hydrogeology 101 - mrwa 101.pdf · 2014. 5. 8. · hydrogeology 101 . teaching my grandmother to...
TRANSCRIPT
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