Wis. Admin. Code Department of Natural Resources NR 102.26

Current through September 30, 2024

Section NR 102.26 - Site-specific ambient temperatures

(1) DEVELOPMENT OF SITE-SPECIFIC AMBIENT TEMPERATURES. An owner or operator of a facility with a discharge subject to regulation under this chapter may submit a request to the department for the determination of a site-specific ambient temperature. The department may approve, disapprove or approve with modifications the request for the site-specific ambient temperature. The request for site-specific ambient temperatures shall include all of the following:

(a) A demonstration that the data used to derive the ambient temperatures in s. NR 102.25 do not apply to the specific water segment or body in question.

(b) Site-specific water temperature that represents the ambient temperature of the site. For purposes of this paragraph, data must be:

1. Collected daily using a continuous recorder or similar device that takes measurements at least hourly, except as follows:

a. Monthly data sets may be missing no more than 10 days of temperature data for the months of December through February,

b. Monthly data sets may be missing no more than 5 days of temperature data for the months of March through November.

2. Collected for each month in which the request for site-specific ambient temperatures is requested,

3. Collected at any time since October 1987,

4. Collected for at least 2 consecutive years.

(c) Calculated daily average temperatures from the data from par. (b).

(d) Calculated monthly average temperatures from the daily average temperatures in par. (c) for each individual month that data has been collected. Alternatively, calculated monthly average temperatures directly from the data from par. (b) for each individual month.

(e) All individual monthly averages organized by month.

(f) A determination of the monthly site-specific ambient temperatures by calculating the geometric mean of all monthly averages for each given month.

(g) Alternative methods for developing site-specific ambient temperatures, if the department approves the method as representative of ambient temperatures as those in pars. (a) to (d).

(2) USE OF SITE-SPECIFIC AMBIENT TEMPERATURES TO ESTABLISH ACUTE CRITERIA. Once site-specific ambient temperatures have been approved by the department in accordance with sub. (1), the acute water quality criteria listed in Table 6 will be applicable for the protection of fish and other aquatic life.

(3) USE OF SITE-SPECIFIC AMBIENT TEMPERATURES TO ESTABLISH SUB-LETHAL CRITERIA. Once site-specific ambient temperatures have been approved by the department in accordance with sub. (1), the sub-lethal water quality criteria applicable for the protection of fish and other aquatic life shall be calculated as follows:

(a) Use Table 7 to determine the appropriate sub-lethal criteria for the fish and other aquatic life use.

(b) Modify the sub-lethal criteria as follows:

1. If a sub-lethal criterion from par. (a) is less than the site-specific ambient temperature from sub. (1) for a given month, increase the sub-lethal criterion to be equal with the site-specific ambient temperature.

2. If a sub-lethal criterion from par. (a) is greater than an acute criterion for a given month from sub. (2) decrease the sub-lethal criterion to be equal with the acute criterion.

(c) Perform a fifth order polynomial regression of the 12 monthly sub-lethal criteria resulting from par. (b). Using the resulting equation of the regression, calculate the final sub-lethal criteria for each month by replacing the "x" variables in the equation with a numeric representation for each month, where January "x" = 1, for February "x" = 2, ... and for December "x" = 12.

(d) The final sub-lethal criteria from par. (c) shall be used in combination with the site-specific ambient temperatures developed in sub. (1) and the acute criteria determined in sub. (2).

Table 6

Acute Criteria Across All Ambient Temperatures

(All values are expressed as degrees Fahrenheit)

Inland Waters					Great Lakes Waters
1	2	3	4	5	6	7	8	9	10	11	12
Ta	Cold	Warm	LFF	N Lake	S Lake	SGB	NGB	NLKMI	SLKMI	LKSUP	CB
32	68	75	77	75	76	74	69	69	69	68	68
33	68	76	77	76	76	74	69	69	69	69	69
34	68	76	77	76	76	75	69	69	69	69	69
35	68	76	77	76	77	75	69	69	69	69	69
36	68	76	78	76	77	75	70	69	69	69	69
37	69	77	78	77	77	75	70	70	70	69	69
38	69	77	78	77	77	76	70	70	70	69	69
39	69	77	79	77	78	76	71	70	70	70	70
40	69	77	79	77	78	76	71	70	70	70	70
41	69	78	79	78	78	77	71	70	70	70	70
42	69	78	79	78	78	77	71	70	70	70	70
43	69	78	80	78	78	77	71	70	70	70	70
44	70	78	80	78	79	78	71	71	71	71	71
45	70	79	80	79	79	78	71	71	71	71	71
46	70	79	80	79	79	78	72	72	72	71	71
47	70	79	81	79	80	79	72	72	72	71	71
48	70	79	81	79	80	79	72	72	72	72	72
49	70	79	81	80	80	79	73	72	72	72	72
50	70	80	81	80	80	79	73	73	73	72	72
51	71	80	82	80	81	80	73	73	73	72	72
52	71	80	82	80	81	80	73	73	73	72	72
53	71	80	82	81	81	80	74	73	73	72	72
54	71	81	82	81	81	80	74	73	73	73	73
55	71	81	83	81	82	81	74	73	73	73	73
56	72	81	83	81	82	81	75	73	73	73	73
57	72	82	83	82	82	81	75	73	73	73	73
58	72	82	83	82	82	81	75	74	74	73	73
59	72	82	84	83	83	81	76	74	74	74	74
60	72	82	84	83	83	82	76	74	74	74	74
61	72	83	84	83	83	82	77	75	75	74	74
62	72	83	84	83	84	82	77	75	75	75	75
63	73	83	85	84	84	82	78	76	76	75	75
64	73	84	85	84	85	82	78	77	77	76	76
65	73	84	85	84	85	83	78	77	77	76	76
66	73	84	85	85	85	83	79	78	78	77	77
67	74	84	86	85	85	83	79	78	78	77	77
68	74	85	86	85	85	83	80	79	79	78	78
69	74	85	86	85	86	83	80	79	79	78	78
70	74	85	86	86	86	83	81	80	80	79	79
71	74	85	87	86	86	84	81	81	81	79	79
72	75	85	87	86	86	84	82	81	81	80	80
73	75	85	87	86	86	84	82	82	82	80	80
74	75	86	87	86	87	84	82	82	82	81	81
75	75	86	88	87	87	85	83	83	83	81	81
76	86	88	87	87	85	83	83	83	82	82
77	87	88	87	87	85	84	84	84	83	83
78	87	88	87	88	86	84	84	84	83	83
79	87	89	88	88	86	84	84	84	83	83
80	87	89	88	88	86	84	84	84	83	83
81	88	89	88	88	86	84	84	84	83	83
82	88	89	88	89	87	84	84	84	84	84
83	88	90	89	89	87	84	84	84	84	84
84	88	90	89	89	88	85	85	85	84	84
85	89	90	89	89	88	85	85	85
86	89	90	89	90	89
87	89	91	90	90	89
88	90	91	90	90	89
89	90	91	90	91	89
90	91	91	91	91
91	91	92	91	92
92	92	92

