APES Chp 14 Water Pollution

Pollutants Impacting Aquatic Ecosystems

Anthropogenic Pollutants (Chemical)

  • Sewage Treatments: Human waste from sewage treatment plants.

  • Animal Wastes: From concentrated feeding operations.

  • Pesticides & Fertilizers: Used in agriculture and residential areas.

  • Pharmaceutical Drugs: Residual medicines entering the environment.

  • Oils, Metals, and Acids: From various industrial and residential sources.

Natural Pollutants (Non-Chemical)

  • Algal Blooms: Caused by excess nutrients (nitrogen and phosphorus).

  • Sediment: Soil washed into waterways, reducing sunlight penetration.

    • turbidity, deposition of sediments

    • erosion!!!

  • Noise and Thermal Pollution: From industrial and recreational activities.

Consequences of Pollution

  • Case Study: 2009 issue where largemouth bass developed hermaphroditism due to chemical exposure, affecting both fish populations and human consumption.

Solutions to Water Pollution

  • Chesapeake Bay Action Plan:

    1. Reduce nitrogen and phosphorus pollution.

    2. Enhance water quality through rigorous testing.

    3. Increase blue crab populations by reducing over-harvesting.

Definition of Water Pollution

  • Water Pollution: Contamination of water bodies by human and animal waste, inorganic and organic compounds, negatively affecting aquatic and terrestrial organisms.

Sources of Water Pollution

  1. Point Sources: Specific locations (e.g., factories, sewage treatment plants).

  2. Nonpoint Sources: Diffuse sources (e.g., agricultural runoff).

    1. rainwater that runs off of arg. fields and → streams

Human Wastewater

  • Definition: Water produced from human activities, including sewage and gray water from washing.

    • nutrients from wastewater decomposition and leached from arg. lands during precipitation

Concerns About Human Wastewater

  1. Oxygen Demand: Bacteria consume oxygen during decomposition, decreasing oxygen availability for other organisms.

  2. Eutrophication: Nutrient release can lead to excessive fertility in water bodies.

  3. Disease Transmission: Wastewater can carry pathogens causing illnesses.

Biochemical Oxygen Demand (BOD)

  • Definition: Measure of oxygen used by microbes in water over time at a specific temp

    • oxygen-demand waste

      • organic matter that enters a body of water and feeds the growth of microbes (decomposer) in turn, requires more oxygen to decompose

      • the more waste, the more microbes grow

  • Implications:

    • Low BOD: Less pollution

    • High BOD: More pollution, can create
      Dead Zones due to low oxygen levels.

Eutrophication

  • Process: Excess nutrients from fertilizers lead to algal blooms, which die and decompose, further increasing BOD and reducing oxygen.

  • limit the abundance of producers in aquatic ecosystems

  • Cultural Eutrophication: Human-induced nutrient inflow.

    • anthropogenic imputes

  • Mitigation: Tertiary sewage treatment to remove nutrients.

Common Diseases from Wastewater

  • Pathogens: Fecal coliform bacteria, Cholera, Typhoid fever, diarrhea, Hepatitis, E. Coli, etc.

Dead Zones

  • Statistic: Nearly 200 dead zones globally, example: Mississippi River affecting the Gulf of Mexico.

Treatments for Human Wastewater

  1. Septic Systems: Treats wastewater from households, where solids settle and are broken down by bacteria.

  2. Sewage Treatment Plants: Centralized treatment involving multiple stages to separate sludge and break down waste with bacteria.

legal sewage dumping

  • raw sewage can be directly pumped into rivers and lakes

  • when heavy rain flow→ overflows of raw sewage dumped right into the surrounding bodies of water

  • Incidents result in the contamination of drinking water, beaches, marine life, and human illness

Pollution from Livestock Operations

  • Manure Lagoons: Storage for livestock waste, preventing contamination if managed correctly but can overflow or leak.

Heavy Metals and Health Risks

  • Lead, Mercury, Arsenic: Sources include natural deposits and industrial activity; can disrupt health and ecosystems.

    • lead- sources of drinking water

    • mercury- in water

      • human activity- burning fossil fuel, incineration of garbage, hazardous waste or medical wastes

    • arsenic- naturally in earth’s crust (mining)

      • can dissolve in groundwater, leading to drinking water

    • all result in cancer

  • acids- industrial plants burning coal and releasing sulfur dioxide and nitrogen dioxide → air

    • cause forests, lakes, streams, and bodies of water to → acidic

    • low PH from mines mix with low pH streams

      • iron to precipitate out of solution forming rusty and oxidized iron

  • synthetic compounds

    • DDT, PCB, PBDE chemicals

    • toxic, carcinogens, genetic defects, interfere with growth & sexual development (reproduction – survival of the fittest) found in the water, soil, and agricultural

Oil Pollution

  • Sources: Natural seeps, extraction, spills from tankers, etc.; highly toxic to marine life.

  • Historic Examples: Exxon Valdez (1989), BP Oil Spill (2010).

  • extremely difficult to remove

Remediation Strategies

  • Manual cleanup, containment booms (plastic barriers), vacuum boats, absorbent materials, dispersal chemicals, and genetically modified bacteria.

Non-Chemical Pollution

  • Noise Pollution: Disturbance to marine mammals (whales)

    • oil tanker, sonar

  • Solid Waste: Plastic and garbage in water bodies.

  • Sediment Pollution: Increased by human activities leading to erosion.

    • originally a natural process

  • Thermal Pollution: Heated water from industries causing temperature shifts in natural water sources. Solutions include cooling towers and closed systems.

    • thermal shock- kill organism due to lack of O bc of warmer water

Water Laws

Clean Water Act (1972)

  • Aims to protect aquatic life and recreation by maintaining water properties, applies to surface water.

    • done by maintaining and restoring the chemical, physical, and biological properties of natural waters

    • does not protect groundwater

    • issued water quality standards that defined acceptable limits of various pollutants in US waterways

    • allows EPA and state gov to issue permits to control how much pollution industries can discharge into the water

Safe Drinking Water Act (1974, 1986, 1996)

  • Establishes drinking water safety standards, and sets Maximum Contaminant Levels (MCLs) for 77 dif elements or substances

    • microorganisms, organic and inorganic chemicals)

    • are subjective to political pressure and affordability

Challenges in Regulation

  • While regulations have improved point source pollution control, nonpoint source pollution remains inadequately addressed.

Developed vs. Developing Nations

  • Comparison:

    • Developed countries have historical industrial pollution

    • Developing nations face pollution challenges in current industrialization processes but lack resources for management.

  • Potential Solutions: Technology transfers, stricter regulations, and economic incentives for cleanup.