Statutory Rules of Northern Ireland

1996 No. 603

WATER AND SEWERAGE

The Surface Waters (Abstraction for Drinking Water) (Classification) Regulations (Northern Ireland) 1996

Made

20th December 1996

Coming into operation

20th February 1997

The Department of the Environment, in exercise of the powers conferred on it by section 4B of the Water Act (Northern Ireland) 1972(1) and now vested in it(2), section 56B of the Water and Sewerage Services Order (Northern Ireland) Order 1973(3) and, being a department designated(4) for the purposes of section 2(2) of the European Communities Act 1972(5) in relation to measures relating to the prevention, reduction and elimination of pollution of water, in exercise of the powers conferred on it by that section and of every other power enabling it in that behalf, hereby makes the following Regulations:

Citation and commencement

1. These Regulations may be cited as the Surface Waters (Abstraction for Drinking Water) (Classification) Regulations (Northern Ireland) 1996 and shall come into operation on 20th February 1997.

Interpretation

2.—(1) In these Regulations—

“the Department” means the Department of the Environment; and

“pollution control functions” means the Department’s functions under or by virtue of the following statutory provisions, that is to say—

(a)

the Water Act (Northern Ireland) 1972;

(b)

the Water and Sewerage Services (Northern Ireland) Order 1973;

(c)

regulations made by virtue of section 2(2) of the European Communities Act 1972, to the extent that the regulations relate to pollution of water.

(2) Expressions used in these Regulations which are also used in Directive 75/440/EEC(6) (quality required of surface waters used for abstraction of drinking water) or Directive 79/869/EEC(7) (methods of measurement and frequency of sampling and analysis of such waters) shall have the same meaning as in those Directives.

(3) In these Regulations any reference to the supply of water as drinking water shall be taken to be a reference to the supply of that water as drinking water after it has undergone purification treatment.

(4) The Interpretation Act (Northern Ireland) 1954(8) shall apply to these Regulations as it applies to a Measure of the Northern Ireland Assembly.

Classification of waters

3. The classifications DW1, DW2 and DW3 and the criteria for those classifications set out in Schedule 1 shall apply for classifying waters by reference to their suitability for abstraction by the Department for supply (after treatment) as drinking water.

Compliance with relevant limits

4.—(1) Subject to paragraphs (2) and (3), any waters classified under these Regulations shall be treated in any year as complying with the limits specified in column I of Schedule 1 for waters of the relevant class in relation to a parameter if—

(a)95 per cent of the samples taken in relation to those waters in accordance with regulation 7 comply with the limits specified in column I of Schedule 1;

(b)none of the samples exceeds the limit by more than 50 per cent;

(c)there is no associated danger to public health where any of the samples exceeds the limit; and

(d)there have been no occasions on which consecutive samples so taken at statistically suitable intervals exceed the limit.

(2) Non-compliant samples shall be ignored for the purposes of paragraph (1) if they are the result of a flood, natural disaster or abnormal weather conditions.

(3) Paragraph 1(b) shall not apply in the case of any standard adopted by the Department in relation to temperature.

Guideline values and no deterioration principle

5. In discharging its pollution control functions in relation to any waters classified under these Regulations, the Department shall—

(a)endeavour to respect the guideline values specified in column G of Schedule 1 for waters of the relevant class;

(b)act in accordance with the principle that implementation of measures taken pursuant to Directive 75/440/EEC(9) may under no circumstances lead directly or indirectly to deterioration of the current quality of surface water.

Compliance with standards

6.—(1) Subject to paragraphs (2) and (3), any waters classified under these Regulations shall be treated as complying with any standard in relation to any parameter adopted by the Department as a result of regulation 5 in relation to those waters if—

(a)90 per cent of the samples taken in relation to the waters in accordance with regulation 5 comply with the standard;

(b)none of the samples fails the standard by more than 50 per cent;

(c)there is no associated danger to public health where any of the samples fails to comply with the standard; and

(d)there have been no occasions on which consecutive samples so taken at statistically suitable intervals fail to comply with the standard.

(2) Non-compliant samples shall be ignored for the purposes of paragraph (1) if they are the result of a flood, natural disaster or abnormal weather conditions.

