Water Quality

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uMsunduzi at Caluza Bridge1012030102160426018504130146741908800
uMsunduzi below Kwapata1565013170594034410884020630344861310111990
uMsunduzi at Edendale Weir114501017050402613069702481056304884077010
Slangspruit above Duzi confluence66906867015531017329047200987066907270019350
Duzi at Camps Drift Bridge3654012740172206488031300712098043873022470
uMsunduzi above Dorpspruit confl4884017250344803255001334011060111999804019890
Dorpspruit just above Townbush stream4710504052806010480049603410120106500
Townbush Stream just above Dorpspruit51208603270959047202750246035907440
Dorpspruit Ohrtmann Road / just above Duzi confluence2909016690410602909024950770101119903784015530
uMsunduzi above Refuse Dump4884036540178502613002046035408664613103090
uMsunduzi above Darvill WWW4352030760196801565001455017309208325506200
uMsunduzi U/S Baynespruit4106030760166901198001043017106131285103230
Baynespruit at Greytown Road29090512012997092080755502187016240>24196035500
Baynespruit behind Epol38730909017250>2419601299702489017820>24196046400
Baynespruit at Sobantu547500517200866400>2419600410600325500461100>2419600435200
uMsunduzi U/S Darvill mat river1046207270011199026130066900129970>241963990047200
Darvill Final Effluent normal discharge site52052009641613100216759481341
uMsunduzi D/S Darvill mat river686709070
uMsunduzi at Motorcross weir68670579406867012590011199093309804307608600

 


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.