FNB Dusi Canoe Marathon

15-17 February 2018

Water Quality

Site31 Oct7 Nov14 Nov21 Nov28 Nov5 Dec12 Dec
uMsunduzi at Caluza Bridge3448365438731850238226132460
uMsunduzi below Kwapata90909900111990160705120209805380
uMsunduzi at Edendale Weir813083601119901483048002178011000
Slangspruit above Duzi confluence2481011620550401553106867012033046110
Duzi at Camps Drift Bridge42248034112997547501989010710
uMsunduzi above Dorpspruit confl428233373770124196>241967980
Dorpspruit just above Townbush stream40801872980417329198900199006300
Townbush Stream just above Dorpspruit10034489804141369590613105940
Dorpspruit Ohrtmann Road / just above Duzi confluence550405200173295794081303968020980
uMsunduzi above Refuse Dump64881119910810504019863770111199
uMsunduzi above Darvill WWW214212033n/s, no accessn/s, no accessn/s, no accessn/s, no accessn/s, no access
uMsunduzi U/S Baynespruit5172045704083344802142012033057940
Baynespruit at Greytown Road275519863172202909027550198904352
Baynespruit behind Epol870453801299729090248102359046110
Baynespruit at Sobantu4520019180048840057940014600727000131300
uMsunduzi U/S Darvill mat river27550218704106038730387309208046110
Darvill Final Effluent normal discharge site2625822603500630282158
uMsunduzi D/S Darvill mat river5938
uMsunduzi at Motorcross weir1046230634225547512997920814136

 


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.

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