In the year 2021, the Water Collaboratory and 3 Rivers Waterkeeper secured funding through the University of Pittsburgh’s Year of Engagement Program. Their mission: to gather 100 samples from the tributaries that nourish the Ohio, Monongahela, and Allegheny Rivers. Over the course of four quarters, from August 2021 to May 2022, these dedicated teams meticulously collected samples from 25 distinct locations. The findings that emerged were eye-opening, revealing heightened levels of both nutrients and metals coursing through our river systems. This data underscores the ongoing and substantial impact of industry on the overall health of our rivers.
Special thanks to the University of Pittsburgh’s Year of Engagement, the Frederick Honors College, and the Heinz Endowments for their support in this endeavor and gratitude to the Three Rivers Waterkeeper for their valuable collaboration on this project.
The intricate chemistry of rivers plays a pivotal role in shaping their water quality and, consequently, impacting human communities and the environment. In the context of southwestern Pennsylvania, the story of water quality is a complex one, shaped by a historical legacy of industrial activities and human interactions. This narrative revolves around the Allegheny, Monongahela, and Ohio Rivers, collectively known as the “Three Rivers,” and the network of smaller streams and rivers known as tributaries. It’s within these tributaries that we unearth valuable insights into the health of our rivers. Learn more about the data.
The Exploration
In 2019, the Pittsburgh Collaboratory for Water Research, Education, and Outreach (Pittsburgh Water Collaboratory) embarked on a journey to fill the gaps in our understanding of the city’s water systems. Community meetings shed light on the absence of data regarding historical industrial pollution and the water quality in tributaries flowing into the Three Rivers.
To uncover these hidden stories, a team of dedicated individuals set out to explore 25 tributary mouths that were accessible by boat along the Three Rivers. The goal was to collect samples that could provide a comprehensive view of water quality. To prevent contamination from the main stem rivers, samples were taken above the first riffle. These expeditions spanned four sampling quarters, covering the seasons from August 2021 to May 2022.
The Findings
In the quest to uncover the hidden stories of Pittsburgh’s waterways, the research team made a striking discovery: nutrient pollution is a significant and varied concern in the tributaries feeding into the Three Rivers.
The Nutrient Conundrum
Nutrient pollution in water bodies occurs when excessive amounts of nutrients, such as nitrogen (N) and phosphorus (P), find their way into the aquatic environment. In our context, these nutrients enter the tributaries through various pathways, with potentially detrimental consequences for the entire river system. One of the standout findings was the remarkable variability of nutrient pollution across the sampled tributaries. Some of these smaller streams and rivers exhibited conditions described as “extremely bad,” indicating an overabundance of nutrients. In contrast, others were categorized as “good,” reflecting healthier water quality.
The above image shows the Febraury 2022 (Q3) results of Nitrate in Pittsburgh.
A consistent trend emerged during the research, highlighting the tributaries draining into the Monongahela River. They consistently showed elevated levels of nitrogen and phosphorus throughout all four sampling seasons. This raises significant concerns about the health of the Monongahela River and, by extension, the broader Three Rivers system.
The elevated nitrogen concentrations in these tributaries could be attributed to outdated and poorly maintained sewer systems, a familiar issue in aging urban areas. Additionally, permitted discharges from facilities under the National Pollutant Discharge Elimination System (NPDES) could be contributing to the problem. On the other hand, the high phosphorus concentrations observed may be tied to a combination of factors. Contemporary facilities with phosphorus discharge allowances, along with a legacy of pollution from slag, an industrial byproduct from the iron ore smelting process, may be responsible for these heightened levels. These findings emphasize the interplay between historical industrial activity and modern practices in shaping the water quality of the Three Rivers. Nutrient pollution was not limited to tributaries feeding the Monongahela River alone. The research revealed that high concentrations of nutrients were found in streams that drain into all three of the mainstem rivers—Allegheny, Monongahela, and Ohio. An important note is that most of the sampled tributaries did not have Total Maximum Daily Loads (TMDLs) established for nutrient impairment. The revelation of nutrient pollution in the Three Rivers is a serious concern. With consistently high concentrations of nitrogen and phosphorus in many of the 25 streams sampled, it becomes imperative to address this issue to prevent eutrophication and harmful algal blooms (HABs) from occurring.
