Winter is the hardest season on a septic system, and spring is when it tells you how it coped.
The ground out here has spent months wet. Absorption trenches work by letting treated water soak away into soil, and soil that is already full cannot take much more. Most of the time the system rides it out and dries off as the weather warms. Sometimes winter leaves damage behind that only shows up now.
This is a walk-around you can do yourself in ten minutes, no tools and nothing to open. It is worth doing before the weather heats up and the house gets busy.
Start at the absorption trench
The trench is where problems appear first, long before anything goes wrong inside the house.
Walk the ground over and downhill from it and look for:
- Water sitting on the surface, or ground that stays soggy days after the last rain. Everywhere else has dried out and this patch has not.
- A stripe of grass that is greener and growing faster than the lawn around it. It is being fertilised by something.
- Smell. A properly working trench does not smell. A whiff of sewage outside means effluent is surfacing instead of soaking away.
- Ground that has slumped or sunk along the line of the trench.
One soggy patch after a wet winter is not automatically a failed trench. It might simply be ground that has not caught up yet. What matters is whether it dries out as spring goes on. If it is still wet after a fortnight of fine weather, that is worth a phone call.
Check the ground has actually recovered
Give it a few weeks of decent weather and look again. A system that was only overloaded by rain comes good on its own. A system with a real problem stays wet regardless of what the sky is doing.
That distinction is the single most useful thing you can work out yourself, and all it costs is looking twice.
Look at the tank lids and the access
While you are out there, check the lids are sitting flat, unbroken and properly in place. Winter storms shift things, and a cracked or displaced lid lets stormwater straight into the tank, which is the last thing it needs. A lid that is not secure is also a genuine safety problem if there are kids or animals about.
Have a look at the path a truck would take, too. Growth after winter rain is fast, and access that was clear in autumn can be closed in by spring. Less of an issue here than most places, because the truck carries 90 metres of hose and does not need to drive up to the tank, but it still has to get somewhere within reach.
Listen to the house
Inside, the early signs are subtle and easy to explain away:
- Drains running slower than they used to, particularly the ones furthest from the tank
- Gurgling from a toilet or a shower drain when something else empties
- A toilet that needs two flushes
- Smell near floor wastes
One slow drain is probably just a blockage. Several at once, in different parts of the house, usually points at the system rather than the pipe.
Think about what summer is about to ask of it
Spring is the quiet window. Summer is when a septic system gets pushed hardest: visitors staying, more showers, more washing, kids in and out. Household water use can climb sharply for a few weeks, and everything that goes down the drain lands in the same tank.
A system already near its limit is one that will let you know about it on the worst possible weekend. If yours has been struggling, sorting it in spring is a great deal easier than sorting it in January.
It is also worth knowing when your tank was last pumped out. NSW on-site sewage management guidance puts household pump-outs at every three to five years, though the right interval for your place depends on the tank, the size of the household and how hard it works. If you cannot remember the last one, it has probably been long enough.
What heavy rain actually does
Rain affects a septic system in ways that surprise people, and it is worth understanding rather than guessing at. There is a separate write-up here: How Heavy Rain Can Affect Septic Systems.
When to pick up the phone
Ring if you find:
- Ground over the trench still wet after a couple of weeks of fine weather
- Sewage smell outside, or effluent visible on the surface
- Slow drains or gurgling in more than one part of the house
- A cracked, loose or missing tank lid
- An alarm that has gone off, on an aerated system
None of these are emergencies on the day you spot them. All of them get worse, and dearer, if they are left until summer.
Call Paul on 0438 315 514, Monday to Saturday, 7am to 5pm. Tell him what you have found and roughly how long since the last pump-out, and you will get a straight answer about whether it needs attention now or can wait. There is an estimate before any work starts.
Ward Septics covers the Central Coast, Lake Macquarie and the Lower Hunter, from Gosford to Wollombi and Wisemans Ferry to the lake.