April, 16th, 2017
As of the end of March 2017, I am now licenced to work in the Eurobodalla.
January, 19th, 2017
Just like changing the oil in your car, Septic systems require de-sludging.
A septic pump-out is needed when the thickness of the floating scum layer and settled sludge layer occupy so much of the tank volume that the free liquid area is "too small" - the "net free area" has become so small that the EFFLUENT RETENTION TIME, the time that wastewater has in the tank to allow for solids and floating scum to separate from effluent being discharged to the absorption trench is too short.
Short septic tank effluent retention time means we're pushing solids into the absorption trench, clogging it up & shortening its remaining life.
The tell tail sign that an overload of solids has flushed into the trench, is it generally breaks out in the weakest point and flows out over the ground.
NSW Health recommend septics to be de-sludged every 3 to 5 years, it can be more or less depending on size of tank and the number of people in the household. The only true way to measure sludge depth is with the use of a core sampler, however this will not accurately sample on one that has been neglected.
The majority of older tanks in the Bega Valley are of 3000L or less and have no internal baffle as above. Newer ones do and they help restrict the movement of solids passing out of the tank somewhat.
Also if you are looking at buying a property on septic, it may be a good idea to have it de-sludged before settlement. I have experienced people who have bought properties having to have this done not long after purchase and also up for the cost of a new absorption trench.
September, 11th, 2016
When a tank inspection reveals excessive solids accumulation, sticking with a three- to five-year pumpout schedule is not enough.
If a tank is operating properly, solids are retained and take up increasingly more volume. At some time they must be removed. (If there is little accumulation of solids, either the household is extremely conservative with water use and waste generation or there is a problem causing solids to pass through the tank.)
When there is little clear zone left, proper solids separation will no longer occur, detention time for settling is further reduced, and solids will wash out of the tank, eventually clog the soil treatment area, and cause system failure.
Research on solids accumulation shows the interval between pumping depends on tank size, number of people in the house, and the nature of the sewage (which in turn depends on household habits and lifestyles). Many Local Governments recommend a three- to five-year pumpout interval. This interval is probably reasonable, but checking sludge levels at the time of service can provide a better estimate for the necessary pumpout interval.
Solids are the enemy of a septic tank, but unfortunately many tanks are not regularly assessed for accumulation.
Does your septic tank have an effluent filter, is the effluent filter clogging regularly? Most septics do not have a filter but they are cheap prevention to having a clogged drain field, however they require periodic cleaning and an accurate way of detecting your tank requires pumping.
Also is your aerated wastewater treatment system (AWTS) burning out pumps? This can also mean the sludge level is high and has moved throughout the tank and requires pumping out the solids.
For more information follow the links at the bottom of page