he reservoir), check for blockage in the drainpipe under the house. Similarly, if sewage runs into the bathtub when you flush the toilet, check the drain- pipe. Locate the clean-out port between the septic tank and the house, and unscrew the cap or plug. If no sewage comes out and the toilet bowl is still full, there is probably a blockage in the drainpipe under the house. To verify this, run a length of stiff wire into the clean-out toward the house. If you encounter significant resistance, mark that place on the wire at the clean-out and withdraw the wire. The length of wire removed tells you how far down the pipe the blockage is. The solution is to call a plumber or rent a "sewer snake" (a rotating wire cable with cutting teeth at the front end) to remove the blockage. If sewage pours out of the clean-out port with the plug out, and the toilet works again, then the blockage is on the drain field side of the clean-out port. Do the stiff wire trick again. If you feel a blockage in the pipe before the wire reaches the septic tank, the problem could be material in the pipe or a broken connection to the septic tank. The "sewer snake" won't fix the broken connection. Chances are that if the blockage is right at the septic tank inlet, it's a broken connection. If it's somewhere back toward the clean-out, it's proba- bly material clogging the pipe. If the latter is the case, use a "sewer ONSITE WASTEWATER DISPOSAL SYMPTOM : TOILET DOESN'T FLUSH NORMALLY Open drainpipe cleanout port If sewage doesn't flow past If sewage flows past or out of when toilet is flushed, port when toilet is flushed, blockage is in under-house blockage is toward drain field drainpipe Probe for blockage Use sewer snake from cleanout toward toilet If blockage is at septic tank If no blockage If blockage is before Fix broken connection to Remove septic septic tank Remove tank inlet cover with sewer snake If sewage is below inlet If sewage is above inlet pipe level pipe level Remove Clear the inlet baffle septic tank outlet cover If sewage is abov