Sizing of the Chamber System

Sizing of the Chamber System. 1. Chamber systems installed in a trench configuration shall be sized in accordance with Table 9. 2. Chamber systems installed in a bed configuration shall have the same number of chamber sections as indicated for a trench system. The length and width of the bed to be constructed will depend on the number of chamber sections to be installed as indicated by Table 9. Any side-by-side placement of chambers shall constitute a bed: a. Absorption beds and trenches should be located a minimum of 10 feet from any trees. b. The bottom of the bed should have a relatively level grade; the grade within the bed shall not exceed the grade allowed for trench installations. c. The chambers shall be placed side by side in a bed with separation between each chamber row per individual manufacturer’s requirements. d. Care should be taken to prevent heavy machinery from damaging the bed during backfilling. e. The effluent must be equally distributed to the bed by means of a distribution box or with a pipe manifold. Source: Miss. Code Ann. § 41-67-3. TABLE 3 - SETBACK REQUIREMENTS FROM SENSITIVE WATER Minimum Distance from the Water Edge Soil Textural Class Slope of Less Than 8 Percent Slope of More Than 8 Percent Gravel NOT APPLICABLE Coarse Sand 50 feet 50 feet Medium Sand 50 feet 50 feet Fine Sand 50 feet 50 feet Loamy Sand 50 feet 50 feet Sandy Loam 50 feet 50 feet Light Loam 50 feet 50 feet Heavy Loam 50 feet 50 feet Silt Loam 50 feet 50 feet Sandy Clay Loam 50 feet 50 feet Light Clay Loam 50 feet 50 feet Heavy Clay Loam 50 feet 50 feet Light Silty Clay Loam 50 feet 50 feet Heavy Silty Clay Loam 50 feet 50 feet Sandy Clay 50 feet 50 feet Silty Clay 50 feet 50 feet Clay 50 feet 50 feet The effluent disposal setback is based on the soil texture of the horizon in which the absorption trench or bed is to be placed. These setbacks are to be used on all individual on-site wastewater disposal systems except spray irrigation disposal and overland discharge. Source: Miss. Code Ann. § 41-67-3. TABLE 4 - SIZING: AGGREGATE REPLACEMENT (Large Diameter Pipe) Results of the Soil and Site Evaluation Soil Textural Class Ribbon Lengths (Inches) Application Rate GPD/ Ft2 ** Absorption Area Per Bedroom*** Additional Absorption Area Over 2 Persons Per Bedroom*** Ft2 Lf* Ft2 Lf* 6” 8” 10” 6” 8” 10” 6” 8” 10” 6” 8” 10” Gravel - - NOT SUITABLE Coarse Sand - 1.2 Medium Sand - 1.2 Fine Sand - 0.8 Loamy Sand - 0.8 Sandy Loam <.5 0.6 Light Loam <.5 0.6 Heavy Loam .5 – 1 0.45 Silt Loam <1 0.45 Sandy Clay Loam 1 – 2 0.45 Light Clay Loam 1 – 1.5 0.30 Heavy Clay Loam 1.5 – 2.0 0.20 Light Silty Clay Loam 1 – 1.5 0.30 Heavy Silty Clay Loam 1.5 – 2.0 0.20 Sandy Clay >2.0 - NOT SUITABLE Silty Clay >2.0 - NOT SUITABLE Clay >2.0 - NOT SUITABLE Minimum and maximum trench widths are 24 and 36 inches, respectively. *Linear footages assume 24 inch 36-inch trench width. **Application rate assumes 10” pipe. *** Bedroom is equivalent to 130 gallons per day. Source: Miss. Code Ann. § 41-67-3. TABLE 5 – SIZING: AGGREGATE REPLACEMENT (Multi-Pipe System) Results of the Soil and Site Evaluation Soil Textural Class Ribbon Lengths (Inches) Absorption Area Per Bedroom** Additional Absorption Over 2 Person Per Bedroom** MPS -14 & 36XX*** MPS-13 MPS-11 MPS-9 MPS-14 & 36XX*** MPS-13 MPS-11 MPS-9 Ft2 Lf Lf Lf Lf Ft2 Lf Lf Lf Lf Gravel - NOT SUITABLE Coarse Sand - Medium Sand - Fine Sand - Loamy Sand - Sandy Loam <.5 Light Loam <.5 Heavy Loam .5 – 1 Silt Loam <1 Sandy Clay Loam 1 – 2 Light Clay Loam 1 – 1.5 Heavy Clay Loam 1.5 – 2.0 Light Silty Clay Loam 1 – 1.5 Heavy Silty Clay Loam 1.5 – 2.0 Sandy Clay >2.0 NOT SUITABLE Silty Clay >2.0 NOT SUITABLE Clay >2.0 NOT SUITABLE Minimum and maximum trench widths are 24 and 36 