Hydrogeology 101 - MRWA 101.pdf · 2014-05-08 · Hydrogeology 101 . Teaching my grandmother to...

Hydrogeology 101 Teaching my grandmother to suck eggs

Rich Soule

Thank You! • You provide most of the information that is

used to prevent people from getting sick because of their water.

• You provide most of the information used to understand the geology and hydrogeology of Minnesota.

• You maintain high standards and professionalism while doing a dangerous and dirty job.

Love MDH

Hydrogeology Hydro Geology

Idiot Speaker

Darcy Darcy, Henry (1856) Les fontaines publiques de la ville de Dijon

springs city

Height =H1 Flow = Q1

springs

SAND L2

H2,Q2

H1,Q1

springs

L2

H1,Q1

H2,Q2

H3,Q3

L3

Sand

Head Loss Water

Flow

Sand = L

Head Loss = H Water

Flow = Q

Flow = Q

Head Loss = H Sand = L

Area = π r 2

= Gradient = i

Area = A

Hydraulic Conductivity = K

𝑄𝑄 = 𝑘𝑘 𝑖𝑖 𝐴𝐴

Not Just an Engineer

CWI: 479,548 Well Records 2,291,491 Geologic Descriptions 422,591 Water Levels 240,305 Specific Capacity Tests

How Many are Enough?

Geology Before

A Little Help Goes a Long Way

Geology After

? ? ?

Original Water Level

Information

New Flow Field

From New

Locations

Sand

Limestone

Sandstone River

Fractures

Bad Stuff

Clay

Lake

Clay

Old Unsealed Multi-Aquifer

Well

Limestone Aquifer

Well

Sandstone Aquifer

Well

How Fast Does it Move? Different Materials have VERY Different Hydraulic Conductivity (K) Values

MW 1 MW 2 MW 3

1 Sec.

0.1 Sec.

1 Min.

1 Hr. 1 Day

Distance

W p ump

MW 2

MW 3

MW 1

Time

Theis, Charles V. (1935). "The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using ground-water storage". Transactions, American Geophysical Union 16: 519–524

𝑠𝑠 = 𝑄𝑄4 𝜋𝜋 𝑇𝑇

𝑊𝑊 𝑢𝑢 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤 𝑢𝑢 = 𝑟𝑟2𝑆𝑆

4 𝑇𝑇 𝑡𝑡 𝑎𝑎𝑎𝑎𝑎𝑎,

𝑊𝑊 𝑢𝑢 = −.577216 − ln 𝑢𝑢 + 𝑢𝑢 − 𝑢𝑢2

2×2!+ 𝑢𝑢3

3×3! − 𝑢𝑢4

4×4!+ . . . . .

Hol

e

Aquifer Damage

Collapse

You Do This All The Time: Specific Capacity Tests

Ground

Clay

Sand

Grout Static Water Level

Pumping Water Level & Time (t)

Pumping Rate = Q

Drawdown= s

𝑠𝑠 = 𝑄𝑄

4 𝜋𝜋 𝑇𝑇𝑊𝑊

𝑤𝑤2𝑆𝑆4 𝑇𝑇 𝑡𝑡

𝑇𝑇 = 𝑄𝑄

4 𝜋𝜋 𝑠𝑠𝑊𝑊

𝑤𝑤2𝑆𝑆4 𝑇𝑇 𝑡𝑡

𝑇𝑇 = 𝐾𝐾 𝐻𝐻

Clay

Aquifer Thickness

= H

Aquifer Water Level ???????? THE WELL EFFICIENCY PROBLEM

You Do This All The Time: Specific Capacity Tests

Ground

Static Level = ?? ft.

Pumping Rate = Q

Air

Lin

e =

80 ft

.

PSI Compressor

Starts Air Starts Bubbling @ PSI = 138 138 PSI / 2.3 = 60 ft. water

138 PSI / 2.3 = 60 ft. water Static = Air Line – 60 ft. water Static = 80 – 60 = 20 ft.

Pumping Level = ?? ft.

Air

Lin

e =

80 ft

.

PSI Compressor

Running

115 PSI / 2.3 = 50 ft. water Pumping = Air Line – 50 ft. water Pumping = 80 – 50 = 30 ft.

Mud Box Bucket

After Some Time….. PSI = 115

Well Information is the key

Otherwise we are clueless

All the Digits Deserve a Chance The Last Digit of Water Level Measurements on Well Logs:

All Should be about 10%

“0” and “5” Are

Overworked

How about giving 1, 3,

4, 6, 7, and

9 a chance?

Thank You!

Love MDH

You Do This All The Time: Specific Capacity Tests

Pumping Rate :

Ground

Air

Lin

e =

80 ft

.

Compressor Running

115 PSI / 2.3 = 50 ft. water Pumping = Air Line – 50 ft. water Pumping= 80 – 50 = 30 ft.

Pumping Level = ?? ft.

Air

Lin

e =

80 ft

.

PSI Compressor

Running

115 PSI / 2.3 = 50 ft. water Pumping = Air Line – 50 ft. water Pumping = 80 – 50 = 30 ft.

Mud Box Bucket

After Some Time….. PSI = 115 Pressure

Drops to 115 PSI

Valve