Pollutants & Sources

Phosphorus Ammonia & Nitrite Combined Sewer Overflows Mercury & Other Industrial Wastes Sediment Loading: Tully Valley Mudboils Salinity Nonpoint Source Pollution

Nonpoint pollution originates over a broad area and a variety of sources; its impacts on Onondaga Lake are under investigation.

What Is Nonpoint Source Pollution?

Nonpoint source pollution refers to water pollution which does not originate from a single clearly identifiable source like a pipe which discharges from a factory into a water body. Nonpoint pollution originates over a broad area and a variety of sources.

Nonpoint Source Pollution Examples

Examples of nonpoint source pollution are:

• Sediment from construction
• Uncovered salt storage for highway operations
• Leachate from septic tanks
• Contaminants which are carried into area streams and lakes with runoff, such as pesticides
• Fertilizers used on agricultural lands or lawns in residential areas.

An example of urban nonpoint source pollution is street litter which is transported to street drains through wind, rain and snow and then is carried into waterways. Rural nonpoint source pollution refers to contaminants generated in a rural/agricultural setting.

Impacts of Nonpoint Source Pollution

Because of its dispersed sources, nonpoint source pollution can be more difficult to control, and it may be more difficult assess its impacts on the lake's water quality than point source pollution.

The extent of the impacts of nonpoint source pollution on Onondaga Lake is under investigation. However, any activities which generate nonpoint pollution in the lake's square mile watershed can lead to pollution in the Lake. Fertilizers contain phosphorus, which is one of the leading contaminants of concern for Onondaga Lake. Phosphorus leads to algae growth which impacts the lake's water clarity and when the algae die, oxygen is consumed which leads to depletion of oxygen in the lake. Urban nonpoint source pollution, including street debris, lawn chemicals, and petroleum-based products such as motor oil, can all end up in the lake and contribute to reduced aesthetics and water quality problems.