Territory Stories

Nabarlek Pit decommissioning migration of sulphate, nitrate and radium ions in groundwater - preliminary modelling

Details:

Title

Nabarlek Pit decommissioning migration of sulphate, nitrate and radium ions in groundwater - preliminary modelling

Creator

Appleyard, S.

Collection

E-Publications; E-Books; PublicationNT; Report ; 41/1984

Date

1984-04-01

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).

Notes

Date:1984-04

Language

English

Publisher name

Dept. of Transport and Works

Place of publication

Darwin

Series

Report ; 41/1984

File type

application/pdf.

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/228496

Citation address

https://hdl.handle.net/10070/674076

Page content

Technical Report WRD84041 Viewed at 14:07:09 on 29/07/2010 Page 18 of 34. I I I I I I I I I I I I I I I I I I I I I seepage ;vater reaches the highly transmissive zone to the south east of the pit. Diffusion and dispersion processes will reduce concentrations of sulphate and nitrate ions between the pit and this area. As a first approximation, it will be assumed that this effect is negligible and that initial nitrate ion concentrations lie in the range 250 - 500 giro' and initial sulphate ion concentrations lie in the range 9000 - 18000 g/m 3 Sulphate and nitrate icn lcads reaching Cooper Creek in a single dry season vary with grcundwater velocity are equal to: vJhere L == dry season load of N0 3 or so~ p. - area under breakthrough cur',7e o~ a time period corres90ncing to a dry season (assumed 200 days) - Don dispe~sed dry ~ season load of NO~ .5 or At groundwater velocities of about 2m/day, dispersion is unimportant, and so nitrate and sulphate loads are as previously calculated, ie: Nitrate ion load (expressed as N) - 430 to 860 kg A == 7.0xlo":l:kg to ~ 1.40xlO~kg However, if a velocity of 0.03 m/day is assumed, the situation is quite different. The breakthrough curve shown in Fig 3.2(a) is a normal distribution curve with a standard deviation equal to c= (2 DL t)" (t == arrival time (Fried, 1975) at Cooper Creek = 2 x l04 days) SA2/ll :TJ