17-19 February 2022

Water Quality

Sample Site Description29th Nov 20216th Dec 202113th Dec 202120th Dec 2021
Msunduzi at Caluza bridge1723001112001413677010
Msunduzi d/s of Kwapata1374001145001732948840
Msunduzi at Edendale weir bh Prison1017001198002419661310
Slangspruit u/s of Msunduzi confluence1203300378400>2419664400
Msunduzi at Camps Drift bridge9050563002419629090
Msunduzi u/s of Dorpspruit confluence44308600>241966131
Dorpspruit at polo fields428027500>2419664880
Townbush stream at polo fields483039700>2419646110
Dorpspruit Ohrtmann Road504033600>2419692080
Msunduzi u/s of Refuse Dump42805100>2419611199
Msunduzi u/s of Darvill WWW31806300137117329
Msunduzi u/s of Baynespruit29204100161617329
Baynespruit at Greytown road6867001483001011219900
Baynespruit488400104300>2419632300
Baynespruit at Sobantu61310012460054750035000
Msunduzi u/s of Darvill Maturation river4884069700>24196>24196
Darvill final effluent6612177012755
Duzi d/s of Darvill Mat river41900
Msunduzi at Motorcross27550292001732928090

 


WHAT DO E. COLI NUMBERS MEAN?

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.