Hydrologic Cycle/Water Supply

Aquifers/Properties Well Construction

Hydrologic Cycle/Water Supply

Aquifers/Properties Well Construction

Waterworks OperationsWQT 111

Lecture 1

Waterworks OperationsWQT 111

Lecture 1

http://ga.water.usgs.gov/edu/watercycle.html Albany and Purdue

http://www.purdue.edu/dp/envirosoft/private/src/main.htm

ObjectivesObjectives

Parts the Hydrologic CycleParts the Hydrologic Cycle

Aquifer TypesAquifer Types

Porosity vs. PermeabilityPorosity vs. Permeability

Water Sources and SupplyWater Sources and Supply

Groundwater ProblemsGroundwater Problems

Well Construction and MaintenanceWell Construction and Maintenance

The objectives of today’s lecture are to learn the basics of:The objectives of today’s lecture are to learn the basics of:

Sources of Drinking WaterSources of Drinking Water

• Surface water

• Ground water

• Desalinated sea water

• Rain water

• Surface water

• Ground water

• Desalinated sea water

• Rain water

Many sources of water are directly suitable for drinking purposes without treatment?

Many sources of water are directly suitable for drinking purposes without treatment?

Tru

e

Fal

se

67%

33%

1. True

2. False

1. True

2. False

Source waters include these two broad categories

Source waters include these two broad categories

Surfa

ce w

ater

...

Res

ervo

irs a

nd...

Res

ervo

irs a

nd...

Flo

win

g wat

er ..

.

86%

7%7%0%

1. Surface water and ground water

2. Reservoirs and wells

3. Reservoirs and ground water

4. Flowing water and stagnant water

1. Surface water and ground water

2. Reservoirs and wells

3. Reservoirs and ground water

4. Flowing water and stagnant water

The Drinking Water Cycle

Water System

Distribution System

Sewer Lines

Wastewater Plant

Discharge

Homes or Businesses

Septic System

Infiltration

Source(aquifer, lake,

etc.)

Distribution of Earths WaterDistribution of Earths Water

Water For Human ConsumptionWater For Human Consumption

• 98% of available fresh water for human use is groundwater

• 98% of available fresh water for human use is groundwater

• We use 100 gal/day per person• We use 100 gal/day per person

Water For Human ConsumptionWater For Human Consumption

• 50% of US population (municipal water systems)

• 45-50% of US population groundwater

• 50% of US population (municipal water systems)

• 45-50% of US population groundwater

The mineral content and water quality of a particular well is usually pretty consistent.

The mineral content and water quality of a particular well is usually pretty consistent.

Tru

e

Fal

se

7%

93%1. True

2. False

1. True

2. False

What percentage of the water used in the United States comes

from underground sources?

What percentage of the water used in the United States comes

from underground sources?

45%

30%

60%

90%

56%

25%19%

0%

1. 45%

2. 30%

3. 60%

4. 90%

1. 45%

2. 30%

3. 60%

4. 90%

Nearly 95 percent of the rural population of the US relies on

ground water.

Nearly 95 percent of the rural population of the US relies on

ground water.

Tru

e

Fal

se

0%

100%1. True

2. False

1. True

2. False

It is estimated that daily water usage in the U.S is 88 billion gallons per day, two thirds of

which is used for crop irrigation.

It is estimated that daily water usage in the U.S is 88 billion gallons per day, two thirds of

which is used for crop irrigation.

Tru

e

Fal

se

20%

80%1. True

2. False

1. True

2. False

Hydrologic CycleHydrologic Cycle• Water moves from earth to sky

(evaporation and transpiration)

• Water vapor forms tiny droplets (condensation=clouds)

• Water falls back to earth (precipitation)

• Water on the earth penetrates the ground or runs off the surface (infiltration, percolation, surface runoff)

• Water moves from earth to sky (evaporation and transpiration)

• Water vapor forms tiny droplets (condensation=clouds)

• Water falls back to earth (precipitation)

• Water on the earth penetrates the ground or runs off the surface (infiltration, percolation, surface runoff)

EvapotranspirationEvapotranspiration

RechargeRecharge

Ground WaterGround WaterGround Water / Surface Water

InteractionGround Water / Surface Water

Interaction

StreamStream

LakeLake

PrecipitationPrecipitation

Plant UptakePlant UptakeLakeLake

Surface RunoffSurface Runoff

Riparian Zone

Riparian Zone

WetlandWetland

Hydrologic Cycle

http://ga.water.usgs.gov/edu/watercycle.html

(solid to gas)

