SOIL ABSORPTION / PERCOLATION RATES AND CORRESPONDING ABSORPTION AREA REQUIREMENTS
Absorption / Percolation | Absorption Area (As Trench Bottom Rates Area) | |
(mpi) | (ft2/gallon) | (ft2/bedroom) |
10 | 1.2 | 165 |
15 | 1.4 | 190 |
30 | 2.0 | 250 |
45 | 2.5 | 300 |
60 | 2.9 | 330 |
75 | 3.2 | 370 |
80 | 3.3 | 380 |
85 | 3.4 | 390 |
90 | 3.5 | 400 |
95 | 3.6 | 415 |
100 | 3.7 | 430 |
105 | 3.8 | 445 |
NOTE: Round percolation rates to next highest increment of five (5).
NOTE: Trenches of two (2) to three (3) feet in width are preferred. For trenches greater than three(3) feet in width, increase the absorption area by the following factors:
Trench Width | Factor |
4 ft | 1.33 |
6 ft | 1.50 |
8 ft | 1.60 |
EXAMPLES:
NOTE: Flow rates for non-residential establishments shall be based on the memo from Kent D.
Taylor to the Division of Ground Water Protection Field Office Managers dated July 8, 1993, regarding expected sewage flow from non-residential establishments.
Tenn. Comp. R. & Regs. 1200, 1200-01, ch. 1200-01-06, app II