22. Does the septic tank illustrated below need cleaning? ___________________
23. A septic tank system is to be installed to serve a small unit with an average
wastewater flow of 1500 gallons per day. A 2,500 gallon septic tank will be
installed. The soil percolation rate is 30 minutes per inch. Absorption trenches will
be 36 inches wide. Will this septic tank require a dosing tank? _____________
If so, how many siphons will be required? _______________________
24. A small unit requiring a septic tank system finds that the soil percolation rate
exceeds 60 minutes per inch. Which options may be used?
Sand filter trenches.
Subsurface sand filters.
25. Using the information described in exercise 24, what additional provision must be
made to the effluent?
Check Your Answers on Next Page