Washdown Separators
Vehicle washdown separators are designed to remove silt, sediment, oils and hydrocarbons from contaminated wash water before it enters the drainage system. They play an essential role in commercial and industrial vehicle washing applications, helping to reduce pollution, protect drainage infrastructure and support compliance with environmental requirements.
At Online Tank Store, we supply a range of high-quality washdown separators suitable for commercial vehicle wash bays, agricultural machinery cleaning, fleet maintenance depots, construction equipment, pressure washing facilities and industrial washdown areas. Manufactured in the UK from durable rotationally moulded polyethylene, our separators are built for long-term underground installation and easy maintenance.
Whether you’re washing cars, HGVs, tractors, plant machinery or commercial vehicles, our washdown separators provide an effective solution for separating contaminants before wastewater is discharged. Read More A washdown separator is an underground treatment system that separates contaminants from vehicle wash water before it enters the foul drainage system. During vehicle washing, wastewater commonly contains: Without treatment, these contaminants can enter drainage systems, leading to blockages, pollution and increased maintenance costs. Washdown separators are designed to retain these contaminants within dedicated chambers while allowing cleaner water to leave the system. Our washdown separators are suitable for a wide range of commercial and agricultural applications, including: Our underground washdown separators offer several advantages over traditional concrete alternatives. Lightweight Construction Manufactured from high-strength rotationally moulded polyethylene for easier transport and installation. Corrosion Resistant HDPE will not rust or corrode, providing excellent durability in underground installations. Shallow Dig Design Reduced excavation depth helps lower installation costs and makes the separators suitable for sites with higher groundwater levels. Easy Maintenance Large inspection openings provide easy access for routine emptying and cleaning. UK Manufactured Designed and manufactured in the UK using high-quality materials for reliable long-term performance. Selecting the correct washdown separator depends on several factors, including: If you’re unsure which model is suitable for your project, our experienced team will be happy to help recommend the most appropriate solution. What is a Washdown Separator?
Typical Applications
Why Choose a Polyethylene Washdown Separator?
Choosing the Right Washdown Separator
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Atlantis Double Stage 13,600 Litre Inline Washdown Separator
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Atlantis Double Stage 13600 Litre Side-by-Side Washdown Separator
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Atlantis Double Stage 20,000 Litre Side-by-Side Washdown Separator
Where are washdown separators typically used?
Washdown separators are suitable for a wide range of commercial, industrial and agricultural applications. They're commonly installed at:
- Commercial vehicle wash bays
- Car washes and valeting centres
- HGV and fleet maintenance depots
- Agricultural farms and machinery wash areas
- Construction and plant hire companies
- Bus and coach depots
- Local authority maintenance yards
- Sports ground and golf course machinery wash facilities
If vehicles or equipment are regularly washed and the water contains mud, oils or other contaminants, a washdown separator is often an effective solution.
What contaminants do washdown separators remove?
Vehicle wash water can contain much more than just dirt. Depending on the application, it may include mud, sand, grit, brake dust, oils, grease, fuel residues and other hydrocarbons.
A washdown separator is designed to separate and retain these contaminants within the system, helping to reduce the amount of pollution entering the drainage network while protecting downstream pipework from excessive sediment build-up.
What's the difference between a washdown separator and a silt trap?
Although they perform similar roles, they are designed for different applications.
A silt trap primarily captures heavy solids such as sand, grit and mud before they enter the drainage system.
A washdown separator goes a step further by also separating oils and hydrocarbons, making it the preferred choice for vehicle wash bays, machinery cleaning and commercial washdown areas where fuel residues or lubricants may be present.
Are washdown separators suitable for farms?
Yes. Washdown separators are widely used within the agricultural sector for cleaning tractors, combines, trailers, sprayers and other farm machinery.
Agricultural equipment often carries significant amounts of mud, soil and organic material, together with oils and grease from normal operation. A washdown separator helps manage this contaminated wash water before it enters the drainage system, making it a practical solution for many farms and agricultural businesses.
Why are our washdown separators installed underground?
Installing the separator below ground keeps the system out of the way while making the most of the available space around a wash bay.
Our underground washdown separators are manufactured from durable polyethylene and feature a shallow dig design, helping to reduce excavation work and making installation easier than many traditional alternatives. They're also well suited to sites where ground conditions or higher water tables may influence the installation.
How often does a washdown separator need emptying?
There isn't a fixed schedule, as maintenance depends on how frequently the wash facility is used and how much contamination enters the system.
Sites washing several vehicles each day will generally require more frequent inspections than those used occasionally. Regular maintenance helps ensure the separator continues to operate efficiently and prevents excessive build-up of silt or hydrocarbons within the chambers.
How do I choose the right washdown separator?
The right model depends on several factors, including the type of vehicles being washed, the expected volume of wash water, the level of contamination and the available installation space.
If you're unsure which separator is most suitable, our team will be happy to discuss your project and recommend the most appropriate option for your application.
Can Online Tank Store help me specify the right system?
Absolutely. Choosing the correct washdown separator isn't always straightforward, particularly for commercial sites with specific drainage requirements.
Whether you're installing a new vehicle wash bay or upgrading an existing facility, our experienced team can help you select the most suitable separator based on your application, expected usage and site conditions.