The Water Supply (Water Quality) (Scotland) Regulations 2001

Regulations 2 and 4

SCHEDULE 1 PRESCRIBED CONCENTRATIONS AND VALUES

TABLE A Microbiological parameters

Part I: Directive requirements

Item	Parameters	Concentration or Value (maximum)	Units of Measurement	Point of compliance
1.	Enterococci	0	number/100ml	consumers' taps
2.	Escherichia coli (E. coli)	0	number/100ml	consumers' taps

Part II: National requirements

Item	Parameters	Concentration or Value (maximum)	Units of Measurement	Point of compliance
Note:
* compliance required as to 95% of samples from each service reservoir (regulation 4(6))
1.	Coliform bacteria	0	number/100ml	service reservoirs* and water treatment works
2.	Escherichia coli (E coli)	0	number/100ml	service reservoirs and water treatment works

TABLE B Chemical parameters

Part I: Directive requirements

Item	Parameters	Concentration or Value (maximum)	Units of Measurement	Point of compliance
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 also regulation 6(6).
(iii) See also regulation 4(2)(d).
(iv) See the definition of “pesticides and related products” in regulation 2.
(v) The parametric value applies to each individual pesticide.
(vi) “Pesticides: Total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring procedure.
(vii) “PAH” means Polycyclic Aromatic Hydrocarbons, 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.
(viii) The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
(ix) “THM: Total” means total Trihalomethanes, 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.
1.	Acrylamide	0.10	μg/l	(i)
2.	Antimony	5.0	μgSb/l	consumers' taps
3.	Arsenic	10	μgAs/l	consumers' taps
4.	Benzene	1.0	μg/l	consumers' taps
5.	Benzo(a)pyrene	0.010	μg/l	consumers' taps
6.	Boron	1.0	mgB/l	consumers' taps
7.	Bromate	10	μgBrO3/l	consumers' taps
8.	Cadmium	5.0	μgCd/l	consumers' taps
9.	Chromium	50	μgCr/l	consumers' taps
10.	Copper(ii)	2.0	mg Cu/l	consumers' taps
11.	Cyanide	50	μgCN/l	consumers' taps
12.	1,2 dichloroethane	3.0	μg/l	consumers' taps
13.	Epichlorohydrin	0.10	μg/l	(i)
14.	Fluoride	1.5	mg F/l	consumers' taps
15.	Lead(ii)	(a) 25, from 25/12/03 until 24/12/13	μgPb/l	consumers' taps
		(b) 10, from 25/12/13	μgPb/l	consumers' taps
16.	Mercury	1.0	μgHg/l	consumers' taps
17.	Nickel(ii)	20	μgNi/l	consumers' taps
18.	Nitrate(iii)	50	mgNO3/l	consumers' taps
19.	Nitrite(iii)	0.50	mgNO2/l	consumers' taps
		0.10	mgNO2/l	treatment works
20.	Pesticides(iv)(v)–
	Aldrin	0.030	μg/l	consumers' taps
	Dieldrin	0.030	μg/l	consumers' taps
	Heptachlor	0.030	μg/l	consumers' taps
	Heptachlor epoxide	0.030	μg/l	consumers' taps
	other pesticides	0.10	μg/l	consumers' taps
21.	Pesticides: Total(vi)	0.50	μg/l	consumers' taps
22.	PAH(vii)	0.10	μg/l	consumers' taps
23.	Selenium	10	μgSe/l	consumers' taps
24.	Tetrachloroethene & Trichloroethene(viii)	10	μg/l	consumers' taps
25.	THM: Total(ix)	100	μg/l	consumers' taps
26.	Vinyl chloride	0.50	μg/l	(i)

Part II: National requirements

Item	Parameters	Concentration or Value (maximum unless otherwise stated)	Units of Measurement	Point of compliance
1.	Aluminium	200	μg Al/l	consumers' taps
2.	Colour	20	mg/l Pt/Co	consumers' taps
3.	Hydrogen ion	9.5	pH value	consumers' taps
		6.5 (minimum)
4.	Iron	200	μgFe/l	consumers' taps
5.	Manganese	50	μgMn/l	consumers' taps
6.	Odour	3 at 25°C	Dilution number	consumers' taps
7.	Sodium	200	mgNa/l	consumers' taps
8.	Taste	3 at 25°C	Dilution number	consumers' taps
9.	Tetrachloromethane	3	μg/l	consumers' taps
10.	Turbidity	4	NTU	consumers' taps

