Phosphorus is a naturally occurring element that is found in rocks and sediment. Through natural processes, this phosphorus is released into streams. Phosphorus is also an important element for plant growth and an ingredient in fertilizing products. When a lot of phosphorus is added to a water body, excessive weed growth can occur, as well as odor and bad taste in drinking water.

Although Groton does contribute through its wastewater treatment plant, there are several other sources of phosphorus loading to Owasco Lake. Both residential and agricultural runoff are a major concern and threat to Owasco Lake.

Over 50 percent of the 208 square mile Owasco Lake Watershed is in agricultural production. This makes runoff from agriculture particularly influential on the entire watershed. With the rising cost of fuel and commercial fertilizer (over $500 per ton), runoff can be costly. Agricultural runoff can best be addressed through good management of farm resources. Programs like the Agricultural Environmental Program and Certified Nutrient Management Plans can help reduce a farm's runoff potential.

Residential areas are also a concern to the watershed for a variety of reasons. Many residential areas around Owasco Lake have septic systems, which can leach nutrients into the water. Having structures along the lakeshore increases the amount of impervious surfaces (roofs, driveways, etc), increasing water velocities from these surfaces, causing erosion. The application of lawn fertilizers for “golf course” lawns is a serious residential concern. Populated areas also increase phosphorus loading because of sources like leaf and lawn clipping litter and domestic pet waste. Homeowners can make simple adjustments on their property that will cumulatively have a dramatic effect on the amount of phosphorus in Owasco Lake.

Although Groton is a serious concern in the Owasco Lake Watershed, it is certainly not the only source of pollution. Education is crucial in both the agricultural and residential arenas to help inform both parties of better techniques and practices. Every property owner in the watershed can have some impact and together we can decrease the phosphorus entering Owasco Lake.