Water Quality

Sample Site Description28th/29th Sep1st January 19002nd January 19003rd January 1900
Msunduzi at Caluza bridge4611>24196341004890
Msunduzi d/s of Kwapata155310816407380012960
Msunduzi at Edendale weir bh Prison98040980407890013540
Slangspruit u/s of Msunduzi confluence3730>241961870024196
Msunduzi at Camps Drift bridge48001267155317590
Msunduzi u/s of Dorpspruit confluence11305043799600
Dorpspruit at polo fields1081003100>24206131
Townbush stream at polo fields>2419698021871014
Dorpspruit Ohrtmann Road6488014136010120
Msunduzi u/s of Refuse Dump14454822851810
Msunduzi u/s of Darvill WWW59101046211780>24196
Msunduzi u/s of Baynespruit2909770110760>24196
Baynespruit at Greytown road72300185002909016690
Baynespruit155310198901467019863
Baynespruit at Sobantu4611001730024600866400
Msunduzi u/s of Darvill Maturation river12460088472700155310
Darvill final effluent2035770689
Duzi d/s of Darvill Mat rivern/s54750
Msunduzi at Motorcross2489028406050>24196

 


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.