The Water Framework Directive (Priority Substances and Classification) Regulations (Northern Ireland) 2011

PART 2 Environmental Standards

Environmental standards for river water quality

1.  Once the Department has, in accordance with paragraphs 1 and 2 of Part I of this Schedule, assigned to a river or any part thereof a Type—

(a) specified in column 1 of Table 1 below, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” dissolved oxygen standard specified in columns 2, 3, 4, 5 and 6 respectively of that Table to that river or part thereof;

(b) specified in column 1 of Table 2 below, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” ammonia standard specified in columns 2, 3, 4, 5 and 6 respectively of that Table to that river or part thereof;

(c) specified in column 1 of Table 3 below, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” biochemical oxygen demand standard specified in columns 2, 3, 4, 5 and 6 respectively of that Table to that river or part thereof.

2.  The Department shall apply the “high”, “good”, “moderate”, “poor” or “bad” biochemical oxygen demand standard specified in Table 3 below only for the purpose of deciding action to meet the standard for dissolved oxygen.

3.  Once the Department has, in accordance with paragraph 3 of Part I of this Schedule, assigned to a river or part thereof a Type specified in column 1 of Table 4 below, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” reactive phosphorus standard specified in columns 2, 3, 4, 5 and 6 respectively of that Table to that river or part thereof.

4.  The Department shall, as applicable, apply the “high”, “good”, “moderate”, “poor” or “bad” acid condition standards specified in columns 1, 2, 3, 4 and 5 respectively of Table 5 below to any river or part thereof.

Environmental standards for river flows

5.—(1) Once the Department has, in accordance with paragraph 6 of Part I of this Schedule, assigned to a river or part thereof a Type specified in column 1 of Tables 6, 7, 8, 9 or 10 below, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” river flow standards as specified by the boundary values in those Tables to that river or part thereof.

(2) The result of this classification shall be used only to determine “high” status in accordance with Part 1 of Schedule 2.

Environmental standards for lake water quality

6.  Once the Department has, in accordance with paragraph 7 of Part I of this Schedule, assigned to a lake or part thereof the Type “salmonid” or “cyprinid”, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” dissolved oxygen standard specified in Table 11 below to that lake or part thereof.

7.  The Department shall apply the “good” salinity standard specified in Table 12 below to all lakes or parts of such lakes.

8.  Once the Department has, in accordance with paragraph 8 of Part I of this Schedule, assigned to a lake or part thereof a geological category, depth category and colour category specified in Tables 7, 8 and 9 in that Part, it shall apply, as applicable, the “high”, “good”, “moderate”, “poor” or “bad” total phosphorus standard to that lake or part thereof, calculated in accordance with the formulae specified in columns 1, 2, 3, 4 and 5 respectively of Table 13 below, where in relation to those formulae—

• “R” represents the annual mean total phosphorus concentration expected for the lake in the absence of more than very minor phosphorus inputs to the lake resulting from human activities and, where a reliable estimate of ‘C’ is available, shall have the value given by the formula: Antilog₁₀ [1.36 – (0.09 x A) + (0.24 x B)] for non-humic lakes; and Antilog₁₀ [1.62 – (0.09) x A + (0.24 x B)] for humic lakes;

• “A” = Log₁₀ of the altitude in metres above mean sea level of the lake;

• “B” = Log₁₀ (C÷D);

• “C” = the mean alkalinity of the lake in milli-equivalents per litre estimated for the lake;

• “D” = the mean depth of the lake in metres;

• “H” = 0.755 + (0.012 x C) – (0.001 x D); or 0.7, whichever is larger value; and

• “G” = 0.506 + (0.023 x C) – (0.002 x D); or 0.46, whichever is the larger value.

9.  If the Department does not have the necessary data to calculate the total phosphorus standard applicable to a lake or part thereof in accordance with paragraph 8, it shall apply, as applicable to the lake or part thereof, the “high”, “good”, “moderate”, “poor” or “bad” total phosphorus standard specified in column 2, 3, 4, 5 and 6 respectively, of Table 14 below which corresponds with the combination of geological category and depth categories specified in column 1 of that Table that is applicable to the lake or part thereof.