(3) Paragraph 1(b) shall not apply in the case of any standard adopted by the Department in relation to temperature, pH, dissolved oxygen and microbiological parameters

Waivers

7.—(1) Subject to the provisions of this regulation, the Department may waive any requirement to comply with the relevant limit value for any parameter in relation to waters classified under these Regulations or any standard adopted as a result of regulation 5 for any parameter in relation to any water classified under these Regulations if it considers it appropriate to do so—

(a)as a result of any flood or other natural disaster;

(b)in the case of any parameter marked (O) in Schedule 1, as a result of exceptional meteorological or geographical conditions;

(c)where the waters undergo natural enrichment in certain substances as a result of which the waters would exceed the relevant limit value for that parameter;

(d)in the case of a shallow lake or virtually stagnant surface water, for parameters marked with an asterisk in Schedule 1.

(2) The Department shall not waive any requirement if that would result in a danger to public health.

(3) Paragraph (1)(d) shall only apply in the case of a shallow lake where—

(a)the depth of the lake does not exceed 20 metres;

(b)the exchange of water is slower than a year; and

(c)waste water is not discharged into the lake.

(4) In this regulation “natural enrichment” means a process whereby without human intervention a given body of water receives from the soil certain substances contained therein.

Sampling and analysis

8.—(1) Subject to Regulation 9, the Department shall ensure that waters classified under these Regulations are sampled and samples are analysed in accordance with paragraphs (2) to (5).

(2) Samples shall always be taken at the same sampling point at times when water is being abstracted by the Department for supply as drinking water and the sampling point chosen by the Department must be—

(a)at the place where water is abstracted before being sent for purification treatment; and

(b)so situated that samples taken at that point are representative of the quality of the water at that place.

(3) Samples shall be analysed for compliance with the parameters listed in Part I of Schedule 2 for the relevant class of waters using methods of measurement which are at least as reliable as those specified in that Part and respect the values shown in that Part for limits of detection, precision and accuracy.

(4) Sampling and analysis shall be carried out at the frequency fixed by the Department in relation to the sampling point for those waters for each parameter listed in Schedule 1 and, in fixing the frequency, the Department shall ensure that—

(a)sampling is carried out at regular intervals;

(b)the annual frequency of sampling and analysis for each parameter is not less than that specified in Part II of Schedule 2 for the relevant class of waters; and

(c)sampling is as far as possible spread over the year so as to give a representative picture of the quality of the water.

(5) The containers used for samples, the agents or methods used to preserve part of the sample for the analysis of one or more parameters, the conveyance and storage of the samples and the preparation of samples for analysis must not be such as to bring about any significant change in the results of the analysis.

Reduction of frequency of sampling, etc.

9.—(1) Where a survey of any waters classified for the purposes of these Regulations shows that the values obtained for any parameters are considerably superior to—

(a)the quality required by Schedule 1, or

(b)the standard adopted by the Department as a result of regulation 5 in relation to the waters,

the Department may reduce the frequency of sampling of the waters in relation to that parameter or standard.

(2) The Department may decide that regular sampling and analysis of waters classified under these Regulations is not needed if—

(a)the requirements of paragraph (1) are satisfied in relation to the waters;

(b)there is no pollution of the waters;

(c)there is no risk of the quality of the waters deteriorating; and

(d)the quality of the waters is superior to the minimum required for waters classified as DW1.

Modification of section 4C of the Water Act (Northern Ireland) 1972

10. Section 4C of the Water Act (Northern Ireland) shall have effect—

(a)as if it imposed a duty on the Department to exercise the powers conferred on it by that section to classify under these Regulations such waters as are necessary to give effect to Directive 75/440/EEC; and

(b)in relation to the performance of that duty, as if subsections (4), (5) and (7) of that section were omitted.

Systematic plan of action

11. The Department shall draw up a systematic plan of action including a timetable for the improvement of surface water and especially that falling within category DW3.

Revocation of the Surface Waters (Classification) Regulations (Northern Ireland) 1995

12. The Surface Waters (Classification) Regulations (Northern Ireland) 1995(10) are hereby revoked.

Sealed with the Official Seal of the Department of the Environment on 20th December 1996.

L.S.

