R 323.1070 Temperature of Great Lakes and connecting waters.

Rule 70. (1) The Great Lakes and connecting waters shall not receive a heat load which would warm the receiving water at the edge of the mixing zone more than 3 degrees Fahrenheit above the existing natural water temperature. (2) The Great Lakes and connecting waters shall not receive a heat load which would warm the receiving water at the edge of the mixing zone to temperatures in degrees Fahrenheit higher than the following monthly maximum temperature: (a) Lake Michigan north of a line due west from the city of Pentwater. J F M A M J J A S O N D 40 40 40 50 55 70 75 75 75 65 60 45 (b) Lake Michigan south of a line due west from the city of Pentwater. J F M A M J J A S O N D 45 45 45 55 60 70 80 80 80 65 60 50 (c) Lake Superior and the St. Marys river: J F M A M J J A S O N D 38 36 39 46 53 61 71 74 71 61 49 42 (d) Lake Huron north of a line due east from Tawas point: J F M A M J J A S O N D 40 40 40 50 60 70 75 80 75 65 55 45 (e) Lake Huron south of a line due east from Tawas point, except Saginaw bay. J F M A M J J A S O N D 40 40 40 55 60 75 80 80 80 65 55 45 (f) Lake Huron, Saginaw bay: J F M A M J J A S O N D 45 45 45 60 70 75 80 85 78 65 55 45 (g) St. Clair river: J F M A M J J A S O N D 40 40 40 50 60 70 75 80 75 65 55 50 (h) Lake St. Clair: J F M A M J J A S O N D 40 40 45 55 70 75 80 83 80 70 55 45 (i) Detroit river: J F M A M J J A S O N D 40 40 45 60 70 75 80 83 80 70 55 45 (j) Lake Erie: J F M A M J J A S O N D 45 45 45 60 70 75 80 85 80 70 60 50