Septic tank, cesspit or treatment plant?
It matters which you have, because each is emptied and maintained differently. Cornwall Council describes a septic tank as a set of compartments where waste settles and bacterial activity creates sludge that builds up and needs regular removal. A cesspit is a leak-proof holding tank, usually much larger, which is emptied when full. It normally needs emptying more frequently than a septic tank because all the liquid is removed as well as the sludge.
A package treatment plant treats sewage to a higher standard and may have pumps, blowers or other mechanical parts that need servicing. Sludge removal is still required, but the appropriate procedure depends on the particular plant. The general binding rules do not apply to cesspits, which must be emptied regularly and must not leak or overflow. Our cesspit vs septic tank guide explains the differences.
Lanes, hedges and hose runs
Narrow lanes between high hedges, steep drives and tanks at the bottom of sloping gardens can complicate emptying in Cornwall. A tanker needs somewhere suitable to stand while the hose reaches the tank. A tight entrance, sharp bend, weight restriction or long distance from the road can affect the collection.
Before arranging emptying, check where the tank is, how far it is from possible tanker standing space and whether the cover is accessible. Mention gates, restricted lanes, soft ground and any difficulty reaching the property. A tank hidden beneath paving or vegetation may also need to be located before collection. The tanker should not be assumed capable of driving over a buried tank or its drainage field.
Holiday lets and seasonal loading
A holiday cottage or chalet can have much heavier wastewater use during busy periods than when it is unoccupied. This affects the amount entering the system and can influence maintenance and desludging requirements. For properties with regular changeovers, it is worth checking the tank’s condition and sludge level rather than relying only on a previous emptying date.
GOV.UK says holiday accommodation should calculate daily sewage flow using industry flows and loads guidance, adding all sources together. If a barn is converted, accommodation extended or another property connected to the same system, its maximum daily discharge must be recalculated. Where several cottages use one tank, access and arrangements for emptying need to take account of the shared system. Our holiday park septic tank emptying page covers larger sites with multiple tanks.