R. W. Rogers

Assistant Secretary

regulations 3, 4, 5, 7, 8 and 9

SCHEDULE 1Characteristics of Surface Water intended for the Abstraction of Drinking Water

No in Annex II to 75/440/EEC	Parameters		DW1		DW2		DW3
			G	I	G	I	G	I
⁽¹⁾ The values given are upper limits set in relation to the mean annual temperature (high and low).
⁽²⁾ This parameter has been included to satisfy the ecological requirements of certain types of environment.
^* See regulation 6(1)(d)
^(O) See regulation 6(1)(b)
1	pH		6.5 to 8.5		5.5 to 9		5.5 to 9
2	Coloration (after simple filtration)	mg/l Pt scale	10	20^(O)	50	100^(O)	50	200^(O)
3	Total suspended solids	mg/l SS	25
4	Temperature	°C	22	25^(O)	22	25^(O)	22	25^(O)
5	Conductivity	μs/cm⁻¹ at 20°C	1,000		1,000		1,000
6	Odour	(dilution factor at 25°C)	3		10		20
7^*	Nitrates	mg/l NO₃	25	50^(O)		50^(O)		50^(O)
8⁽¹⁾	Fluorides	mg/l F	0.7 to 1	1.5	0.7 to 1.7		0.7 to 1.7
10^*	Dissolved iron	mg/l Fe	0.1	0.3	1	2	1
11^*	Manganese	mg/l Mn	0.05		0.1		1
12	Copper	mg/l Cu	0.02	0.05^(O)	0.05		1
13	Zinc	mg/l Zn	0.5	3	1	5	1	5
14	Boron	mg/l B	1		1		1
19	Arsenic	mg/l As	0.01	0.05		0.05	0.05	0.1
20	Cadmium	mg/l Cd	0.001	0.005	0.001	0.005	0.001	0.005
21	Total Chromium	mg/l Cr		0.05		0.05		0.05
22	Lead	mg/l Pb		0.05		0.05		0.05
23	Selenium	mg/l Se		0.01		0.01		0.01
24	Mercury	mg/1 Hg	0.0005	0.001	0.0005	0.001	0.0005	0.001
25	Barium	mg/l Ba		0.1		1		1
26	Cyanide	mg/l CN		0.05		0.05		0.05
27	Sulphates	mg/l SO₄	150	250	150	250^(O)	150	250^(O)
28	Chlorides	mg/l Cl	200		200		200
29	Surfactants (reacting with methyl blue)	mg/l (lauryl sulphate)	0.2		0.2		0.5
30^*⁽²⁾	Phosphates	mg/l P₂O₅	0.4		0.7		0.7
31	Phenols (phenol index) paranitraniline 4 amino-antipyrine	mg/l C₆H₅OH		0.001	0.001	0.005	0.01	0.1
32	Dissolved or emulsified hydrocarbons (after extraction by petroleum ether)	mg/l		0.05		0.2	0.5	1
33	Polycyclic aromatic hydrocarbons	mg/l		0.0002		0.0002		0.001
34	Total pesticides (parathion, hexachlorocyclohexane, dieldrin)	mg/l		0.001		0.0025		0.005
35^*	Chemical oxygen demand (COD)	mg/l O₂					30
36^*	Dissolved oxygen saturation rate	% O₂	>70		>50		>30
37^*	Biochemical oxygen demand (BOD₅) (at 20°C without nitrification)	mg/l O₂	<3		<5		<7
38	Nitrogen by Kjeldahl method (except NO₃)	mg/l N	1		2		3
39	Ammonia	mg/l NH₄	0.05		1	1.5	2	4^(O)
40	Substances extractable with chloroform	mg/l SEC	0.1		0.2		0.5
43	Total coliforms 37°C	/100 ml	50		5,000		50,000
44	Faecal coliforms	/100 ml	20		2,000		20,000
45	Faecal streptococci	/100 ml	20		1,000		10,000
46	Salmonella		Not Present in 5,000 ml		Not Present in 1,000 ml

