The Wild Horse Wind Facility (Wild Horse) is located in Kittitas County, Washington, approximately 11 miles east of the City of Kittitas. Wild Horse consists of 127 V80 1.8-MW wind turbines with a total nameplate capacity of 229 MW. As part of the conditions for Wild Horse Site Certificate Agreement (SCA) with the Washington State Energy Facility Site Evaluation Council (EFSEC), Puget Sound Energy (PSE) is required to implement a two year operational (post construction) monitoring study to evaluate impacts to avian and bat species. With the assistance of a Technical Advisory Committee, PSE developed a post-construction study plan to monitor impacts to birds and bats over a period of two years. The first year of monitoring surveys were conducted on the site between January and December 2007.
The primary objective of the monitoring study is to estimate the number of avian and bat casualties attributable to collisions with wind turbines and meteorological towers for the entire project on an annual basis. The monitoring study consists of four components: (1) standardized carcass searches of selected turbines or turbine strings; (2) searcher efficiency trials to estimate the percentage of carcasses found by searchers; (3) carcass removal trials to estimate the length of time that a carcass remains in the field for possible detection; and (4) a Wildlife Incident Reporting and Handling System for wind project personnel to handle and report casualties found in the project incidentally to the study.
Thirty-two rectangular plots were searched for carcasses. Each plot consisted of two turbines for a total of 64 turbines searched in the monitoring year. Search plots were a minimum of 110 m from the two turbines included in the plot. Surveyors walked parallel transects within the search plot spaced approximately 10-12 meter apart while scanning the ground for fatalities or injured birds or bats.