Radiation Tests in Greater Victoria's Drinking Water
Radiological Testing
Several radiological samples have been collected recently from the water entering the Greater Victoria Drinking Water System (PDF 
)and analyzed at SRC Analytical in Saskatoon.
These samples were collected in the Japan Gulch Water Treatment Plant (near Goldstream Park) from a tap located just upstream of the ultraviolet disinfection process. This water comes from Sooke Reservoir and enters the low level gates in the intake tower approximately 17 metres (55 ft) below the water surface.
The samples were tested for gross alpha and gross beta activity using the broad screening approach for radioactivity testing suggested in the Guidelines for Canadian Drinking Water Quality (PDF ) and for several of the artificial radionuclides that might be expected from the Japanese sources.
2011 Test Results
| Analyte | Units |
D.L.* |
30-Mar |
12-Apr |
19-May |
12-July |
27-Sept | 29-Nov | Limit |
|---|---|---|---|---|---|---|---|---|---|
| Gross Alpha | Bq/L |
0.02 |
<0.02 |
<0.02 |
0.02 |
<0.03 |
<0.04 | <0.02 | 0.5 |
| Gross Beta | Bq/L |
0.02 |
0.02 ± 0.01 |
<0.02 |
0.05 |
0.02±0.01 |
<0.04 | <0.02 | 1.0 |
| Cesium-134 | Bq/L |
0.4 |
Not tested |
<0.05 |
<0.4 |
<0.2 |
<0.2 | Not tested | 7** |
| Cesium-137 | Bq/L |
0.4 |
Not tested |
<0.07 |
<0.4 |
<0.08 |
<0.2 | Not tested | 10 |
| Iodine-131 | Bq/L |
0.9 |
Not tested |
<0.02 |
<0.9 |
<0.4 |
<0.2 | Not tested | 6 |
| Ruthenium-103 | Bq/L |
0.4 |
Not tested |
<0.06 |
<0.4 |
<0.2 |
<0.1 | Not tested | 200* |
< = Less than, Bq/L = Becquerel per litre, D.L. = Detection Limit
* = The detection limits for the May 19th sample changed from previous. On the report for the May 19th sample, SRC Analytical noted that "As a result of a detection limit study conducted in May 2011, the detection limits for gamma spectroscopy have increased".
** = Not an actual limit, but a calculated concentration based on adults consuming 2 L of water per day for a period of 1 year.
Alpha & Beta Emissions
Alpha emissions are generally associated with naturally occurring radionuclides. Beta emissions are generally associated with artificial radionuclides.
Water Quality Monitoring Program
The CRD Water Quality Division monitors gross alpha and gross beta emissions semi-annually as part of its on-going water quality monitoring program and has been doing so for more than a decade. These water quality results (PDF ) are posted on the CRD website.
Compliance with the Guidelines
All test results are well within the limits provided in the Guidelines for Canadian Drinking Water Quality for radiological parameters.
The results were compared to last year's radiological results and to those collected over the past 10 years. No change is indicated from previous year's results.
The radiological test results have been provided to Dr. Richard Stanwick, Chief Medical Health Officer, Vancouver Island Health Authority. He is satisfied that there are no radiological health concerns with Greater Victoria's Drinking Water at this time.
Additional Samples
Additional radiological samples will be collected and tested for radionuclides as part of the on-going water quality monitoring program during the period when there is some concern about radiation from Japan.
Radiological Information Links
For additional information, please contact:
Stewart Irwin, CRD Water Quality
Tel: 250.474.9603
email
Dr. Richard Stanwick, Chief Medical Health Officer, VIHA
Tel: 250.519.3406