regulation 8

SCHEDULE 2

Part IMethod of Measuring the Values of Parameters

No. in Annex 1 to 79/869 /EEC	Parameters		Limit of detection¹	Precision²	Accuracy³	Method of measurement	Materials recommended for the container
¹ “Limit of detection” means the minimum value of the parameter examined which it is possible to detect.
² “Precision” means the range within which 95% of the results of measurements made on a single sample, using the same method, are located.
³ “Accuracy” means the difference between the true value of the parameter examined and the average experimental value obtained.
⁴ For values in the column of Category DW1 in Schedule 1.
⁵ For waters classified as DW2 or DW3.
⁶ For waters classified as DW3.
⁷ For values in the I columns of Schedule 1.
⁸ For values in the I column of Category DWI, and values in Category DW3 in Schedule 1.
⁹ For values in the G columns of Categories DW2 and DW3 in Schedule 1
¹⁰ Mixture of six standard substances all of the same concentration to be taken into consideration: fluoranthene; 3, 4-benzofluoranthene; 11, 12-benzofluoranthene; 3, 4-benzopyrene; 1, 12 benzoperylene; indano/1, 2, 3-cd/pyrene.
¹¹ Mixture of three substances all of the same concentration to be taken into consideration; parathion, hexachlorocyclohexane, dieldrin.
¹² If the samples contain so much suspended matter as to require special preliminary treatment, the accuracy values shown in the above Table may as an exception be exceeded and are to be regarded as a target. The samples must be treated so as to ensure that the analysis covers the largest quantity of substances to be measured.
¹³ As this method is not in current use in all Member States it is not certain that the limit of detection required for checking values can be attained.
¹⁴ Absence in this volume for values in the G column of Category DW1 in Schedule 1.
¹⁵ Absence in this volume for values in the G column of Category DW2 in Schedule 1.
1	pH	pH unit	—	0.1	0.2	Electrometry, measured in situ at the time of sampling without prior treatment of the sample.
2	Coloration (after simple filtration)	mg/l Pt Scale	5	10%	20%	Filtering through a glass fibre membrane. Photometric method using platinum-cobalt scale.
3	Total suspended solids	mg/l SS	—	5%	10%	Filtering through a 0.45 μm filter membrane, drying at 105°C and weighing. Centrifuging (for at least 5 mins with mean acceleration of 2,800 to 3,200 g), drying at 105°C and weighing.
4	Temperature	°C	—	0.5	1	Thermometry. Measured in situ at the time of sampling without prior treatment of the sample.
5	Conductivity at 20°C	μs/cm	—	5%	10%	Electrometry.
6	Odour	(dilution factor at 25°C)	—	—	—	By successive dilutions.	Glass.
7	Nitrates	mg/l NO₃	2	10%	20%	Molecular absorption spectrophotometry.
8	Fluorides	mg/l F	0.05	10%	20%	Molecular absorption spectrophotometry after distillation if necessary. Ion selective electrodes.
10	Dissolved iron	mg/1 Fe	0.02	10%	20%	Atomic absorption spectrophotometry after filtering through a filter membrane (0.45 μm). Molecular absorption spectrophotometry after filtering through a 0.45 μm filter membrane.
11	Manganese	mg/l Mn	0.01⁴ 0.02⁵	10%⁴ 10%⁵	20%⁴ 20%⁵	Atomic absorption spectrophotometry. Atomic absorption spectrophotometry. Molecular absorption spectrophotometry.
12	Copper¹²	mg/l Cu	0.005 0.02⁶	10% 10%⁶	20% 20%⁶	Atomic absorption spectrophotometry. Polarography. Atomic absorption spectrophotometry. Molecular absorption spectrophotometry. Polarography.
13	Zinc¹²	mg/l Zn	0.01⁴ 0.02	10%⁴ 10%	20%⁴ 20%	Atomic absorption spectrophotometry. Atomic absorption spectrophotometry. Molecular absorption spectrophotometry.
14	Boron¹²	mg/l B	0.1	10%	20%	Molecular absorption spectrophotometry. Atomic absorption spectrophotometry.	Materials not containing boron in any significant quantities.
19	Arsenic¹²	mg/l As	0.002⁴ 0.01⁷	20%⁴ 10%⁷	20%⁴ 20%⁷	Atomic absorption spectrophotometry. Atomic absorption spectrophotometry. Molecular absorption spectrophotometry.
20	Cadmium¹²	mg/l Cd	0.0002 0.001⁷	30%	30%	Atomic absorption spectrophotometry. Polarography.
21	Total chromium¹²	mg/l Cr	0.01	20%	30%	Atomic absorption spectrophotometry. Molecular absorption spectrophotometry.
22	Lead¹²	mg/1 Pb	0.01	20%	30%	Atomic absorption spectrophotometry. Polarography.
23	Selenium¹²	mg/l Se	0.005	10%	10%	Atomic absorption spectrophotometry.
24	Mercury¹²	mg/l Hg	0.0001 0.0002⁷	30%	30%	Flameless atomic absorption spectrophotometry (cold vaporisation).
