If you can smell the sewage
* Your wastewater treatment system may not be working if you can smell sewage from the general area of the tank and percolation area; have slow-draining toilets, sinks or drains or backing up of sewage at the inlet, overflow of wastewater from the tank, or ponding of sewage on the percolation area, or discolouration of nearby watercourses with greyish slime growths.
* Roof and yard water should be excluded from the system.
* Grey water should be included.
* Do not allow oils, grease and fats to enter your septic tank system.
* Avoid use of food macerators or in-sink disposal units.
* Excessive amounts of bleach, disinfectants and detergents will temporarily reduce the treatment capacity, because the micro-organisms needed to treat the biological waste will be killed off.
* Septic tanks from before 1990 may not be built to current standards. Householders are advised to check the tank structure, provide access points for maintenance and de-sludging, replace soak pits and pipes to drains (if present) with a properly designed percolation area or other approved polishing system.
* A six monthly visual check by the owner is recommended. The electrical components of advanced treatment systems should be checked. Do not turn off the power to save electricity. If there is no air going to the system, the treatment is ineffective.
* Check the distribution box, at the manhole between the wastewater system and the percolation area, to ensure even distribution of effluent, and there are no blockages.
* It is recommended to de-sludge a septic tank at least once a year, but it varies with the system’s capacity and use. You must de-sludge the septic tank if scum is present in the second chamber, or if sludge comes to about 400mm from the bottom of the tank. A minimum of 75mm of sludge should remain in the tank, to assist in the re-seeding of the new sludge.
* A waste collector with an appropriate waste collection permit should be employed. A list of collectors is available from your local authority.
* If sludge builds up, it may make its way out of the tank and block the distribution box and the percolation area or polishing filter. Replacing these is expensive.
* Keep records, including the planning documentation, site maps showing the exact location of treatment system/septic tank and percolation area, system details including installation details and certification, de-sludging records, service records, etc.
* Frequently asked questions, and the wastewater treatment manual are on the www.epa.ie website.