Regulations 2 and 4

SCHEDULE 2 INDICATOR PARAMETERS

Item	Parameters	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(i)	250	mgCl/l	supply point*
3.	Clostridium perfringens (including spores)	0	Number/100 ml	supply point*
4.	Coliform bacteria	0	Number/100ml	consumers' taps
5.	Colony count	No abnormal change	Number/1 ml at 22°C	consumers' taps
			Number/1 ml at 37°C	service reservoirs and treatment works
6.	Conductivity(i)	2500	μS/cm at 20°C	supply point*
7.	Sulphate(i)	250	mgSO4/l	supply point*
8.	Total indicative dose (for radioactivity)(ii)	0.10	mSv/year	supply point*
9.	Total organic carbon (TOC)	No abnormal change	mgC/l	supply point*
10.	Tritium (for radioactivity)	100	Bq/l	supply point*
11.	Turbidity	1	NTU	treatment works

Part IV

SCHEDULE 3 MONITORING

TABLE 1 PARAMETERS AND CIRCUMSTANCES FOR CHECK MONITORING

(1)	(2)	(3)
Item	Parameter	Circumstances
1.	Aluminium	– When used as flocculant or where the water originates from, or is influenced by, surface waters
2.	Ammonium
3.	Clostridium perfringens (including spores)	– Where the water originates from, or is influenced by, surface waters
4.	Coliform bacteria
5.	Colony counts
6.	Colour
7.	Conductivity
8.	Escherichia coli (E. Coli)
9.	Hydrogen ion
10.	Iron	– When used as flocculant or where the water originates from, or is influenced by, surface waters
11.	Manganese	– Where the water originates from, or is influenced by, surface waters
12.	Nitrate	– When chloramination is practised
13.	Nitrite	– When chloramination is practised
14.	Odour
15.	Taste
16.	Turbidity

TABLE 2 ANNUAL SAMPLING FREQUENCIES: WATER SUPPLY ZONES

(1)	(2)	(3)	(4)
Substances and parameters subject to check monitoring	Estimated population of water supply zone	Reduced	Standard
Notes:
+ See regulation 6(2) and Table 1 in Schedule 3.
* Sampling for these parameters may be within water supply zones or at supply points as specified in Table 3, subject to notes (ii) and (iii) below.
(i) Where the population is not an exact multiple of 5000, the population figure should be rounded up to the nearest multiple of 5000.
(ii) 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.
(iii) To monitor for total indicative dose (for radioactivity).
E.Coli	<100		4
Coliform bacteria Residual disinfectant	≥100		12 per 5000 population(i)
Aluminium*
Ammonium
Clostridium perfringes (including spores)*(i)
Colony counts	<100	1	2
Colour	100 – 4,999	2	4
Conductivity*	5,000 – 9,999	6	12
Hydrogen ion	10,000 – 29,999	12	24
Iron+	30,000 – 49,999	18	36
Manganese+	50,000 – 79,999	26	52
Nitrate+	80,000 – 100,000	38	76
Nitrite+
Odour
Taste
Turbidity
Parameters subject to audit monitoring
Antimony
Arsenic
Benzene*
Benzo(a)pyrene
Boron*
Bromate(ii)*
Cadmium
Chromium	<100		1
Copper	100 – 4,999		4
Cyanide*	5,000 – 100,000		8
1, 2 dichloroethane*
Enterococci
Flouride*
Lead
Mercury*
Nickel
Pesticides*
PAH
Selenium
Sodium
Trichloroethene/Tetrachloroethene*
Tetrachloromethane*	<100		1
THM	100 – 4,999		4
Chloride*	5,000 – 100,000		8
Sulphate*
Total Organic Carbon*
Tritium*
Gross alpha(iii)*
Gross beta(iii)*

