The Private Water Supplies (Scotland) Regulations 2006

Regulations 2(1), 7, 8, 17-26 and 28

SCHEDULE 1SPRESCRIBED CONCENTRATIONS AND VALUES

Table A SMicrobiological parameters

Part I: Directive requirements

(1)Item(2)Parameters(3)Concentration or Value (maximum)(4)Units of Measurement
1.Enterococci0number/100ml
2.Escherichia coli (E. coli)0number/100ml

Part II: National requirements

(1)Item(2)Parameters(3)Concentration or Value (maximum)(4)Units of Measurement
1.Coliform bacteria0number/100ml

Table B SChemical parameters

Part I: Directive requirements

(1)Item(2)Parameters(3)Concentration or Value (maximum)(4)Units of Measurement
1.Acrylamide(i)0.10µg/1
2.Antimony5.0µgSb/l
3.Arsenic10µgAs/l
4.Benzene1.0µg/l
5.Benzo(a)pyrene0.010µg/l
6.Boron1.0mgB/l
7.Bromate10µgBrO3/l
8.Cadmium5.0µgCd/l
9.Chromium50µgCr/l
10.Copper2.0mg Cu/l
11.Cyanide50µgCN/l
12.1,2 dichloroethane3.0µg/l
13.Epichlorohydrin(i)0.10µg/l
14.Fluoride1.5mg F/l
15.Lead

(a)25, from 3/7/06 until 24/12/13

µgPb/l
  

(b)10, from 25/12/13

µgPb/l
16.Mercury1.0µgHg/l
17.Nickel20µgNi/l
18.Nitrate50mgNO3/l
19.Nitrite0.50mgNO2/l
20.Pesticides(ii)  
 Aldrin0.030µg/l
 Dieldrin0.030µg/l
 Heptachlor0.030µg/l
 Heptachlor epoxide0.030µg/l
 other pesticides0.10µg/l
21.Pesticides: Total(iii)0.50µg/l
22.PAH(iv)0.10µg/l
23.Selenium10µgSe/l
24.Tetrachloroethene & Trichloroethene(v)10µg/l
25.THM: Total(vi)100µg/l
26.Vinyl chloride(i)0.50µg/l

Notes:

(i)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.

(ii)See the definition of “pesticides and related products” in regulation 2(1). The parametric value applies to each individual pesticide.

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

(iv)PAH” means Polycyclic Aromatic Hydrocarbons, the specified compounds being:

  • – 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.

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

(vi)THM: Total” means total Trihalomethanes, the specified compounds being:

  • – 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.

Part II: National requirements
(1)Item(2)Parameters(3)Concentration or Value (maximum unless otherwise stated))(4)Units of Measurement
1.Aluminium200µgA1/1
2.Colour20mg/l Pt/Co
3.F1. . .F1. . .F1. . .
4.Iron200µgFe/l
5.Manganese50µgMn/l
6.F2. . .F2. . .F2. . .
7.Silver(i)10µg Ag/l
8.Sodium200mgNa/l
9.F3. . .F3. . .F3. . .
10.Tetrachloromethane3µg/l
11.Turbidity(ii)4NTU
12.Zinc5000µg Zn/l

Notes:

(i)If Silver is used in a water treatment process, 80 may be substituted for 10.

(ii)Every effort should be made to achieve 1 NTU whenever possible.

Table C SIndicator parameters

Directive requirements

(1)Item(2)Parameters(3)Concentration or Value (maximum [F4unless otherwise stated]) or State(4)Units of Measurement
1.Ammonium0.50mgNH4/l
2.Chloride(i)250mgC1/1
3.Clostridium perfringens (including spores)0Number/100 ml
4.Coliform bacteria0Number/100 ml
5.Colony countNo abnormal changeNumber/1 ml at 22°C
[F55A ColourAcceptable to consumers and no abnormal change]
6.Conductivity(i)2500µS/cm at 20°C
[F66A Hydrogen ion

9.5

6.5 (minimum)

pH value]
[F66B OdourAcceptable to consumers and no abnormal change]
[F66C. Radon (for radioactivity)(ii)100Bq/l]
7.Sulphate(i)250mgSO4/l
[F77A TasteAcceptable to consumers and no abnormal change]
8.Total indicative dose (for radioactivity)F8...0.10mSvF8...
9.Total organic carbon (TOC)No abnormal changemgC/l
10.Tritium (for radioactivity) [F9(iii)]100Bq/l
[F1010A TurbidityAcceptable to consumers and no abnormal change]

Notes:

(i)The water should not be aggressive.

