1910 /:17 c..1

071794 JB)li.il;~ 21IJ.£LlcAz:~n2.",,~;::C'JY.illI'ACIUS · {lLENIDl!NG §~{;l1laN},

DEPARTMENT OF NATIONAL RESOURCES NATIONAL DEVELOPMENT

BUREAU OF MINERAL RESOURCES, GEOLOGY .AND · GEOPHYSICS

BMR

Record 1980/29 .

GROUNDWATER SUPPLY FOR NATIONAL FITNESS CAMP

AT BLOCK 10, PADDYS RIVER DISTRICT, ~CT.

by

P.D. Hohnen

The informati'on contained in this report has been obtained by the Department of National Resources a .. oart of the policy of the Australian Government to assist in the exploration and development of

'al resources . It may not be published in any form or used in a company prospectus or statement ut the permission in writing of the Director • . Bureau of Mineral Resources. Geology and Geophysics.

Record 1980/29

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Record 1980/29

GROUNDWATER SUPPLY FOR NATIONAL FITNESS CAMP

AT BLOCK 10, PADDYS RIVER DISTRICT, ACT.

by

P.D. Hohnen

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CONTENTS

ABSTRACT

INTRODUCTION

BORE SITING

CONSTRUCTION OF BORES

Bore PR1

Bore PR2

Bore PR3

Bore PR4

Bore PRS

AQUIFER TESTS

ANALYSIS OF AQUIFER TESTS

GROUNDWATER. CHEMIS TRY

CONCLUSIONS AND RECOMMENDATIONS

REFERENCES

TABLES

1. Logs of water bores

2. Hydraulic parameters of fractured-rock aquifers

FIGURES

1. Location of National Fitness Camp in Paddys River

District (I55/A16/2290).

2.

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Location of water bores at National Fitness Camp

(ISS/ A16/229l).

'Slug' test on bore No. PR1 (I55/A16/2292).

32-hour drawdown test on pumping bore No. PR4

(I55/A16/2293).

Page

1

2

3

3

-4

5

5. Residual drawdown test on bore No. PR4 (I55/A16/2294).

6. 48-hour drawdown test on pumping bore No. PR5

(I55/A16/2295).

7. 48-hour drawdown test: pumping bore = PRS,

observation bore = PR4 (I55/A16/2296).

8. Residual drawdown test, bore No. PRS (I55/A16/2297).

9. Analysis of pumping test on bore PR5, observation

bore PR4, using Stallman's method (I55/A16/2298).

10. Image-well method of explaining recharge boundary

intercepted during pumping tests (I55/A16/2299).

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ABSTRACT

In 1974, BMR drilled a 45.7-m bore through fresh granite at

the National Fitness Camp to test fractured-granite aquifers; it yielded

3 a flow of 1 m /h. Of four production bores that BMR drilled at the camp

in 1978, two were successfully completed, cased, and tested by pumping

for 48 hours. The quality of the groundwater - having a total dissolved

solids content of 200 mg/l - is suitable for domestic use, and the

yield of the bores - 13 500 l/h and 4000 l/h - is more than adequate to

supply the needs of the camp (68 000 l/day).

"\ '\O~\"l>\I\O Founo

..,-Resefve

10

-- Ali-photo /ineomen/

APPROX. SCALE

\ \. \

\/ \ \

50C 1 ::01:1 :::I:::I=:J::::J0E=====::r:::=====1 O~O=O====M:Jelres

Fig.1

N

/ / /

~~

\

for J~ATIONAL FITNESS CAMP - - -------------------------_ ... _-------------Air photo: CAC.£p7 RUN 14 8322 . PADDY'S RIVER . ---- . -- - ---- ----- -- -- ---- - - - - . - - - - -.--- -------.---------------------------------------_. I: 10000 Grid ref. ofbl;'re: PR1_ J~_5.91Q~ 585270N r-----'-----------=.::..:..:.==::...-J To oce~PQ~or& Site Advjce No 68/=====.===:~=~ t-::=:::-__ Sk_e_t_c_h_p_'a_n_.-N_o_t_t_o_S_c.:...a_l..:..e ___ ~

,. InitioIL.~, __ -.- Dote __ L.c.."-_______ 2~OI)OO SHEET ._t~~~l~._. __ ._. ___ .

