Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981
Alligator Rivers Region - Regional Surface Water Quality Monitoring, Volumes 1,2,3 (Plus draft)
Northern Territory. Department of Transport and Works. Water Division, Environmental Section
E-Publications; E-Books; PublicationNT; Report ; 49/1983
1983-04-01
At head of title: Water Division, Dept. of Transport & Works, Northern Territory. "April 1983".
English
Water quality -- Northern Territory -- Alligator Rivers Region; Hydrology -- Northern Territory -- Alligator Rivers Region
Northern Territory Government
Darwin
Report ; 49/1983
3 volumes. ; 30 cm
application/pdf
Attribution International 4.0 (CC BY 4.0)
Northern Territory Government
https://creativecommons.org/licenses/by/4.0
https://hdl.handle.net/10070/672725 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_1.pdf]; https://hdl.handle.net/10070/672727 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_2.pdf]; https://hdl.handle.net/10070/672729 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_3.pdf]
https://hdl.handle.net/10070/229664
https://hdl.handle.net/10070/672725
https://hdl.handle.net/10070/672729; https://hdl.handle.net/10070/672727
Technical Report WRD83049 Viewed at 14:07:10 on 29/07/2010 Page 42 of 440. I I I I I I I I I I I I I I I I I I I I 41. 7.3.4 The majority of the anomalous data fell into the following groups and was checked by the criteria quoted. a) Nitrate cont~~ination, suspected to be due to poor rinsing of HN0 3 residue from supplied containers. These results are checked with total N results. b) Heavy metals - for an increase in a single heavy metal's concentration, the same conditions will normally be reflected by other metals, eg. a large Cu result vwuld be expected to be accompanied by a large Pb, Zn and Cd result. c) Zinc as a particular case of b) above was often also accompanied by a pH drop. d) Uranium and R.l\.225 fluctuations may be correlated. e) pH fluctuations may be checked between field and &~DEL results, also as in c) above. f) Large turbidity and suspended solids fluctuations may be verified by visual field observations. g) Phosphate fluctuations may be checked by total P results and associated eutrophic indicators (eg. N, NO, and TOC, chlorophyll and vice versa). 7.3.5 It has been noted that analyses of samples taken in the months of Feb, March, April and Hay, 1980 shmvs higher than previous levels of most heavy metals in both waters and residues. This was found in samples from all sites, including control sites (Bowerbird, U/S Nabarlek Arnhem Border Site and U/S Koongarra). This is an indication that contamination probably occurred and from its nature it is suspected from one of the following sources. 1) reagents (acids, etc. used by Al1DEL) 2) contamination from filter papers, filter apparatus, or filter wash acid and equipment. 3) fallout (sampling, pre-treatment or final analysis) 7.4 DISCUSSION The following points may be deduced from the water quality results which have been presented. 7.4.1 Overall water quality is excellent at most sites throughout the entire year especially in nutrient and heavy metals. 7.4.2 The backflow billabongs show a gradual degradation of water quality towards the end of the wet season particularly those which are hydrologically isolated. The most obvious indicators of degradation are high conductivity and turbidity