more than 40 micrograms/liter of chlorophyll, more than 100 micrograms/liter of phosphorus, and a visibility depth of less than 3 feet. The Trophic State Index scale also helps with these classifications. If a lake scores a TSI of above 50 it will be considered hypereutrophic. Lake Koshkonong has a TSI score of 67. Algal blooms can result in high levels of blue-green algae which can be harmful to humans and pets under certain circumstances. Blue-green algae has been found in parts of Lake Koshkonong. It is advised by the Rock County Public Health Department to not swim in areas with floating green scum, and blue or white paint looking areas that resemble pea soup. Proposed nuclear power plant In the 1970s, Lake Koshkonong was the primary site considered for a billion dollar nuclear power station. Wisconsin Electric Power Company, Wisconsin Power and Light Company, Madison Gas and Electric, and Wisconsin Public Service Corporation jointly proposed the project. They chose Lake Koshkonong out of 84 potential sites because of the solid rock found here that could be used for the foundation, and the Rock River could be used as an adequate water source. In 1974, it was estimated that the utilities would lose $40 million if the two-unit, 900 MW each, facility was not approved. At that time, the timetable had already slipped to a 1983/1984 commissioning. The proposed two pressurized-water reactor system had hopes of beginning construction in 1978. The plan was met with strong resistance from environmental groups. It was eventually killed in 1977 by concerns regarding the lake's shallow depth and consequences to the plant during drought conditions. Water would have been exiting the lake to cool down the plant, and residents were uneasy about that along with other aspects of the project. The power plant was intended to relocate many residents and disrupt farmland as well. It was estimated that the disruption to farmland would cost farmers a total of $27,500 each year for lost crops. The Koshkonong Alert Group was an anti-nuclear group that formed in opposition of the power plant. Attempts were made to salvage the $40 million investment by moving the facility to Haven, Wisconsin, near Sheboygan, but state utilities gave up on their plans for construction of a nuclear station in Wisconsin following the Three Mile Island accident in Pennsylvania. The plant was planned to be built on Vickerman Road, east of the