Pittsburgh Rivers: Polluted Or Pristine?

Pittsburgh's rivers have been a source of concern for the community, with the city's industrial past leaving a legacy of pollution. While the waterways are cleaner than during the steelmaking heyday, they continue to face serious contamination. A recent study by the University of Pittsburgh investigated pollutants in the tributaries that feed into the three main rivers—the Allegheny, Monongahela, and Ohio. The research revealed high levels of nitrogen and phosphorus in many of the streams, indicating nutrient pollution, and the presence of rare toxic metals associated with steelmaking. The findings highlight the urgent need to address sewage overflows, failing septic systems, and outdated sewer infrastructure to protect the health of the rivers and the communities they serve. With climate change intensifying the risk of pollution and flooding, coordinated efforts and investments are required to safeguard Pittsburgh's rivers and ensure clean water access for its residents.

Sewage overflows

Pittsburgh's rivers are cleaner than they were during the city's steelmaking heyday, but they still suffer from serious contamination. A recent study by the Pittsburgh Water Collaboratory at the University of Pittsburgh found that sewage overflows continue to adversely impact the streams that feed into the city's three rivers: the Ohio, Allegheny, and Monongahela.

The study identified more than three dozen possible pollutants at 25 different tributaries and sewage outfalls. It also found that the impacts of acid mine runoff and sewage overflow into the rivers continue to harm the streams. In addition, the streams are contaminated with rare toxic metals, such as cadmium, which are associated with coke production, a key ingredient in steelmaking.

To address the problem of sewage overflows, the Allegheny County Sanitary Authority (ALCOSAN) has proposed several solutions. One proposal includes enlarging the Woods Run wastewater treatment plant to increase its capacity from 250 gallons per day to 480 gallons per day. This expansion is estimated to cost $335 million. However, even with the enlarged plant, the sewer pipes would still not have sufficient capacity to convey all the water during heavy rainfall. As a result, ALCOSAN previously proposed a $2 billion "gray" solution to the EPA, which included plans to build miles-long underground reservoirs and tunnels along the rivers to store more sewage and stormwater.

While the "gray" solution is costly, implementing exclusively "green" projects to solve sewer overflows can also be expensive and may not always be the most cost-effective approach. A hybrid approach that utilizes both gray and green infrastructure may be optimal. ALCOSAN is currently negotiating with the EPA to finalize a plan to address the sewer overflows. The EPA has indicated a willingness to extend the deadline for solving the problem from 2026 to 2036, which could help spread costs over a more extended period.

Industrial runoff

Pittsburgh's rivers played a significant role in the city's growth and development, particularly during the industrial revolution. However, this progress came at a high ecological cost, and the city's waterways continue to bear the scars of industrial activity.

A recent study by the Pittsburgh Water Collaboratory at the University of Pittsburgh found evidence of serious contamination in the city's three rivers—the Allegheny, Monongahela, and Ohio—as well as the streams that feed into them. The study identified over three dozen possible pollutants, including acid mine runoff, sewage overflows, and rare toxic metals like cadmium, a byproduct of steelmaking. These pollutants have had adverse impacts on the streams and, by extension, the rivers they flow into.

Industrial pollution is a significant contributor to the degradation of Pittsburgh's rivers. A report by PennEnvironment identified 10 Pennsylvania companies as major water polluters, with industrial facilities nationwide exceeding federal water pollution levels 8,100 times between January 2016 and September 2017. Eastman Chemical Resins, located on the banks of the Mon River upstream from Pittsburgh, was the second-worst offender, exposing the river to chemicals like zinc, aluminum, and nitrate. The report underscores the need for stricter enforcement of the EPA's Clean Water Act and highlights the potential consequences of proposed cuts to the EPA's budget.

The legacy of Pittsburgh's industrial past continues to impact its waterways. Failing septic systems, a result of unsuitable soil conditions, have further contaminated the rivers. Additionally, the city's old and degraded sewage system often experiences uncontrolled overflows, even under dry conditions. These issues are compounded by the lack of sewage connections in thousands of local homes, despite it being illegal for 33 years.

Despite these challenges, there is a concerted effort to improve the water quality of Pittsburgh's rivers. The Allegheny County Sanitary Authority has plans to remove billions of gallons of sewage runoff by expanding its plant and constructing underground storage tunnels. The Watershed Alliance for the Three Rivers Region (WATRR) aims to coordinate regional cooperation, technology, and revenue generation to address the remaining gaps in funding for river cleanup efforts. These initiatives reflect a commitment to making Pittsburgh's rivers ecologically healthy and economically productive assets for the region.