TABLE 3 ANNUAL SAMPLING FREQUENCIES: SUPPLY POINTS

(1)	(2)	(3)	(4)	(5)
Item	Substances and parameters subject to check monitoring	Volume of water supplied m3/d	Reduced	Standard
Notes:
(i) Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3), otherwise audit monitoring.
(ii) Audit monitoring at supply points is permitted 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.
(iii) To monitor for total indicative dose (for radioactivity).
1.	Clostridium perfringens (including spores)(i)	<20		2
		20 – 999	2	4
2.	Conductivity	1,000 – 1,999	6	12
		2,000 – 5,999	12	24
		6,000 – 9,999	18	36
		10,000 – 15,999	26	52
		16,000 – 32,999	52	104
		33,000 – 49,999	78	156
		50,000 – 67,999	104	208
		68,000 – 84,999	130	260
		85,000 – 101,999	156	312
		102,000 – 119,999	183	365
		120,000 – 241,999	365	730
		242,000 – 484,999	730	1,460
		485,000 – 728,999	1,095	2,190
	Parameters subject to audit monitoring
3.	Benzene
4.	Boron
5.	Bromate(ii)
6.	Cyanide
7.	1,2 dichloroethane
8.	Fluoride	<20		1
9.	Mercury	20 – 999		4
10.	Pesticides	1,000 – 49,999		8
11.	Trichloroethene/Tetrachloroethene	50,000 – 89,999		12
		90,000 – 299,999		24
12.	Tetrachloromethane	300,000 – 649,999		36
13.	Chloride	≥650,000		48
14.	Sulphate
15.	Total organic carbon
16.	Tritium
17.	Gross alpha(iii)
18.	Gross beta(iii)

TABLE 4 ANNUAL SAMPLING FREQUENCIES: WATER TREATMENT WORKS

(1)	(2)	(3)	(4)	(5)
Item	Substances and parameters subject to check monitoring	Volume of water supplied m3/d	Reduced	Standard
Notes:
(i) check monitoring at treatment works is required only when chloramination is practised. In other circumstances, audit monitoring is required.
1.	E. coli	<20		4
2.	Coliform bacteria	20 – 1,999	12	52
3.	Colony counts	2,000 – 5,999	52	104
4.	Residual disinfectant	6,000 – 11,999	104	208
		≥12,000	104	365
5.	Nitrite(i)	<20		2
6.	Turbidity	20 – 999	2	4
		1,000 – 1,999	6	12
		2,000 – 5,999	12	24
		6,000 – 9,999	18	36
		10,000 – 15,999	26	52
		16,000 – 32,999	52	104
		33,000 – 49,999	78	156
		50,000 – 67,999	104	208
		68,000 – 84,999	130	260
		85,000 – 101,999	156	312
		102,000 – 119,999	183	365
		120,000 – 241,999	365	730
		242,000 – 484,999	730	1,460
		485,000 – 728,999	1,095	2,190
	Substances and parameters subject to audit monitoring
7.	Nitrite(i)	<20		1
		20 – 999		4
		1,000 – 49,999		8
		50,000 – 89,999		12
		90,000 – 299,999		24
		300,000 – 649,999		36
		>650,000		48

Regulation 16

SCHEDULE 4 ANALYTICAL METHODOLOGY

TABLE A1 Parameters for which, subject to regulation 16(5), methods of analysis are prescribed

(1)	(2)
Parameter	Method
a The composition of m-CP agar is: Basal medium Tryptose 30.0g Yeast extract 20.0g Sucrose 5.0g L–cysteine hydrichloride 1.0g MgSO4 • 7H2O 0.1g Bromocresol purple 40.0mg Agar 15.0g Water 1,000.0ml 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-cycloserine 400.0mg Polymyxine-B sulphate 25.0mg Indoxyl-•-D-glucoside to be dissolved in 8ml sterile water before addition 60.0mg Filter – sterilised 0.5% phenolphthalein disphosphate solution 20.0ml Filter – sterilised 4.5% FeC13 • 6H2O 2.0ml
Clostridium perfringens (including spores)	Membrane filtration followed by anaerobic incubation of the membrane on m–CP agara 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 bacteria	ISO 9308–1
Colony count 22°C – enumeration of culturable microorganisms	prEN ISO 6222
Colony count 37°C – enumeration of culturable microorganisms	pr EN 6222
Enterocci	ISO 7899–2
Escherichia coli (E. coli)	ISO 9308–1

TABLE A2 Parameters in relation to which methods of analysis must satisfy prescribed characteristics

