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The Water Supply (Water Quality) Regulations 2010

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This is the original version (as it was originally made).

Regulations 2 and 4

SCHEDULE 1PRESCRIBED CONCENTRATIONS AND VALUES

Table A

Microbiological Parameters

Part I: Directive requirements
ItemParametersConcentration or Value (maximum)Units of MeasurementPoint of compliance
Note:
a

Note: Compliance required as to 95% of samples from each service reservoir (regulation 4(6)).

1Enterococci0number/100 mlConsumers' taps
2Escherichia coli (E coli)0number/100 mlConsumers' taps
Part II: National requirements
ItemParametersConcentration or Value (maximum)Units of MeasurementPoint of compliance
1Coliform bacteria0number/100 mlService reservoirsa and water treatment works
2Escherichia coli (E coli)0number/100 mlService reservoirs and water treatment works

Table B

Chemical Parameters

Part I: National requirements
ItemParametersConcentration or Value (maximum)Units of MeasurementPoint of compliance
Notes:
a

The parametric value refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water. This is controlled by product specification.

b

See also regulation 6(6).

c

See also regulation 4(2)(d).

d

See the definition of “pesticides and related products” in regulation 2.

e

The parametric value applies to each individual pesticide.

f

“Pesticides: Total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring procedure.

g

The specified compounds are:

  • benzo(b)fluoranthene

  • benzo(k)fluoranthene

  • benzo(ghi)perylene

  • indeno(1,2,3-cd)pyrene.

The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

h

The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

i

The specified compounds are:

  • chloroform

  • bromoform

  • dibromochloromethane

  • bromodichloromethane.

The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.

1Acrylamide0.10μg/la
2Antimony5.0μgSb/lConsumers' taps
3Arsenic10μgAs/lConsumers' taps
4Benzene1.0μg/lConsumers' taps
5Benzo(a)pyrene0.010μg/lConsumers' taps
6Boron1.0mgB/lConsumers' taps
7Bromate10μBrO3/lConsumers' taps
8Cadmium5.0μgCd/lConsumers' taps
9Chromium50μgCr/lConsumers' taps
10Copper b2.0mgCu/lConsumers' taps
11Cyanide50μgCN/lConsumers' taps
121, 2 dichloroethane3.0μg/lConsumers' taps
13Epichlorohydrin0.10μg/la
14Fluoride1.5mgF/lConsumers' taps
15Lead b

(a)25, from 25th December 2003 until immediately before 25th December 2013

μgPb/lConsumers' taps

(b)10, on and after 25th December 2013

μgPb/lConsumers' taps
16Mercury1.0μgHg/lConsumers' taps
17Nickel b20μgNi/lConsumers' taps
18Nitrate c50mgNO3/lConsumers' taps
19Nitrite c0.50mgNO2/lConsumers' taps
0.10Treatment Works
20Pesticides de
Aldrin)0.030μg/lConsumer’s taps
Dieldrin)
Heptachlor)
Heptachlor
epoxide)
other pesticides0.10μg/lConsumers' taps
21Pesticides: Total f0.50μg/lConsumers' taps
22Polycyclic aromatic hydrocarbons g0.10μg/lConsumers' taps
23Selenium10μgSe/lConsumers' taps
24Tetrachloroethene and Trichloroethene h10μg/lConsumers' taps
25Trihalomethanes: Total i100μg/lConsumers' taps
26Vinyl chloride0.50μg/la
Part II: National requirements
ItemParametersConcentration or Value (maximum unless otherwise stated)Units of MeasurementPoint of compliance
1Aluminium200μgAl/lConsumers' taps
2Colour20mg/l Pt/CoConsumers' taps
3Iron200μgFe/lConsumers' taps
4Manganese50μgMn/lConsumers' taps
5OdourAcceptable to consumers and no abnormal change ... ... ... ...Consumers' taps
6Sodium200mgNa/lConsumers' taps
7TasteAcceptable to consumers and no abnormal change ... ... ... ...Consumers' taps
8Tetrachlorome-thane3μg/lConsumers' taps
9Turbidity4NTUConsumers' taps

Regulations 2 and 4

SCHEDULE 2INDICATOR PARAMETERS

ItemParametersSpecification Concentration or Value (maximum unless otherwise stated) or StateUnits of MeasurementPoint of compliance
Notes:
a

The water should not be aggressive.

b

Excluding tritium, potassium-40, radon and radon decay products.

c

May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.

