Greywater System Maintenance Schedule: Monthly, Seasonal & Annual Tasks

Why Maintenance Matters

A well-installed greywater system can run reliably for 10–15 years with minimal intervention. But like any water system, periodic checks prevent small issues from becoming expensive repairs. The most common failure modes — pooling, clogs, and odor — are all preventable with simple quarterly attention.

This schedule is organized by frequency. Post it near your washing machine or diverter valve.

After Every Use (2 minutes)

• For bleach loads, diapers, or heavily soiled items: confirm diverter is in the SEWER position before running the cycle
• During wet seasons or after heavy rain: check whether switching to sewer makes sense before adding more water to saturated soil

Monthly Checks (15 minutes)

• Walk each mulch basin — is water absorbing within 30 minutes of a laundry cycle? Any pooling is a flag to address.
• Check diverter valve for drips or loose hose connections at all three ports.
• Confirm purple "NON-POTABLE" labels on valve and visible tubing sections are still legible.
• Look for any tubing that has shifted, kinked, or become exposed above ground.
• If you have a pump (shower system): confirm pump is cycling correctly and no fault lights are showing.
• Note any changes in plant health — significant decline in a greywater zone may indicate soil sodium buildup or root-zone saturation.

Seasonal Tasks (1–2 hours)

Spring (March–April)

• Switch from sewer (winter position) back to greywater as landscape irrigation demand increases
• Inspect all above-ground tubing for UV damage or cracking from winter temperature swings
• Rake back mulch in basins and check that outlets are still buried and intact — frost heaving can shift them
• Test soil absorption in each basin by running a laundry load and observing

Fall (October–November)

• Before rainy season begins, switch to sewer or significantly reduce greywater applications
• Leaf fall: check that decomposing leaves aren't blocking basin outlets (some decomposition is beneficial, but blockage is not)
• Inspect surge tank (if present) before cold weather — in freezing climates, protect from freeze damage

Annual Tasks (2–4 hours)

• Mulch replenishment: Wood chips decompose over 12–18 months. Add 2–3 inches of fresh mulch to each basin annually to maintain the filtering and odor-control function.
• Valve inspection: Disassemble the diverter valve if possible and check internal seals for wear or debris. Most valves last 5–10 years — replace if you notice reduced flow or leaking past the valve.
• Surge tank cleaning (shower systems): Drain the tank and scrub the interior with a dilute bleach solution (1 tbsp per gallon of water). Rinse thoroughly. Direct the next 2 laundry or shower cycles to sewer before resuming greywater use.
• Soil assessment: In one of your oldest basins, dig down 6 inches and assess soil structure. Well-functioning greywater soil should be dark, crumbly, and smell earthy — not gray or compacted. Degraded soil may need amendment or the basin location may need to rotate.
• Permit record review: If your jurisdiction required a permit, verify you still have a copy and that any annual reporting requirements (rare but possible in some counties) have been met.

Troubleshooting Reference