Plan' MCWBI._. _______________ .

Record 198Q/29 155/AIG/2290

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INTRODUCTION

In 1972 p the National Capital Development Commission (NCDC)

asked BMR's advice on the provision of a groundwater supply for the

National Fitness Camp (Fig. 1). As the project developed, it was found

necessary to drill a bore to test fractured-granite aquifers. BMR drillers

completed a 45.7 m bore (PR1) through fresh granite at the camp in June

1974 and assessed its yield as 1 m3/hour. In 1975, BMR helped to prepare

contract documents for additional drilling, and in March and April 1978,

supervised the drilling of four bores, of which two (PR4 and PRS) were

equipped as production bores and tested by pumping. This report describes

the development of groundwater as a water supply for the National Fitness

Camp at Tidbinbilla. The cost of drilling bores PR2-5 and of casing bores

PR4 and PRS was $lB,300 •

BORE SITING

Sites for drilling were selected by E.G. Wilson and the author •

Several quartz-veined faults were delineated by traverses within the

catchment, which is underlain by fresh Shannons Flat Adamellite. The faults

and an aplite dykes (Fig. 2) were considered to be favourable targets for

drilling, and fracture permeability adjacent to the faults and to the dyke

was expected to be higher than that of less-fractured adamellite elsewhere.

Drilling was expected to be easier in the fractured rock. Airphotos were

examined to find other lineaments •

CONSTRUCTION OF BORES

Bore PR1

Fresh to slightly weathered pink adamellite was intersected to

a depth of about 45.7 m. A fractured zone in the interval 30 to 32 m produced

most of the yield assessed on completion of drilling, i.e. 1.0 m3/h. Fresh

rock was intersected from about 40 m to the completed depth of the bore

(45.7 m). The bore has a diameter of 18.7 em to a depth of 24 m and a

diameter of 13.3 cm to the bottom. The bore was cased with 15 cm I.D. steel

casing to a depth of 16.2 m.

Bore PR2

A depth of 48 m was drilled using 17-cm-diameter button bits; the

drilling rate was about 0.75 m/h. The last metre or so of drilling intersected

a quartz vein which eroded badly under the high drilling-air pressures

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required to remove rock cuttings and water inflows of about 3-4 m3/h. The

erosion formed a cavity at the bottom of the hole which prevented the upward

passage of cuttings and groundwater; the drill string was removed from the

hole with difficulty, and the hole immediately collapsed below 32.4 m •• The

stabilised standing water-level was -16.9 m (28.3.78). After careful

consideration of the problem of cleaning out and casing the hole p it was

decided that the risk of jamming the drill string and air hammer was too

great~ and the hole was abandoned.

Bore PRJ

A depth of 14 m was rapidly drilled through sandy, gravelly

alluvium and highly weathered granite. Moderately weathered rock was

intersected between 14 and 17 m~ at which depth the upper part of the hole

caved badly. Despite the loss of drilling-air velocity caused by cavingp

water was airlifted at about 4-5 m3/h. This hole was also abandoned because

of the problems of caving if drilling continued. The bore flowed at about

500 Ilh for most of ~archp 1978.

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~rePAA •

Granitic colluvium was intersected to a depth of 9 m. The hole

was reamed and cased to that depth with 20-em I.D. steel casing. Drilling

through granite between about 20 m to about 68 m was hard and slow (about

0.7 m/h). No significant groundwater discharge occurred in this interval.

From 68 m to the final depth of 73.6 m, groundwater discharge increased

from about 1 m3/h to about 18 m3/h. The hole was equipped with 12.7-cm

I.D. AWW steel casing from 25 cm above the surface to the bottom of the

hole. The lowest two lengths of casing were torch-slotted in three rows.

The annulus was packed with 7-mm diameter screened river gravel, and the

bore was airlifted until the discharging water was free of sediment.

Bore PRS

Drilling intersected highly weathered granite to a depth of

20 m. Moderately weathered to slightly weathered, highly fractured granite

was intersected from 15 m down to the final depth of 49 m. At this depth,

a yield of 4.5 m3/h was airlifted for several hours. The bore was equipped

with 49 m of 12.7-em I.D. AWW steel casing: the lower two lengths (12 m)

were slotted in three rows. The annulus was gravel packed and the bore

developed by airlifting.

