#2 OPSD Cumulative Impact Guidance

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include effects that are later in time or farther removed in distance from the proposed action or alternatives. (40 CFR §1508.1) Hawaii Administrative Rules (HAR) Chapter 11-200.1 under the HEPA, HRS Chapter 343, continues the requirement of cumulative effects/impacts assessment, and defines Cumulative impact as "the impact on the environment that results from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions regardless of what agency or person undertakes other actions. " All EAs/EISs are supposed to provide cumulative impact assessments for their proposed actions. According to the CEQ handbook on Considering Cumulative Effects under the National Environmental Policy Act (CEQ, 1997), the primary purpose of cumulative effects/impacts analysis is to determine the magnitude and significance of the environmental consequences of a proposed action in the context of cumulative effects of other past, present, and future actions. Significance of cumulative effects/impacts depends on how they compare with the environmental baseline and relevant resource threshold such as regulatory standards. Cumulative effects are usually categorized into eight scenarios for assessment as follows (CEQ, 1997): 1) time crowding — effects of frequent and repetitive actions on the environment; 2) time lags — delayed effects of a proposed action; 3) space crowding — effects of spatial density on the environment; 4) cross -boundary — effects occurring away from the source; 5) fragmentation — effects or changes in landscape pattern; b) compounding effects — effects arising from multiple pathways; 7) indirect effects — secondary effects; and 8) triggers or thresholds — effects defined by agency laws, policies or regulations. 3. Principles of cumulative effects/impacts assessment Analyzing cumulative effects/impacts is challenging, primarily because of the difficulty of defining the geographic (spatial) and time (temporal) boundaries. No single formula is available for determining an appropriate scope and extent of a cumulative impact analysis. However, Guidance for Preparers of Cumulative Impact Analysis — Approach and Guidance (Caltrans, 2005) states that the following principles have gained a general acceptance: 1) Cumulative effects are caused by the aggregate of past, present, and reasonably foreseeable future actions. 2) Cumulative effects are the total effect, including both direct and indirect effects, on a given resource, ecosystem, and human community of all actions taken, no matter who has taken the actions. 3) Cumulative effects need to be analyzed in terms of the specific resource, ecosystem, and human community being affected. 4) It is not practical to analyze the cumulative effects of an action on the universe, and the list of environmental effects must focus on those that are truly meaningful. 3