Water Quality Flashcards
(28 cards)
What is stream degradation?
A decline in water quality and habitat in a stream due to pollutants or physical alterations.
What is the primary source of oxygen in streams?
Atmospheric reaeration and photosynthesis by aquatic plants.
What is dissolved oxygen (DO)?
The amount of oxygen dissolved in water, essential for aquatic life.
What affects DO levels in streams?
Temperature, organic matter, flow velocity, and reaeration rate.
What is biochemical oxygen demand (BOD)?
The amount of oxygen required by microbes to decompose organic matter.
What is the oxygen sag curve?
A graph showing the drop and recovery of DO downstream of a pollutant discharge.
What is critical DO deficit?
The maximum reduction in DO in a stream after a pollution event.
What is reaeration?
The process of oxygen transfer from the atmosphere to the water.
How does stream flow affect oxygen dynamics?
Higher flow increases turbulence and reaeration.
What is TMDL?
Total Maximum Daily Load; the maximum amount of a pollutant a waterbody can receive and still meet standards.
What are the components of a TMDL?
WLA (waste load allocation), LA (load allocation), and a margin of safety.
What is a waste load allocation (WLA)?
The portion of TMDL assigned to point sources like wastewater treatment plants.
What is a load allocation (LA)?
The portion of TMDL assigned to nonpoint sources like agricultural runoff.
What role does DO play in TMDL development?
DO is a key parameter for aquatic life, and TMDLs are set to maintain sufficient DO levels.
Why are nutrients regulated in TMDLs?
Excess nutrients lead to algal blooms, oxygen depletion, and ecosystem imbalance.
What is the Clean Water Act’s role in TMDL?
It requires states to develop TMDLs for impaired water bodies.
What are common pollutants with TMDLs?
Nutrients (N, P), pathogens, sediments, temperature, and toxic substances.
What are common biological contaminants in water?
Bacteria, viruses, protozoa, and parasites.
What is E. coli a common indicator of?
Fecal contamination in water.
What are chemical contaminants?
Substances such as heavy metals, pesticides, and industrial chemicals.
What is nitrate contamination linked to?
Agricultural runoff and fertilizer application.
What health problem is caused by high nitrate levels?
Methemoglobinemia (blue baby syndrome).
What are emerging contaminants?
Newly recognized or poorly regulated substances like pharmaceuticals and PFAS.
What is the Maximum Contaminant Level (MCL)?
The highest allowable concentration of a contaminant in drinking water set by the EPA.