[F11(ii)Remedial action is to be deemed justified on radiological protection grounds, without further consideration, where radon concentrations exceed 1,000 Bq/l.

(iii)If the concentration of tritium exceeds this value, an analysis of the presence of other artificial radionuclides must be also carried out by Scottish Water.]

Textual Amendments

F11Sch. 1 Table C Note (ii)(iii) substituted for Sch. 1 Table C Note (ii) (28.11.2015) by The Private and Public Water Supplies (Miscellaneous Amendments) (Scotland) Regulations 2015 (S.S.I. 2015/346), regs. 1(1), 8(c)

Table D SMicrobiological and Chemical Parameters: Type B Supplies

National Requirements

(1)Item(2)Parameters(3)Concentration or Value (maximum)(4)Units of Measurement
1.Coliform Bacteria0number/100ml
2.Conductivity (i)2500µS/cm at 20°C
3.Enterococci0number/100ml
4.Escherichia coli (E.coli)0number/100ml
5.Hydrogen ion

9.5

6.5 (minimum)

pH value
6.Lead

(a)25, from 3/7/06 until 24/12/13

(b)10, from 25/12/13

µgPb/l
7.Nitrate50mgNO3/l
8.Odour-qualitative--
9.Taste-qualitative--
10.Turbidity4NTU

Notes:

(i)The water should not be aggressive.

Regulations 21-23, 29 and 30

SCHEDULE 2SPARAMETERS, MONITORING AND SAMPLING FREQUENCIES

Table AS

F12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table BS

F13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table CSRoutine Monitoring: Type B Supplies

Parameters

1.  Coliform bacteriaS

2.  ConductivityS

3.  EnterococciS

4.  Escherichia coli (E. coli)

5.  Hydrogen ionS

6.  LeadS

7.  Nitrate(i)S

8.  Odour – qualitative(ii)S

9.  Taste – qualitative(ii)S

10.  TurbidityS

Notes:

(i)Samples need not be analysed for nitrate if there are reasonable grounds for believing that nitrate levels in the locality concerned are below 25 mg NO3/l.

(ii)Samples should not be assessed qualitatively if there are reasonable grounds for suspecting that the water may give rise to a health hazard.

Regulation 21(2A)

F14SCHEDULE 2ASMONITORING OF RADIOACTIVE SUBSTANCES

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Regulation 26

F15SCHEDULE 3SCIRCUMSTANCES AND CONDITIONS TO BE CONSIDERED BY A MONITORING LOCAL AUTHORITY: DECISION ON AUDIT MONITORING

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Regulations 16 and 26 and 27

SCHEDULE 4SREQUIREMENTS FOR RISK ASSESSMENT

—(1) When undertaking or reviewing and updating a risk assessment for the purposes of regulations F16... 27, a monitoring local authority shall do so in accordance with the provisions of this Schedule.S

(2) A risk assessment shall comprise the following–

(a)documentation on and a description of the private water supply, including the catchment from which the supply draws water;

(b)a hazard assessment and risk characterisation;

(c)an identification of the measures by which risks may be controlled; and

(d)establishment of verification procedures,

and for the purposes of this paragraph, “hazard” means a biological, chemical, physical or radiological agent that has the potential to cause harm or danger to human health; and “risk” means the likelihood of identified hazards causing harm in exposed populations in a specified time, including the magnitude of that harm and/or the consequences of such harm.

(3) In respect of a private water supply which comprises, either alone or in any combination thereof, catchments, surface water or ground water, the risk assessment shall include provision in relation to the relevant matters specified in Table A of this Schedule.

(4) In respect of a private water supply which receives treatment, including treatment at source and at any point thereafter, the risk assessment shall make provision in relation to the relevant matters specified in Table B of this Schedule.

(5) In respect of a private water supply which comprises intermediate tanks and distribution, the risk assessment shall include provision in relation to the relevant matters specified in Table C of this Schedule.

