Introduction to Groundwater
Monitoring
Define aquifer - answer saturated geologic unit that can store transmit and yield
groundwater in sufficient quantity to constitute a usable supply
What is the upper boundary in an unconfined aquifer - answer water table
What is the lower boundary in an unconfined aquifer - answer impervious layer
What is the potentiometric surface - answer the height the water could potentially rise to
if the confined aquifer is tapped by a well
When do flowing artesian conditions occur - answer when the potentiometric surface is
above the top of the well casing
Wells must be constructed and installed properly to permit accurate measurement of
what three things - answerGroundwater elevation, in-situ hydraulic conductivity testing
and aquifer testing
Stainless steel, corrugated galvanized steel, PVC pipe, and concrete - answerWhat are
four types of casing materials
What is the size of the outer diameter for the casing of a drilled well - answer5 to 6
inches
What is the size of the outer diameter for the casing of a bored well - answer24 to 48
inches
What is the maximum installation depth of a groundwater well - answer300m
Horizontal hydraulic conductivity is determined by conducting what test - answerslug
test
Name three unconsolidated surficial deposits - answercolluvial, fluvial,lacustrine
Describe glaciolacustrine - answerfine-grained sediments deposited in glacial lakes
Describe glaciofluvial - answerdeposited by glacial melt water channels
What is a nested piezometer - answermultiple piezometers installed side by side with
screens or intakes set at different depths
, What are nested piezometers used to determine - answerVertical hydraulic gradient
The upper boundary of the unconfined aquifer is at ___ pressure - answeratmospheric
Recharge of an aquifer occurs from what type of water movement - answerPercolation
What type of formation does not contain water - answerAquifuge
Of the type of formations that contain water which one has the lowest permeability -
answerAquiclude
Name two objectives of GW level monitoring - answerassessing depth to water level,
detecting impact of GW recharge and discharge
Name two objectives of GW quality monitoring - answertracking changes in GW quality,
identifying potential contaminant sources
What does darcy's law describe - answerthe flow of fluid through a porous and fractured
media
What are the two assumptions of darcy's law - answerlaminar flow, and saturated
medium
What is porosity - answera measure of the void spaces in a formation
What is effective porosity - answerporosity available to contribute to fluid flow
Porosity not considered effective includes what - answerunconnected pores, water
bound to clay particles
Name three factors that influence hydraulic conductivity - answersoil grain size,porosity
of the soil matrix, soil saturation
If the properties of the geologic formation are invariable in space, the formation is
considered to be what - answerhomogeneous
Describe an isotropic geological formation - answerwhen the horizontal and vertical
hydraulic conductivity are equal to each other
Describe an anisotropic geological formation - answerwhen the horizontal and vertical
hydraulic conductivity are unequal to each other
What instrument is used to measure vertical hydraulic conductivity -
answerpermeameter
Monitoring
Define aquifer - answer saturated geologic unit that can store transmit and yield
groundwater in sufficient quantity to constitute a usable supply
What is the upper boundary in an unconfined aquifer - answer water table
What is the lower boundary in an unconfined aquifer - answer impervious layer
What is the potentiometric surface - answer the height the water could potentially rise to
if the confined aquifer is tapped by a well
When do flowing artesian conditions occur - answer when the potentiometric surface is
above the top of the well casing
Wells must be constructed and installed properly to permit accurate measurement of
what three things - answerGroundwater elevation, in-situ hydraulic conductivity testing
and aquifer testing
Stainless steel, corrugated galvanized steel, PVC pipe, and concrete - answerWhat are
four types of casing materials
What is the size of the outer diameter for the casing of a drilled well - answer5 to 6
inches
What is the size of the outer diameter for the casing of a bored well - answer24 to 48
inches
What is the maximum installation depth of a groundwater well - answer300m
Horizontal hydraulic conductivity is determined by conducting what test - answerslug
test
Name three unconsolidated surficial deposits - answercolluvial, fluvial,lacustrine
Describe glaciolacustrine - answerfine-grained sediments deposited in glacial lakes
Describe glaciofluvial - answerdeposited by glacial melt water channels
What is a nested piezometer - answermultiple piezometers installed side by side with
screens or intakes set at different depths
, What are nested piezometers used to determine - answerVertical hydraulic gradient
The upper boundary of the unconfined aquifer is at ___ pressure - answeratmospheric
Recharge of an aquifer occurs from what type of water movement - answerPercolation
What type of formation does not contain water - answerAquifuge
Of the type of formations that contain water which one has the lowest permeability -
answerAquiclude
Name two objectives of GW level monitoring - answerassessing depth to water level,
detecting impact of GW recharge and discharge
Name two objectives of GW quality monitoring - answertracking changes in GW quality,
identifying potential contaminant sources
What does darcy's law describe - answerthe flow of fluid through a porous and fractured
media
What are the two assumptions of darcy's law - answerlaminar flow, and saturated
medium
What is porosity - answera measure of the void spaces in a formation
What is effective porosity - answerporosity available to contribute to fluid flow
Porosity not considered effective includes what - answerunconnected pores, water
bound to clay particles
Name three factors that influence hydraulic conductivity - answersoil grain size,porosity
of the soil matrix, soil saturation
If the properties of the geologic formation are invariable in space, the formation is
considered to be what - answerhomogeneous
Describe an isotropic geological formation - answerwhen the horizontal and vertical
hydraulic conductivity are equal to each other
Describe an anisotropic geological formation - answerwhen the horizontal and vertical
hydraulic conductivity are unequal to each other
What instrument is used to measure vertical hydraulic conductivity -
answerpermeameter