inches, respectively. ** Bedroom is equivalent to 130 gallons per day. ***XX represents either 9, 11, or 14 pipes. Note – A design using a GPD value rather than a bedroom number may be converted to a bedroom equivalent by dividing the GPD value by 130, then using that bedroom equivalent value to determine the required disposal area. Source: Miss. Code Ann. § 41-67-3. TABLE 6 - SIZING: AGGREGATE REPLACEMENT (Expanded Polystyrene System) “Horizontal” Configuration Results of the Soil and Site Evaluation Soil Textural Class Ribbon Lengths (Inches) Absorption Area Per Bedroom** Additional Absorption Over 2 Person Per Bedroom** 3-10H 1-12 2-12 3-12 1-14 3-10H 1-12 2-12 3-12 1-14 Ft2 Lf Lf Lf Lf Lf Ft2 Lf Lf Lf Lf Lf Gravel - NOT SUITABLE Coarse Sand - Medium Sand - Fine Sand - Loamy Sand - Sandy Loam <.5 Light Loam <.5 Heavy Loam .5 – 1 Silt Loam <1 Sandy Clay Loam 1 – 2 Light Clay Loam 1 – 1.5 Heavy Clay Loam 1.5 – 2.0 Light Silty Clay Loam 1 – 1.5 Heavy Silty Clay Loam 1.5 – 2.0 Sandy Clay >2.0 NOT SUITABLE Silty Clay >2.0 NOT SUITABLE Clay >2.0 NOT SUITABLE Minimum and maximum trench widths are 24 and 36 inches, respectively. ** Bedroom is equivalent to 130 gallons per day. Note – A design using a GPD value rather than a bedroom number may be converted to a bedroom equivalent by dividing the GPD value by 130, then using that bedroom equivalent value to determine the required disposal area. Source: Miss. Code Ann. § 41-67-3. TABLE 7 - SIZING: AGGREGATE REPLACEMENT (Expanded Polystyrene System) “Triangular” Configuration Results of the Soil and Site Evaluation Soil Textural Class Ribbon Lengths (Inches) Application Rate GPD/ Ft2 Absorption Area Per Bedroom** Additional Absorption Over 2 Person Per Bedroom** 3-10 Inch 3-10 Inch Ft2 Lf Ft2 Lf Gravel - - NOT SUITABLE Coarse Sand - 2.41 Medium Sand - 2.41 Fine Sand - 1.57 Loamy Sand - 1.57 Sandy Loam <.5 1.19 Light Loam <.5 1.19 Heavy Loam .5 – 1 0.89 Silt Loam <1 0.89 Sandy Clay Loam 1 – 2 0.89 Light Clay Loam 1 – 1.5 0.60 Heavy Clay Loam 1.5 – 2.0 0.40 Light Silty Clay Loam 1 – 1.5 0.60 Heavy Silty Clay Loam 1.5 – 2.0 0.40 Sandy Clay >2.0 - NOT SUITABLE Silty Clay >2.0 - NOT SUITABLE Clay >2.0 - NOT SUITABLE Minimum and maximum trench widths are 24 and 36 inches, respectively. The Triangular Configuration can only be installed in a trench. ** Bedroom is equivalent to 130 gallons per day. Source: Miss. Code Ann. § 41-67-3. TABLE 8 - CHAMBER SYSTEM CLASSIFICATIONS CLASS SQUARE FEET/CHAMBER SECTION I 7.51 – 9.50 II 9.51 – 11.50 III 11.51 – 13.50 IV 13.51 – 15.50 V 15.51 – 17.50 VI 17.51 – 19.50 VII 19.51 – 21.50 VIII 21.51 – 23.50 Source: Miss. Code Ann. § 41-67-3. TABLE 9 - SIZING: AGGREGATE REPLACEMENT (Chamber System) Results of the Soil and Site Evaluation Soil Textural Class Ribbon Lengths (Inches) Application Rate GPD/ Ft2 Absorption Area in Ft2 Per Bedroom** Number of Pieces Per Bedroom based on Chamber Class** Additional Pieces Over 2 Persons Per Bedroom Based on Chamber Class** I II III IV I II III IV Gravel - - NOT SUITABLE Coarse Sand - 1.71 Medium Sand - 1.71 Fine Sand - 1.13 Loamy Sand - 1.13 Sandy Loam <.5 0.85 Light Loam <.5 0.85 Heavy Loam .5 – 1 0.64 Silt Loam <1 0.64 Sandy Clay Loam 1 – 2 0.64 Light Clay Loam 1 – 1.5 0.43 Heavy Clay Loam 1.5 – 2.0 0.29 Light Silty Clay Loam 1 – 1.5 0.43 Heavy Silty Clay Loam 1.5 – 2.0 0.29 Sandy Clay >2.0 - NOT SUITABLE Silty Clay >2.0 - NOT SUITABLE Clay >2.0 - NOT SUITABLE Minimum and maximum trench widths are 18 and 36 inches, respectively. ** Bedroom is equivalent to 130 gallons per day. Source: Miss. Code Ann. § 41-67-3. FIGURE 13 – Top View of Connecting Laterals for Large Diameter Pipes Source: Miss. Code Ann. § 41-67-3. FIGURE 14 – Connection Laterals of Multi-pipe System, Expanded Polystyrene System, and Chamber System