Absorption trench.
Omaha Municipal Code § 49-2169
in effectSec. 49-2169. - Absorption trench.
The required square footage for an absorption trench for a dwelling shall be determined by Table 49-2169 when a percolation test was performed:
Table 49-2169
Absorption Trench Requirements
Perc Rate in minutes per inch | 1 Bedroom 200 gpd | 2 Bedroom 300 gpd | 3 Bedroom 400 gpd | 4 Bedroom 500 gpd | 5 Bedroom 600 gpd | 6 Bedroom 700 gpd | 7 Bedroom 800 gpd | 8 Bedroom 900 gpd | 9 Bedroom 1,000 gpd
< 5 | Systems must be designed with a 12-inch loamy sand liner that would have a percolation rate of 15 to 20 minutes per inch and shall be designed at the 11-20 minute per inch level
5—10 | 165 | 330 | 495 | 660 | 825 | 990 | 1155 | 1320 | 1485
11—20 | 210 | 420 | 630 | 840 | 1050 | 1260 | 1470 | 1680 | 1890
21—30 | 250 | 500 | 750 | 1000 | 1250 | 1500 | 1750 | 2000 | 2250
31—40 | 275 | 550 | 825 | 1100 | 1375 | 1650 | 1925 | 2200 | 2475
41—50 | 330 | 660 | 990 | 1320 | 1650 | 1980 | 2310 | 2640 | 2970
51—60 | 350 | 700 | 1050 | 1400 | 1750 | 2100 | 2450 | 2800 | 3150
>60 | Systems be designed by a professional engineer. Construction Permit Needed.
The required square footage for establishments shall be determined by the following equation: The daily design flow divided by (Five divided by the square root of the percolation rate). sq. ft. = design flow (gpd) ÷ (5 ÷ √ percolation (min/in)).
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(Ord. No. 40524, § 1, 10-20-15)
Source: City of Omaha, Municipal Code and City Charter (Municode Library, library.municode.com)URL: https://library.municode.com/ne/omaha/codes/code_of_ordinances?nodeId=OMMUCOCHGEORVOII_CH49PL_ARTXXIPRSETRSY_DIV4CORE_S49-2169ABTRFetched: 10/28/2026