Environmental standards for protection of inland lake water levels

10.  Once the Department has assigned the characteristics of a lake or part thereof, in accordance with paragraph 9 of Part I of this Schedule, it shall apply, as applicable, to the lake or part thereof the “good” lake standard specified in columns 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 of Table 15 below which, in accordance with Table 15, applies to that lake or part thereof with the combination of characteristics applicable to the lake or part thereof.

Environmental standards for transitional and coastal water quality

11.  The Department shall apply, as applicable, the dissolved oxygen standards for “high”, “good”, “moderate”, “poor” or “bad” specified in Table 16 and Table 17 below to transitional or coastal waters or parts thereof.

12.  The Department shall apply, as applicable, the dissolved inorganic nitrogen standards for “high”, “good”, “moderate”, “poor” or “bad” specified in Table 18 below to transitional or coastal waters or parts thereof.

Environmental standards for specific pollutants

13.  The Department shall apply, as applicable, the standards for specific pollutants given in Tables 19 to 37 below to surface waters or parts thereof.

Environmental Standards for River Water Quality

Table 1

Standards for dissolved oxygen in rivers

Dissolved oxygen (percent saturation)
(1) Where a lowland, high alkalinity river is a salmonid river (as designated by Directive 2006/44/EC ‘on the quality of freshwaters needing protection or improvement in order to support fish life’) the standards for the upland, low alkalinity type will apply.
(10-percentile)
Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
Type(1)	High	Good	Moderate	Poor	Bad
Upland and low alkalinity	80	75	64	50	< 50
Lowland and high alkalinity	70	60	54	45	< 45

Table 2

Standards for ammonia in rivers

Total ammonia (mg/l)
(90-percentile)
Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
Type	High	Good	Moderate	Poor	Bad
Upland and low alkalinity	0.2	0.3	0.75	1.1	> 1.1
Lowland and high alkalinity	0.3	0.6	1.1	2.5	> 2.5

Table 3

Standards for Biochemical Oxygen Demand in rivers

Biochemical oxygen demand (mg/l)(i)
(i) The standard for Biochemical Oxygen Demand shall be used when deciding action to meet the standard for dissolved oxygen.
(ii) Where a lowland, high alkalinity river is a salmonid river (as designated by Directive 2006/44/EC ‘on the quality of freshwaters needing protection or improvement in order to support fish life’) the standards for the upland, low alkalinity type will apply.
(90-percentile)
Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
Type(ii)	High	Good	Moderate	Poor	Bad
Upland and low alkalinity	3	4	6	7.5	> 7.5
Lowland and high alkalinity	4	5	6.5	9	> 9

Table 4

Standards for reactive phosphorus in rivers

Reactive phosphorus (ug/l)
(annual mean)
Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
Type	High	Good	Moderate	Poor	Bad
1n	30	50	150	500	> 500
2n	20	40	150	500	> 500
3n+4n	50	120	250	1000	> 1000

Table 5

Standards for acid conditions in rivers

pH
Column 1	Column 2	Column 3	Column 4	Column 5
High	Good	Moderate	Poor	Bad
(5 and 95 percentile)		(10 percentile)	(10 percentile)	(10 percentile)
≥ 6 to ≤ 9		4.7	4.2	< 4.2

Table 6

High environmental standards for river flows

Permitted abstraction per day as a percentage of the natural mean daily flow(Qn)(1)
(1) ‘Qn’ is the naturalized mean daily flow for a specified period of record
(2) ‘Qnx’ is the Qn that is expected to be exceeded by ‘x’ percent of the naturalized mean daily flows within a specified period of record
High
Column 1	Column 2	Column 3
	Maximum permitted % abstraction at Qn exceeding Qn95(2)	Maximum permitted % abstraction at Qn not exceeding Qn95
A1, A2 (downstream), A2 (headwaters), B1, B2, C2, D2	10	5

