Metal | Conversion Factors | |
Acute | Chronic | |
Arsenic | 1.000 | 1.000 |
Cadmium* | 0.944 | 0.909 |
Chromium (III) | 0.316 | 0.860 |
Chromium (VI) | 0.982 | 0.962 |
Copper | 0.960 | 0.960 |
Lead* | 0.791 | 0.791 |
Mercury | 0.85 | N/A |
Nickel | 0.998 | 0.997 |
Silver | 0.85 | N/A |
Zinc | 0.978 | 0.986 |
*Conversion factors for cadmium and lead are hardness dependent. The values shown are for a hardness of 100 mg/L as calcium carbonate (CaCO3). The methods for determining the conversion factors for cadmium and lead given the hardness are as follows:
Cadmium
Acute: Conversion Factor (CF) = 1.136672 - [ln (hardness) (0.041838)]
Chronic: CF = 1.101672 - [ln (hardness) (0.041838)]
Lead
Acute and Chronic: CF = 1.46203 - [ln (hardness) (0.145712)]
Minn. R. agency 167, ch. 7052, ANTIDEGRADATION, pt. 7052.0360
Statutory Authority: MS s 115.03; 115.44