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Historic Pollution in the Hudson

Unit Plan: Water Quality & HealthTime: One-two 45-minute class periods Setting: Classroom
9-12Hudson River Ecology
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Students will know how the pollution in the Hudson River has changed over time, and be able to explain the consequences of these changes.


    1. Students discuss impacts of excess sewage on the Hudson using historic readings from the New York Times
    2. Students graph 100 years of data on nitrogen, phosphorus, total suspended solids, and biochemical oxygen demand
    3. Students discuss results


    • Computers with Excel or graph paper
    • Copies of handout & readings
    • Optional: readings on pollution and different water quality indicators

    Engagement: Students should read the excerpts from the New York Times, titled “A Poor Sewerage System” and “Albany’s Dangerous Basin”, along with a short synopsis of water quality in New York City. Reading (or discussion) questions are provided.

    Divide students into pairs and ask them to brainstorm the effects of increased nitrogen and phosphorus on an aquatic system. If they have not done any work with water quality indicators, they should be asked to write down what they would need to know in order to answer the question. Review the ideas as a group, and discuss what the impacts of sewage discharge into the Hudson might be.

    Exploration: You should decide whether you want to focus on the Upper Hudson or the Lower/Mid Hudson data. You can also have students compare data for both areas, although the concentrations are very similar when adjusted for population. Upper Hudson data includes the region from the source of the Hudson to the Federal dam at Troy. Mid Hudson starts at the Federal dam at Troy and ends at the Bronx-Westchester County boundary. Lower Hudson starts at the Bronx-Westchester County boundary and ends at the Verrazano-Narrows Bridge in the NYC harbor.

    Students will open “History of Wastewater” in Excel. Students can graph all of the variables, or they can be split up into groups where each group completes one graph and then reports their results to the class. Give enough time for students to do some research on their topic(s): effluent, BOD (biochemical oxygen demand), TSS (total suspended solids), TN (total nitrogen), TP (total phosphorus). One group should be responsible for graphing the population changes.

    Note: Graphing the Lower/Mid Hudson data with the Upper Hudson data eliminates much of the noticeable change in the Upper Hudson trends. Creating a secondary axis for these data is important if students want to see the changes more clearly. Remind students to label axes carefully since it can become confusing when there are different numbers of different y-axes. You can use the Excel tutorial in the Hudson River Ecosystem module of this curriculum for help with Excel.

    Explanation: Population levels have been increasing since the 1900s as people move into the area and up into the suburbs of New York City. This data shows the mid and lower Hudson Valley grouped together (the area of the Hudson River Estuary from Troy to NYC), compared with the Upper Hudson. Primary water treatment plants were constructed in 1924 at Passaic Valley, New Jersey and in Yonkers, and an additional three were added by 1938. There were seven total primary treatment plants by 1952. After the 1972 Clean Water Act, upgrades were made to the plants and additional secondary treatment procedures were added. Dramatic improvements can be seen after the early 1970s. Unfortunately, coliform bacteria was not collected in a standardized fashion before 1974.

    Extend: Students can graph additional parameters.

    Evaluate: Based on their graphs, students should be able to answer the questions on the worksheet. 


    Lesson Files

    Worksheet for use with Excel
    Worksheet with data embedded
    Worksheet with graphs embedded

    Benchmarks for Science Literacy

    1B Scientific Inquiry, 2C Mathematical Inquiry, 9D Uncertainty, 9E Reasoning, 11C Constancy and Change, 12A Values and Attitudes, 12C Manipulation and Observation, 12D Communication Skills

    NYS Standards

    MST 1 - Mathematical analysis, scientific inquiry, and engineering design, MST 3- Mathematics in real-world settings, MST 4- Physical setting, living environment and nature of science, MST 6- Interconnectedness of mathematics, science, and technology (modeling, systems, scale, change, equilibrium, optimization), MST 7- Problem solving using mathematics, science, and technology (working effectively, process and analyze information, presenting results)
    Next Generation Science Standards

    Science and Engineering Practices

    Asking questions and defining problems, Analyzing and interpreting data

    Cross Cutting Concepts

    Patterns, Cause and effect

    Disciplinary Core Ideas

    ESS3A: Natural Resources
    New York State Science Learning Standards

    Performance Expectations

    HS-ESS3-6. Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity.

    Brosnan, Stoddard and Hetling. 2006. Hudson River Sewage Inputs and Impacts” The Hudson River Estuary, edited by Levinton and Waldman, Cambridge Univ. Press.