2012 wq report_z0325_lewisham south

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THAMES WATER UTILITIES

WATER QUALITY REPORT - 2012 DATA

Water Supply Zone: SLE43 Zone No.: 0325

Population: 47,541

Time Period: 01/01/2012 to 31/12/2012

Date extracted: 14/03/2013

Coliform bacteria no./100ml 0 0 0.017 2 120 1 0.8

E. coli no./100ml 0 0 0 0 120 0 0

Enterococci no./100ml 0 0 0 0 8 0 0

Clostridium perfringens no./100ml 0 0 0 0 1233 0 0

Colony count 22ºC cfu/ml - 0 2 71 36 0 0

Colony count 37ºC cfu/ml - 0 1.58 18 36 0 0

Residual Disinfectant mg/l - 0.14 0.37 0.63 120 0 0

Colour (Pt/Co scale) mg/lPt/Co 20 0.8 2.033 4.9 36 0 0

Hydrogen Ion pH 6.50-9.50 7.2 7.8 8 36 0 0

Turbidity FTU 4.00 <0.070 0.080 0.200 36 0 0

Conductivity at 20ºC uS/cm 2500 575 614 660 36 0 0

Ammonium as NH4 mg/l 0.50 <0.030 0.091 0.160 36 0 0

Chloride as Cl mg/l 250 37.7 47.7 61.9 27 0 0

Sodium as Na mg/l 200 26.1 35.4 42.4 8 0 0

Sulphate as SO4 mg/l 250 29.1 55.2 62.4 27 0 0

Nitrate as NO3 mg/l 50 21.8 26.38 37.7 36 0 0

Nitrite as NO2 mg/l 0.5 0.01 0.052 0.19 36 0 0

Nitrate/Nitrite calculation mg/l 1 0.45 0.544 0.75 36 0 0

Total Organic Carbon as C mg/l - 2.100 2.846 3.700 100 0 0

Total Hardness as CaCO3 mg/l N/A 247 261.7 299 25 0 0

Odour (quantitative) dilution no. 0 0 0 0 18 0 0

Taste (quantitative) dilution no. 0 0 0 0 18 0 0

Iron as Fe µg/l 200 <1.000 3.5 12.7 36 0 0

Manganese as Mn µg/l 50 <0.700 0.7 1.2 36 0 0

Aluminium as Al µg/l 200.00 <6.300 6.797 10.200 36 0 0

Antimony as Sb µg/l 5.00 <0.500 <0.500 <0.500 8 0 0

Arsenic as As µg/l 10.00 0.900 1.088 1.300 8 0 0

Cadmium as Cd µg/l 5.00 <0.200 <0.200 <0.200 8 0 0

Chromium as Cr µg/l 50 <1.200 1.213 1.3 8 0 0

Copper as Cu mg/l 2 0.002 0.011 0.039 8 0 0

Lead as Pb µg/l 25 <0.300 0.688 1.7 8 0 0

Mercury as Hg µg/l 1 <0.120 <0.120 <0.120 101 0 0

Nickel as Ni µg/l 20 <1.600 1.7 2 8 0 0

Fluoride as F mg/l 1.5 0.06 0.13 0.162 8 0 0Selenium as Se µg/l 10 <0.800 0.88 1 8 0 0

Boron as B mg/l 1.00 0.056 0.063 0.072 8 0 0

Bromate as BrO3 µg/l 10.00 <0.200 1.235 10.200 101 1 1

Cyanide as CN µg/l 50 <1.000 1.00 1.2 102 0 0

PAHs (Sum of 4 substances) µg/l 0.1 0 0 0 8 0 0

Benzo (a) pyrene µg/l 0.01 <0.001 <0.001 <0.001 8 0 0

Trihalomethanes µg/l 100.00 2.500 13.888 30.200 8 0 0

Tetra- & Trichloroethene calc. µg/l 10.00 0.000 0.363 1.700 8 0 0

Tetrachloromethane µg/l 3.00 <0.100 <0.138 <0.200 8 0 0

1,2 dichloroethane µg/l 3.00 <0.100 <0.175 <0.300 8 0 0

Benzene µg/l 1.00 <0.100 <0.100 <0.100 8 0 0

Atrazine µg/l 0.10 0.003 0.005 <0.005 100 0 0Bentazone µg/l 0.10 <0.003 <0.004 <0.005 101 0 0