25	Barium¹²	mg/l Ba	0.02	15%	30%	Atomic absorption spectrophotometry.
26	Cyanide	mg/l CN	0.01	20%	30%	Molecular absorption spectrophotometry.
27	Sulphates	mg/l SO₄	10	10%	10%	Gravimetric analysis. EDTA compleximetry. Molecular absorption spectrophotometry.
28	Chlorides	mg/l Cl	10	10%	10%	Titration (Mohr’s method). Molecular absorption spectrophotometry.
29	Surfactants (reacting with methylene blue)	mg/l (lauryl sulphate	0.05	20%		Molecular absorption spectrophotometry.
30	Phosphates	mg/l P₂O₅	0.02	10%	20%	Molecular absorption spectrophotometry.
31	Phenols (phenol index) parani-traniline 4 amino-antipyrene	mg/l C₆H₅OH	0.0005 0.001⁸	0.0005 30%	0.0005 50%	Molecular absorption spectrophotometry. 4 aminoantipyrine method. Paranitraniline method.	Glass.
32	Dissolved or emulsified hydro- carbons (after extraction by petroleum ether)	mg/l	0.01 0.04⁵	20% 20%⁵	30% 30%⁵	Infra-red spectrometry after extraction by carbon tetrachloride. Gravimetry after extraction by petroleum ether.	Glass.
33	Polycyclic aromatic hydro-carbons¹²	mg/l	0.00004	50%	50%	Measurement of fluorescence in the UV after thin layer chromatography. Comparative measurements in relation to a mixture of six control substances with the same concentration.¹⁰	Glass or aluminium.
34	Total pesticides (parathion, hexachloro- cyclohexane, dieldrin)¹²	mg/l	0.0001	50%	50%	Gas or liquid chromatography after extraction by suitable solvents and purification. Identification of the constituents of the mixture. Quantitative analysis.¹¹	Glass.
35	Chemical oxygen demand (COD)	mg/l O₂	15	20%	20%	Potassium dichromate method.
36	Dissolved oxygen saturation rate	% O₂	5	10%	10%	Winkler’s method. Electro-chemical method.	Glass.
37	Biochemical oxygen demand (BOD₅) (at 20°C without nitrification)	mg/l O₂	2	1.5	2	Determination of dissolved oxygen before and after five day incubation at 20°C ± 1°C in complete darkness. Addition of a nitrification inhibitor.
38	Nitrogen, Kjeldahl method (except NO₂ or NO₃)	mg/l N	0.3	0.5	0.5	Mineralisation, distillation by the Kjeldahl method and ammonium determination by means of molecular absorption spectrophotometry or titration.
39	Ammonium	mg/l NH₄	0.01⁴ 0.1⁵	0.03⁴ 10%⁵	0.03⁴ 20%⁵	Molecular absorption spectrophotometry.
40	Substances extractable with chloroform	mg/l	(¹³)			Extraction at neutral pH value by purified chloroform, evaporation in vacuo at room temperature, weighing of residue.
43	Total coliforms	/100 ml	5⁴ 500⁹			Culture at 37°C on an appropriate specific solid medium (such as Tergitol lactose agar, Endo agar, 0.4% Teepol broth) with filtration⁴ or without filtration⁹ and colony count. Samples must be diluted or, where appropriate, concentrated in such a way as to contain between 10 and 100 colonies. If necessary, identification by gasification. Alternative method:— Method of dilution with fermentation in liquid substrates in at least three tubes in three dilutions. Sub-culturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number). Incubation temperature 37°C ± 1°C.	Sterilised glass.
44	Faecal coliforms	/100 ml	2⁴ 200⁹			Culture at 44°C on an appropriate specific solid medium (such as Tergitol lactose agar, Endo agar, 0.4% Teepol broth) with filtration⁴ or without filtration⁹ and colony count. Samples must be diluted or, where appropriate, concentrated in such a way as to contain between 10 and 100 colonies. If necessary, identification by gasification. Alternative method:— Method of dilution with fermentation in liquid substrates in at least three tubes in three dilutions. Sub-culturing of the positive tubes on a confirmation medium. Count according to MPN (most probable number). Incubation temperature 44°C ± 0.5°C.	Sterilised glass.
45	Faecal streptococci	/100 ml	2⁴ 200⁹			Culture at 37°C on an appropriate specific solid medium (such as sodium azide) with filtration⁴ or without filtration⁹ and colony count. Samples must be diluted or, where appropriate, concentrated in such a way as to contain between 10 and 100 colonies. Alternative method:— Method of dilution in sodium azide broth in at least three tubes in three dilutions. Count according to MPN (most probable number.
46	Salmonella	1/5,000 ml¹⁴ 1/1,000 ml¹⁵				Concentration by filtration (on membrane or appropriate filter). Inoculation into pre-enrichment medium. Enrichment and transfer into isolating gelese. Identification.	Sterilised glass.

