Illinois Administrative Code
Title 77 - PUBLIC HEALTH
Part 905 - PRIVATE SEWAGE DISPOSAL CODE
Appendix A - Illustrations and Exhibits
ILLUSTRATION H - Subsurface Seepage System Size Determination
Exhibit B - Gravelless System
Universal Citation: 77 IL Admin Code ยง B
Current through Register Vol. 48, No. 12, March 22, 2024
Time (minutes) required for last 6 inches of water to fall |
FOR RESIDENTIAL USE Required Absorption Area (sq ft)/bedroom) |
FOR INSTITUTIONAL OR COMMERCIAL USE Allowable application rate (GPD/sq ft) (5) |
Recommended depth from bottom of the trench to the limiting layer |
|||
8 inch |
10 inch |
8 inch |
10 inch |
|||
18 - 60 |
100 |
70 |
2.00 |
3.00 |
||
90 |
105 |
70 |
1.90 |
2.86 |
3 feet |
|
120 |
120 |
80 |
1.66 |
2.50 |
||
150 |
135 |
90 |
1.48 |
2.22 |
||
180 |
145 |
100 |
1.38 |
2.00 |
||
240 |
160 |
110 |
1.25 |
1.82 |
||
300 |
175 |
120 |
1.14 |
1.66 |
2 feet |
|
360 |
195 |
130 |
1.0 |
1.54 |
||
NOTE: |
||||||
1. |
Over 360 is unsuitable for subsurface seepage systems. |
|||||
2. |
Under 18 is unsuitable for subsurface seepage systems. |
|||||
3. |
Divide the required total gallons per day by this number to get the number of lineal feet required. |
Disclaimer: These regulations may not be the most recent version. Illinois may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.