6. The minimum sampling and analysis frequency for the monitoring of radon, tritium and indicative dose in water (where required by this schedule) from a private water supply system or from a tanker or used in a food production undertaking is set out in the following table.
| Volume of water (in m3) distributed or produced each day within a supply zone (Note 1) | Number of samples per year (Notes 2 and 3) | |
|---|---|---|
| > 0 | ≤ 100 | 1 |
| > 100 | ≤ 1,000 | 1 |
| > 1,000 | ≤ 10,000 | 1, plus 1 for each 3,300 m3/day and part thereof of the total volume |
| > 10,000 | ≤ 100,000 | 3, plus 1 for each 10,000 m3/day and part thereof of the total volume |
| > 100,000 | 10, plus 1 for each 25,000 m3/day and part thereof of the total volume | |
| Note 1: The volumes are calculated as averages taken over a year. The number of inhabitants in a supply zone may be used instead of the volume of water to determine the minimum frequency, assuming water consumption of 200 litres/day per person. | ||
| Note 2: As far as possible, the number of samples must be distributed equally in time and location. | ||
| Note 3: In the event of intermittent short-term supply the monitoring frequency of water distributed by tankers must be decided by each enforcing authority in relation to the water. | ||