Pollution

Like many urban streams, Nine Mile Run suffers from pollution. In addition to trash littering the stream, the water is contaminated by runoff and sewer overflows. This pollution has a negative impact on both the local environment and the people who visit Frick Park.

Trash in the lower section of the stream

A sewer manhole next to the stream

Urban Runoff

Urban runoff is the biggest problem facing the stream. Natural areas like forests and wetlands can absorb water from precipitation, allowing it to slowly seep into the water table. However, in urban watersheds like Nine Mile Run, most of the rain and snow falls onto impervious surfaces, like roads, parking lots and buildings. The water collects chemicals and other pollutants before flowing into the stream (Nonpoint source: Urban Areas, 2015).

The parkway east runs over the stream. Surfaces like this cause runoff that flows into the water.

Combined Sewer Overflows

During storms or snow-melts, large volumes of water run off into the sewers. When this water enters our streams and waterways, it causes erosion and pollution, harming aquatic life. Pollutants like sediment, oil, pesticides, bacteria, and road salt are common in runoff.

This sign is posted above the sewer outlet pictured below

Sewer overflows into Nine Mile Run are one of the main sources of its pollution. Near the sewer outlets, water in the stream has higher pH levels, along with higher concentrations of heavy metals, sodium chloride, nitrate, and sulfate. Bacteria also comes into the stream through sewer overflows. Enterococci and e coli are both present in the stream in high amounts. (Willis, 2011)

Water flows out of this sewer into Nine Mile Run