Schedule 3 MONITORING

Changes not yet applied. Later legislation changes this provision in ways not yet written into the text below:

Sch. 3 Table 1 Item 4A inserted by Water Supply (Water Quality) 2001 Sch. para. 12(a)
Sch. 3 Table 1 word omitted by Water Supply (Water Quality) 2001 Sch. para. 12(b)
Sch. 3 Table 2 words inserted by Water Supply (Water Quality) 2001 Sch. para. 13(a)(i)
Sch. 3 Table 2 words inserted by Water Supply (Water Quality) 2001 Sch. para. 13(a)(ii)
Sch. 3 Table 2 word substituted by Water Supply (Water Quality) 2001 Sch. para. 13(b)
Sch. 3 Table 3 word substituted by Water Supply (Water Quality) 2001 Sch. para. 14(a)
Sch. 3 Table 3 word substituted by Water Supply (Water Quality) 2001 Sch. para. 14(b)
Sch. 3 Table 3 words substituted by Water Supply (Water Quality) 2001 Sch. para. 14(c)
Sch. 3 Table 3 Note (ii) (iia) substituted for Sch. 3 Table 3 Note (ii) by Water Supply (Water Quality) 2001 Sch. para. 14(d)
Sch. 3 Table 2 substituted by Water Supply 2010 reg. 9(1) Sch. 1
Sch. 3 Table 3 substituted by Water Supply 2010 reg. 9(2) Sch. 2
Sch. 3 Table 2 words inserted by Water Supply (Water Quality) Regulations 2000 2007 Sch. Para. 4(a)
Sch. 3 Table 3 word inserted by Water Supply (Water Quality) Regulations 2000 2007 Sch. Para. 4(b)(i)
Sch. 3 Table 3 words inserted by Water Supply (Water Quality) Regulations 2000 2007 Sch. Para. 4(b)(ii)

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.	Colour
6.	Conductivity
7.	Escherichia coli (E. coli)
8.	Hydrogen ion concentration
9.	Iron	When used as flocculant or where the water originates from, or is influenced by, surface waters
10.	Manganese	Where the water originates from, or is influenced by, surface waters
11.	Nitrate	When chloramination is practised
12.	Nitrite	When chloramination is practised
13.	Odour
14.	Taste
15.	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: * 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 5,000, the population figure should be rounded up to the nearest multiple of 5,000.
(ii) Check monitoring in water supply zones is required only where chloramination is practised. In other circumstances audit monitoring is required.
(iii) 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.
(iv) To monitor for total indicative dose (for radioactivity).
E. coli	<100		4
Coliform bacteria Residual disinfectant	>–100		12 per 5,000 population ^f1
Aluminium
Ammonium
Clostridium perfringens
Colony counts	<100	1	2
Colour	100–4,999	2	4
Conductivity^f2	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 ^f3	80,000–99,999	38	76
Nitrite
Odour
Taste
Turbidity
Parameters subject to audit monitoring
Aluminium
Antimony
Arsenic
Benzene	<100		1
Benzo(a)pyrene	100–4,999		4
Boron	5,000–99,999		8
Bromate ^f4
Cadmium
Chromium
Copper
Cyanide
1,2 dichloroethane
Enterococci
Fluoride
Iron
Lead
Manganese
Mercury
Nickel
Nitrate
Nitrite
Pesticides and related products	<100		1
Pesticides and related products	100–4,999		4
Polycyclic aromatic hydrocarbons	5,000–99,999		8
Selenium
Sodium
Trichloroethene/Tetrachloroethene
Trihalomethanes
Chloride
Sulphate
Total organic carbon
Tritium
Gross alpha ^f5
Gross beta

TABLE 3

ANNUAL SAMPLING FREQUENCIES: TREATMENT WORKS OR SUPPLY POINTS^f6

(1)	(2)	(3)	(4)	(5)
Item	Substances and parameters	Volume of water supplied m³/d	Reduced	Standard
Notes: * 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, subject to notes (ii) and (iii) below.
(i) Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3).
(ii) Check monitoring at treatment works is required only when chloramination is practised. In other circumstances, audit monitoring is required.
(iii) 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.
(iv) To monitor for total indicative dose (for radioactivity).
1.	E. coli	<20		4
2.	Coliform bacteria	20–1,999	12	52
3.	Colony counts	2,000–5,999	52	104
4.	Nitrite ^f7	6,000–11,999	104	208
5.	Residual disinfectant	>12,000	104	365
6.	Turbidity
Subject to check monitoring
7.	Clostridium perfringens ^f8	<20		2
7.	Clostridium perfringens ^f8	20–999	2	4
8.	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
Subject to audit monitoring
9.	Benzene
10.	Boron
11.	Bromate ^f9
12.	Cyanide
13.	1,2 dichloroethane
14.	Fluoride
15.	Mercury	<20		1
16.	Nitrite	20–999		4
17.	Pesticides and	1,000–49,999		8
	related products	50,000–89,999		12
		90,000–299,999		24
		300,000–649,999		36
18.	Trichloroethene/Tetrachloroethene	>–650,000		48
19.	Tetrachloromethane
20.	Chloride
21.	Sulphate
22.	Total organic carbon
23.	Tritium
24.	Gross alpha ^f10
25.	Gross beta

Annotations

Footnotes

f1

(i)

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.

f2

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.

f3

(ii)

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

f4

(iii)

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.

f5

(iv)

To monitor for total indicative dose (for radioactivity).

f6

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, subject to notes (ii) and (iii) below.

f7

(ii)

Check monitoring at treatment works is required only when chloramination is practised. In other circumstances, audit monitoring is required.

f8

(i)

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

f9

(iii)

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.

f10

(iv)

To monitor for total indicative dose (for radioactivity).