Table 7

Good environmental standards for river flows

abstraction per day as a percentage of the natural mean daily flow(Qn)
Good
Column 1		Column 2	Column 3	Column 4	Column 5
River type		Maximum % abstraction at Qn exceeding Qn60	Maximum % abstraction at Qn exceeding Qn70	Maximum % abstraction at Qn exceeding Qn95	Maximum % abstraction at Qn not exceeding Qn95
A1	April-Oct	30	25	20	15
	Nov-Mar	35	30	25	20
A2 (downstream), B1, B2	April-Oct	25	20	15	10
	Nov-Mar	30	25	20	15
A2 (headwaters), C2, D2	April-Oct	20	15	10	7.5
	Nov-Mar	25	20	15	10

Table 8

Moderate environmental standards for river flows

abstraction per day as a percentage of the natural mean daily flow(Qn)
Moderate
Column 1		Column 2	Column 3	Column 4	Column 5
River type		Maximum % abstraction at Qn exceeding Qn60	Maximum % abstraction at Qn exceeding Qn70	Maximum % abstraction at Qn exceeding Qn95	Maximum % abstraction at Qn not exceeding Qn95
A1	April-Oct	55	50	45	40
	Nov-Mar	60	55	50	45
A2 (downstream), B1, B2,	April-Oct	50	45	40	35
	Nov-Mar	55	50	45	40
A2 (headwaters), C2, D2	April-Oct	45	40	35	32.5
	Nov-Mar	50	45	40	35

Table 9

Poor environmental standards for river flows

abstraction per day as a percentage of the natural mean daily flow(Qn)
Poor
Column 1		Column 2	Column 3	Column 4	Column 5
River type		Maximum % abstraction at Qn exceeding Qn60	Maximum % abstraction at Qn exceeding Qn70	Maximum % abstraction at Qn exceeding Qn95	Maximum % abstraction at Qn not exceeding Qn95
A1	April-Oct	80	75	70	65
	Nov-Mar	85	80	75	70
A2 (downstream), B1, B2,	April-Oct	75	70	65	60
	Nov-Mar	80	75	70	65
A2 (headwaters), C2, D2	April-Oct	70	65	60	57.5
	Nov-Mar	75	70	65	60

Table 10

Bad environmental standards for river flows

abstraction per day as a percentage of the natural mean daily flow(Qn)
Bad
Column 1		Column 2	Column 3	Column 4	Column 5
River type		Maximum % abstraction at Qn exceeding Qn60	Maximum % abstraction at Qn exceeding Qn70	Maximum % abstraction at Qn exceeding Qn95	Maximum % abstraction at Qn not exceeding Qn95
A1	April-Oct	>80	>75	>70	>65
	Nov-Mar	>85	>80	>75	>70
A2 (downstream), B1, B2,	April-Oct	>75	>70	>65	>60
	Nov-Mar	>80	>75	>70	>65
A2 (headwaters), C2, D2	April-Oct	>70	>65	>60	>57.5
	Nov-Mar	>75	>70	>65	>60

Environmental Standards for Lake Water Quality

Table 11

Standards for dissolved oxygen in lakes

Status	Mean in July – August (mg/l)
	Salmonid	Cyprinid
High	9	8
Good	7	6
Moderate	4	4
Poor	1	1
Bad	< 1	< 1

Table 12

Salinity Standards for lakes with no natural saline influence

Status	Proposed Boundary
	Annual Mean (micro Siemens per centimetre)
Good	1000

Table 13

Total phosphorus standards for lakes

Annual mean concentration of total phosphorous (µg/l)
Column 1	Column 2	Column 3	Column 4	Column 5
High	Good	Moderate	Poor	Bad
R ÷ H; or 5, whichever value is the larger value	R ÷ G; or 8, whichever is the larger value	(R ÷ G) ÷ 0.5	(R ÷ G) ÷ 0.25	> (R ÷ G) ÷ 0.25

Table 14

Type-specific total phosphorus standards for lakes where the standards specified in Table 13 above do not apply

