Drinking Water Chemistry WS Proficiency Study Schedule
| 2024 WS Drinking Water Chemistry PT Study Schedule | ||
| Study Number | Study Opens | Study Closes |
| WS-137 | Jan. 8, 2024 | Feb. 21, 2024 |
| WS-138 | April 3, 2024 | May 17, 2024 |
| WS-139 | July 2, 2024 | Aug. 15, 2024 |
| WS-140 | Oct. 15, 2024 | Nov. 28, 2024 |
Analyte
| Arsenic | 5-50 ug/L |
| Barium | 500-3000 ug/L |
| Cadmium | 2-50 ug/L |
| Chromium | 10-200 ug/L |
| Lead | 5-100 ug/L |
| Lithium | 10-50 ug/L |
| Selenium | 10-100 ug/L |
| Copper | 50-2000 ug/L |
| Antimony | 6-50 ug/L |
| Beryllium | 2-20 ug/L |
| Nickel | 10-500 ug/L |
| Thallium | 2-10 ug/L |
| Vanadium | 50-1000 ug/L |
| Silver | 20-300 ug/L |
| Boron | 800-2000 ug/L |
| Aluminum | 130-1000 ug/L |
| Manganese | 40-900 ug/L |
| Molybdenum | 15-130 ug/L |
| Zinc | 200-2000 ug/L |
| Iron | 100-1800 ug/L |