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T.N.

LOCATION OF WATER BORES AT NATIONAL FITNESS CAMP

o 50 100 150 200 250 300m ! • , I , I I

. -.- .~ +

+

o·

o·

o·

o·

o·

o·

o·

o

o

0 -r-I-

9

8

7

6

5

4

3

2

·1

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o -s 10

'SLue' rES T ON BonE N'" PR. I

-:::: r.:::: -:::: ~ ........

r--..... 't--

~ ......... ,

~ ~

r--..r-,

I

I -10 2

~ ,

~ ~ ~

~ N 1\

1\ 1\

\ 1\ \

I

1 I

I I

I 1

-I 10 Tt/r/

~~ R ~~ ~ \\

\\ \\ \\ \

\1 \ , 1\

\ \\

\11

N

,

I

II

1

-10

(

~ 1/9

~ ~ \ \ \ 1\ ,

~ '\J\ ~.\G , "'" \

\..1

'1'\ 0'\

~~ ~ ~ \ ,\ \ \

1\\ ~l~ tl

\ \1\ ~.... \ \ l\ \\ 0

loP

~ I\O~~ ~\ \ \

\ \i\ \ \ ". \\

"' ~,I\ ch F 0;, ,t' ,~

1

0(= r 1-

-~ P r:

I

~ ~ ~ ~ ~

10

Tjpe curves for instantaneous he:;i/ ch,gnge in a we/I of finite

diamefer

Nom /7?o~h po/nr: W'hen Tt-_ I f = /30 .sec 'C-z - J

ie. T = /·0 rc! = (0-751 J _

f /.30

=O·+3~5~C.

I.(!, /"ransmiSSiV/&,T, = .3-7 m 2/ day

FIGURE .3

I55/AI6/2292

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~r-------~~~----------------------------~r-~~----------------------------------~----------------------------------~~ .,. 100 1000 100= n ~ Q.

W c:o ~ N ID

37 0

* 3E-flOVR t?RAWPOWN rEST ON P'U/"1P/No BORE Nq'p~+

co,.,t!!: a d~ ~s,o.-r

¥/'ec::u:)I;~ J-I//i?,ovr r(!'cha

~= 13 · b h"7 3/£ = 3~7"..,3/d

/"foci/ned non-.5I-~0clJt ~ ~vaha,.,. . ·

7rar!SP7/Ss/vdfi~ 2 ·3 Q 4-tr.44

:::2·3.3:2.7 /~·S6 . /5"-0

(~I [=~,n '2,0t

1.Z" 0/83.327 4 ·G

I.;t.j t;. ~ /.2 . s-~YP':J

~. An;-"-~ :~ e3~nt c?:7d d 1 o~~ : ~1'" leas-I 7 ;'OUr$ , cu/" < /2 Aov~ , ~/~ s!arh~'1 /s/,~ 4L5""-._ belOre S~r/ t?r' 1'/,/5 32 hr 2~_/)..., -feSI

- - - -'. .~--'-_~ _ _ '- --'--..l.I.....!.' ...-_____ -' ___ . _ .L _._.L-.-.-.l..-----L- I I , ,

t;nf;O .5lnCe srart~d (mk7Vr~r

III 10 B ., a.

Z

N 4-In

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8

10

I {2

14-

-----~ 76

~ 18 ~

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~ ~

Z

........ f1J :)

.~ 2 ~

~ Z6

c8

30 .... UI .]I ..... 32 ~ 10

" . - - I. ..... \) \)

D ~

• •

~:-'-.., -/-

• •

100

RES/OUAL

l I.

100 I. .1

ORAWOOWN TEST, BORE N9 PR.4-

+-----_-1- L

· ~l-+

1000 • , I I

IO(X)O

2QG/.d. T:: 0-/83€:( /.1 Ll..&

;~'I r= /2.0"'/-6:lMj

, T

-I-

5000 10 __ I. . _J_ 1_1 L _ 1_...1_

time Since pumpry sTarred -+- I"ime Since purnpl/7y' sl-o'p~d r%) ;::-/GU~E S 2.

