# The Water Supply (Water Quality) Regulations (Northern Ireland) 2002, Schedule 2: INDICATOR PARAMETERS

Extent: N.I.

Item
Parameters
Specification Concentration or Value (maximum) or State
Units of Measurement
Point of monitoring
Notes:
(i)The water should not be aggressive.
(ii)Excluding tritium, potassium-40, radon and radon decay products.
*May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.
1.
Ammonium
0.50
mgNH4/l
Consumers' taps
2.
Chloride
250
mgCl/l
Supply point
3.
Clostridium perfringens (including spores)
0
Number/100ml
Supply point
4.
Coliform bacteria
0
Number/100ml
Consumers' taps
5.
Colony counts
No abnormal change
Number/1ml at 22°C Number/1ml at 37°C
Consumers' taps, service reservoirs and treatment works
6.
Conductivity
2500
μS/cm at 20°C
Supply point
7.
Hydrogen ion
9.5
pH value
Consumers' taps
8.
Sulphate
250
mgSO4/l
Supply point
9.
Total indicative dose (for radioactivity)
0.10
mSv/year
Supply point
10.
Total organic carbon (TOC)
No abnormal change
mgC/l
Supply point*
11.
Tritium (for radioactivity)
100
Bq/l
Supply point
12.
Turbidity
1
NTU
Treatment works

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Source: https://www.legislation.gov.uk/nisr/2002/331/schedule/2 (the official version)
Page: https://openlegislation.uk/water-supply-water-quality-regulations-northern-ireland-2002/schedule-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.