Annual mean concentration of total phosphorus (µg/l)
Column 1	Column 2	Column 3	Column 4	Column 5	Column 6
Geological and depth category	High	Good	Moderate	Poor	Bad
High alkalinity; shallow	16	23	46	92	> 92
High alkalinity; very shallow	23	31	62	124	> 124
Moderate alkalinity; deep	8	12	24	48	> 48
Moderate alkalinity; shallow	11	16	32	64	> 64
Moderate alkalinity; very shallow	15	22	44	88	> 88
Low alkalinity; deep	5	8	16	32	> 32
Low alkalinity; shallow	7	10	20	40	> 40
Low alkalinity; very shallow	9	14	28	56	> 56
Marl; shallow	9	20	40	80	> 80
Marl; very shallow	10	24	48	96	> 96

Table 15

Good environmental standards for lake water levels

Good Lake Standards
percentage reduction in mean daily inflow
Column 1		Col 2	Col 3	Col 4	Col 5	Col 6	Col 7	Col 8	Col 9	Col 10	Col 11	Col 12	Col 13	Col 14
Geology		Altitude	Low				Mid				High
		Size	Small		Large		Small		Large		Small		Large
		Basin form	L	V	L	V	L	V	L	V	L	V	L	V
		Depth
Peat	Summer	Deep	15	15	15	10	15	15	15	10	15	15	15	10
		Shallow	15	10	10	10	15	10	10	10	15	10	10	10
	Winter	Deep	15	15	15	10	15	10	10	10	12	10	10	10
		Shallow	15	10	10	10	10	10	10	10	10	10	10	5
Low Alkalinity	Summer	Deep	30	25	25	25	30	25	25	25	30	25	25	25
		Shallow	25	25	25	25	25	25	25	25	25	25	25	25
	Winter	Deep	20	20	20	20	20	20	20	15	20	15	15	15
		Shallow	20	20	20	15	20	15	15	15	15	15	15	15
Medium Alkalinity	Summer	Deep	20	20	20	20	20	20	20	20	20	20	20	20
		Shallow	20	20	20	15	20	15	15	15	15	15	15	15
	Winter	Deep	20	20	20	20	20	20	20	15	20	15	15	15
		Shallow	20	20	20	15	20	15	15	15	15	15	15	15
High Alkalinity, Marl	Summer	Deep	30	25	25	25	30	25	25	25	30	25	25	25
		Shallow	25	25	25	25	25	25	25	25	25	25	25	25
	Winter	Deep	30	25	25	25	25	25	25	25	25	25	25	25
		Shallow	25	25	25	25	25	25	25	25	25	25	25	20
Brackish	Summer	Deep	20	20	20	20	20	20	20	20	20	20	20	20
		Shallow	20	20	20	15	20	20	20	15	20	20	20	15
	Winter	Deep	30	25	25	25	30	25	25	25	25	25	25	25
		Shallow	25	25	25	25	25	25	25	25	25	25	25	25

Environmental Standards for Transitional and Coastal Water Quality

Table 16

Dissolved oxygen standards for transitional and coastal waters with salinities normalised to 35

	Dissolved oxygen concentrations (mg/l) as 5-percentile values
High	5.7
Good	4.0
Moderate	2.4
Poor	1.6
Bad	<1.6

Table 17

Dissolved oxygen standards for transitional and coastal waters with salinities <35

	Dissolved oxygen concentrations (mg/l) as 5-percentile values
High	≥5.7
Good	≥4.0 and <5.7
Moderate	≥2.4 and <4.0
Poor	≥1.6 and <2.4
Bad	<1.6

Table 18

Dissolved inorganic nitrogen standards for coastal waters with salinities from 30-34.5 normalised to salinity of 32, and transitional waters with salinities < 30 normalised to a salinity of 25.

