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Manual Aquifer Testing Methods for

Groundwater Supply Development Groundwater Supply Development

Essa Paterson, Cara Shonsey, John Gierke

PIRE

0530109

Peace Corps Master’s

International Program

Student field site

Watershed inventories &

seasonal fluctuations

Santa RitaManagua

23

1

Extensive pumping tests performed to, establish method, gauge

reproducibility, and monitory productivity changes

5

Intro Tests Analyses Applications What now?

0

40

80

120

0 4 8 12 16 20 24

Dra

wdow

n (

ft)

Elapsed time (hrs)

5 gpm 15 gpm

25 gpm

37 gpm

Conventional Pump Test 9/25/07

Results from conventional test indicate equil. approx. overestimate Sc by 15%

Dra

wdow

n

Time

0

1

2

3

4

35 36 37 38 39 40 41 42 43 44

Sp

ecific

ca

pa

city (g

pm

/ft)

Static water level (ft below top of casing)

Manual tests - equilibrium approx

Conventional step-drawdown test -36.9 gpm recov AQTESOVL

Intro Tests Analyses Applications What now?

60

70

80

90

100

3

4

5

Pre

cip

itatio

n (m

m)

Specific

Capacity (

gpm

/ft)

3

Wells 1, 2

Well 3

Changes in well productivity over the 10 month study varied.

Specific Capacity = QΔs

0

10

20

30

40

50

0

1

2

11/06 12/06 2/07 4/07 5/07 7/07 8/07 10/07

Pre

cip

itatio

n (m

m)

Specific

Capacity (

gpm

/ft)

Date

Manual pumping tests for

exploring supply

development options

Explore

Input parameters

Topo & aquifer thickness

Recharge

Groundwater modeling facilitates exploration of resource.

groundwater

development

options

Groundwater flow

modelWater demands

Observed groundwater levels

Hydraulic conductivity

1432

4056

Tested Dug Wells

Ephemeral Stream/Wetland

Dug Wells

Road

N

Pumping tests conducted in four community wells.

1432

100m

Explore

Input parameters

Topo & aquifer thickness

Recharge4

5

6

7

8

Hyd

rau

lic C

on

duct

ivity

(f

t/d

ay)

Average Kh = 3.22

Hydraulic conductivity estimated by conducting multiple tests.

Explore

groundwater

development

options

Groundwater flow

modelObserved groundwater levels

Water demands

Hydraulic conductivity

0

1

2

3

4

0 10 20

Hyd

rau

lic C

on

duct

ivity

(f

t/d

ay)

Static Water Level (ft)

Average Kh = 3.22

Groundwater model determined that two wells placed 0.3 mi apart can meet

current demand of 560 ft3/d.

Summary:

- Urgent needs to characterize developing nations’ groundwater

supplies exist

- Appropriate method in this study generated well productivity

data useful for resource monitoring

- Manual pumping tests coupled with sophisticated data analysis

software enable characterization of the hydrogeologic setting

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Questions?Questions?

PIRE

0530109