Part IIMinimum Annual Frequency of Sampling for each Parameter

Population Served	Classification DW1			Classification DW2			Classification DW3
	I¹	II²	III³	I¹	II²	III³	I¹	II²	III³
¹ This column applies to the parameters −pH, coloration, total suspended solids, temperature, conductivity, odour, nitrates, chlorides, phosphates, chemical oxygen demand (COD), dissolved oxygen saturation rate, biochemical oxygen demand (BOD₅) and ammonium.
² This column applies to the parameters — dissolved iron, manganese, copper, zinc, sulphates, surfactants, phenols, nitrogen by the Kjeldahl method, total coliforms and faecal coliforms.
³ This column applies to the parameters — fluorides, boron, arsenic, cadmium, total chromium, lead, selenium, mercury, barium, cyanide, dissolved or emulsified hydrocarbons, polycyclic aromatic hydrocarbons, total pesticides, substances extractable by chloroform, faecal streptococci and salmonella.
<10,000	1	1	1	1	1	1	2	1	1
> 10,000 to ≤30,000	1	1	1	2	1	1	3	1	1
>30,000 to ≤100,000	2	1	1	4	2	1	6	2	1
>100,000	3	2	1	8	4	1	12	4	1

Explanatory Note

(This note is not part of the Regulations.)

These Regulations prescribe a system for classifying the quality of waters intended for abstraction for drinking water according to their suitability for abstraction by the Department of the Environment for supply after treatment as drinking water.

The classifications DW1, DW2 and DW3 prescribed by regulation 3 reflect the values assigned by Directive 75/440/EEC (the quality required of surface water intended for abstraction of drinking water) to the parameters listed in Schedule 1 to the Regulations. The values in the “I” column of the Schedule (regulation 4) represent those values which the Department is required to meet by the Directive.

The values in the “G” column of the Schedule (regulation 5) are values which the Department is required to endeavour to respect when discharging its water pollution control functions.

Regulation 6 sets out the standards which waters will be required to meet to comply with the Regulations.

The Department is also required to draw up a systematic plan of action for the improvement of the waters (regulation 11).

The Regulations also incorporate the methods of measurement and frequency of sampling and analysis in 79/869/EEC laid down in that Directive for those parameters.

The Surface Waters (Classification) Regulations (Northern Ireland) 1995 are revoked as a consequence of these Regulations.

Copies of the Directives may be obtained from The Stationery Office Ltd, 16 Arthur Street, Belfast BT1 4GD.

(1)

1972 c. 5 (N.I.) as amended by the Water and Sewerage Services (Amendment) (Northern Ireland) Order 1993 (S.I. 1993/3165 (N.I. 16) Art. 16)

(2)

S.R. & O. (N.I.) 1973 No. 504 Art. 4

(3)

S.I. 1973/70 (N.I. 2) as amended by the Water and Sewerage Services (Amendment) (Northern Ireland) Order 1993 (S.I. 1993/3165 (N.I. 16) Art. 12)

(4)

S.I. 1989/2393

(5)

1972 c. 68

(6)

O.J. No. L194, 25.7.75, p. 26

(7)

O.J. No. L271, 29.10.79, p. 44

(8)

1954 c. 33 (N.I.)

(9)

O.J. No. L194, 25.7.75, p. 26

(10)

S.R. 1995 No. 11