1Ammonium0.50mgNH4/lConsumers' taps
2Chloride a250mgCl/lSupply pointc
3Clostridium perfringens (including spores)0Number/100 mlSupply pointc
4Coliform bacteria0Number/100 mlConsumers' taps
5Colony countsNo abnormal changeNumber/1 ml at 22°CConsumers' taps, service
Number/1 ml at 37°CReservoirs and treatment works
6Conductivity a2500μS/cm at 20°CSupply pointc
7Hydrogen ion9.5pHvalueConsumers' taps
6.5 (minimum)pH value
8Sulphate a250mgSO4/lSupply pointc
9Total indicative dose (for radioactivity) b0.10mSv/yearSupply pointc
10Total organic carbon (TOC)No abnormal changemgC/lSupply pointc
11Tritium (for radioactivity)100Bq/lSupply pointc
12Turbidity1NTUTreatment works

SCHEDULE 3MONITORING

PART IV

Table 1Parameters and Circumstances for Check Monitoring

(1)(2)(3)
ItemParameterCircumstances
1AluminiumWhen used as flocculant or where the water originates from, or is influenced by, surface waters
2Ammonium
3Clostridium perfringens (including spores)Where the water originates from, or is influenced by, surface waters
4Coliform bacteria
5Colony counts
6Colour
7Conductivity
8Escherichia coli (E coli)
9Hydrogen ion
10IronWhen used as flocculant or where the water originates from, or is influenced by, surface waters
11ManganeseWhere the water originates from, or is influenced by, surface waters
12NitrateWhen chloramination is practised
13NitriteWhen chloramination is practised
14Odour
15Taste
16Turbidity

Regulation 9

Table 2Annual Sampling Frequencies: Water Supply Zones

Note: This table sets out the annual sampling frequencies for all the substances and parameters in column 1. These are determined for each water supply zone according to its estimated population (column 2). The number of samples is either the standard number in column 4 or the reduced number in column 3 (if one is given). Regulation 9 provides for the circumstances in which the reduced number of samples may be taken.

(1)(2)(3)(4)
Substances and parameters subject to check monitoringEstimated population of water supply zoneReducedStandard
Subject to check monitoring
a

Where the population is not an exact multiple of 5,000, the population figure should be rounded up to the nearest multiple of 5,000.

b

Sampling for these parameters may be within water supply zones or at supply points as specified in Table 3, subject to notes (iii) and (iv) below.

c

Check monitoring in water supply zones is required only where chloramination is practised. In other circumstances audit monitoring is required.

d

Audit monitoring in water supply zones is required only where sodium hypochlorite is added after water has left the treatment works. In other circumstances, audit monitoring is required at supply points.

e

To monitor for total indicative dose (for radioactivity).

E coli<1004
Coliform bacteria≥10012 per 5,000 populationa
Residual disinfectant
Aluminium
  • <100

  • 100—4,999

  • 5,000—9,999

  • 10,000—29,999

  • 30,000—49,999

  • 50,000—79,999

  • 80,000—100,000

  • 1

  • 2

  • 6

  • 12

  • 18

  • 26

  • 38

  • 2

  • 4

  • 12

  • 24

  • 36

  • 52

  • 76

Ammonium
Clostridium perfringens (including spores)b
Colony counts
Colour
Conductivityb
Hydrogen ion
Iron
Manganese
Nitrate c
Nitrite c
Odour
Taste
Turbidity
Subject to audit monitoring
Aluminium
  • <100

  • 100—4,999

  • 5,000—100,000

  • 1

  • 4

  • 8

Antimony
Arsenic
Benzeneb
Benzo(a)pyrene
Boronb
Bromate d
Cadmium
Chromium
Clostridium perfringens (including spores)
Copper
Cyanideb
1,2 dichloroethaneb
Enterococci
Fluorideb
Iron
Lead
Manganese
Mercuryb
Nickel
Nitrate c
Nitrite c
Pesticides and related products b
Polycyclic aromatic hydrocarbons
Selenium
Sodium
Trichloroethene /Tetrachloroetheneb
Tetrachloromethaneb
Trihalomethanes
Chlorideb
Sulphateb
Total organic carbonb
Tritiumb
Gross alpha b e
Gross beta b e

Regulation 9

Table 3Annual Sampling Frequencies: Treatment Works or Supply Points

Note 1: Sampling is at treatment works for the substances and parameters shown in column (1) of the Table as items (1) to (6) and at supply points for the other substances and parameters, except nitrate subject to footnotes (ii) and (ii)(a) to the Table below.

Note 2: This table sets out the annual sampling frequencies for all the substances and parameters in column 2 at treatment works or supply points. The frequencies are determined according to the volume of water supplied at each treatment works or supply point (column 3). The number of samples is either the standard number in column 5 or the reduced number in column 4 (if one is given). Regulation 9 provides for the circumstances in which the reduced number of samples may be taken.

(1)(2)(3)(4)(5)
ItemSubstances and parametersVolume of water supplied m3/dReducedStandard
a

Sampling at treatment works when chloramination is practised.

b

Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3).

c

Audit monitoring at supply points is required only where sodium hypochlorite is not added after water has left the treatment works. In other circumstances, audit monitoring is required in water supply zones.

d

Sampling at treatment works when chloramination is not practised.

e

To monitor for total indicative dose (for radioactivity).