	Mean dissolved inorganic nitrogen concentration (micromoles per litre) during the period 1st December to 28th February
High	12
Good	18
Moderate	30
Poor	40.5
Bad	>40.5

Environmental Standards for Specific Pollutants

Table 19

Environmental standards for 2,4-Dichlorophenoxyacetic acid (2,4-D)

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for 2,4 D specified in Column 2 and Column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
0.3	1.3	0.3	1.3

Table 20

Environmental standards for 2,4-Dichlorophenol

Good standard for rivers and freshwater lakes	Good standard for transitional and coastal waters
Column 1	Column 2
Annual mean (µg/l)	Annual mean (µg/l)
20	20

Table 21

Environmental standards for arsenic (dissolved)

Good standard for rivers and freshwater lakes	Good standard for transitional and coastal waters
(1) The standard for arsenic refers to the dissolved fraction of a water sample obtained by filtration through a 0.45µm filter or any equivalent pre-treatment
Column 1(1)	Column 2(1)
Annual mean (µg/l)	Annual mean (µg/l)
50	25

Table 22

Environmental standards for chlorine

Good standards for rivers and freshwater lakes		Good standard for transitional and coastal waters
(1) The standards for chlorine specified in Column 2 and 3 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
(2) The term “total residual oxidants” refers to the sum of all oxidising agents existing in water, expressed as available chlorine.
Column 1	Column 2(1)	Column 3(1)
Annual mean concentration (µg/l) of total available chlorine	95-percentile concentration (µg/l) of total available chlorine	95-percentile concentration (µg/l) of total residual oxidant(2)
2	5	10

Table 23

Environmental standards for chromium VI

Good standard for rivers and freshwater lakes	Good standards for transitional and coastal waters
(1) The standard for chromium VI specified in column 3 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2	Column 3(1)
Annual mean concentration (µg/l) of dissolved chromium VI	Annual mean concentration (µg/l) of dissolved chromium VI	95-percentile concentration (µg/l) of dissolved chromium VI
3.4	0.6	32

Table 24

Environmental standards for chromium III

Good standards for rivers and freshwater lakes
(1) The standard for chromium III specified in column 2 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water
Column 1	Column 2(1)
Annual mean concentration (µg/l) of dissolved chromium III	95-percentile concentration (µg/l) of dissolved chromium III
4.7	32

Table 25

Environmental standards for copper

Water hardness bands to which the corresponding river and freshwater lake standards in column 2 apply	Good standards for rivers and freshwater lakes	Good standards for transitional and coastal waters
Column 1	Column 2	Column 3
Annual mean concentration of CaCO3 (mg/l)	Annual mean concentration (µg/l) of dissolved copper	Annual mean concentration (µg/l) of dissolved copper
0 – 50	1	5
50 – 100	6
100 – 250	10
> 250	28

Table 26

Environmental standards for cyanide

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for cyanide specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean concentration (µg/l) of hydrogen cyanide	95-percentile concentration (µg/l) of hydrogen cyanide	Annual mean concentration (µg/l) of hydrogen cyanide	95-percentile concentration (µg/l) of hydrogen cyanide
1	5	1	5

Table 27

Environmental standards for cypermethrin

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The 95-percentile standards for cypermethrin must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2	Column 3	Column 4
Annual mean (ng/l)	0.1	Annual mean (ng/l)	0.1
95-percentile (ng/l)(1)	0.4	95-percentile (ng/l)(1)	0.41

Table 28

Environmental standards for diazinon

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for diazinon specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
0.01	0.02	0.01	0.1

Table 29

Environmental standards for dimethoate

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for dimethoate specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
0.48	4.0	0.48	4.0

Table 30

Environmental standards for iron

Good standard for rivers and freshwater lakes	Good standard for transitional and coastal waters
Column 1	Column 2
Annual mean concentration (mg/l) of dissolved iron	Annual mean concentration (mg/l) of dissolved iron
1	1

Table 31

Environmental standards for linuron

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for linuron specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
0.5	0.9	0.5	0.9

Table 32

Environmental standards for mecoprop

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for mecoprop specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
18	187	18	187

