1. Phosphorus in Southern Cayuga Lake and Its Tributary Streams A Public Information Forum February 27, 6-8 PM, Tompkins County Library Purpose 1.Present facts about phosphorus 2.Inform the public about phosphorus monitoring programs 3.Promote dialogue and collective problem-solving

2. Framing the Phosphorus Issue Phosphorus is the limiting nutrient in Cayuga Lake. Excessive phosphorus increases the risk of aquatic weeds, algae blooms and fish kills. Upper concentration considered “safe” is 20 ug/L (TP) Three potential sources of excess phosphorus are: –Tributary streams –Sewage treatment plants –Lake Source Cooling If concentrations are higher on average than Cayuga Lake, then a source is a potential net contributor of phosphorus.

3. Types of Phosphorus Two general types of phosphorus in nature 1. Dissolved phosphorus 2. Particulate phosphorus a. In algae and other organisms b. Attached to sediment Two main types of phosphorus tests in the laboratory 1. Soluble reactive phosphorus (SRP) 2. Total phosphorus (TP) Dissolved phosphorus in nature = SRP in the laboratory Particulate phosphorus in nature = (TP – SRP)

7. Average Phosphorus Concentrations in Cayuga Lake, Salmon Creek Cluster, 2006-7 Regional stream conditions: Base flow Shallow lake waterDeep lake water SRP 6.2 ug/L SRP 7.2 ug/L TP16.0 ug/L TP 8.8 ug/L Regional stream conditions: Elevated flow Shallow lake waterDeep lake water SRP 5.7 ug/L SRP 8.0 ug/L TP 32.8 ug/L TP 16.6 ug/L

8. Average Phosphorus Concentrations in Cayuga Lake, South End Cluster, 2007 Regional Stream Conditions: Base Flow Sampling site SRP (ug/L) TP (ug/L) Control site 3.1 21.8 LSC outfall 3.6 20.1 CHWWTP outfall 5.2 18.3 IAWWTP outfall 5.8 28.6

12. Average Phosphorus Concentrations Entering Cayuga Lake from Tributary Streams Base Flow Averages StreamSRP (ug/L)TP (ug/L) Fall Creek1728 Six Mile Creek1015 Salmon Creek 7 9 Averages of Base Flow and Stormwater Fall Creek21 117 Six Mile Creek12 124 Salmon Creek2232

13. Conclusions 1.Total phosphorus is more concentrated in shallow water than in deep water in Cayuga Lake, 11.6 ug/L compared to 7.6 ug/L near Frontenac Point. 2.Total phosphorus averaged 22.2 ug/L in shallow water at the far south end of Cayuga Lake, twice as high as the mid-lake value. 3.Fall, Six Mile and Salmon Creek are net contributors of sediment-attached phosphorus to Cayuga Lake. 4.Fall and Salmon Creek are net contributors of dissolved phosphorus to Cayuga Lake.