My water supply

We’re committed to delivering high-quality drinking water to our customers. Each year we carry out thousands of tests on samples we have taken from treatment works, reservoirs and homes across the region. 

The samples we take are analysed in a UKAS accredited laboratory to ensure they comply with drinking water safety standards.

Schedule 1 Parameters

  Units PCV Number of Samples Number of Samples contravening PCV % No. of samples contravening PCV Min Mean Max
Colour mg/l Pt/Co 20 2 0 0 <1.00 <1.00 <1.00
Turbidity FTU 4 2 0 0 <0.13 <0.13 <0.13
Odour Dil Number 0 2 0 0 0 0 0
Taste Dil Number 0 2 0 0 0 0 0
Sodium mg/l 200 1 0 0 9.7 9.7 9.7
Nitrate (as NO3) mg/l 50 1 0 0 31 31 31
Nitrite (as NO2) mg/l 0.1 2 0 0 <0.01 <0.01 <0.01
Nitrate/Nitrite Ratio mg/l 1 1 0 0 0.62 0.62 0.62
Aluminium ug/l 200 1 0 0 <6.00 <6.00 <6.00
Iron ug/l 200 1 0 0 <4.00 <4.00 2
Manganese ug/l 50 1 0 0 <1.70 <1.70 <1.70
Copper mg/l 2 1 0 0 <0.008 <0.008 <0.008
Fluoride mg/l 1.5 1 0 0 0.19 0.19 0.19
Arsenic ug/l 10 1 0 0 <1.00 <1.00 <1.00
Cadmium ug/l 5 1 0 0 <0.12 <0.12 <0.12
Chromium ug/l 50 1 0 0 <0.70 <0.70 <0.70
Nickel ug/l 20 1 0 0 2.6 2.6 2.6
Lead ug/l 10 1 0 0 <0.90 <0.90 <0.90
Antimony ug/l 5 1 0 0 <0.20 <0.20 <0.20
Selenium ug/l 10 1 0 0 <0.90 <0.90 <0.90
PAH ug/l 0.1 1 0 0 0 0 0
Escherichia coli No./100ml 0 5 0 0 0 0 0
Intestinal Enterococci cfu/100ml 0 1 0 0 0 0 0
Boron mg/l 1 1 0 0 <0.04 <0.04 <0.04
Benzo(a)pyrene ug/l 0.01 1 0 0 <0.003 <0.003 <0.003
Trihalomethanes (total) ug/l 100 1 0 0 8.31 8.31 8.31


Indicator parameters

  Units PCV Number of samples Number of Samples contravening PCV % No. of samples contravening PCV Minimum Mean Maximum
pH (New Reg Limit) Env   - 2 0 0 7.30 7.40 7.50
Sulphate (as SO4) mg/l 250 1 0 0 24.50 24.50 24.50
Ammonium (as NH4) mg/l 0.5 2 0 0 <0.03 <0.03 <0.03
Total coliforms No./100ml 0 5 0 0 0 0 0
3 day count,22 deg C cfu/ml - 2 0 0 0 0 0
Free chlorine mg/l - 5 0 0 0.06 0.07 0.08
Conductivity uS/cm 2500 2 0 0 555 614 673
Chloride mg/l 250 1 0 0 20 20 20

* All of the samples collected from this zone in 2020 complied with the Water Supply (Water Quality) (Amendment) Regulations 2018. 

Water hardness

Average of Mg Average of Ca mg/l or ppm CaCO3 Degrees Clark (*0.07) Degrees French (*0.10) Degrees German (*0.056)
2.80 110.00 286.2 20.0 28.6 16.0


Water quality terms

Find out what the technical terms used in the water quality reports mean.