The Natural Mineral Water, Spring Water and Bottled Drinking Water Regulations (Northern Ireland) 2015

Regulation 25(1)(b)

SCHEDULE 11 Sampling and analysis for indicative dose in water bottled and labelled as “spring water” and bottled drinking water

PART 1 General

Analysis of samples

1.  The district council must ensure that each sample is analysed for indicative dose in accordance with Annex III to Directive 2013/51 and this Part.

2.  For each parameter and radionuclide specified in the first column of Table 1 in Part 2, the derived concentration and dose coefficient for calculating the indicative dose is specified in the second column of that table.

3.  For each parameter specified in the first column of Table 2 in Part 2, the method of analysis must be one that is capable of detecting the parameter at the limit of detection specified in the second column of that table.

4.  If the following formula is satisfied, the indicative dose is considered to be less than the parametric value of 0.1 mSv and no further investigation is required—

where

• Ci(obs) = observed concentration radionuclide i

• Ci(der) = derived concentration of radionuclide i

• n = number of radionuclides detected

PART 2 Methods of analysis and performance characteristics

Table 1

Derived concentrations for radioactivity

Origin	Nuclide	Derived concentration
(1) This table allows only for the radiological properties of uranium, not for its chemical toxicity.
Natural	U-238(1)	3.0 Bq/l
	U-234(1)	2.8 Bq/l
	Ra-226	0.5 Bq/l
	Ra-228	0.2 Bq/l
	Pb-210	0.2 Bq/l
	Po-210	0.1 Bq/l
Artificial	C-14	240 Bq/l
	Sr-90	4.9 Bq/l
	Pu-239/Pu-240	0.6 Bq/l
	Am-241	0.7 Bq/l
	Co-60	40 Bq/l
	Cs-134	7.2 Bq/l
	Cs-137	11 Bq/l
	I-131	6.2 Bq/l

Table 2

Performance characteristics and methods of analysis

Parameters and radionuclides	Limit of detection(1) (2)
(1) The limit of detection is calculated according to the ISO standard 11929: Determination of the characteristic limits (decision threshold, detection limit and limits of the confidence interval) for measurements of ionising radiation – Fundamentals and application, with probabilities of errors of 1st and 2nd kind of 0.05 each.
(2) Measurement uncertainties are calculated and reported as complete standard uncertainties, or as expanded standard uncertainties with an expansion factor of 1.96, according to the ISO Guide for the Expression of Uncertainty in Measurement.
(3) The limit of detection for tritium and for radon is 10% of its parametric value of 100 Bq/l.
(4) The limit of detection for gross alpha activity and gross beta activities are 40% of the screening values of 0.1 and 1.0 Bq/l respectively.
(5) This limit of detection applies only to initial screening for indicative dose for a new water source. If initial checking indicates that it is not plausible that Ra-228 exceeds 20% of the derived concentration, the limit of detection may be increased to 0.08 Bq/l for routine Ra-228 nuclide specific measurements, until a subsequent re-check is required.
Tritium	10 Bq/l (3)
Radon	10 Bq/l (3)
gross alpha activity gross beta activity	0.04 Bq/l (4) 0.4 Bq/l (4)
U-238	0.02 Bq/l
U-234	0.02 Bq/l
Ra-226	0.04 Bq/l
Ra-228	0.02 Bq/l (5)
Pb-210	0.02 Bq/l
Po-210	0.01 Bq/l
C-14	20 Bq/l
Sr-90	0.4 Bq/l
Pu-239/Pu-240	0.04 Bq/l
Am-241	0.06 Bq/l
Co-60	0.5 Bq/l
Cs-134	0.5 Bq/l
Cs-137	0.5 Bq/l
I-131	0.5 Bq/l