FAQs
(Frequently Asked Questions)
Septic Tank Guide
- A septic tank is an underground, watertight container made of concrete, fiberglass, or plastic. It’s part of a home’s wastewater treatment system, used when you’re not connected to a municipal sewer. The tank collects wastewater from toilets, sinks, and drains, allowing solids to settle at the bottom and oils/grease to float to the top.
- Wastewater flows into the tank.
- Solids settle at the bottom (sludge), and oils/grease
float (scum). - Naturally occurring bacteria help break down some solids.
- The partially treated liquid (effluent) flows out into a drain field, where soil further filters and cleans it.
- Pump it regularly (don’t wait until it backs up).
- Watch what goes down the drain: avoid flushing wipes, sanitary products, grease, oils, or chemicals.
- Conserve water: spreading out laundry and fixing leaks helps prevent overload.
- Protect the drain field: don’t park vehicles or plant deep-rooted trees over it.
- Healthywa.wa.gov recommends every 4 years for a 4-person household
Warning signs include:
- Slow drains or toilets backing up.
- Gurgling sounds in pipes.
- Sewage smells near drains or outside.
- Wet spots or pooling water over the drain field.
- Lush, unusually green grass above the tank/drain field
(sign of leaks).

Septic Tank Maintenance Checklist
- Pump septic tank every 3–5 years*
- Avoid flushing wipes, sanitary items, grease, oils, or chemicals.
- Spread out laundry and fix any leaking taps or toilets.
- Keep heavy vehicles and deep-rooted trees off the drain field.
- Watch for warning signs: slow drains, odors, wet spots, or unusually green grass.
Grease Trap Guide
- A grease trap (or grease interceptor) is a device that captures fats, oils, and grease (FOG) from wastewater before it flows into the sewer system.
- Wastewater flows into the tank.
- Solids settle at the bottom (sludge), and oils/grease
float (scum). - Prevent clogs and costly plumbing repairs
- Reduce foul odors in your kitchen
- Protect the sewer system and environment
- Meet local health and safety regulations
- The partially treated liquid (effluent) flows out into a drain field, where soil further filters and cleans it.
- Pump it regularly (don’t wait until it backs up).
- Scrape food scraps into the bin before washing
- Never pour oils or fats directly down the sink
- Use sink strainers to catch food particles
- Clean the trap regularly to avoid buildup
- Conserve water: spreading out laundry and fixing leaks helps prevent overload.
- Protect the drain field: don’t park vehicles or plant deep rooted trees over it.
- Refer to your Water Corp Trade Permit or
- Commercial kitchens: every 1–3 months
(depending on usage) - Small under-sink traps: every 1–2 weeks
- General rule: clean when 25% full
- Follow local regulations for exact requirements.

CONTACT US
Protect Your Property & Environment with Expert Waste Management
For reliable, eco-friendly liquid and hazardous waste solutions across South West and Great Southern WA. Contact us today for safe, compliant disposal backed by purpose-built equipment.
- Head Office: 1 Warrego Road, Picton East WA 6229
- Busselton Branch: 2 Trumper Drive, Busselton WA 6280
- Cowaramup Branch: 7 Friesian St, Cowaramup WA 6284
- 0403 487 894
- info@sandgropercontracting.com.au
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