Part IV MONITORING

Northern Ireland

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:
* 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 }
(including spores)^f2 }
Colony counts }
Colour }	<100	1	2
Conductivity }	100–4,999	2	4
Hydrogen ion }	5,000–9,999	6	12
Iron }	10,000–29,999	12	24
Manganese }	30,000–49,999	18	36
Nitrate ^f3 }	50,000–79,999	26	52
Nitrite }	80,000–100,000	38	76
Odour }
Taste }
Turbidity }
Parameters subject to audit monitoring
Aluminium }
Antimony }
Arsenic }
Benzene }
Benzo(a)pyrene }
Boron }
Bromate ^f4 }
Cadmium }
Chromium }
Copper }
Cyanide }
1,2 dichloroethane }	<100		1
Enterococci }	100–4,999		4
Fluoride }	5,000–100,000		8
Iron }
Lead }
Manganese }
Mercury }
Nickel }
Nitrate }
Nitrite }
Pesticides and related products }
Polycyclic aromatic hydrocarbons }
Selenium }
Sodium }
Trichloroethene/Tetrachloroethene }
Tetrachloromethane }
Trihalomethanes }	<100		1
Chloride }	100–4,999		4
Sulphate }	5,000–100,000		8
Total organic carbon }
Tritium }
Gross alpha ^f5 }
Gross beta }

TABLE 3.

ANNUAL SAMPLING FREQUENCIES: TREATMENT WORKS OR SUPPLY POINTS

(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, except nitrite, subject to notes (ii) and (iii);
(i) Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3).
(ii) Sampling at treatment works when chloramination is practised.
(iii) Sampling at treatment works when chloromination is not practised.
(iv) 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.
(v) 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 ^f6 }	6,000–11,999	104	208
5.	Residual disinfectant }	≥12,000	104	365
6.	Turbidity }
Subject to check monitoring
7.	Clostridium perfringens ^f7 }	<20		2
	}	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 ^f8 }
12.	Cyanide }
13.	1,2 dichloroethane }	<20		1
14.	Fluoride }	20–999		4
15.	Mercury }	1,000–49,999		8
16.	Nitrite ^f9 }	50,000–89,999		12
17.	Pesticides and }	90,000–299,999		24
	related products }	300,000–649,999		36
18.	Trichloroethene }	≥650,000		48
	Tetrachloroethene }
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

(ii)

Sampling at treatment works when chloramination is practised.

f7

(i)

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

f8

(iv)

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.

f9

(iii)

Sampling at treatment works when chloromination is not practised.

f10

(v)

To monitor for total indicative dose (for radioactivity).

Notes on Schedule 3

Commencement

I1: Sch. 3 in operation at 1.1.2004, see reg. 1(5) (by virtue of references to Sch. 3 by regulations which are in operation at 1.1.2004)
I2: Sch. 3 in operation at 1.1.2004 (by virtue of references to Sch. 3 by regulations which are in operation at 1.1.2004), see reg. 1(5)