N.H. Code Admin. R. Env-Wq 1703.25
(a) Subject to (b) through (d), below, to determine freshwater acute aquatic life criteria for ammonia, in milligrams of nitrogen per liter (mg N/L), the applicant shall use:
(b) The freshwater acute water quality criteria for ammonia in Table 1703-4A where salmonids in the genus Oncorhynchus are or might be present shall be calculated by taking the lesser of the value resulting from dividing 0.275 by the sum of one plus 10 raised to the power of 7.204 minus the pH, and adding the resulting value to the value found by dividing 39.0 by the sum of one plus 10 raised to the power of the pH minus 7.204, to the value resulting from dividing 0.0114 by the sum of one plus 10 raised to the power of the 7.204 minus pH, and adding the resulting value found by dividing 1.6181 by the sum of one plus 10 raised to the power of the pH minus 7.204 and multiplying this value by 0.7249 multiplied by the value resulting from multiplying 23.12 by 10 raised to the power of 0.036 multiplied by value of 20 minus the temperature, as shown in the following equation:
Freshwater Acute Criteria, Salmonids in the Genus Onchorhynchus Present =
MIN { [0.275 / (1+10 7.204-pH) + 39.0 / (1+10 pH-7.204)],
[0.7249 x[0.0114/(1+10 7.204-pH) + 1.6181 / (1+10 pH-7.204)] x (23.12 x 10 0.036 x(20-T))] }
Where MIN indicates the lesser of the two values separated by a comma.
(c) The freshwater acute water quality criteria for ammonia in Table 1703-4B where salmonids in the genus Oncorhynchus are absent shall be calculated by dividing 0.0114 by the sum of one plus 10 raised to the power of 7.204 minus the pH, and adding the resulting value to the value found by dividing 1.6181 by the sum of one plus 10 raised to the power of the pH minus 7.204, and multiplying this value by 0.7249 multiplied by the lesser of 51.93 or the value resulting from multiplying 23.12 by 10 raised to the power of 0.036 multiplied by value of 20 minus the temperature as shown in the following equation:
Freshwater Acute Criteria, Salmonids in the Genus Onchorhynchus Absent =
{0.7249 x[0.0114/(1+10 7.204-pH) + 1.6181 / (1+10 pH-7.204)]} x MIN [ 51.93, (23.12 x 10 0.036 x(20-T))]
Where MIN indicates the lesser of the 2 values separated by a comma.
(e) Table 1703-4A and Table 1703-4B shall be as follows:
Table 1703-4A: Freshwater Acute Aquatic Life Criteria For Ammonia in mg N/L
Salmonids in the Genus Oncorhynchus Present
pH
Temperature, Degrees C
0-14
15
16
18
20
22
24
26
28
30
6.5
33
33
32
27
23
19
16
14
12
9.9
6.6
31
31
30
26