1 Ta = ambient temperature

2 Cold = waters with a fish and other aquatic life use designation of "cold water community"

3 Warm = waters with a fish and other aquatic life use designation of "warm water sport fish community" or "warm water forage fish community"

4 LFF = waters with a designation of "limited forage fish community"

5 N Lake = applicable for those lakes north of State Highway 10

6 S Lake = applicable for those lakes south of State Highway 10

7 SGB = Green Bay waters south of the Brown County line to the Fox River mouth

8 NGB = Green Bay waters north of the Brown County line to the northernmost point on Washington Island

9 NLKMI = Lake Michigan waters north of the Milwaukee River mouth (downtown Milwaukee)

10 SLKMI = Lake Michigan waters south of the Milwaukee River mouth (downtown Milwaukee)

11 LKSUP = waters in Lake Superior except those in Chequamegon Bay

12 CB = Chequamegon Bay waters within the region enclosed by Chequamegon Point and a straight line west to the mainland

Table 7

Raw Monthly Sub-Lethal Criteria for Use In Determining Final Sub-Lethal Criteria with Site-Specific Ambient Temperatures

(All values are expressed as degrees Fahrenheit)

Month	C	W-L	W-S	LFF	NIL	SIL	MR	RR	UWR
January	47	50	50	54	50	50	50	50	50
February	45	50	50	54	50	50	50	50	50
March	53	54	54	54	54	54	54	54	54
April	59	65	65	64	63	64	65	65	65
May	59	70	70	75	70	70	70	70	70
June	67	72	72	75	72	72	72	72	72
July	68	74	74	75	75	74	74	74	74
August	68	78	78	77	77	77	78	78	78
September	52	87	87	92	87	87	87	87	87
October	52	54	54	54	54	54	54	54	54
November	50	50	50	54	50	50	50	50	50
December	46	50	50	54	50	50	50	50	50

Month	LWR	LFR	SGB	NGB	SLM	NLM	LS	CB
January	50	50	50	44	44	44	42	42
February	50	50	50	43	43	43	43	43
March	54	54	54	54	52	54	52	52
April	65	65	60	59	61	60	58	58
May	70	70	66	64	67	65	65	65
June	72	72	70	67	68	67	67	67
July	74	74	70	68	68	68	69	69
August	78	78	71	67	67	67	69	69
September	87	87	83	79	79	79	79	79
October	54	54	50	50	50	50	45	54
November	50	50	47	47	47	47	44	46
December	50	50	47	45	45	45	43	44

C = Cold = waters with a fish and other aquatic life use designation of "cold water community"

W-L = Warm -Large = waters with a fish and other aquatic life use designation of "warm water sport fish community" or "warm water forage fish community" and

unidirectional 7Q10 flows >= 200 cfs (129 mgd)

W-S = Warm - Small = waters with a fish and other aquatic life use designation of "warm water sport fish community" or "warm water forage fish community" and unidirectional 7Q10 flows < 200 cfs (129 mgd)

LFF = waters with a designation of "limited forage fish community"

NIL = Northern Inland Lakes = applicable for those lakes north of State Highway 10

SIL = Southern Inland Lakes = applicable for those lakes south of State Highway 10

MR = Mississippi River = applies to any portion of Wisconsin's Mississippi River reach

RR = Rock River = applies to waters downstream of Lake Koshkonong

UWR = Upper Wisconsin River = applies to waters upstream of Petenwell Dam

LWR = Lower Wisconsin River = applies to waters downstream of Petenwell Dam to the confluence with the Mississippi River

LFR = Lower Fox River = applies to waters downstream of the Lake Winnebago outlet

SGB = Green Bay waters south of the Brown County line to the Fox River mouth

NGB = Green Bay waters north of the Brown County line to the northernmost point on Washington Island

SLM = Lake Michigan waters south of the Milwaukee River mouth (downtown Milwaukee)

NLM = Lake Michigan waters north of the Milwaukee River mouth (downtown Milwaukee)

LS = Lake Superior = waters in Lake Superior except those in Chequamegon Bay

CB = Chequamegon Bay = waters within the region enclosed by Chequamegon Point and a straight line west to the mainland

Wis. Admin. Code Department of Natural Resources NR 102.26

CR 07-111: cr. Register September 2010 No. 657, eff. 10-1-10; renumbering of (1) (b) 1. a. and b. made under s. 13.92(4) (b) 1, Stats., Register September 2010 No. 657.