• • • • • • • •

N CD

H UI UI

~ ~ N N CD 01

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~ -g :t ~ ~

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z

S

6

7 I ,-I

8 -,

9

10

11

12

15

1~

15

16

2.

• • • •

I .-,. -(.,-

\ -'\,

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Pu-?pt"":J /Ci1re" ~ ;= B 7~ 0/ d~

h-~ H70c:/;/7ea" ,-?or7-skaay ~ ertJ"~ :~_O-=./::;;..;:;.....q ~A

. r- - am3. 87-." 2 0-5

,k. . Tz" ::: 32 r.H&

'\r ce>r>-rd dr.Clw-aown j'rad/<:,.,T-

~ f +- - -l--i---_-L _______ : ____ A~A~2C::;.:::O=_.~5" ______ ~-n::":-~-__

+ -2 -11 -'- _ --.1-. _ ~__,__,_~O_O__ 000 (0 So

_ __ _ 1-- _ -----L_--'-_--L., -----'L- I I I

Time since pumping starteci (minutes) F/6URE 6

if '/, vo 0

~ ,-t := 3 ·7n?ir7. CD 122.

" -3 (I) = Z.SxIO Clays ~

,

N 12'~ <D ,

'. ,

/2+ I-

1,3·2. I-

1$·3

15'S

/5· 6

H UI

~ 151

m ~ /3 ·8 N U)

I

20 .30

en

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I , /0000

.

.,.g-HOUR DKAWOoWN res r: PUMPING BORE =P.R.5, 08S£~VA TION BOREzr PI? 4-

I I 4-0 50 60 i'b 80 30 100

• • •

/'tod/ned non-sl-ead!l srare. equal-Ibn : T= 23 6t j 41TL1~

wher-e T..i& rransrnissivdy (= K.6 )J' • Q::: ~H7pin!1 rate; Ll A =orawdowrt//c:f' cyc/e

1£.,T=OIB3. 87 o·G+-

= cS /n2/day_

.st-orage coer~icient") S.> ::: 2·25 Tt"o J ,2 ~h~ r- 0: o/srance befweer? pt../rnp/~ bore. (,oR.,s) and ooserratlon 6orl!!. (PI<'. 4) .

5 -3 = 225. 25: Z5xlO 3>< 10.3

~ = O·4-Tx IO-~

.

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•

::0 (11 0

~ \D 1 Cl)

~ N to

3

of

5

6

---. ~ 7

~ B

~ ~ !J

~ ~ 10

"-CU fI ~ ~ V) 12

~ IS

/1-

15 .... (JI (JI

....... ~ C;;

I\i N to

. -...1

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0 20 100

10 20 I

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200 1000 2000

RESI(X/AL ORAW/X)WN rES[ BORE No. PR.5

Mod///~d rlO""-ST~8~ src91'~ ~l1:. ~::: o·/e.3 4?

.slcpe affecled by c.as/og .:foraoe

AA,

'4 T, ~ 2· 8 I'n ~a:t

IOc:vO

Z 0 set) "'fOo 500 1 t}() cOOo 5000 10000

time Since purnpli'y started -=- time Since p("/n7j//~ sro;:ped (t.~2) ,c16U~£" 8

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3.

AgUIFER TESTS

While bore PR5 was being drilled, bore PR4 was pumped for 3 48 hours at 13.6 m /h. Drawdown and recovery of PR4 were monitored and

the aquifer constants (see Table 2) were calculated.

After drilling bore PRS, it was pumped for 48 hours at 4.5 m3/h,

and drawdown was monitored in the pumped bore and in PR4 50 m to the south.

Residual drawdown was monitored in PRS on cessation of pumping: the bore

recovered fully in 7 hours.

ANALYSIS OF AQUIFER TESTS

Plots of drawdown and residual drawdown for the pumped bores

are shown in Figures 4 to 10. Two of these plots (Figs 6 & 8) approximate

s·traight lines. The steeper slopes are attributed to casing-storage '

effects and are disregarded in the analyses. The flatter slopes were used

to determine transmissivity by the non-steady-state equation:

T=~ 4'11'liS

where Q=pumping rate (m3/day); and liS = drawdown/

log cycle.

