74:53:01:32Alternative method of

determining required absorption trench system area. 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.

Source: 12 SDR 2, effective July 18, 1985; 13 SDR 129, 13 SDR 141, effective July 1, 1987; transferred from § 74:03:01:69, July 1, 1996.