1.E Coli
  • <20

  • 20—1,999

  • 2,000—5,999

  • 6,000—11,999

  • ≥12,000

  • 12

  • 52

  • 104

  • 104

  • 4

  • 52

  • 104

  • 208

  • 365

2.Calliform bacteria
3.Colony counts
4.Nitrite a
5.Residual disinfectant
6.Turbidity
Subject to check monitoring
7.Clostridium perfringens b
  • <20

  • 20—999

  • 1,000—1,999

  • 2,000—5,999

  • 6,000—9,999

  • 10,000—15,999

  • 16,000—32,999

  • 33,000—49,999

  • 50,000—67,999

  • 68,000—84,999

  • 85,000—101,999

  • 102,000—119,999

  • 120,000—241,999

  • 242,000—484,999

  • 485,000—728,999

  • 2

  • 6

  • 12

  • 18

  • 26

  • 52

  • 78

  • 104

  • 130

  • 156

  • 183

  • 365

  • 730

  • 1,095

  • 2

  • 4

  • 12

  • 24

  • 36

  • 52

  • 104

  • 156

  • 208

  • 260

  • 312

  • 365

  • 730

  • 1,460

  • 2,190

8.Conductivity
Subject to audit monitoring
9.Benzene
  • <20

  • 20—999

  • 1,000—49,999

  • 50,000—89,999

  • 90,000—299,999

  • 300,000—649,000

  • ≥650,000

  • 1

  • 4

  • 8

  • 12

  • 24

  • 36

  • 48

10.Boron
11.Bromate c
11A.Clostridium perfringens (including spores)
12.Cyanide
13.1,2 dichloroethane
14.Fluoride
15.Mercury
16.Nitrite d
17.Pesticides and Related products
18.Trichloroethene
Tetrachloroethene
19.Tetrachloromethane
20.Chloride
21.Sulphate
22.Total organic carbon
23.Tritium
24.Gross alpha e
25.Gross beta e

Regulation 16

SCHEDULE 4ANALYTICAL METHODOLOGY

Regulation 16

Table A1Parameters for which, Subject to Regulation 16(7), Methods of Analysis are Prescribed

(1)(2)
ParameterMethod
Clostridium perfringens (including spores)Membrane filtration followed by anaerobic incubation of the membrane on m-CP agar* at 44 ± 1°C for 21 ± 3 hours. Count opaque yellow colonies that turn pink or red after exposure to ammonium hydroxide vapours for 20 to 30 seconds.
Coliform bacteriaISO 9308-1
Colony count 22°C-enumeration of culturable microorganismsprEN ISO 6222
Colony count 37°C-enumeration of culturable microorganismsprEN ISO 6222
EnterococciISO 7899-2
Escherichia coli (E coli)ISO 9308-1
*The composition of m-CP agar is:
Basal medium
Tryptose30.0g
Yeast extract20.0g
Sucrose5.0g
L-cysteine hydrochloride1.0g
MgSO4·7H2O0.1g
Bromocresol purple40.0mg
Agar15.0g
Water1,000.0ml
Dissolve the ingredients of the basal medium, adjust pH to 7.6 and autoclave at 121°C for 15 minutes. Allow the medium to cool and add:
D-cycloserine400.0mg
Polymyxine-B sulphate25.0mg
Indoxyl-[beta]-D-glucoside to be dissolved in 8 ml sterile water before addition60.0mg
Filter-sterilised 0.5% phenolphthalein diphosphate solution20.0 ml
Filter-sterilised 4.5% FeCl3·6H2O2.0 ml

Table A2Parameters for which, Subject to Regulation 16(7), Methods of Analysis are Prescribed

(1)(2)(3)(4)
ParametersTrueness % of prescribed concentration or value or specificationPrecision % of prescribed concentration or value or specificationLimit of detection % of prescribed concentration or value or specification
Notes:
a

The method of analysis should determine total cyanide in all forms.

b

The performance characteristics apply to each individual pesticide and will depend on the pesticide concerned.

c

The performance characteristics apply to the individual substances specified at 25% of the parametric value in Part I of Table B in Schedule 1.

d

The performance characteristics apply to the individual substances specified at 50% of the parametric value in Part I of Table B in Schedule 1.

e

The performance characteristics apply to the prescribed value of 4NTU.

f

The performance characteristics apply to the specification of 1NTU for water leaving treatment works.

Aluminium101010
Ammonium101010
Antimony252525
Arsenic101010
Benzene252525
Benzo(a)pyrene252525
Boron101010
Bromate252525
Cadmium101010
Chloride101010
Chromium101010
Colour101010
Conductivity101010
Copper101010
Cyanide a101010
1,2-dichloroethane252510
Fluoride101010
Iron101010
Lead101010
Manganese101010
Mercury201020
Nickel101010
Nitrate101010
Nitrite101010
Pesticides and related products b252525
Polycyclic aromatic hydrocarbons c252525
Selenium101010
Sodium101010
Sulphate101010
Tetrachloromethane202020
Trichloroethene d252510
Trihalomethanes: Total c252510
Turbidity e101010
Turbidity f252525

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