The six aquifer tests done on interconnected fractured-rock

aquifers intersected by bores PR4 and PRS indicated transmissivities ranging 2 from 7 to 32 m /day, and the mean value is 2 16 m /day. Two values of storage

coefficient were calculated 8.4 x 10-4 and 0.5 x 10-4 • , these values confirm

earlier findings that the aquifers are confined.

The plot of drawdown recorded in pumping bore PR4 against log

time, shows a point of inflection about six hours after the start of pumping

(Fig. 4). This may indicate that about six hours after pumping started, the

cone of depression had spread to intersect an aquifer of much higher

transmissivity. producing a recharging effect on the drawdown curve (Fig. 4).

There is no clear evidence of recharge on the drawdown plot of pumping bore

PRS (Fig. 6). Here, the point of inflection occurred about 18 minutes after

the start of pumping, and appears to be the time at which casing storage

has ceased to affect the slope of the drawdown curve. The change of slope

of the drawdown curve could also be attributed to intersection of a ~echarge

4.

boundary close to PRS but distal to PR4 - i.e., just to the north of PRS.

This interpretation is supported by the fact that pumping from PR4 at

13.6 m3/h for 48 hours caused no measurable drawdown in PRS, whereas when

bore PRS was pumped at only 3.6 m3/h, a drawdown of one metre was effected

in PR4. Because a recharge boundary was suspected to have been intersected

by the pumping test on PR4, the aquifer test was analysed by Stallman's

method (Hazel, 1973; Fig. 9). This interpretation shows that a recharge

boundary was intersected at a distance of 50 m from the observation well,

distal to the pumped well. The mechanism used to explain this occurrence

is shown schematically in Fig. 10. Image well theory is used to simulate

the effects of the recharging source, which may be a fault just to the north

of bore PRS (Fig. 2).

GROUNDWATER CHEMISTRY

A full chemical analysis has been made of a sample of water

pumped from bore PRI in 1975. The water is essentially a carbonate water

comprising calcium carbonate (120 mg/l), magnesium carbonate (80 mgl/) ,

and sodium carbonate (94 mg/I). The total dissolved solid content was

calculated by AMDEL to be 200 mg/l. Groundwater samples obtained after

48 hours pumping from each of bores PR4 and PRS were analysed by the

Department of Construction (S. Rosborough, pers. comm.), both chemically

and biochemically.

CONCLUSIONS AND RECOMMENDATIONS

1. Groundwater is chemically suitable for domestic purposes.

2. Either bore (PR4 or PRS) is theoretically capable of supplying

the needs of the camp (68 000 l/day). It is recommended that the higher

yielding bore (PR4) be used as a production bore, and that PR5 be used

for emergencies, such as periods of unusually high demand or during

maintenance of PR4.

3. Because the catchment area to the production bores is small.,

use of groundwater should be as efficient as possible, so as to ensure

continuity of supply during prolonged periods of low rainfall.

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ANAL YS/S OF' PU/VtPING rff.5T ON BORE p~S-, (}8~/? VAT/ON BO~£ RP. -+ VS/Na .srALL/'1ANS

/

I"1ET/-/O,o

Hatch poiaf

+ ~~o: 0 78rn

t" 83n?in

-{-

I. 6!cvla -lio1'1 01 ~~"""Ss)J'/&(r) FrOI77 1/8Ze/ (/.963) L'9!:!.· (j4

A ::: ~ (iI/(v)) o ~7l" T

.', Toe BT 12S'b)( o · 7f3

/~ /::; 9~~d~ 2 . C~cw/afio~ 01" Sn:vci)1'70&§: ~d ~; 'k2.:s £tXjf:1.g,6]

4-rt :z L -, -·~"e,r~7 ::-~o;:..) T= 9_ 2(q-

t ". 83' d.t2V'5 /~~o

1 - ::-1 vf

r?C>l-fio c:J-,C m~L'~ ~ CJb5~Y-~,4,,- A.Ae//

.,to 1-7 4J.e.// r4;, vr1im-u:.~ ~ ,. ,.