Ocean

Evaporation Evapo-transpiration

runoff

Water Supply

Discharge treated water

Salt Water IntrusionAquifer

Infiltration

Recharge

Evaporation

Extraction

Precipitation

PrecipitationEvaporation/ETSurface WaterGroundwater

Soil moistureInfiltration (Art)

ExtractionReturn flowTreated water Aquifer intrusion

Soil moisture

Soil moisture

Detailed Hydrologic Cycle

Kennedy 2003

Condensation

http://ga.water.usgs.gov/edu/watercycle.html

Evaporation

http://ga.water.usgs.gov/edu/watercycle.html

Transpiration

http://ga.water.usgs.gov/edu/watercycle.html

Infiltration

http://ga.water.usgs.gov/edu/watercycle.html

Water TableWater Table• zone of aeration (vadose)

= air and water in pores (unsaturated)

• zone of saturation = water only in pores

• groundwater = water beneath soil and above bedrock

• zone of aeration (vadose) = air and water in pores (unsaturated)

• zone of saturation = water only in pores

• groundwater = water beneath soil and above bedrock

Ground WaterGround Water

UNSATURATEDZONE

Ground Water

UNSATURATEDZONE

WATER TABLE

ZONE OFSATURATION

Aquifer Types

Aquifers and Wells

Artesian wells are defined asArtesian wells are defined as

Hav

ing w

ater

u...

Bei

ng loca

ted ..

.

Any

wel

l use

d ...

Wel

ls c

ompl

ete.

..

This

des

ignat

i...

20% 20% 20%20%20%1. Having water under a

pressure greater than atmospheric which causes the water to rise

2. Being located in an aquifer more than 200 feet deep

3. Any well used to pump high quality drinking water

4. Wells completed less then 25 ft below the ground

5. This designation is just a clever marketing ploy as it applies to all wells

1. Having water under a pressure greater than atmospheric which causes the water to rise

2. Being located in an aquifer more than 200 feet deep

3. Any well used to pump high quality drinking water

4. Wells completed less then 25 ft below the ground

5. This designation is just a clever marketing ploy as it applies to all wells

Confined AquiferConfined Aquifer

Porosity and PermeabilityPorosity and Permeability

• porosity = percent pore space in sediment or rock

• permeability = capability of a substance to allow the passage of water

– depends on porosity and connectivity of pores or fractures

• porosity = percent pore space in sediment or rock

• permeability = capability of a substance to allow the passage of water

– depends on porosity and connectivity of pores or fractures

Porosity and PermeabilityPorosity and Permeability

• high porosity materials:

– clay, sand, well sorted gravel

• low porosity materials

– granite, gabbro, metamorphic rocks

– may have high permeability due to fractures

• high porosity materials:

– clay, sand, well sorted gravel

• low porosity materials

– granite, gabbro, metamorphic rocks

– may have high permeability due to fractures

Porosity and PermeabilityPorosity and Permeability

Clay Porosity and PermeabilityClay Porosity and Permeability

• Clay is a high porosity material!!!

• Clay is a low permeability material!!!

• Clay is a high porosity material!!!

• Clay is a low permeability material!!!

Porosity may be defined as Porosity may be defined as

The

perce

ntage.

..

The

ratio

of f

...

The

number

of .

..

None

of the

se ..

.

25% 25%25%25%1. The percentage of open

space or voids in a particular soil

2. The ratio of filtered to reject water for a sand filter

3. The number of wells sunk per area into a particular aquifer

4. None of these is correct

1. The percentage of open space or voids in a particular soil

2. The ratio of filtered to reject water for a sand filter

3. The number of wells sunk per area into a particular aquifer

4. None of these is correct

Limestone has more porosity than clay?

Limestone has more porosity than clay?

Tru

e

Fal

se

81%

19%

1. True

2. False

1. True

2. False

As groundwater moves through the soil, this type of material may be removed as the soil behaves

like a natural filter.

As groundwater moves through the soil, this type of material may be removed as the soil behaves

like a natural filter.

Susp

ended

mat

e...

Dis

solv

ed m

ate.

..

Sal

ts

Am

mon

ia a

nd o

t...

