Runoff & Infiltration
Water soaking into the ground is called _____.
Infiltration
Runoff pollution comes from one pipe or many small sources? Name pollution source type.
Many → Nonpoint source.
Excess nutrients in water cause along with runoff causes?
Eutrophication
Which surface allows the most infiltration: grass, pavement, or sand?
Grass or sand.
You pour 75 mL of water. Runoff collected = 18 mL.
What percent infiltration occurred?
76% infiltration.
Which surface creates the most runoff: pavement or grass?
Pavement.
Give one example of a pollutant runoff can carry.
Oil, salt, fertilizer, litter, pet waste
Which two nutrients are the main cause?
Nitrogen & Phosphorus.
Which surface would cause the fastest runoff: clay, gravel, or pavement?
Pavement.
200: A group pours 125 mL of water. Runoff = 52 mL.
What percent runoff occurred?
42% runoff.
Why does pavement cause more flooding?
Impermeable → no infiltration → more runoff.
What type of pollution is fertilizer running into a stream?
Nonpoint source or nutrient pollution.
What do algae blooms do to sunlight under water?
Block it; plants die.
Why does clay have low permeability?
Tiny pores → water can’t flow easily.
90 mL poured onto a tray. Runoff = 37 mL.
What percent infiltration occurred?
59% infiltration.
Which surface would best recharge groundwater: mulch, pavement, or gravel?
Gravel or mulch.
Why is nonpoint source pollution harder to control?
Diffuse sources, widespread, weather-driven.
Why do fish die in eutrophication?
Decay uses oxygen → hypoxia (suffocation)
Which type of soil is often used as a filter: gravel, sand, or clay?
Sand or gravel.
150 mL poured. Runoff collected = 111 mL.
What percent runoff occurred?
74% runoff.
Explain the difference between porosity and permeability.
Porosity = % empty space; Permeability = flow through pores.
Explain how runoff connects to Lake Erie’s pollution problems
Runoff → nutrients → algal blooms → toxins & O₂ depletion.
Give one real-world example of eutrophication
Lake Erie, Gulf of Mexico, Toledo 2014.
Why do different surfaces matter for water quality?
They control infiltration vs. runoff → pollution transport.
Compare two surfaces:
Surface X → 135 mL poured, 48 mL runoff
Surface Y → 120 mL poured, 84 mL runoff
Which surface had the higher percent infiltration, and by how much?
X = 64% infiltration; Y = 30% infiltration; X higher by 34%.