If you’re looking for an eco-friendly and cost-effective way to dispose of grey water from your home, you may be wondering:
👉 Can grey water go into a soakaway?
The answer is yes, but only if done correctly. While some people discharge grey water into soakaways, this is not always legal or advisable. Without proper treatment, grey water can clog the soakaway, cause foul odors, and even lead to environmental contamination.
Before you install a grey water soakaway, you need to understand the regulations, risks, and proper setup methods to ensure your system works efficiently and legally.
Let’s break it all down step by step.
What Is Grey Water?
Grey water is wastewater that comes from sinks, showers, washing machines, and dishwashers. Unlike black water (toilet waste), grey water does not contain human waste, but it still has:
- Soap, detergents, and cleaning products
- Food particles, grease, and fat (from kitchen sinks and dishwashers)
- Hair, dirt, and skin cells (from showers and sinks)
- Bacteria and organic matter
Because of these contaminants, grey water cannot be treated like rainwater and must be filtered before it enters a soakaway. If not properly treated, grey water can:
🚫 Clog soakaways with soap scum and fat buildup
🚫 Produce bad odors due to bacterial growth
🚫 Attract pests and rodents
🚫 Contaminate groundwater
This is why most countries have strict rules about how and where grey water can be discharged.
Is It Legal to Discharge Grey Water into a Soakaway?
The legality of using a soakaway for grey water depends on your country, region, and local environmental regulations.
✅ United Kingdom (Environment Agency & Building Regulations)
- Direct grey water discharge to a soakaway is NOT legal under standard UK regulations.
- A properly designed drainage field or reed bed system is required.
- Percolation tests must be conducted to ensure wastewater does not pollute groundwater.
✅ United States (EPA & Local Health Departments)
- Most states prohibit direct grey water discharge into a soakaway unless it’s filtered first.
- Some states allow grey water recycling for irrigation, but strict guidelines apply.
- If soil conditions are poor, an advanced treatment system may be required.
✅ Australia & Canada
- Direct grey water soakaways are illegal in most areas because of the risk of groundwater contamination.
- However, filtered grey water can sometimes be used for irrigation if it meets local standards.
📌 Always check local laws before installing a grey water soakaway to avoid fines and environmental issues.
Why You Should NOT Use a Standard Soakaway for Grey Water
A standard soakaway (such as a gravel pit or soakaway crates) is designed for rainwater only. If you discharge grey water directly into a soakaway, you risk:
❌ 1. Blockages from Soap Scum & Grease
- Soap residue, fats, and detergents can clog the soakaway over time.
- This can lead to water pooling on the surface and eventual system failure.
❌ 2. Bad Odors & Bacterial Growth
- Unlike rainwater, grey water contains organic matter that can decompose and cause strong smells.
- This can attract flies, rodents, and other pests.
❌ 3. Groundwater Contamination
- Untreated grey water contains bacteria and chemicals that can seep into groundwater.
- This is especially dangerous in areas with high water tables or near drinking water sources.
❌ 4. Legal Issues & Fines
- Using an illegal grey water soakaway can result in fines or enforcement action from local environmental agencies.
- If your system causes pollution or health hazards, you may be legally required to remove and replace it at your own cost.
How to Properly Discharge Grey Water into a Soakaway
If you want to safely use a soakaway for grey water, you need to treat the water first. Here’s how:
✅ 1. Install a Pre-Filter System
Before grey water enters a soakaway, it must pass through:
✔️ Grease traps – Prevents fats and oils from clogging pipes.
✔️ Settling tanks – Allows solids and debris to settle before water is discharged.
✔️ Biological filters – Helps remove bacteria and organic matter.
A basic mesh filter is NOT enough—you need a proper multi-stage filtration system to remove harmful contaminants.
✅ 2. Use a Drainage Field (Not Just a Soakaway Crate!)
A rainwater soakaway crate system is NOT suitable for grey water. Instead, use:
✔️ A perforated pipe drainage field – Allows water to spread out and filter through the soil naturally.
✔️ A reed bed system – Uses plants to help break down pollutants before the water enters the soil.
✔️ A gravel-based infiltration trench – Provides extra filtration and prevents pooling.
📌 A properly designed drainage field is the safest and most effective way to dispose of grey water.
✅ 3. Use Eco-Friendly Soaps & Cleaning Products
To prevent chemical buildup in the soil, use:
✔️ Biodegradable soaps & detergents
✔️ Low-phosphate and plant-based cleaning products
✔️ Natural alternatives like vinegar and baking soda for cleaning
🚨 Harsh chemicals (like bleach) can kill beneficial bacteria in the soil and cause system failure.
✅ 4. Perform Regular Maintenance & Inspections
✔️ Check for blockages & odors every few months.
✔️ Clean grease traps & filters regularly.
✔️ Monitor soil drainage to prevent oversaturation.
If you notice slow drainage, bad smells, or pooling water, your system may need repairs or adjustments.
Alternatives to a Grey Water Soakaway
If a soakaway is not suitable, consider these alternative grey water disposal methods:
✅ 1. Grey Water Irrigation System
- Treated grey water can be used to water gardens & landscaping.
- Requires a filtration system and proper permits in most areas.
✅ 2. Reed Bed Treatment System
- A natural filtration system that uses plants to remove pollutants.
- Can be combined with a drainage field for extra purification.
✅ 3. Mains Sewer Connection
- If possible, connecting to the public sewer is the safest option.
- Some areas require a permit for alternative grey water systems.
Final Answer: Can Grey Water Go Into a Soakaway?
🚫 No – If you’re using a standard soakaway crate or gravel pit designed for rainwater.
✅ Yes – If the grey water is filtered and discharged into a properly designed drainage field.
Best Practices for a Safe & Legal Grey Water Soakaway
✔️ Pre-filter grey water before discharge.
✔️ Use a perforated pipe drainage field, NOT a standard soakaway.
✔️ Choose eco-friendly cleaning products to protect soil bacteria.
✔️ Check local regulations before installing a grey water system.
💡 Always follow proper guidelines to prevent system failure, pollution, and legal trouble!