Table A

Hazard Information and Risk Characterisation

(1)Source of private water supply(2)Information to be considered in the risk assessment
(1) Catchments(i) geology and hydrology
 (ii) meteorology and weather patterns
 (iii) general catchment and river health
 (iv) wildlife
 (v) competing water uses
 (vi) nature and intensity of development and land use
 (vii) other activities in the catchment that potentially release contaminants into source water
 (viii) planned future activities
(2) Surface water(i) description of water body type (e.g. river, reservoir, dam)
 (ii) flow and reliability of source water
 (iii) retention times
 (iv) water constituents (physical, chemical, microbial)
 (v) protection (e.g. enclosures, access)
 (vi) recreational and other human activity
 (vii) bulk water transport
(3) Groundwater(i) confined or unconfined aquifer
 (ii) aquifer hydrogeology
 (iii) flow rate and direction
 (iv) dilution characteristics
 (v) recharge area
 (vi) wellhead protection
 (vii) depth of casing
 (viii) bulk water transport

Table B

Treatment: Hazard Identification and Risk Characterisation

(i) treatment processes
(ii) equipment design
(iii) monitoring equipment and automation
(iv) water treatment chemicals used
(v) treatment efficiencies
(vi) disinfection removals of pathogens
(vii) disinfection residuals/contact time

Table C

Intermediate Tanks and Distribution: Hazard Identification and Risk Characterisation

(i) reservoir/tank design
(ii) retention times
(iii) seasonal variations
(iv) protection (e.g. covers, enclosures, access)
(v) distribution system design
(vi) hydraulic conditions (e.g. water age, pressures, flows)
(vii) backflow protection
(viii) disinfectant residuals

Regulations 22, 29 and 31

SCHEDULE 5SANALYTICAL METHODOLOGY

Table A

Parameters for which, subject to regulation 31(4), methods of analysis are prescribed

(1)Parameter(2)Method
Clostridium perfringens (including spores)Membrane filtration followed by anaerobic incubation of the membrane on m–CP agar(i) 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 micro-organismsprEN ISO 6222
EnterococciISO 7899–2
Escherichia coli (E.coli)ISO 9308–1

(i)The composition of m–CP agar is:

  • Basal medium

    Tryptose30g
    Yeast extract20g
    Sucrose5g
    L–cysteine1g
    MgSO4 . 7H2O0.1g
    Bromocresol purple40mg
    Agar15g
    Water1,000ml
  • 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–cycloserine400mg
    Polymyxine–B–sulphate25mg

    Indoxyl–β-D-glucoside

    to be dissolved in 8ml sterile water before addition

    60mg
    Filter – sterilised 0.5% phenolphthalein disphosphate solution20ml
    Filter – sterilised 4.5% FeC13 . 6H2O2ml

Table B

Parameters in relation to which methods of analysis must satisfy prescribed characteristics

(1)Item No.(2)Parameters(3)Trueness % of prescribed concentration or value or specification(4)Precision % of prescribed concentration or value or specification(5)Limit of detection % of prescribed concentration or value or specification
1.Aluminium101010
2.Ammonium101010
3.Antimony252525
4.Arsenic101010
5.Benzene252525
6.Benzo(a)pyrene252525
7.Boron101010
8.Bromate252525
9.Cadmium101010
10.Chloride101010
11.Chromium101010
12.Colour101010
13.Conductivity101010
14.Copper101010
15.Cyanide(i)101010
16.1,2–dichloroethane252525
17.Fluoride101010
18.Iron101010
19.Lead101010
20.Manganese101010
21.Mercury201020
22.Nickel101010
23.Nitrate101010
24.Nitrite101010
25.Pesticides and related products(ii)252525
26.Polycyclic aromatic hydrocarbons(iii)252525
27.Selenium101010
28.Sodium101010
29.Sulphate101010
30.Tetrachloroethene(iv)252510
31.Tetrachloromethane202020
32.Trichloroethene(iv)252510
33.Trihalomethanes:Total(iii)252510
34.Turbidity(v)101010

Notes:

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

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

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

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

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

Regulation 21(2A)

F17SCHEDULE 5ASMONITORING FOR TOTAL INDICATIVE DOSE AND ANALYTICAL PERFORMANCE CHARACTERISTICS

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