Table 33

Environmental standards for permethrin

Good standard for rivers and freshwater lakes	Good standard for transitional and coastal waters
Column 1	Column 2
95-percentile (µg/l)	95-percentile (µg/l)
0.01	0.01

Table 34

Environmental standards for phenol

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for phenol specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
7.7	46	7.7	46

Table 35

Environmental standards for toluene

Good standards for rivers and freshwater lakes		Good standards for transitional and coastal waters
(1) The standards for toluene specified in column 2 and column 4 must not be used for the purpose of classifying the ecological status or potential of bodies of surface water.
Column 1	Column 2(1)	Column 3	Column 4(1)
Annual mean (µg/l)	95-percentile (µg/l)	Annual mean (µg/l)	95-percentile (µg/l)
50	380	40	370

Table 36

Environmental standards for zinc

Water hardness to which the corresponding river and freshwater lake standards in column 2 apply(1)	Good standards for rivers and freshwater lakes	Good standards for transitional and coastal waters
(1) The standards applicable to intermediate water hardness must be calculated by simple linear interpolation.
Column 1	Column 2	Column 3
Annual mean concentration of CaCO3 (mg/l)	Annual mean concentration (µg/l) of total zinc	Annual mean concentration (µg/l) of dissolved zinc
0 – 50	8	40
50 – 100	50
100 – 250	75
> 250	125

Table 37

Environmental standards for un-ionised ammonia as nitrogen

Good standard for rivers and freshwater lakes	Good standard for transitional and coastal waters
Annual mean (µg/l)	Annual mean (µg/l)
Not applicable	21

Environmental Standards for Priority Substances and other Substances

Table 38

Environmental quality standards for priority substances and other substances for which standards have been set at EU-level

