DrainEezy® Bund Filters

These innovative oil removal filters trap hydrocarbon contaminants while allowing rainwater to drain freely into the environment. They prevent bunds from overflowing and offer significant cost-savings over oil water separators and vacuum tankers. Commonly used as transformer bund filters.

  • Low-cost, low-maintenance drainage for bunds
  • Easy-to-install solution for low-risk sites.
  • Remove hydrocarbons to non-detect levels
  • Use smart polymers to neutralise oil-based liquids
  • Automatically shut off when capacity reached

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GRR030000HRC DrainEezy Bund Filter for Hydrocarbons 1L 1.5” Thread Up to 1L Oil
GRR030020HRC DrainEezy Bund Filter for Hydrocarbons 2.5L 2” Thread Up to 2.5L Oil
GRR030003ERC DrainEezy Bund Filter for Midel 7131 1.5” Thread Up to 1L Oil
GRR030004ERC DrainEezy Bund Filter for FR3 1.5” Thread Up to 1L Oil


GRR 03 51 00 FITK DrainEezy 1.5″ ABS Fitting Kit (Most popular) 25.9 x 16.2cm
GRR 03 51 01 FITK DrainEezy 1.5″-2″ ABS Fitting Kit 26.1 x 19.1cm
GRR 03 51 02 FITK DrainEezy 1.5″ ABS XL Fitting Kit 25.9 x 66.2cm
GRR 03 51 50 FITK DrainEezy 1.5″ SS Fitting Kit 22.7 x 13.5cm
GRR 03 52 00 FITK DrainEezy 2″ ABS Fitting Kit 28.6 x 17.5cm
GRR 03 52 50 FITK DrainEezy 2″ SS Fitting Kit 26.5 x 15.1cm

See Fitting Kits for more details.

Product Overview

How do DrainEezy Bund Filters work?

DrainEezy Bund Filters contain smart polymers which extract hydrocarbons from the flow of water. The polymers transform the liquid hydrocarbons into a rubber-like solid, trapping the pollutants inside the filter. When the filter reaches its capacity, the solidified pollutants block the cartridge. This prevents the escape of contaminants when the filter needs replacing. In the event of a catastrophic breach and the filter becoming inundated with hydrocarbons, it will seal before any oil can leak out.

How cost-effective are DrainEezy Bund Filters?

For low-risk scenarios where leakage or a catastrophic breach is highly unlikely, more elaborate systems like oil water separators are expensive and unnecessary. DrainEezy filters are low-cost to purchase, install and maintain.

These filters require only a port on the side of the bund. Installation and replacement takes no more than a couple of minutes and requires no specialist knowledge. With no power requirements and no moving parts, minimal maintenance is required making the filters ideal for remote and infrequently-visited locations.

Where can I use a DrainEezy Bund Filter?

Environmental regulations require containers or equipment filled with oil-based liquids to be situated on or in a secondary containment bund. Electrical transformers may be situated inside a concrete bund or may have an integral bund. Containers of oils and fuels may be stored on bunded pallets or flooring.

If situated outdoors, these bunds can fill with rainwater which will mix with any leaked or spilt hydrocarbons. This creates a pool of contaminated water which, if allowed to overflow, would pollute the environment (and render the bund pointless).

DrainEezy Bund Filters provide the solution, neutralising the hydrocarbon contaminants as the bund water drains freely into the environment. They are commonly used as transformer bund filters, particularly on new transformers where the leakage risk is minimal.

Another popular application is for bunds used for the temporary storage of oils, fuels and other hydrocarbon-based liquids. Note that with bulk storage of hazardous liquids, The Control of Pollution (Oil Storage) (England) Regulations 2001 do not permit a drainage device to be ported to a bund wall. There are exceptions to this so we recommend that you read the regulations to see if they apply to you or contact the Environment Agency for advice. Read our blog piece on this subject.

Which pollutants will DrainEezy Bund Filters capture?

Our standard bund filter is for use with a range of hydrocarbons including mineral transformer oil, engine oil, petrol and diesel. We also have specific filters for use with Midel 7131 synthetic ester oil and FR3 natural ester fluid.


How will I know when a filter needs replacing?

An accumulation of water in the bund indicates that the filter needs replacing. Check first, however, that the drainage outlet on the inside of the bund isn’t blocked with debris. If fitted to a transformer bund, your remote monitoring system may indicate a rapid drop in oil levels which will suggest that the filter has been called into action and needs changing.

How long will a DrainEezy Bund Filter last?

The lifespan of a DrainEezy Bund Filter depends entirely on the volume of hydrocarbons absorbed and at what rate. The stated capacity relates to the volume of oil that can be retained if a ‘clean’ filter is inundated. If a filter only ever receives smaller doses of diluted hydrocarbons over a period of time then it may block anywhere between half and full capacity. On a new transformer bund, for example, where there is a low risk of leaks, spills or a breach, a filter could last for years.

Do DrainEezy Bund Filters represent a safety risk?

By transforming hazardous liquids into non-hazardous solids, DrainEezy oil removal filters are decreasing the risk on your site. The solidified hydrocarbons have lower flammability and off-gassing properties than liquid oils and fuels. The smart polymer inside the filters poses no health and safety issues to maintenance operatives. Spent filters can be disposed of in standard hazardous waste bins.

“For low-risk sites, Green Rhino’s DrainEezy Filters are a game changer”

Independent Connections Provider