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

Regulation 3

SCHEDULE 2 GUIDELINE VALUES

No in Annex II to 75/440/EEC	Parameters		DW1	DW2	DW3
1 The value given is an upper limit 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 8(1)(c)
1	pH		6.5 to 8.5	5.5 to 9	5.5 to 9
2	Coloration (after simple filtration)	mg/1 Pt Scale	10	50	50
3	Total suspended solids	mg/1 SS	25
4	Temperature	°C	22	22	22
5	Conductivity at 20°C	μs/cm	1000	1000	1000
6	Odour	dilution factor at 25°C	3	10	20
7*	Nitrates	mg/1 NO3	25
81	Fluorides	mg/1 F	0.7 to 1	0.7 to 1.7	0.7 to 1.7
10*	Dissolved iron	mg/1 Fe	0.1	1	1
11*	Manganese	mg/1 Mn	0.05	0.1	1
12	Copper	mg/1 Cu	0.02	0.05	1
13	Zinc	mg/1 Zn	0.5	1	1
14	Boron	mg/1 B	1	1	1
19	Arsenic	mg/1 As	0.01		0.05
20	Cadmium	mg/1 Cd	0.001	0.001	0.001
24	Mercury	mg/1 Hg	0.0005	0.0005	0.0005
27	Sulphates	mg/1 SO4	150	150	150
28	Chlorides	mg/1 Cl	200	200	200
29	Surfactants (reacting with methyl blue)	mg/1 (laurylsulphate)	0.2	0.2	0.5
30*2	Phosphates	mg/1 P2O5	0.4	0.7	0.7
31	Phenols (phenol index) paranitroaniline 4-aminoantipyrine	mg/1 C6H5OH		0.001	0.01
32	Dissolved or emulsified hydro carbons (after extraction by petroleum ether)	mg/1			0.5
35*	Chemical oxygen demand (COD)	mg/1 O2			30
36*	Dissolved oxygen saturation rate	% O2	>70	>50	>30
37*	Biochemical oxygen demand (BOD5) (at 20°C without nitrification)	mg/1 O2	<3	<5	<7
38	Nitrogen Kjeldahl method (except NO3)	mg/1 N	1	2	3
39	Ammonia	mg/1 NH4	0.05	1	2
40	Substances extractable with chloroform	mg/1 SEC	0.1	0.2	0.5
43	Total coliforms 37°C	/100ml	50	5,000	50,000
44	Faecal coliforms	/100ml	20	2,000	20,000
45	Faecal streptococci	/100ml	20	1,000	10,000
46	Salmonella		Not present in 5,000ml	Not present in 1,000ml