5. Extreme values for the water quality in question shall not be taken into consideration when they are the result of unusual situations such as those due to heavy rain.
| Series of samples taken in any year | Maximum permitted number of samples which fail to conform |
|---|---|
| 4-7 | 1 |
| 8-16 | 2 |
| 17-28 | 3 |
| 29-40 | 4 |
| 41-53 | 5 |
| 54-67 | 6 |
| 68-81 | 7 |
| 82-95 | 8 |
| 96-110 | 9 |
| 111-125 | 10 |
| 126-140 | 11 |
| 141-155 | 12 |
| 156-171 | 13 |
| 172-187 | 14 |
| 188-203 | 15 |
| 204-219 | 16 |
| 220-235 | 17 |
| 236-251 | 18 |
| 252-268 | 19 |
| 269-284 | 20 |
| 285-300 | 21 |
| 301-317 | 22 |
| 318-334 | 23 |
| 335-350 | 24 |
| 351-365 | 25 |