15-17 February 2024

Water Quality

Sample Site Description2024-01-082024-01-152024-01-222024-01-292024-02-052024-02-12
Msunduzi at Caluza bridge488405710410607701054750141360
Msunduzi d/s of Kwapata4106058803448019863041060129970
Msunduzi at Edendale weir bh Prison4106048004611019863046110120330
Slangspruit u/s of Msunduzi confluence2359005200129970173290218700>241960
Msunduzi at Camps Drift bridge579410462064880107606488019890
Msunduzi u/s of Dorpspruit confluence517207701061310461107555068670
Dorpspruit at polo fields24196068670>241960325500686700435200
Townbush stream at polo fields>24196054920>241960517200461100461100
Dorpspruit Ohrtmann Road>24196092080>241960344800435200435200
Msunduzi u/s of Refuse Dump4611081640727005794092080129970
Msunduzi u/s of Darvill WWW2755051720193502247014136098040
Msunduzi u/s of Baynespruit38730258601274019510129970141360
Baynespruit at Greytown road517200235900>2419603448001986300547500
Baynespruit at Sobantu313000156500>2419605475001203300222400
Msunduzi u/s of Darvill Maturation river41060920804884046110173290104620
Darvill final effluent (Out Of Range if >500)172228096036586133
Duzi d/s of Darvill Mat river (Monthly sample)155310
Msunduzi at Motorcross4352098040410603654017329068670
Non-routine additional data before the Dusi race
lower Kwapata>241960>241960
Lower Ashdown stream>241960>241960
Masons mill stream173290>241960
Duzi inflow to Camps Drift155310141360
lower Slangspruit at cd confluence365400410600
Makro side swd by bridge>241960100
Duzi Camps Drift outlet2909057940
Duzi at YMCA weir2142072700
Blackboroughspruit at lower golf course4611>24196
Baynespruit @duzi confluence461100378400
Duzi at Doornhoek below PMB6131017890

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.