(a) Dissolved metal shall be determined by multiplying total recoverable metal by the conversion factor listed in Table 1703-2 for that metal, shown in equation form as follows: Dissolved Metal = Total Recoverable Metal x Conversion Factor
(b) Total recoverable metals shall be determined by dividing dissolved metals by the conversion factor listed in table 1703-2, shown in equation form as follows: Total Recoverable Metal = Dissolved Metal / Conversion Factor
(c) The conversion factors in Table 1703-2 shall be used as translators to go from the dissolved metals criteria listed in Table 1703-1 to permit limits expressed as total recoverable metals by dividing dissolved metal by the conversion factor.(d) If the hardness of the receiving water is different than 20 mg/l, then aquatic life criteria for hardness-dependent metals shall be calculated as follows: (1) The equations in Env-Wq 1703.24(a) and (b) shall be used in conjunction with the coefficients shown in Table 1703-3 to calculate the total recoverable metal for freshwater;(2) The equations shown in (a) and (b), above, shall be used in conjunction with the factors shown in Table 1703-2 to convert total recoverable metal to dissolved metal or dissolved metal to total recoverable metal;(3) For hardness less than 20 mg/l, a hardness of 20 mg/l shall be used in the equations; and(4) For hardness values greater than 400 mg/l, a hardness of 400 mg/l shall be used in the equations.(e) Table 1703-2 shall be as follows, provided that the conversion factors for cadmium and lead shall be no greater than 1.0: Table 1703-2: Factors to Convert Total Recoverable Metals to Dissolved Metals
| FRESHWATER Conversion Factors | MARINE Conversion Factors |
Acute | Chronic | Acute | Chronic |
Arsenic | 1.0 | 1.0 | 1.0 | 1.0 |
Cadmium | 1.136672 - [(Ln Hardness)(0.041838)] | 1.101672 - [(Ln Hardness)(0.041838)] | 0.994 | 0.994 |
Chromium (+3) | 0.316 | 0.860 | - | - |
Chromium (+6) | 0.982 | 0.962 | 0.993 | 0.993 |
Copper | 0.960 | 0.960 | 0.83 | 0.83 |
Lead | 1.46203 - [(Ln Hardness)(0.145712)] | 1.46203 - [(Ln Hardness)(0.145712)] | 0.951 | 0.951 |
Mercury | 0.85 | 0.85 | 0.85 | 0.85 |
Nickel | 0.998 | 0.997 | 0.990 | 0.990 |
Selenium | - | - | 0.998 | 0.998 |
Silver | 0.85 | - | 0.85 | - |
Zinc | 0.978 | 0.986 | 0.946 | 0.946 |
N.H. Admin. Code § Env-Wq 1703.23
(See Revision Note #1 at chapter heading for Env-Wq 1700) #7151, eff 12-10-99; ss by #9034, INTERIM, eff 12-10-07; ss by #9162, eff 5-21-08 (See Revision Note #2 at chapter heading for Env-Wq 1700)
Amended by Volume XXXVI Number 49, Filed December 8, 2016, Proposed by #12042, Effective 12/1/2016, Expires 12/1/2026.