Environmental Impact and Water Treatment

Chesapeake Bay Issues:

• Pennsylvania (PA) contribution to nonpoint source pollution.
• Runoff from agriculture into Susquehanna River affects Chesapeake Bay.
• Maryland also has point sources of pollution that can be improved.

Nonpoint and Point Sources:

• Nonpoint sources are diffuse and difficult to pinpoint; e.g., urban runoff or farming runoff.
• Point sources are identifiable, such as a manufacturing plant discharging directly into a water body.

Wastewater and Biological Oxygen Demand (BOD):

• BOD measures the oxygen required by aquatic organisms.
• High levels of nutrients lead to more bacteria and algae growth, increasing BOD.
• Excessive BOD can create dead zones where fish cannot survive due to depleted oxygen.

Eutrophic vs. Oligotrophic Waters:

• Eutrophic: High nutrient levels, often leading to algae blooms.
• Oligotrophic: Low nutrient levels, considered pure water, but can be challenging for some species.

Environmental Indicators:

• Indicator species (sensitive to pollution) help assess ecosystem health.
• Examples:
• Mayflies (indicative of clean waters)
• Midges and tube worms (tolerant of poor conditions)

Wastewater Treatment:

• Septic Systems:
• Two-tank system; solids settle in the first tank, and liquids move to a second tank for leaching.
• Importance of soil type for effective drainage; sand and silt preferred over clay.
• Public Treatment Facilities:
• Larger systems treat waste quickly and often also use bacteria for breakdown.
• Primary Treatment: Removes solids (e.g., screening).
• Secondary Treatment: Involves aeration to enhance bacterial growth and effluent breakdown.
• Tertiary Treatment: Uses chemicals for disinfection (e.g., chlorine).

Endocrine Disruptors:

• Pollutants that can mimic or interfere with hormonal functions.
• Includes various household chemicals and heavy metals that may have long-term health effects.
• Nonpoint source pollution may also carry various endocrine disruptors into water bodies.