Name of substance	Chemical Abstracts Service number	All rivers and lakes		All transitional and coastal waters
		Good		Good
		Annual mean(i) (AA-EQS) (µg/l)	Maximum allowable concentration(ii) (MAC-EQS) (µg/l)	Annual mean(i) (AA-EQS) (µg/l)	Maximum allowable concentration(ii) (MAC-EQS) (µg/l)
(i) This parameter is the Environmental Quality Standard expressed as an annual average value (AA-EQS). Unless otherwise specified, it applies to the total concentrations of all isomers of the pollutant concerned.
(ii) This parameter is the Environmental Quality Standard expressed as a maximum allowable concentration (MAC-EQS). Where the MAC-EQS are marked as “not applicable”, the AA-EQS values are considered protective against short-term pollution peaks in continuous discharges since they are significantly lower than the values derived on the basis of acute toxicity.
(iii) For the group of priority substances covered by brominated diphenylethers listed in Decision 2455/2001/EC, an EQS is established only for congener numbers 28, 47, 99, 100, 153 and 154.
(iv) For cadmium and its compounds the EQS values vary dependent upon the hardness of the water as specified in five class categories (class 1: <40mg CaCO3/l, class 2: 40 to <50mg CaCO3/l, class 3: 50 to <100mg CaCO3/l, class 4: 100 to <200mg CaCO3/l and class 5: ≥200mg CaCO3/l).
(v) DDT total comprises the sum of the isomers 1,1,1-trichloro-2,2 bis (p-chlorophenyl) ethane (CAS number 50-29-3; EU number 200-024-3); 1,1,1-trichloro-2 (o-chlorophenyl)-2-(p-chlorophenyl) ethane (CAS number 789-02-6; EU number 212-332-5); 1,1-dichloro-2,2 bis (p-chlorophenyl) ethylene (CAS number 72-55-9; EU number 200-784-6); and 1,1-dichloro-2,2 bis (p-chlorophenyl) ethane (CAS number 72-54-8; EU number 200-783-0).
(vi) If the Department does not apply standards for biota it shall introduce stricter standards for water in order to achieve the same level of protection as the standards for biota set out in regulation 4. The Department shall notify the European Commission of the reasons and basis for using this approach, the alternative standards used, the data and the methodology by which the alternative standards were derived and the categories of surface water to which they would apply.
Application of the standards set out in Table 37 For any given surface water body, applying the AA-EQS means that, for each representative monitoring point within the water body, the arithmetic mean of the concentrations measured at different times during the year does not exceed the standard. The calculation of the arithmetic mean, the analytical method used and, where there is no appropriate analytical method meeting the minimum performance criteria, the method of applying a standard must be in accordance with implementing acts adopting technical specifications for chemical monitoring and quality of analytical results, in accordance with the Water Framework Directive. For any given surface water body, applying the MAC-EQS means that the measured concentration at any representative monitoring point within the water body does not exceed the standard. However, in accordance with section 1.3.4. of Annex V to the Water Framework Directive, the Department may introduce statistical methods, such as a percentile calculation, to ensure an acceptable level of confidence and precision for determining compliance with the MAC-EQS. With the exception of cadmium, lead, mercury and nickel (hereinafter “metals”) the standards set out in Table 37 are expressed as total concentrations in the whole water sample. In the case of metals the standards refer to the dissolved concentration i.e. the dissolved phase of a water sample obtained by filtration through a 0.45 µm filter or any equivalent pre-treatment. The Department may, when assessing the monitoring results against the standards, take into account: natural background concentrations for metals and their compounds, if they prevent compliance with the standard; and hardness, pH or other water quality parameters that affect the bioavailability of metals.
Alachlor	15972-60-8	0.3	0.7	0.3	0.7
Anthracene	120-12-7	0.1	0.4	0.1	0.4
Atrazine	1912-24-9	0.6	2.0	0.6	2.0
Benzene	71-43-2	10	50	8	50
Brominated diphenylether(iii)	32534-81-9	0.0005	not applicable	0.0002	not applicable
Cadmium and its compounds (depending on water hardness classes)(iv)	7440-43-9	≤ 0.08 (class 1) 0.08 (class 2) 0.09 (class 3) 0.15 (class 4) 0.25 (class 5)	≤ 0.45 (class 1) 0.45 (class 2) 0.6 (class 3) 0.9 (class 4) 1.5 (class 5)	0.2	≤ 0.45 (class 1) 0.45 (class 2) 0.6 (class 3) 0.9 (class 4) 1.5 (class 5)
Carbon-tetrachloride	56-23-5	12	not applicable	12	not applicable
C10-13 Chloroalkanes	85535-84-8	0.4	1.4	0.4	1.4
Chlorfenvinphos	470-90-6	0.1	0.3	0.1	0.3
Chlorpyrifos (Chlorpyrifos-ethyl)	2921-88-2	0.03	0.1	0.03	0.1
Cyclodiene pesticides:
Aldrin	309-00-2	Σ=0.01	not applicable	Σ=0.005	not applicable
Dieldrin	60-57-1
Endrin	72-20-8
Isodrin	465-73-6
DDT total(v)	not applicable	0.025	not applicable	0.025	not applicable
Para-para-DDT	50-29-3	0.01	not applicable	0.01	not applicable
1,2-Dichloroethane	107-06-2	10	not applicable	10	not applicable
Dichloromethane	75-09-2	20	not applicable	20	not applicable
Di(2-ethylhexyl)-phthalate (DEHP)	117-81-7	1.3	not applicable	1.3	not applicable
Diuron	330-54-1	0.2	1.8	0.2	1.8
Endosulfan	115-29-7	0.005	0.01	0.0005	0.004
Fluoranthene	206-44-0	0.1	1	0.1	1
Hexachloro-benzene	118-74-1	0.01(vi)	0.05	0.01(vi)	0.05
Hexachloro-butadiene	87-68-3	0.1(vi)	0.6	0.1(vi)	0.6
Hexachloro-cyclohexane	608-73-1	0.02	0.04	0.002	0.02
Isoproturon	34123-59-6	0.3	1.0	0.3	1.0
Lead and its compounds	7439-92-1	7.2	not applicable	7.2	not applicable
Mercury and its compounds	7439-97-6	0.05(vi)	0.07	0.05(vi)	0.07
Naphthalene	91-20-3	2.4	not applicable	1.2	not applicable
Nickel and its compounds	7440-02-0	20	not applicable	20	not applicable
Nonylphenol (4-Nonylphenol)	104-40-5	0.3	2.0	0.3	2.0
Octylphenol ((4-(1,1’,3,3’-tetramethylbutyl)-phenol))	140-66-9	0.1	not applicable	0.01	not applicable
Pentachloro-benzene	608-93-5	0.007	not applicable	0.0007	not applicable
Pentachloro-phenol	87-86-5	0.4	1	0.4	1
Benzo(a)pyrene	50-32-8	0.05	0.1	0.05	0.1
Benzo(b)fluor-anthene	205-99-2	Σ=0.03	not applicable	Σ=0.03	not applicable
Benzo(k)fluor-anthene	207-08-9
Benzo(g,h,i)-perylene	191-24-2	Σ=0.002	not applicable	Σ=0.002	not applicable
Indeno(1,2,3-cd)-pyrene	193-39-5
Simazine	122-34-9	1	4	1	4
Tetrachloro-ethylene	127-18-4	10	not applicable	10	not applicable
Trichloro-ethylene	79-01-6	10	not applicable	10	not applicable
Tributyltin compounds (Tributhyltin-cation)	36643-28-4	0.0002	0.0015	0.0002	0.0015
Trichloro-benzenes	12002-48-1	0.4	not applicable	0.4	not applicable
Trichloro-methane	67-66-3	2.5	not applicable	2.5	not applicable
Trifluralin	1582-09-8	0.03	not applicable	0.03	not applicable

