A Cleaner Stream
About the Stream
Upper Portion
Most of Nine Mile Run is underground. The main branch of the stream runs through a concrete culvert, starting east of Frick Park. Several storm sewers flow into this portion of the stream. The stream then emerges from from under South Braddock Avenue and flows through Frick Park (Willis, 2011).
Nine Mile Run's location
Lower Portion
Nine Mile Run then passes underneath Commercial Street and the Parkway East. The lower portion of the stream flows through a valley into the Monongahela River.
The lower portion of the stream
History
Up until the 19th century, the Nine Mile Run valley was used for farming. As the area became more urban though, the stream would change drastically. In 1910, portions of the stream in Swissvale, Wilkinsburg, and Edgewood were redirected into underground culverts. The main branch of the stream now runs in a concrete culvert east of Frick Park, where it receives a large flow input from the sewer system. (Frank-Ratchye STUDIO, 2000)
 Condition of Wooden Drain (1911)The stream was redirected through this drain |  9 Mile Run Sewer System (1921)The sewer system is integrated with the underground stream |  Nine Mile Run (1911)The stream flows under a building |
|---|---|---|
 Nine Mile Run Culvert (1911)The stream flows through a culvert under a road |  Nine Mile Run Conditions (1911)The stream has been in poor condition since the early 20th century |  Nine Mile Run Double Culverts (1911)The stream comes out from underground culverts |
 Nine Mile Run (1911)Another culvert going underneath the road |  Grading Commercial Street Angle (191The stream now flows underneath Commercial Street. |
These photos show Nine Mile Run when it was being redirected underground (Historic Pittsburgh)
The disregard for the health of Nine Mile Run in the early 20th century would have severe negative effects on the stream. The sewer systems that are now integrated with the stream are the main cause of its pollution. Combined sewer overflows release chemicals and bacteria into the water. Another major source of pollution is runoff, especially from the large steel slag dumps around the lower portion of the stream (Bain, 2014).
From 1922 to 1972, the Duquesne Slag Company dumped slag from the steel mills in the Nine Mile Run watershed. Over 17 million cubic yards of slag were dumped near the lower portion of Nine Mile Run (Frank-Ratchye STUDIO, 2000).
The slag dumps
The slag dumps now fill 22 cubic megameters on both sides of the stream. They are also filled with litter and debris. Due to their proximity to the stream, runoff from this area is a major contributer to the pollution (Bain, 2014).
A pile of trash left in the slag dumps