Abstract |
This Phase I Inspection/Evaluation Report presents the results of a visual dam inspection of the Allete, Inc. Laskin Energy Center (LEC) Cells A-D and Cell E Impoundments located at 5699 Colby Lake Road in Hoyts Lake, Minnesota. The inspection was performed on September 23 and 24, 2010 by representatives of GZA GeoEnvironmental, Inc (GZA), accompanied by representatives of LEC. The Cells A-D Impoundment, in its current configuration, has a maximum crest height of approximately 32 feet above the natural ground surface but a typical height of about 6 feet. The impoundment has a maximum storage volume of approximately 970 acre-feet at the minimum embankment elevation of approximately 1,450 feet MSL. Under U.S. Army Corps of Engineers (COE) guidelines, the impoundment is classified a Small size structure. The Hazard Potential Classification for the Cells A-D Impoundment is Less-Than-Low under the EPA hazard rating criteria due to the limited potential for failure and limited are of potential impact. |