No project of the size and scope of LSC can be undertaken without some potential inconvenience and negative effects; and while all evidence suggests that the project is overwhelmingly positive from virtually every standpoint, there have been some short-term negative impacts:
Detours and Delays
A plan to minimize inconvenience during construction had been prepared in consultation with residents and landowners along the route, Tompkins County Area Transit, the City of Ithaca Traffic Engineer, Cornell's Transportation Services Department, and the City of Ithaca Police and Fire departments.
Lake Sediments
To maintain at least nine feet of overlying water for summer recreation and navigation, some sections of intake pipe were buried in the lake bottom. Some of the sediments excavated in this process - those that contain low-level contaminants from past industrial activity - have been removed from the lake, a process that temporarily increasde water turbidity in the construction area. These were safely disposed of on land. Any disruptions were minimized by using modern techniques such as closed-bucket dredging and silt curtains.
Aquatic Habitat
Sediment excavation disturbed a small portion of the shallows at the edge of the lake. The limited populations of plants and benthic invertebrates removed should quickly reestablish themselves from the surrounding area.
Water Temperature
The total heat added to Cayuga Lake by the warmed return water is the equivalent of what would be caused by an additional four to five hours of sunlight on the lake's surface per year. The added heat will be shed each winter, and will have no measurable effect on water temperature, stratification, or ice cover. Water-temperature change is greatest near the end of the outfall pipe; even there, no ecological impact is anticipated because the temperature change caused by LSC is well within the natural variability of the lake water.
Phosphorus
Some already-dissolved phosphorus will be carried with the water from the lake's lower level to the region of the outfall during the summer, an annual increase of five percent in the southern portion of Cayuga Lake. The impact of this additional phosphorus on algal growth is expected to be low, and no discernible change in lake clarity is projected.
The Food Chain
There has been concern that fish and Mysis relicta (a species of small shrimp fed upon by fish) might be drawn into the intake pipe. From June through November, when the lake is thermally stratified, few fish are present at the depth proposed for the intake. In winter and spring, when a small number of alewives and rainbow smelt swim at this level, there is little demand for campus cooling and the system will operate at low velocity. Some Mysis relicta are active at the intake level, but they avoid light. The LSC design incorporates low light levels (two eight-watt bulbs) to deter Mysis relicta from approaching the intake pipe and high-frequency sound to repel alewives.
