Case Study 45:

HD Q-PAC® eliminates maintenance headache of oil water separator at Car Wash in Finland

$10,000+ Per Year Media Savings
$1,200+ Per Year Maintenance Savings


Getting your vehicle washed is always a good idea. But the dirt (leaves, sand and other grit) and especially oils that wash off vehicles need to be collected and removed from the water before the water can be reused or discharged.

The problem

A car wash, with an average of 150 vehicles per day, located near Helsinki, Finland had an oil water separator (OWS) that required frequent, costly maintenance. This was because the OWS unit contained a mesh pad that plugged frequently. The mesh pad, when fouled, proved impossible to clean.

The solution

In May of 2002, the Labko Ab (now Wavin-Labko Ab) exchanged the mesh pad media in the oil water separator with HD Q-PAC® manufactured by Lantec Products. The result was a dramatic improvement of the oil water separator:

HD Q-PAC® now operates eight weeks between cleanings and washing HD Q-PAC® is easy and quick, therefore weekly media replacements eliminated / maintenance savings realized.

Note that this is two months between maintenance events vs. the previous biweekly events. The media is simply removed from the OWS unit and then washed with an ordinary high pressure water hose. Rather than disposal of the media, after 20 – 30 minutes of this type of washing the HD Q-PAC® is clean and returned to use in the oil water separator.


The car wash owner was very pleased with the results of the retrofit:

The Results

$10,000+ (USD) per year
in annual media savings

$1,200 (USD) per year
in savings on washes
(6 washes per year vs. 26 washes per year with mesh pad)

The design of HD Q-PAC® has been proven by this and many other projects to be superior to traditional coalescing media (inclined plates, mesh pads). When used in new oil water separators, the fact that all of the surface area of HD Q-PAC® supports oil droplet coalescence is reflected in the liquid flux of 12.7 gpm/ft2 (31.0 m3/m2-h) achieved in the EN 858-1 testing. In the past, a value of 2 – 3 gpm/ft2 (5 - 7 m3/m2-h) has been a typical new design parameter. As a result, when using HD Q-PAC® to design new oil water separators, much smaller OWS units which require less coalescing media become very practical vs. historic design standards. Significant savings will be the result!

(1) American Petroleum Institute, "Design and Operations of Oil Water Separators", Publication 421, 1990
(2) Swedish Standards Institute, "Official English version of EN 858-1:2002", September 2002

Additional Contributor: Timo Sarlin, Wavin-Labko Ab

Case Studies

CS 51: Zero Oil Discharge from HD Q-PAC Filled OWS

CS 45: Superfund Site Eliminates Severe Plugging with HD Q-PAC

CS 38: Significant Improvements Using HD Q-PAC at Car Wash OWS