91%

0%0%9%

1. Suspended material

2. Dissolved material

3. Salts

4. Ammonia and other nitrogen compounds

1. Suspended material

2. Dissolved material

3. Salts

4. Ammonia and other nitrogen compounds

Specific yield may be defined as:Specific yield may be defined as:

The

amount o

f ...

The

amount o

f ...

The

amount o

f ...

The

amount o

f ...

15%8%

62%

15%

1. The amount of water that a particular volume of rock or soil will produce when drained by gravity.

2. The amount of water that a particular well produces when drained by gravity.

3. The amount of water that a particular well produces when pumped forceably.

4. The amount of water that may be squeezed from a volume of rock or soil with a Vadose press.

1. The amount of water that a particular volume of rock or soil will produce when drained by gravity.

2. The amount of water that a particular well produces when drained by gravity.

3. The amount of water that a particular well produces when pumped forceably.

4. The amount of water that may be squeezed from a volume of rock or soil with a Vadose press.

How much water is produced by a given well depends on which of

the following factors?

How much water is produced by a given well depends on which of

the following factors?

The

aquife

r

The

pump

The

wel

l

All

of the

abo...

0%

100%

0%0%

1. The aquifer

2. The pump

3. The well

4. All of the above

1. The aquifer

2. The pump

3. The well

4. All of the above

Well ConstructionWell Construction

• Wells should be at least 5 ft from any building

• Easy to access for repair and maintenance• Typically casing extends 1 to 2 feet above

the surrounding land • Properly fitted pump and pipes (to handle

demand)• Proper gravel pack and well completion• Disinfect w/ 100 mg/L available chlorine

• Wells should be at least 5 ft from any building

• Easy to access for repair and maintenance• Typically casing extends 1 to 2 feet above

the surrounding land • Properly fitted pump and pipes (to handle

demand)• Proper gravel pack and well completion• Disinfect w/ 100 mg/L available chlorine

Well/Pump PartsWell/Pump Parts• Properly fitted pump

– well pump pedestal- supports the weight of the pumping unit.

– Well pump motor base seal -watertight seal between the motor base and the concrete support pedestal.

– well pump blow-off -remove first water (usually sandy) pumped at start-up

– well casing vent (3”)- air enters well during drawdown to prevent vacuum conditions. Vents excess air during well recovery period.

– Air-release vacuum breaker valve (125 psi) -Permits discharge of air in column pipe during start-up and admits air during shutdown.

• Properly fitted pump – well pump pedestal- supports the weight of the pumping

unit.– Well pump motor base seal -watertight seal between the

motor base and the concrete support pedestal.– well pump blow-off -remove first water (usually sandy)

pumped at start-up – well casing vent (3”)- air enters well during drawdown to

prevent vacuum conditions. Vents excess air during well recovery period.

– Air-release vacuum breaker valve (125 psi) -Permits discharge of air in column pipe during start-up and admits air during shutdown.

Well MaintenanceWell Maintenance• Water level in well measured with a

sounder

• Hydrochloric and Sulfamic acid can be used to remove well crust. Chlorine to remove iron bacteria (new well 50 mg/l 24 hrs; old well 100-200 mg/L for shock)

• Well surging- physical cleaning of the well

• Water level in well measured with a sounder

• Hydrochloric and Sulfamic acid can be used to remove well crust. Chlorine to remove iron bacteria (new well 50 mg/l 24 hrs; old well 100-200 mg/L for shock)

• Well surging- physical cleaning of the well

New WellsNew Wells

1. Add enough chlorine to produce a concentration of 50 mg/L in the well casing.

2. Turn the pump on and off several times to mix the well (agitate).

3. Re-mix well several times at one-hour intervals.

4. Wait 24 hours.

5. Pump well water to waste until chlorine smell is gone.

6. Test for chlorine residual @ well sampling tap

7. Collect a bacteriological sample.

1. Add enough chlorine to produce a concentration of 50 mg/L in the well casing.

2. Turn the pump on and off several times to mix the well (agitate).

3. Re-mix well several times at one-hour intervals.

4. Wait 24 hours.

5. Pump well water to waste until chlorine smell is gone.

6. Test for chlorine residual @ well sampling tap

7. Collect a bacteriological sample.

What concentration of residual chlorine should be maintained

for 24 hours in a newly constructed well?

What concentration of residual chlorine should be maintained

for 24 hours in a newly constructed well?

