aid in future studies; and the desirability of considering CI issues early in the EIA process.