In lieu of calculating the absorption trench system area according to §§ 74:53:01:30 and 74:53:01:31, the following criteria in Table 5 may be used for the design of individual or small on-site wastewater systems if the absorption trench system is of an area sufficient for at least three bedrooms. The absorption area shall be determined according to the following table:
TABLE 5
Percolation Rate | Minimum Absorption Trench Area |
(Minutes for water to drop one inch) | (Square feet of trench bottom per bedroom) |
1 but less than 5 minutes per inch | Not permitted--see § 74:53:01:33 |
5 but less than 10 minutes per inch | 125 square feet |
10 but less than 15 minutes per inch | 165 square feet |
15 but less than 30 minutes per inch | 200 square feet |
30 but less than 45 minutes per inch | 250 square feet |
45 but less than 55 minutes per inch | 300 square feet |
55 but no more than 60 minutes per inch | 350 square feet |
Over 60 minutes per inch | Not permitted--see § 74:53:01:33 |
The minimum absorption trench area, as shown in the above table, may be reduced in accordance with § 74:53:01:31 when the depth of fill material below the distribution pipe is 12 inches or greater.
S.D. Admin. R. 74:53:01:32
General Authority: SDCL 34A-2-93.
Law Implemented: SDCL 34A-2-20.