(1)	(2)	(3)	(4)
Parameters	Trueness % of prescribed concentration or value or specification	Precision % of prescribed concentration or value or specification	Limit of detection % of prescribed concentration or value or specification
Notes:
(i) The method of analysis should determine total cyanide in all forms.
(ii) The performance characteristics apply to each individual pesticide and will depend on the pesticide concerned.
(iii) The performance characteristics apply to the individual substances specified at 25% of the parametric value in Part I of Table B in Schedule 1.
(iv) The performance characteristics apply to the individual substances specified at 50% of the parametric value in Part I of Table B in Schedule 1.
(v) The performance characteristics apply to the prescribed value of 4NTU.
(vi) The performance characteristics apply to the specification of 1NTU for water leaving treatment works.
Aluminium	10	10	10
Ammonium	10	10	10
Antimony	25	25	25
Arsenic	10	10	10
Benzene	25	25	25
Benzo(a)pyrene	25	25	25
Boron	10	10	10
Bromate	25	25	25
Cadmium	10	10	10
Chloride	10	10	10
Chromium	10	10	10
Colour	10	10	10
Conductivity	10	10	10
Copper	10	10	10
Cyanide(i)	10	10	10
1,2-dichloroethane	25	25	10
Fluoride	10	10	10
Iron	10	10	10
Lead	10	10	10
Manganese	10	10	10
Mercury	20	10	20
Nickel	10	10	10
Nitrate	10	10	10
Nitrite	10	10	10
Pesticides and related products(ii)	25	25	25
Polycyclic aromatic hydrocarbons(iii)	25	25	25
Selenium	10	10	10
Sodium	10	10	10
Sulphate	10	10	10
Tetrachloroethene(iv)	25	25	10
Tetrachloromethane	20	20	20
Trichloroethene(iv)	25	25	10
Trihalomethanes: Total(iii)	25	25	10
Turbidity(v)	10	10	10
Turbidity(vi)	25	25	25

Regulation 36

SCHEDULE 5 AMENDMENT OF THE WATER SUPPLY (WATER QUALITY) (SCOTLAND) REGULATIONS 1990

The amendments to the 1990 Regulations referred to in regulation 36 are–

(a) after regulation 13, the insertion of the following regulation:–

“Frequency of sampling for particular organisms and substances

13A.— (1) In each of the years 2001, 2002 and 2003 a water authority shall take, or cause to be taken, from its sampling points or, as the case may be, its supply points, for analysis for testing against the concentrations and values specified in column (2) of Table 4A for the organisms and substances listed in column (1) of that Table, not less than the number of samples specified in paragraphs (2) and (3).

(2) In respect of supply points and the supply of a volume of water within a range shown in column (3) of that Table, the number is that shown in column (4) of that Table as applicable to a volume within that range.

(3) In respect of sampling points and the supply of water to an estimated population within a range shown in column (5) of that Table, the number is that shown in column (6) of that Table as applicable to a population within that range.

(4) In each of those years samples shall be taken at regular intervals throughout the year.”;

(b) after regulation 20, the insertion of the following regulation:

“Additional testing for particular parameters

20A.   The samples taken in accordance with regulation 13 shall additionally be tested against the concentrations specified in column (2) of Table 4B.”;

(c) in regulation 21 (collection and analysis of samples)–

(i) in paragraph (2), the insertion, after “means”, of “subject to paragraph (3)”; and

(ii) the addition, at the end, of the following:–

“(3) In relation to each of the parameters and other substances listed in column (1) of Table 4B, paragraph (2)(d) shall have effect as if for sub-paragraph (iii) there were substituted the requirements of regulation 21A.”

(d) after regulation 21, the insertion of the following regulation:–

“Method of analysis of samples for particular parameters and substances

21A.— (1) The method of analysis used for testing for a parameter or other substance listed in column (1) of Table 4B against the concentrations in column (2) of that Table must be capable, at the time of use–

(a) of measuring concentrations with the trueness and precision specified in relation to that parameter or substance in columns (3) and (4) of Table 4B; and

(b) of detecting the parameter or substance at the limit of detection specified in relation to it in column (5) of that Table.