22
18
16
13
11
9.5
6.7
30
30
29
24
21
18
15
13
11
9.0
6.8
28
28
27
23
20
17
14
12
10
8.5
6.9
26
26
25
21
18
15
13
11
9.4
7.9
7.0
24
24
23
20
17
14
12
10
8.6
7.3
7.1
22
22
21
18
15
13
11
9.3
7.9
6.7
7.2
20
20
19
16
14
12
9.8
8.3
7.1
6.0
7.3
18
18
17
14
12
10
8.7
7.4
6.3
5.3
7.4
15
15
15
13
11
9.0
7.7
6.5
5.5
4.7
7.5
13
13
13
11
9.2
7.8
6.6
5.6
4.8
4.0
7.6
11
11
11
9.3
7.9
6.7
5.7
4.8
4.1
3.5
7.7
9.6
9.6
9.3
7.9
6.7
5.7
4.8
4.1
3.5
3.0
7.8
8.1
8.1
7.9
6.7
5.6
4.8
4.0
3.4
2.9
2.5
7.9
6.8
6.8
6.6
5.6
4.7
4.0
3.4
2.9
2.4
2.1
8.0
5.6
5.6
5.4
4.6
3.9
3.3
2.8
2.4
2.0
1.7
8.1
4.6
4.6
4.5
3.8
3.2
2.7
2.3
2.0
1.7
1.4
8.2
3.8
3.8
3.7
3.1
2.7
2.3
1.9
1.6
1.4
1.2
8.3
3.1
3.1
3.1
2.6
2.2
1.9
1.6
1.3
1.1
0.96
8.4
2.6
2.6
2.5
2.1
1.8
1.5
1.3
1.1
0.93
0.79
8.5
2.1
2.1
2.1
1.8
1.5
1.3
1.1
0.90
0.77
0.65
8.6
1.8
1.8
1.7
1.5
1.2
1.0
0.88
0.75
0.63
0.54
8.7
1.5
1.5
1.4
1.2
1.0
0.87
0.74
0.62
0.53
0.45
8.8
1.2
1.2
1.2
1.0
0.86
0.73
0.62
0.52
0.44
0.37
8.9
1.0
1.0
1.0
0.85
0.72
0.61
0.52
0.44
0.37
0.32
9.0
0.88
0.88
0.86
0.73
0.62
0.52
0.44
0.37
0.32
0.27
Table 1703-4B: Freshwater Acute Aquatic Life Criteria For Ammonia in mg N/L,
Salmonids in the Genus Oncorhynchus Absent
pH
Temperature, Degrees C
0-10
12
14
16
18
20
22
24
26
28
30
6.5
51
44
37
32
27
23
19
16
14
12
9.9
6.6
49
42
36
30
26
22
18
16
13
11
9.5
6.7
46
40
34
29
24
21
18
15
13
11
9.0
6.8
44
38
32
27
23
20
17
14
12
10
8.5
6.9
41
35
30
25
21
18
15
13
11
9.4
7.9
7.0
38
33
28
23
20
17
14
12
10
8.6
7.3
7.1
34
30
25
21
18
15
13
11
9.3
7.9
6.7
7.2
31
27
23
19
16
14
12
9.8
8.3
7.1
6.0
7.3
27
24
20
17
14
12
10
8.7
7.4
6.3
5.3
7.4
24
21
18
15
13
11
9.0
7.7
6.5
5.5
4.7
7.5
21
18
15
13
11
9.2
7.8
6.6
5.6
4.8
4.0
7.6
18
15
13
11
9.3
7.9
6.7
5.7
4.8
4.1
3.5
7.7
15
13
11
9.3
7.9
6.7
5.7
4.8
4.1
3.5
2.9
7.8
13
11
9.3
7.9
6.7
5.6
4.8
4.0
3.4
2.9
2.5
7.9
11
9.1
7.7
6.6
5.6
4.7
4.0
3.4
2.9
2.4
2.1
8.0
8.8
7.6
6.4
5.4
4.6
3.9
3.3
2.8
2.4
2.0
1.7
8.1
7.2
6.3
5.3
4.5
3.8
3.2
2.7
2.3
2.0
1.7
1.4
8.2
6.0
5.2
4.4
3.7
3.1
2.7
2.3
1.9
1.6
1.4
1.2
8.3
4.9
4.3
3.6
3.1
2.6
2.2
1.9
1.6
1.3
1.1
0.96
8.4
4.1
3.5
3.0
2.5
2.1
1.8
1.5
1.3
1.1
0.93
0.79
8.5
3.3
2.9
2.4
2.1
1.8
1.5
1.3
1.1
0.90
0.77
0.65
8.6
2.8
2.4
2.0
1.7
1.5
1.2
1.0
0.88
0.75
0.63
0.54
8.7
2.3
2.0
1.7
1.4
1.2
1.0
0.87
0.74
0.62
0.53
0.45
8.8
1.9
1.7
1.4
1.2
1.0
0.86
0.73
0.62
0.52
0.44
0.37
8.9
1.6
1.4
1.2
1.0
0.85
0.72
0.61
0.52
0.44
0.37
0.32
9.0
1.4
1.2
1.0
0.86
0.73
0.62
0.52
0.44
0.37
0.32
0.27
Source. (See Revision Notes #1, #2, and #3 at chapter heading for Env-Wq 1700) #12042, eff 12-1-16; ss by #14203, eff 2-26-25