FE Environmental Part 2

Flashcards from the notes I've taken in preparation for the Environmental FE. This covers these topics: groundwater/soils/sediments, surface water/hydrology, environmental chemistry

aquifer

underground body of rock or sediment that serves as a storage reservoir for large volumes of groundwater

unconfined aquifer

underground water storage supplied by water from Earth’s surface

confined aquifer

underground water storage supplied by water from stormwater flow

45% minerals, 25% water, 25% air, 5% organic materials

soil percentages

weathering

rocks being broken down into smaller pieces

erosion

smaller rocks being carried away from their parent rock

hydrology

study of surface water

hydrogeology

study of groundwater

97%, 3%

Earth is what percent saltwater and what percent freshwater?

porosity

percentage of rock and soil that is void of material

permeability

ability of a material to allow fluids to flow through it

hydraulic conductivity

rate that water can move through a rock

stream gauging

process of measuring the water level and flow rate through streams and rivers

water table

depth where pressure of fluid in pores is equal to atmospheric pressure

aquifuge

impermeable; will not transmit water

aquitard

layer of low permeability that can store groundwater and transit it slowly from one aquifer to another

water well

used to extract groundwater or inject fluids

cone of depression

forms in an aquifer around a well as water declines

recharge areas

deep unsaturated zones between water table and surface (topographic highs)

discharge areas

zones where water table is close to or at land surface (topographic lows)

laminar flow

low energy flow where molecules follow the streamline

turbulent flow

high energy flow where molecules move irregularly

transmissivity

flow rate of water through a thickness of water

storativity

volume of water released from storage per unit surface area of the aquifer

specific storage

volume of water released from storage per unit volume of the aquifer

aquifer testing

pumping on a well for a period of time at a constant rate; measuring flow rate and well drawdown

environmental remediation

the removal, treatment, and containment of contaminants from soil, groundwater, or sediment

heavy metals, pesticides, radioactive material

soil contaminants

agricultural and industrial waste

groundwater contaminants

brownfield

a site having had previous development on it

restoration

returning ecosystem to its original condition

reclamation

preparing land for productive reuse

phase 1 ESA

1. review historical land use

2. identify potential contamination sources

environmental site assessment

ESA

Phase 2 ESA

1. soil/groundwater sampling

2. chemical analyses

3. determine contaminant and extent

ex-situ

contaminated material removed and treated elsewhere

in-situ

contaminated material treated without excavation

soil vapor extraction

method where vacuum removes vapors from unsaturated soil

chemical oxidation

method where oxidants destroy contaminants

thermal desorption

method where heat volatizes chemicals

pump and treat

method where contaminated water is pumped out of the ground, treated ex-situ or recharged

biodegradation

breakdown of contaminants by microbial organisms into smaller compounds

air sparging

air blows into contaminated water which causes volatilization of compounds, which get extracted

natural attenuation

monitoring natural processes over time

capping

method where contaminants are covered and isolated

solidification

method where sediment is mixed with cement to reduce mobility and leaching

water budget

balance between water inputs and outputs

normality

number of equivalent weights per liter of solution

hydrograph

plot of a watershed showing discharge flow rate over time

rational method

used to calculate peak flow rate for a watershed

atomic number

number of protons in the nucleus of an atom

isotope

chemically identical forms of an element

atomic weight

average atomic mass of an element

molecular weight

mass of a mole of a particular substance

mole

Avogadro’s number of a substance (6.022×10²³)

oxidation

losing electrons

reduction

gaining electrons

lose electrons oxidation, gain electrons reduction

LEO goes GER

stoichiometry

measuring the proportions of elements or compounds involved in a reaction

reactants

what is reacting in a chemical reaction

products

what is formed in a chemical reaction

equilibrium

when reactants and products are equal, and forward and reverse reaction rates are equal

half life

time required for the concentration of a chemical to decay to half its original value

BOD

amount of dissolved oxygen consumed by aerobic bacteria

biological oxygen demand

BOD

drawdown

the decrease in groundwater level caused by pumping

increases

drawdown ____ with pumping rate and time

decreases

drawdown ____ with distance from well and transmissivity

Thiem equation

steady-state drawdown solution

large transmissivity

aquifer transmits water easily

small transmissivity

aquifer transmits water poorly

Theis equation

transient drawdown solution

transmissivity

ability of an aquifer to transmit water

erosion

removal and transport of soil by water, wind, ice, gravity

stable channel

sediment entering = sediment leaving

degradation

channel bed lowers due to erosion

aggradation

channel bed rises due to sediment deposition

bank failure

channel widens due to collapsing banks

detention basin

temporarily stores runoff, controls peak flow

retention basin

permanent water pool, improves water quality

infiltration basin

promotes groundwater recharge

wetland

areas where water is present long enough to influence soil, vegetation, and the ecosystem

Streeter-phelps model

predicts dissolved oxygen levels downstream of wastewater discharge

deoxygenation

bacteria consume oxygen while degrading BOD; DO decreases

reaeration

atmospheric oxygen enters water; DO increases