(2) For the purposes of paragraph (1)–

• “limit of detection” is to be calculated as–

  (a)

  three times the relative within batch standard deviation of a natural sample containing a low concentration of the parameter or substance; or

  (b)

  five times the relative within batch standard deviation of a blank sample;

• “precision” (the random error); is to be calculated as twice the standard deviation (within a batch and between batches) of the spread of result about the mean; and

• “trueness” (the systematic error) is to be calculated as the difference between the mean value of a large number of repeated measurements and the true value.”; and

(e) the insertion, after Table 4 in Schedule 2, of the following Tables:

“TABLE 4A

SAMPLING FOR PARTICULAR ORGANISMS AND SUBSTANCES

(1)	(2)	(3)	(4)	(5)	(6)
Organism or substance	Concentration or value and unit of measurement	Volume of water supplied m3/d	Annual sampling frequency	Estimated population of water supply zone	Annual sampling frequency
* where the water originates from, or is influenced by, surface waters
Benzene	1.0 μg/l
Bromate	10 μgBrO3/l
Clostridium perfringens*(including spores)	0 Number/100ml	• 999	2	• 4,999	2
		1,000 – 49,999	4	5,000–	4
		≥ 50,000	8	50,000
1,2 dichloroethane	3.0 μg/l
Enterococci	0 Number/100ml
Nitrite	0.1 mgNO2/l

TABLE 4B

PARAMETERS AND SUBSTANCES IN RELATION TO WHICH, SUBJECT TO REGULATION 21A, METHODS OF ANALYSIS MUST SATISFY THE PRESCRIBED CHARACTERISTICS

(1)	(2)	(3)	(4)	(5)
Parameter or other substance	Concentration and unit of measurement	Trueness % of concentration	Precision % of concentration	Limit of detection % of concentration
+ Polycyclic Aromatic Hydrocarbons (PAH), sum of the concentrations of benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)pyrene, and indeno(1,2,3-cd)pyrene. The performance characteristics apply to the individual substances specified at 25% of the concentration in column (2).
* The performance characteristics apply to the individual substances specified at 50% of the concentration in column (2).”.
Antimony	5.0 μgSb/l	25	25	25
Arsenic	10 μgAs/l	10	10	10
Benzene	1.0 μg/l	25	25	25
Boron	1.0 mgB/l	10	10	10
Bromate	10 μgBrO3/l	25	25	25
Copper	2.0 mgCu/l	10	10	10
1, 2 dichloroethane	3.0 μg/l	25	25	10
Lead	25 μgPb/l	10	10	10
Nickel	20 μgNi/l	10	10	10
Nitrite (ex-works)	0.1 mgNO2/l	10	10	10
PAH+	0.1μg/l	25	25	25
Tetrachloroethene*	10 μg/l	25	25	10
Trichloroethene*	10 μg/l	25	25	10

Regulation 37

SCHEDULE 6 PROGRAMMES OF WORK

A water authority’s programme of work shall–

(a) identify, by reference to the parameters set out in the Table below, those parameters in respect of which the requirements of regulation 38(1)(a) and (b) are unlikely to be satisfied unless steps are taken to secure that those requirements will be met;

(b) identify whether the requirement that the formula [nitrate]/50 + [nitrite]/3 • 1, where the square brackets signify the concentrations in mg/l for nitrate (NO3) and nitrite (NO2) is unlikely to be satisfied;

(c) specify the steps that the water authority intends to take for the purpose of securing that the requirements of regulation 38(1)(a) and (b) are met;

(d) specify the date by which each of the steps specified in accordance with paragraph (c) is proposed to be completed; and

(e) specify the times at which, or the periods within which, reports will be made to the Scottish Ministers in relation to the taking and completion of the steps specified in accordance with paragraph (c).

TABLE

E. coli

Enterococci

Acrylamide

Antimony

Arsenic

Benzene

Benzo(a)pyrene

Boron

Bromate

Cadmium

Chromium

Copper

Cyanide

1,2-dichloroethane

Epichlorohydrin

Lead

Mercury

Nickel

Nitrate

Nitrite

Pesticides

Polycyclic aromatic hydrocarbons

Selenium

Tetrachloroethene/Trichloroethene (sum of concentrations)

Trihalomethanes – Total (sum of concentrations of chloroform, bromoform, dibromochloromethane and bromodichloromethane)

Vinyl chloride