To tackle this problem effectively, the establishment, refinement, and enforcement of TMDLs are vital steps. Additionally, investments in improving the Pittsburgh sewer system are essential in curbing high nutrient concentrations and ensuring the long-term health of the Three Rivers.
Acid Mine Drainage (AMD)
A significant threat to our water quality comes from acid mine drainage (AMD), a result of surface water interacting with pyrite in mines. AMD leads to highly acidic water with elevated levels of heavy metals, which can be harmful to both humans and wildlife.
The comprehensive analysis conducted on Acid Mine Drainage (AMD) holds paramount significance in understanding and addressing the water quality challenges faced by Pittsburgh and its surrounding regions. This research sheds light on the pervasive presence of AMD in the waterways, highlighting the profound and far-reaching consequences it has on both the environment and the community. By unraveling the intricate web of pollutants, acidic waters, and heavy metal contamination associated with AMD, this analysis serves as a vital tool for formulating strategies to mitigate its impact, safeguard drinking water sources, and preserve the ecological balance of Pittsburgh’s rivers. Ultimately, this research underscores the urgency of addressing AMD and taking concrete measures to protect the well-being of the Three Rivers and the communities they serve.
Why it matters?
The importance of the Allegheny and Monongahela Rivers as primary sources of drinking water for Pittsburgh and its neighboring communities cannot be overstated. These rivers are the lifeblood of the region, providing essential freshwater resources for countless residents and businesses. Their contribution to daily life is immeasurable, as they quench the thirst of families, fill the glasses in local eateries, and support various industrial and agricultural processes. Similarly, the Ohio River, which supplies water to nearly 5 million people, plays a critical role in ensuring that the broader region has access to clean and safe drinking water.
However, the presence of manganese (Mn) and iron (Fe) in these water sources, while not directly harmful to human health, introduces a range of undesirable effects. Residents and consumers in areas serviced by these rivers might encounter drinking water with an unpleasant taste or odor, which can affect their overall satisfaction with this fundamental resource. Beyond taste and odor issues, elevated levels of iron can lead to visible discoloration of water, causing concerns about its aesthetic quality. Additionally, this iron buildup can accumulate in various water systems, ranging from household plumbing to industrial machinery. The result is the potential for clogs, blockages, and reduced efficiency in these systems, which not only disrupt daily life but also necessitate the use of corrosive and often environmentally unfriendly cleaning agents to remove these obstructions. These challenges, while not posing an immediate health risk, underscore the need for proactive measures to manage and mitigate iron and manganese in the drinking water supply, ensuring that it remains safe, palatable, and sustainable for the communities that rely on it.
The analysis of the Three Rivers, their tributaries, and the challenges posed by Acid Mine Drainage (AMD) and nutrient pollution matters significantly for Pittsburgh and its residents. These rivers are more than just bodies of water; they are lifelines for the city and its neighboring communities. The Allegheny, Monongahela, and Ohio Rivers serve as essential sources of drinking water, supplying millions of people. Understanding the threats they face, such as AMD and nutrient pollution, is paramount for safeguarding the quality of drinking water. The findings from this analysis provide a crucial roadmap for mitigating these threats and ensuring that Pittsburgh’s residents continue to have access to safe and clean water, an indispensable resource for daily life.
Pittsburgh’s economic, cultural, and environmental identity is closely intertwined with its rivers. These waterways have played a pivotal role in shaping the city’s history, from the industrial era to the present. Recognizing the environmental challenges they face and taking action to address these issues is integral to preserving the city’s natural beauty, supporting its recreational activities, and promoting tourism. Moreover, it aligns with the broader global movement towards sustainable urban development. By mitigating the impact of AMD and nutrient pollution, Pittsburgh can position itself as a model for cities striving to balance environmental conservation with economic and cultural vitality. In essence, the analysis of the Three Rivers is not just an environmental concern; it’s a reflection of the city’s commitment to a brighter, more resilient future.