% of samples

contravening

PCV

TotalContra-

veningUnits PCV Min Mean Max

LEWISHAM SOUTH

Concentration or Value

(all samples)No. of Samples

Parameter

NOTE: PCV = Prescribed Concentration or Value






Population: 47,541

Time Period: 01/01/2012 to 31/12/2012


Bromoxynil µg/l 0.10 <0.002 <0.002 <0.002 101 0 0

Carbetamide µg/l 0.10 <0.003 0.004 0.012 100 0 0

Chlortoluron µg/l 0.1 <0.002 <0.003 <0.003 100 0 0

Clopyralid µg/l 0.1 <0.008 0.009 0.015 101 0 0

2,4-D µg/l 0.10 <0.002 <0.002 <0.002 101 0 0

Dicamba µg/l 0.1 <0.004 <0.005 <0.007 101 0 0

Dichlorprop µg/l 0.1 <0.001 <0.002 <0.003 101 0 0

Diuron µg/l 0.1 <0.003 <0.003 <0.003 100 0 0

Fluroxypyr µg/l 0.1 <0.003 <0.004 <0.004 101 0 0

Isoproturon µg/l 0.1 <0.002 <0.004 <0.004 100 0 0

Ioxynil µg/l 0.1 <0.001 0.002 0.002 101 0 0

Linuron µg/l 0.1 <0.004 <0.004 <0.004 100 0 0

Mecoprop µg/l 0.1 <0.002 0.003 0.008 101 0 0

MCPA µg/l 0.1 <0.002 <0.002 <0.002 101 0 0

MCPB µg/l 0.1 <0.004 <0.005 <0.007 101 0 0

Pentachlorophenol µg/l 0.1 0.001 0.002 <0.002 101 0 0

Propazine µg/l 0.1 <0.002 <0.002 <0.003 100 0 0

Prometryn µg/l 0.1 <0.002 <0.002 <0.003 100 0 0

Propyzamide µg/l 0.1 <0.002 0.005 0.024 100 0 0

Simazine µg/l 0.1 <0.003 <0.005 <0.005 100 0 0

2,4,5-T µg/l 0.10 <0.002 <0.002 <0.003 101 0 0

Terbutryn µg/l 0.10 <0.002 <0.003 <0.003 100 0 0

2,4-DB µg/l 0.10 <0.003 <0.004 <0.004 101 0 0

Fenoprop µg/l 0.1 <0.002 <0.002 <0.002 101 0 0

Monuron µg/l 0.1 <0.002 <0.003 <0.003 100 0 0

Picloram µg/l 0.1 <0.003 0.003 0.009 101 0 0

Triclopyr µg/l 0.10 <0.002 0.003 0.004 101 0 0

Tebuthiuron µg/l 0.10 <0.002 <0.002 <0.002 100 0 0

Ametryne µg/l 0.10 <0.002 <0.002 <0.002 100 0 0

Carbendazim µg/l 0.10 <0.001 <0.002 <0.002 100 0 0

Metaldehyde µg/l 0.1 0.006 0.074 0.387 99 21 21.2

Metazachlor µg/l 0.1 0.002 0.007 0.05 100 0 0

Total Pesticides µg/l 0.50 0.000 0.083 0.442 105 0 0

Parameter Units PCV Min Mean Max Total

No. of SamplesConcentration or Value

(all samples)

LEWISHAM SOUTH

Contra-

vening

% of samples

contravening

PCV







Population: 47,541

Time Period: 01/01/2012 to 31/12/2012


Commentary on Water Quality:

NOTES:

LEWISHAM SOUTH

Very good water quality, however twenty one infringements to report for metaldehyde*, one infringement to

report for bromate and one infringement to report for coliform bacteria. Our investigations showed this

infringement for coliform bacteria was transitory and the infringement for bromate was transitory at a

supplying asset and is not indicative of the quality of water supplied to this zone.

For some parameters, monitoring occurs at the supplying Water Treatment Works rather than the Water

Supply Zone

* Metaldehyde is a substance that is used by farmers to protect their crops from slugs and snails, which

can then ‘run-off’ from fields and enter surface waters such as streams and rivers. This occurs mostly

when there is a lot of rain, such as during the last year. The concentrations that have been detected are

well below levels that pose to risk to health.

Unlike other pesticides, metaldehyde is not easily removed from surface water by conventional treatment

process, and as a result we have identified a number of instances that levels have exceeded the regulatory

limit in treated water.


2012 wq report_z0325_lewisham south

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