N.H. Admin. Code § Env-Wq 1703.24

Current through Register No. 50, December 12, 2024

Section Env-Wq 1703.24 - Freshwater Aquatic Life Criteria For Metals

To calculate freshwater aquatic life criteria for total recoverable metals, the equations described in (a) and (b), below, shall be used in conjunction with the coefficients shown in (c), Table 1703-3, below, provided that the values used for hardness in the equations shall be as specified in Env-Wq 1703.23 (d):

(a) To calculate the acute criteria, in µg/l, for the metals shown Table 1703-3, the exponent "e" shall be raised to the power "x" where "x" is equal to the parenthetical expression "m_a" multiplied by the natural logarithm (ln) of the hardness and to which product the value "b_a" shall be added, as follows:

Acute Criteria = e^x where x = ( m_a [ ln (hardness) ] + b_a)

(b) To calculate the chronic criteria, in µg/l, for the metals shown in Table 1703-3, the exponent "e" shall be raised to the power "x" where "x" is equal to the parenthetical expression "m_c" multiplied by the natural logarithm of the hardness and to which product the value "b_c" shall be added, as follows:

Chronic Criteria = e^x where x = ( m_c[ ln (hardness) ] + b_c)

(c) Table 1703-3 shall be as follows:

Table 1703-3: Coefficients in Equations for Calculating Total Recoverable Aquatic Life Criteria for Metals

m_a	b_a	m_c	b_c
Cadmium	0.9789	-3.866	0.7977	-3.909
Copper	0.9422	-1.700	0.8545	-1.702
Chromium+3	0.8190	3.7256	0.8190	.6848
Lead	1.273	-1.460	1.273	-4.705
Nickel	0.8460	2.255	0.8460	0.0584
Silver	1.72	-6.59	----	----
Zinc	0.8473	0.884	0.8473	0.884

N.H. Admin. Code § Env-Wq 1703.24

(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.