In 2021 the Pittsburgh Water Collaboratory and Three Rivers Waterkeeper received funding from the University of Pittsburgh's Year of Engagement Program to collect 100 samples from the tributaries that feed the Ohio, Monongahela, and Allegheny Rivers. Together we sampled 25 locations over four quarters from August 2021 to May 2022. Learn more about the data collected here.
What, Why, and Who?Pittsburgh’s “Three Rivers” (Allegheny, Monongahela, and Ohio) are known to have legacy contamination caused by industrial pollution and human activities [1]. This legacy contamination enters tributaries from all over southwestern Pennsylvania from multiple sources, carrying pollutants into the three main rivers. This alters water quality and negatively impacts ecosystem health, causing environmental degradation and negatively impacts human health [2,3]. Unlike the mainstem rivers, tributary health has not been consistently monitored yet we know that the majority of tributaries are classified as ‘impaired’. This means that a specific water quality standard called a Total Maximum Daily Load (TMDL) is not being met.
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Due to a lack of data on water quality and the unknown effects of industrial pollution, the Pittsburgh Water Collaboratory began to host meetings in 2019 to identify community needs and gaps in baseline water quality knowledge. You can read about the findings from these community meetings in the Pittsburgh Water Collaboratory Community Consensus Report.
As a result, Three Rivers Waterkeeper and the Pittsburgh Water Collaboratory partnered to collect 100 samples from 25 tributary locations thanks to funding from the University of Pittsburgh’s Year of Engagement Program. Samples collected in 2021 and 2022 were tested for nutrient and metal concentrations, such as nitrogen, phosphorus, arsenic, lead, and more. Samples were collected during four sampling quarters to represent seasonality in data. Measurements were taken in August 2021, November 2021, February 2022, and May 2022. |
What did we find?
Nutrients are essential for biological life, but in excess they can cause “eutrophication.” This process triggers a cascade of effects, such as excessive algae growth that restricts oxygen to aquatic life and leads to excessively acidic environments. In urban environments like Pittsburgh, Nitrogen and Phosphorus leak from multiple sources including sewer systems, septic tanks, landfills, construction sites, and industrial discharge. 3RWK and the Collaboratory found consistently high concentrations of nutrients in tributaries to all Three Rivers.
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Acid Mine Drainage (AMD)
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Metals enter our waterways from processes like steel and coke production, which have been carried out in Pittsburgh for decades. These methods require mining and industrial processing, which leave harmful byproducts in the environment such as Cadmium, Iron, Manganese, and Aluminum. Some of these byproducts are a result of Acid Mine Drainage, which is an acid-rich solution that is produced when surface water infiltrates mines and dissolves pollutants from the coal (The Pennsylvania Department of Environmental Protection estimates that there are around 60 abandoned mines within the city limits of Pittsburgh). 3RWK and the Collaboratory found that historical mining still has a significant impact on water quality in Pittsburgh, showing elevated concentrations of Manganese and Iron in Monongahela and Allegheny tributaries, and concerning Cadmium levels in streams draining to the Monongahela River.
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Why is this study important?
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Water quality is heavily dependent on the chemistry of the rivers, and we know that the tributaries feeding Pittsburgh’s Allegheny, Monongahela, and Ohio Rivers have been altered by industrial outputs and human activities for decades. The impaired status of tributaries and lack of water quality monitoring create dangerous conditions for the economy, ecology, and public health of Pittsburgh. The measurement of contaminants is the first step in establishing, refining, and enforcing safer standards for chemical discharge and a reduction in pollutants. Emerging research from this collaboration between Three Rivers Waterkeeper and the University of Pittsburgh’s Water Collaboratory has quantified chemical threats to tributary health, contributing data that is fundamental to understanding and improving regional water quality.
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The Three Rivers are a source of drinking water, recreation, and pride for Pittsburgh, so it is urgent to address the long-lasting effects of pollution on water quality and ecosystem health. You can find a more detailed account of the study and findings on the Pittsburgh Water Collaboratory website, Pittsburgh’s Three Rivers and Their Tributaries.
1. Reconstructing Early Industrial Contributions to Legacy Trace Metal Contamination in Southwestern Pennsylvania. Rossi et al. 2017. Environmental Science & Technology.
2. Water Pollution: Everything You Need to Know. Denchak 2023. NRDC.
3. Wasting our Waterways: Toxic pollution and the unfulfilled promise of the Clean Water Act. 2022. PennEnvironment Research & Policy Center.
4. Water Quality in Southwestern Pennsylvania: Knowledge Gaps and Approaches. 2019. Pittsburgh Water Collaboratory.
2. Water Pollution: Everything You Need to Know. Denchak 2023. NRDC.
3. Wasting our Waterways: Toxic pollution and the unfulfilled promise of the Clean Water Act. 2022. PennEnvironment Research & Policy Center.
4. Water Quality in Southwestern Pennsylvania: Knowledge Gaps and Approaches. 2019. Pittsburgh Water Collaboratory.
