Otter Tail Power Company’s service area is environmentally diverse—from the lakes and forested regions in Minnesota to the plains in North Dakota and South Dakota. Our 5,900 miles of transmission lines and 2,700 miles of distribution lines run through protected areas such as the Chippewa National Forest and can be found adjacent to several federal wildlife refuges and waterfowl production areas. In our commitment to producing and delivering electricity as environmentally responsibly as possible, we use several techniques to protect biodiversity. When building new assets, we conduct environmental assessments and prepare environmental impact statements as required by law.
Avian contact with power lines and structures can adversely impact avian mortality, disrupt electric service, and implicate potentially applicable bird protection laws. The Migratory Bird Treaty Act (MBTA) is the country’s primary law protecting most species of birds from injury or death associated with human activity. In 2018 the United States Fish and Wildlife Service issued an opinion stating the accidental or incidental injury or death resulting from human activity is no longer an MBTA violation. However, Otter Tail Power Company chooses to voluntarily follow an Avian Protection Plan to minimize incidental injury or death to birds. We’re responsible for minimizing bird interactions with power lines and are committed to reducing the number and consequences of these interactions. Our service area includes many species of resident raptors, such as hawks and owls, and smaller birds. The area also plays an important role as a staging, breeding, and nesting ground for many migratory waterfowl species, shorebirds (including the endangered piping plover), and raptors (such as bald eagles and ospreys). Endangered whooping cranes also migrate through our region.
Transmission and distribution lines that have experienced avian electrocutions are assessed for risk of future electrocutions. Certain structures may be suitable for retrofitting. Retrofitting consists of altering the structure framing by isolation, insulation, installation of perch discouragers or similar apparatus, or a combination of these actions. Agencies such as the U.S. Fish and Wildlife Service and state game and fish departments also may offer recommendations. We ensure all new transmission lines meet avian-safe standards.
We’ll continue to monitor for high bird use areas based on scientific literature, input from federal and state environmental professionals, and observations from company field personnel. We’ll also continue to evaluate and implement measures that reduce or eliminate the risk of collision and electrocution, such as insulating and separating equipment and lines, marking power lines, and providing substitute perches and nest sites.
Wind farms have the potential to affect migratory bird populations. Birds may inadvertently fly into turbine blades. As the operator of our wind facilities, NextEra Energy regularly inspects our turbines, records avian fatalities, and reports fatalities of threatened, endangered, or otherwise protected birds to the U.S. Fish and Wildlife Service. Over the last decade of operation, our turbines have resulted in annual fatalities of fewer than ten migratory birds, of which none have been identified as threatened, endangered, or otherwise protected. Most of these birds were waterfowl species, such as ducks. In 2018 only one recorded incident occurred at our wind turbines. Developers have designed the Merricourt Wind Energy Center to minimize impacts to birds to the greatest extent possible, and we will implement a Bird and Bat Conservation strategy.
In 2018 we relocated two osprey nests from power structures in northern and central Minnesota. Ospreys build large nests on high structures with views of the surrounding environment. We work with the Minnesota DNR to obtain nest removal permits to relocate these nests. We usually erect nesting platforms near the original nest to provide a safer environment for the ospreys to raise their young.
Although the endangered pallid sturgeon (not to be confused with the lake sturgeon) hasn’t been found in the stretch of the Missouri River from which Coyote Station appropriates water, it’s a potential habitat. We employ a closed-cycle cooling system, which the Environmental Protection Agency has classified as a Best Available Technology for reducing fish mortality at cooling water intake structures. Other endangered species in our service area include the rusty patched bumble bee and northern long-eared bat.
We relocated existing coal ash near Hoot Lake Plant and restored riparian habitat along approximately 3,300 feet of the Otter Tail River. Restored habitats include wetlands, upland grassland, and floodplains. We also reclaimed an inert waste disposal site near Coyote Station. Reclamation of this 160-acre site near Beulah, North Dakota, included grading, wetland establishment, topsoil placement, and native grass seeding.