Territory Stories

Renison Goldfields Consolidated Limited, Pine Creek Project. Groundwater Investigation Stage 2, Establishment of Borefield and Management Studies. Report H114/3-AA.

Details:

Title

Renison Goldfields Consolidated Limited, Pine Creek Project. Groundwater Investigation Stage 2, Establishment of Borefield and Management Studies. Report H114/3-AA.

Creator

Coffey & Partners Pty Ltd

Collection

E-Publications; E-Books; PublicationNT; Report no. 87/1984

Date

1983-11-01

Notes

Date:1983-11

Language

English

Publisher name

Northern Territory Government

Place of publication

Darwin

Series

Report no. 87/1984

File type

application/pdf

Use

Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government

License

https://creativecommons.org/licenses/by/4.0/

Parent handle

https://hdl.handle.net/10070/228435

Citation address

https://hdl.handle.net/10070/674167

Page content

Technical Report WRD84087 Viewed at 14:07:14 on 29/07/2010 Page 46 of 167. I I I~ ,~- ~~ I I I I I I I I I I I I I I I I I I 1!114/1-1-tRS Nov 25, 1983 _________________________ ~2~4~. __ __ - -----_. In fractured rock aquifer environmp.''1ts, bore yield ca. often decline under sustained pumping due to a graduA l !"edu ion in permeability at some distance fro:n the bore4 fr'lhere b, lndaries are severe they invariably limit bore performa.i'1Ce in Ute longer- term. The pumping tests were conducted by White Drilling Company / under supervision, using a small electric submersible pump in ccnjunction v-Jith a portable generator. The unit was ca~able of pumping up to 3 l/sec from depths of 20 or 30 metres. Flows were measurer': using an or if ice weir <J.ssembly. ~~st data have been plotted on semi-log and 10g-~og graph paper and interpreted using standard curve matching techniques. Data and i~terpretations are presented in Appendix 4 and results are s~~ri7~d in Table 10. S.4.1 Resul ts The pumpi:1g test zesul ts display characteris'Lics typical of a fractured rock aquifer system. und storativity values are low and bound<Jr'l conditions are present l.n Aquifer transmissivity distinct impermeable all datil. 'I'ypicdl coefficients a.re : Tr[lnsmissivity St()r.J.t~vity l4-70 m'/d/m 10- '_10-4 The lower transmissivity values 0.4 to 25 m3 /d/rn) .ar-e obtained from l~te lime data and reflect the influence of impermeable aqu~fer boundary conditions intercepj ed at some distance from the bore. In one case (Bore W15) dat 1 indicated a finite aquife~ of limited sturage. This resultec in a progressive increase In the rate of drawdown to a point whereby tl"le discharge had to be r~duced to prevent pump failure~ Aquifer storativity values are low/ but typical of fractured bedrock material. Under loncer term drainage -3 ~-2 these values may increase to 10 or 10 I particularly where water is held in storage in highly weathered and decomposed bedrock. The p=esence of boundary conditions precluded me~surement of long term storativity or specific yield values. 5.4.2 Bore Yields Bore yelds during pumping ranged between 0.7 and 1.8 l/sec although higher yields (3-4 l/sec) were obtained during airlifting, and could be maintained in the sho~t term unde~ pUmp1ng conditions.