Sewage Regulations - EN 12566-3 - EPP2

Sewage Treatment Plant - EN12566-3 UK Standard - Why it's a Bad Test

All discharges both to ground and water, from septic tanks and sewage treatment plants, either new or existing, will have to be registered with the Environment Agency under the new EPP2 regulations (6th April, 2010).  All septic tank discharges to watercourse will be refused. Only plants with the EN 12566-3 will be accepted for the 'exemption'.

 Why we think the EN 12566 is a bad test

European Standard EN 12566-3 "Small wastewater treatment systems for up to 50 PE"
Sewage Treatment Plant manufacturers now have to send their units to the Continent to be tested and certified for both tank and process performance over a period of 38 weeks.  They come away with the EN 12566-3 2005+A1 2009 Certificate, which also allows them to be CE marked. CE marking for all construction products became mandatory on 1st July 2013.  Without an EN Certificate, no sewage treatment plant or septic tank conversion unit can be CE marked and is illegal for sale in the UK, though some rogue manufacturers are still selling them to the unwary public. It also cannot be accepted by the Environment Agency under the new gEneral Binding Rules.

The old British Standard was the BS 6297 1983, but this is now superseded for package underground plants. The BBA Certificate also no longer applies.

Confusion Surrounding the EN 12566 Standard

The EN 12566-3 2005, which was supposed to be a 'harmonised' test across all EU member states, in order that sewage plants could be traded freely across Europe, is no longer accepted by some EU countries.  France and Ireland now require a separate, more stringent EN test and Germany - where the major EN test centre is situated - also has its own test criteria. Crystal Tanks supports them in this action, as, in our opinion, the EN 12566-3 2005 is a flawed test that was badly thought out.

Why we think that the EN 12566-3 is a Ridiculous Test

You would think that a test for CE marking would be a set test, like an 'A' level, where every plant sits the same 'exam'? - NO.  Each manufacturer is free to choose the following:
  • The strength of the sewage
  • The amount of the sewage treated per day
  • How long the plant has for its 'start-up' period
  • The number of persons that the plant is designed to serve

Many manufacturers have changed things since they obtained the EN Certificate. Some have reduced the size of the compressors as they now buy cheap, Chinese manufactured blowers, resulting in plants that are not the same as were tested. Other manufacturers have changed the tank - both in materials and methods of manufacture - resulting in tanks that are no longer watertight or strong enough. In theory, ANY change must result in the plants undergoing a re-test, but this does not happen in practise and many plants that are currently on the market with an EN Test Certificate would not pass if they were tested in the same form that they are now sold.

It is like having an 'A' level exam where everyone can choose their own degree of difficulty, subject matter, number of questions, the time allowed for revision and be allowed to alter the answers afterwards if it suits them.

No two plants, sold as the same size, undergo the same test.  Yes, it is ridiculous.  What is more ridiculous is that there is no 'fail' mark level as the test only determines the 'percentage reduction in influent (sewage going in) pollutants', so, in theory, if you filled a bucket with sewage, allowed it to settle and poured off the liquor, the bucket would be given an EN 12566-3 2005 Certificate and classed as a sewage treatment plant as it had reduced the percentage of influent pollutants!  It would then be Legal in the UK!

The EN 12566-3 test only tests the SMALLEST plant in the range, not every model.  We find that it is usually the larger plants in a range that have the worst performance.  This is because plant volume often does not increase pro rata with plant population size, for example, one leading manufacturer's plant has a total retention time for treatment of 50 hours for the 6 person plant but only 26 hours for the 20 person model - almost half the digestion time, so how can it achieve the results obtained for the EN Certificate which tested the smallest plant?

Also, some 'models' that are sold here as 6 person plants were downsized to 4 persons for the test (to make the results better) but are not actually for sale as such!

Now for some more stupidity.  The Environment Agency do not ask for a 'percentage reduction in influent pollutants', but for actual maximum limits in mg/litre of BOD, Suspended Solids and Ammoniacal Nitrogen in the final effluent.  These are NOT stated on the EN test certificate, only on the actual full EN test report which the manufacturers often refuse to give out (why?) - even to us! The EN Test Certificate gives only the average of the 38 test results, not the worst figures.  One of the UK's leading sewage treatment plant manufacturers only JUST scraped through the EN Test with its market-leading plant. Its average BOD figure was 20mg/L, which is the absolute limit allowed, so the plant must have failed on around 50% of the test occasions. We have actually seen test results where plants fail the UK limits on over 30% of the test occasions but still boast the EN Certificate.  You would be in trouble with the Environment Agency for pollution, but their plants are absolutely legal for sale.  France and Ireland only allow a maximum of 3 failures during the 38 tests, so why do we allow inferior plants to be sold? This is why we say, over and over, DO NOT BUY A SEWAGE PLANT WITHOUT SEEING THE ACTUAL EN TEST REPORT which has all of the test results - the Test Certificate only shows the average of the results. You wouldn't buy a car without seeing the performance data.

The EN test is not cheap - around £40,000 per plant tested, so it is no wonder that many smaller manufacturers have not sent plants to the Continent for testing - the UK has no EN test centre.  We have even seen copies of forged EN test certificates where the manufacturer simply copied another manufacturers' certificate and changed the name of the company!  They would find it harder to forge the test report, so again we say DO NOT BUY A SEWAGE PLANT WITHOUT SEEING THE ACTUAL EN TEST REPORT.

We are a responsible company and for this reason, we have suspended sales of all other plants until we have seen their EN 12566-3 Test Report.

The FALCON, VORTEX and the FILTERPOD have the EN 12566-3 and passed the test well within the UK standards..

The EN 12566 now consists of 7 parts. Some parts are still in preparation whilst others are finished and published for adoption as National Standards.  Part 3 below is now a British Standard and designated as BS EN 12566-3:2005+A1:2009.

EN 12566 parts are:

Part 1: Pre-fabricated septic tanks

Part 2: Soil infiltration systems

Part 3: Packaged and/or site assembled domestic wastewater treatment plants

Part 4: Septic tanks assembled in situ from prefabricated kits. (in preparation)

Part 5: Pre-treated effluent filtration systems

Part 6: Prefabricated treatment unit used for septic tank effluent (in preparation)

Part 7: Prefabricated tertiary treatment unit (in preparation)
As far as we are aware, there are no plans for an EN test for above ground plants.

Only sewage treatment plants previously certified and tested to BS EN 12566-3:2005 or newly certified to BS EN 12566-3:2005+A1:2009 (it has been amended in 2009) are considered for the Discharge Exemption and are only actually Legal if they have an EN Certificate.