Nutrient pollution

Pittsburgh's rivers are cleaner than they were during the city's steelmaking heyday, but they still suffer from serious contamination. A recent study by the Pittsburgh Water Collaboratory at the University of Pittsburgh found that the impacts of acid mine runoff and sewage overflow continue to adversely affect the streams that feed into the city's three main rivers: the Allegheny, Monongahela, and Ohio.

One of the key findings of the study was the significant variability in nutrient pollution across the sampled tributaries. Some of these smaller streams and rivers exhibited extremely high levels of nitrogen and phosphorus, indicating an overabundance of nutrients. This is a serious concern as it can lead to eutrophication and harmful algal blooms (HABs). The elevated nitrogen concentrations could be attributed to outdated and poorly maintained sewer systems, a common issue in aging urban areas.

The Allegheny, Monongahela, and Ohio Rivers are primary sources of drinking water for Pittsburgh and its neighbouring communities, serving millions of people. Ensuring the health and safety of these waterways is of utmost importance. The study's findings provide valuable insights for formulating strategies to mitigate nutrient pollution, safeguard drinking water sources, and preserve the ecological integrity of the river systems.

Addressing nutrient pollution in Pittsburgh's rivers requires a multi-faceted approach. Establishing and enforcing Total Maximum Daily Loads (TMDLs) for nutrient impairment is crucial. Additionally, investing in infrastructure upgrades, such as improving the Pittsburgh sewer system and implementing green infrastructure solutions, can help curb high nutrient concentrations. By taking proactive measures, the city can protect the well-being of its river systems and the communities that depend on them.

Acid mine drainage

While Pittsburgh's rivers are cleaner than they were during the city's steelmaking heyday, they continue to suffer from serious contamination. A recent study by the Pittsburgh Water Collaboratory at the University of Pittsburgh found that the impacts of acid mine runoff continue to adversely affect the streams that feed into Pittsburgh's three rivers: the Ohio, Allegheny, and Monongahela.

The Western Pennsylvania Conservancy (WPC) works with local and regional organizations, county conservation districts, and state and federal agencies to restore land and water resources impaired by abandoned coal mines. WPC assesses on-site conditions, collects background data on water chemistry and flow, and develops strategies to reduce or eliminate the causes of AMD. Lab testing of mine drainage water is also used to confirm the most effective treatment methods for varying levels of acidity and metal content.

One example of a successful treatment system is the Cresson Mine in Pennsylvania, which constructed a solids CONTACT CLARIFIER™ to treat acid mine drainage wastewater. Initially, the mine drainage is decarbonated to remove dissolved carbon dioxide, which would otherwise consume lime and increase costs. The concentration of solids by the solids CONTACT CLARIFIER achieves effective solid/liquid separation for mine drainage with low metal concentrations.

Septic systems

Pittsburgh's rivers are cleaner than they were during the city's steelmaking heyday, but they still suffer from serious contamination. A recent study from the University of Pittsburgh found that acid mine runoff and sewage overflow continue to adversely impact the streams that feed into the rivers. The study also identified additional contamination from rare toxic metals associated with coke production, a key ingredient in steelmaking.

One of the main causes of Pittsburgh's polluted rivers is failing septic systems. The region's soil is not well-suited for septic systems, and it is estimated that about half of the existing septic systems have failed. This has led to "uncontrolled overflows" of sewage into the rivers, even under dry conditions. The Allegheny County Sanitary Authority is taking steps to address this issue by expanding its plant and building large underground storage tunnels to reduce sewage runoff into the rivers.

The quality of Pittsburgh's river water is not just an environmental concern but also an economic one. The city's ability to develop economically is tied to its ability to ensure clean rivers. The Allegheny Conference on Community Development is working to create the Watershed Alliance for the Three Rivers Region (WATRR) to coordinate efforts and secure funding from federal and state governments to improve water quality.

In addition to septic pumping and repair, alternative septic systems, and green solutions are also available. Some companies offer agricultural utilization permits that allow farm recycling instead of clogging landfills with septic waste. This innovative approach not only helps reduce landfilling but also promotes the sustainable reuse of treated wastewater. By investing in proper septic system maintenance and exploring eco-friendly alternatives, Pittsburgh is taking proactive steps towards ensuring the ecological restoration and long-term sustainability of its riverine ecosystems.

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