GRAY WATER SYSTEMS

Subpart 1. General. To qualify as a gray water system, the system must meet or exceed the following requirements: A. employ 60 percent of the flow values in parts 7080.1850 to 7080.1885 ; B. meet or exceed applicable technical requirements of parts 7080.1900 to 7080.2030 , 7080.2050 , and 7080.2100 , except as modified in this part; C. provide flow measurement if a pump is to be employed; D. meet or exceed the requirements of parts 7080.2210 to 7080.2230 ; E. meet or exceed requirements of part 7080.2150 , subparts 2 and 3; and F. meet the requirements of subparts 2 and 3. Subp. 2. Toilet waste. Toilet waste must not be discharged to a gray water system. Subp. 3. Sewage tank. The liquid capacity of a gray water septic tank serving a dwelling must be based on the number of bedrooms existing and anticipated in the dwelling served and shall be at least as large as the capacities given in Table X. TABLE X Number of bedrooms (gallons) Tank liquid capacity 3 or less 750 4 or 5 1,000 6 or 7 1,250 8 or 9 1,500 For ten or more bedrooms, the gray water septic tank shall be sized as: (1,500 + ((# of bedrooms - 9) x 150)).