Table 39

Environmental Quality Standards for other dangerous substances

Name of Substance	Chemical Abstracts Service Number	All Rivers and Lakes Annual Mean Concentration (µg/l)	All transitional, coastal and relevant territorial waters(1) Annual Mean Concentration (µg/l)
		Good
(1) “relevant territorial waters” means the waters which extend seaward for 3 miles from the baselines from which the breadth of the territorial sea adjacent to Northern Ireland is measured.
(2) The reference method of measurement shall be gas chromatography with electron capture detection after extraction by means of an appropriate solvent, or an alternative method that is at least as reliable. The limit of detection is 0.1 µg/litre. The accuracy and precision of the method shall be plus or minus 50% at a concentration which represents twice the value of the limit of determination.
(3) Where samples are taken from more than one sampling point in relation to the waters in question, the standard shall be satisfied in relation to the samples from each sampling point.
(4) Maximum Allowable Concentration
Sampling and analysis of the substances set out in Table 38 Samples shall be taken at a frequency sufficient to show any changes in the aquatic environment, having regard in particular to natural variations in hydrological conditions. Where a discharge containing any substance listed is made to any river, lake or transitional, coastal or territorial water, samples shall be taken at a point sufficiently close to the discharge point to be representative of the quality of the aquatic environment in the area affected by the discharge.
Perchloroethylene(2)	127-18-4	10	10
Azinphos-methyl(3)	86-50-0	0.01	0.01
Demeton(3)	8065-48-3	0.5	0.5
Omethoate(3)	1113-02-6	0.01	Not determined
Triazophos(3)	24017-47-8	0.005	0.005
4-chloro-3-methyl-phenol(3)	59-50-7	40	40
Bentazone(3)	25057-89-0	500	500
Fenitrothion(3)	122-14-5	0.01	0.01
2-chlorophenol(3)	95-57-8	50	50
Biphenyl(3)	92-52-4	25	25
Malathion(3)	121-75-5	0.01	0.02
1,1,1-trichloroethane(3)	71-55-6	100	100
Chloronitrotoluenes(3)	89-60-1	10	10
Triphenyltin and its derivatives(3)	379-52-2	0.02(4)	0.008(4)
1,1,2-trichloroethane(3)	79-00-5	400	300
Dichlorvos(3)	95828-55-0	0.001	0.04 0.6(4)
Xylene(3)	1330-20-7	30	30