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

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

{s030} where the water originates from, or is influenced by, surface waters
(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
Benzene	1.0μg/l
Bromate	10μgBrO3/l
Clostridium perfringens {s030} (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	3.0μg/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

{s031} 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). {s032} The performance characteristics apply to the individual substances specified at 50% of the concentration in column (2).”.
(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
Antimony	5.0μgSb/l	25	25	25
Arsenic	10μgAs/l	10	10	10
Benzene	1.0μg/l	25	25	25
Boron	1.0 mgB/l	10	10	10
Bromate	10μgBrO3/l	25	25	25
Copper	2.0 mgCu/l	10	10	10
1, 2 dichloroethane	3.0μg/l	25	25	10
Lead	25μgPb/l	10	10	10
Nickel	20μgNi/l	10	10	10
Nitrite (ex-works)	0.1 mgNO2/l	10	10	10
PAH {s031}	0.1μg/l	25	25	25
Tetrachloroethene {s032}	10μg/l	25	25	10
Trichloroethene {s032}	10μg/l	25	25	10