50

mg/L

50

ug/L

25

mg/L

25

ug/L

100%

0%0%0%

1. 50 mg/L

2. 50 ug/L

3. 25 mg/L

4. 25 ug/L

1. 50 mg/L

2. 50 ug/L

3. 25 mg/L

4. 25 ug/L

What is the purpose of surging?What is the purpose of surging?

To c

lean

min

er...

To re

move

blo

c...

To b

ackw

ash fi

...

To p

repar

e pum

...

80%

0%7%

13%

1. To clean mineral deposits from well screens.

2. To remove blockages from the distribution system.

3. To backwash filters rapidly.

4. To prepare pump motors for erratic power supplies.

1. To clean mineral deposits from well screens.

2. To remove blockages from the distribution system.

3. To backwash filters rapidly.

4. To prepare pump motors for erratic power supplies.

Chlorine (100-200 mg/L) is an effective treatment for well

screens. It helps to remove this material.

Chlorine (100-200 mg/L) is an effective treatment for well

screens. It helps to remove this material.

Slim

e fro

m ir

o...

Bio

film

s fro

m ..

.

Iron a

nd m

anga.

..

Cal

cium

car

bon...

77%

0%

15%8%

1. Slime from iron-oxidizing bacteria

2. Biofilms from ammonia-oxidizing bacteria

3. Iron and manganese oxides

4. Calcium carbonate deposits

1. Slime from iron-oxidizing bacteria

2. Biofilms from ammonia-oxidizing bacteria

3. Iron and manganese oxides

4. Calcium carbonate deposits

Chlorine treatment of wells is sometimes referred to as ________

treatment because of the high concentrations of chlorine that is

agitated (100 and 200 mg/L).

Chlorine treatment of wells is sometimes referred to as ________

treatment because of the high concentrations of chlorine that is

agitated (100 and 200 mg/L).

Shock

Slu

g

Atte

nuat

ed

Chlo

ro-b

iotic

100%

0%0%0%

1. Shock

2. Slug

3. Attenuated

4. Chloro-biotic

1. Shock

2. Slug

3. Attenuated

4. Chloro-biotic

Finished Well Finished Well

• Drilled by cable tool method or rotary hydraulic• Sanitary seal top of the well • Surrounded by a 4-inch thick sloping slab extending at

least 2 feet in all directions• Typically casing extends 1 feet above 100 year flood line • Grout seal well casing with concrete or clay• Well screen keeps out particulates and allows water into

well (properly fitted slot size)• Proper sized pump

• Drilled by cable tool method or rotary hydraulic• Sanitary seal top of the well • Surrounded by a 4-inch thick sloping slab extending at

least 2 feet in all directions• Typically casing extends 1 feet above 100 year flood line • Grout seal well casing with concrete or clay• Well screen keeps out particulates and allows water into

well (properly fitted slot size)• Proper sized pump

Finished Well Finished Well

Well screen

Grout seal

Problems: Contaminated Aquifers

Sources of Contamination

Problems: Overpumping/Land subsidence

USGS Fact Sheet-165-00December 2000

This condition results when more water is removed from an aquifer than is replaced through

rain and snowmelt.

This condition results when more water is removed from an aquifer than is replaced through

rain and snowmelt.

Ove

rdra

ft

Dry

wel

ling

Ris

ing

water

t...

Air

bindin

g

100%

0%0%0%

1. Overdraft

2. Dry welling

3. Rising water table

4. Air binding

1. Overdraft

2. Dry welling

3. Rising water table

4. Air binding

Problems: Overpumping/Land subsidence

20-40ft decline

Problems: Salt Water Intrusion

Potential problems that can affect wells are

Potential problems that can affect wells are

Ove

rdra

ft

Gro

undw

ater

po...

Sal

t wat

er In

t...

All

of the

abo...

7%

93%

0%0%

1. Overdraft

2. Groundwater pollution

3. Salt water Intrusion

4. All of the above

1. Overdraft

2. Groundwater pollution

3. Salt water Intrusion

4. All of the above

The objectives stated in the syllabus to learn the basics of

(Parts the Hydrologic CycleAquifer types, Porosity/permeability, Well

construction, Groundwater problems) were met ?

The objectives stated in the syllabus to learn the basics of

(Parts the Hydrologic CycleAquifer types, Porosity/permeability, Well

construction, Groundwater problems) were met ?

Stro

ngly A

gree

Agre

e

Dis

agre

e

Stro

ngly D

isag

ree

80%

0%0%

20%

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree

1. Strongly Agree

2. Agree

3. Disagree

4. Strongly Disagree