15-17 February 2024

Water Quality

Sample Site Description6-Feb-2313-Feb-2320-Feb-2327-Feb-236-Mar-23
Msunduzi at Caluza bridge1071052000504001779064880
Msunduzi d/s of Kwapata1119059400336002382068670
Msunduzi at Edendale weir bh Prison1259065700309002310057940
Slangspruit u/s of Msunduzi confluence272300435200222400135400172300
Msunduzi at Camps Drift bridge5200098700842006500065000
Msunduzi u/s of Dorpspruit confluence1354026130410602063016690
Dorpspruit at polo fields1071019180461101904026130
Townbush stream at polo fields1119019890461102489019350
Dorpspruit Ohrtmann Road1259016640579402489023820
Msunduzi u/s of Refuse Dump988026130517201935019040
Msunduzi u/s of Darvill WWW537017850191802987014700
Msunduzi u/s of Baynespruit52104611020980290909070
Baynespruit at Greytown road260200275500261300579400365400
Baynespruit at Sobantu365400218700387300579400387300
Msunduzi u/s of Darvill Maturation river3654017200344804352038730
Darvill final effluent (Out Of Range if >500)>2420111866120107
Duzi d/s of Darvill Mat river (Monthly sample)172309350
Msunduzi at Motorcross1968043600325502809010390

Interpretation of results – Umgeni Water

>4000 – some non-natural faecal contamination is likely.
>7000 – a much higher likelihood of faecal contamination.
>10000 – sewage pollution is almost certain, with concomitant serious water quality and environmental risk.
>100 000 – sewage pollution is very bad, with related very high risk.
>241000 – sewage pollution is extreme, with extremely high likelihood of major environmental damage and severe health risk.

Interpretation of results – DUCT

DUCT’s River Water Quality Assessment Guidelines updated 27 October 2013
E. coli bacteria occur naturally within mammal digestive systems and most of them are not harmful in any way. However, because they are so common E. coli data are considered useful as a general indicator of a wide range of other potential human pathogens, and thus also of the possible presence of sewage related water quality problems. In the absence of other data, E. coli numbers are useful in allowing a general assessment of other potential water quality risks.

E. coli count/100mL
Water quality “assessment”
Assessment of probable risk to canoeists

*0 – 130
  WaterExcellent Excellent – Considered acceptable for full contact recreation – excellent / likely natural catchment.
Extremely low risk.

130 – 1000
WaterGood Good – within the range expected for quite good catchment conditions, but significant / increasing risk of illness if used for full contact recreation (e.g. swimming). Very low risk.

1001 – 4000
WaterFair Fair resource condition, natural sources (i.e. not sewage related) are still possibly the E. coli source, but increasing likelihood of human faecal / sewage contamination at the upper end of this range. Unacceptable for swimming. Low, but increasing risk.

4 001 – 10 000
WaterPoor Degraded – Significant faecal input or some sewage contamination is indicated. Other water quality parameters are likely to be poor.
Moderate risk (approx. 1 in 10 may get sick).

10 001 – 25 000
WaterVeryPoor Unacceptably Poor, sewage contamination definitely present.
Moderately high canoeing risk (approx. 1 in 5 may get sick) – some likelihood of illness esp. in white water.

25 001 – 50 000
WaterDangerous Bad, with significant sewage contamination and negative environmental consequences.
High risk (approx. 1 in 3 may get sick) – consider not canoeing or paddle on flat water only, with no risk of falling out.

>50 000
WaterVeryDangerous Severely contaminated with significant sewage contamination and negative environmental consequences.
Very High canoeing risk – (approx. 1 in 2 paddlers may get sick). Avoid canoeing!

*Note, the only acceptable value for drinking water quality is ZERO E.coli counts per 100 mℓ. No naturally occurring surface water should be expected to have E. coli this low (even in large dams). If zero E. coli results are achieved for a natural water, contamination by disinfectants is the likely cause and this may be masking other significant potential pollutants.