-10 j/(/-/~ IN~ ~ ' = K =- 2,. C>

~ , ~' ~ /00 R'7 :;y.~ / R 4- (r'e~~ fo ...c-i/ /0 )

J. ; (t) L/p / .0 /0 FIGURE .9

10

K==Z·O

10

-/ 10

~ Situation A ~ / ' of impression ~ 5 F\.Jmpe.d bore No.PR4 // '''X'-'' CO. ne ~ I Bore N0

1 PR5 (not pumpej)// "

~r-------------------------------t-------------------~--------~~------~--~--~~~--------~G~~~o~u~n~d~~su~r~f.~d~G~e~~N~ "-' ........

Siruation 8 5

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Cone of depre~5ion

Cone. of depression raised

b~ rechor:3€ Sourc .

No drawdown in PRS in r~sponse to pumping P R4 at 136 m3jh

Bore PR5 (pumped at 3·6 m3fh)

-.....

Pote.ntiom ;,:rC-r--__

Recharging image. well (h~pothet;caJ) / (Molj be Iin~m.znt to north of Bore. PR..5)

I

~

Bore PR+(not pumped) I ///. Ground surface N

1m clrawdown ;n ' response to pumping PR5 at 36m3/h

• • •

o /0 , .

/"

"­---Potentiome.tnc.------__ surfac..e

---=*=---~~~~~~------~~~~~----~ ..,..........---~

/"

,Cone- of de.preSSion rdised

-'" COrle of depression if no r-echarge. bound8('"lj present

b~ re.c.harse source.

IMAGE - WELL METHOD Or- £XPlAINING RECHARGE

BOUNDARY INTERCEPTED DURING PUMPING TESTS 20 30 4-0 SO rn

, • , I

FIGURE 10

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REFERENCES

HAZEL, C.P., 1973 - Lecture Notes on Groundwater Hydraulics. Australian

Water Resources Council. 1973, Groundwater School, Adelaide.

PAPADOPULOS, S.S •• BREDEHOEFT, J.D., & COOPER. H.H., 1973 - On the analysis

of slug test data. Water Resources Research, 9(4).

Co-ordina.tes:

1:10 000 ACT SERIES

completed depth (m)

depth range of colluvium/ alluvium (m)

depth range of highly weathered adamellite* (m)

depth range of moderately weathered adamellite (m)

depth range of slightly weathered to fresh adamellite (m)

interval of highly fractured rock (m)

interval of quartz veining

interval of 20 cm ID steel casing (m)

interval of 12.7 cm ID steel casing (m)

S tanding water level (30.3.78)

hole completed as water bore

6.

TABLE I. LOGS OF WATER ·BORES

195330E 585115N

PRI

45.7

0-1

1-9.5

9.5-15

15-45.7

30-32

0-16

- 2 m

Yes

195130E 585090N

PR2

48 (caved to

32)

0-1

1-2

195010E 585270N

PR3

17

0-4

4-14

2-20 14-17

little or none

20-48 intersected

32-35 16-17

32-35

- 17 m + 10 cm

No No

195010E 585008N

PR4

73.6

0-9

9-20

194980E 585012N

PRS

49

0-1

1-20

20-30 20-49

very little 30-73.6 intersected

68-73 15-49

0-9.5 0-20

+0.5 to -73 +0.5 to -49

- 20 m -11m

Yes Yes

* Shannons Flat Adamellite: medium-g~ained, biotite adamellite

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TABLE 20 HYDRAULIC PARAMETERS OF FRACTURED-ROCK AQUIFERS

Test and method Pumped bore Observation Storativity Transmissivity (m2

/d) bore

PRS PR4 -4 25.0 0.5 x 10 1. Drawdown, straight-line approx. (Fig. 7)

2. Drawdown, straight-line approx. PRS PRS 32.0 (Fig. 6)

3. Drawdown, straight-line approx. PR4 PR4 12.5 (Fig. 4)

4. Drawdown, Stallman's method PRS PR4 8.4 x 10-4 9.0

(Fig. 9)

PRS PRS 7.0 --,J . 5. Residual drawdown, straight-

line approx. (Fig. 8)

6. Residual drawdown, straight- PR4 PR4 12.0 line approx. -- 2

(Fig. 5) Mean transmissivity = 16.1 m /d

7. Slug Papadopulos & others (1973; Fig. 3) PR1 3.7