General Briefing



Re: Proposal by RWE Npower to fill th Thrupp Lake, Radley, known (to them) as lake E.




In July 2005, RWE Npower, operators of Didcot Power Station, applied for detailed planning permission to fill lakes E and F in Radley with pulverised fuel ash (PFA) subject to Conditional Planning Permission SUT/RAD/5948 (hereafter referred to as the CPP) granted on 17 February 1982. The planning application went out to public consultation, in July and after a vigorouse campaign by Save Radley Lakes, NPower put the application "into abeyance" .   NPower have, in February 2006, submitted a brand new application in which they suggest leaving the Bullfield Lake and only filling the Thrupp Lake.  This is a sop to the environmentalists and since the two lakes are interconnected, to drain the one will mean the destruction of the other. The civil engineering works proposed will also damage the area beyond repair and the proposal is viewed by Save Radley Lakes as not being acceptable.


The endangered lakes are over 50 years old and are beautiful mature lakes supporting a great wealth of wildlife, including uncommon, rare and protected species. Indeed they have been described by naturalists as a jewel in Oxfordshire's wildlife crown.


SaveRadleyLakes was set up by local people to oppose the proposed continued dumping of fuel ash in Radley and to preserve the remaining lakes and their surroundings. We find that there is overwhelming public support for these aims. Most people are horrified by what is being proposed by RWE Npower and the number of people declining to sign the petition amounts to just one or two percent.



The following summarises our principal concerns:

Damage to Wildlife and surrounding environment


The filling of the Thrupp Lake and the destruction of the aquatic wildlife that they support will severely damage the ecology of the whole area.  The Bullfield Lake will be destroyed by the dewatering and construction process.  The construction of the clay bunds using heavy machinery will inflict severe physical damage on the surrounding land, and involves, as has previously occurred, the wholesale destruction of trees (despite their explicit protection under the previous planning application).


The lakes support a huge diversity of wildlife throughout the surrounding area, which has become one of Oxfordshire's most treasured wildlife sites. There are at least 6 species of orchid, kingfishers, cettis warblers, great crested grebe, water voles, badgers and otters, and many other things. There is a species list at


The area was listed, in the Oxfordshire Local Biodiversity Action Plan of 2001 ( )   (BBowt have moved their page but there is a copy and we have put it here from Google Cache) as a County Wildlife Site (CWS) and an Ecologically Important Landscape (EIL). Lake F , known locally as Bullfield Lake , is also a popular fishing lake and contains a population of large carp. With a bit of vision and some magnanimity, the area could become something really marvellous rivalling the London Wetlands Centre, and would be a superb (even more so than now) amenity for the community.


All this will be destroyed forever if RWE NPower are allowed to continue with their blatantly unsustainable and environmentally damaging activities.


Concerns about Pollution

Fuel ash contains many possible contaminants, many of which are concentrated by the burning process. Heavy metals (arsenic, cadmium, chromium and vanadium) are known to be present and have been measured (by the EA) in discharged water at concentrations around 0.2mg/l. Boron and some light metals are present in even greater amounts, with Boron concentrations reaching several g/l.


Finding out what exactly is in the ash itself and in the aqueous discharges is a problem. Didcot burns coal from many different worldwide sources so there is likely to be a large variability in its composition. These factors mean that it is difficult to establish what is in the fuel ash that has been, and is being, deposited in Radley, and hence to ascertain reasonable assessments of the hazards and risks. Tables provided by RWE Npower in their IPPC application are of little use in this respect and indicate that Didcot operators themselves have little idea what is in the ash they are dumping.


Since 1982, when the CPP was granted, and the first infilling took place about 2 years later, a lot of research into the environmental effects of PFA has been carried out. This shows that, particularly in very large quantities (we are talking about millions of tonnes here) it is not harmless. It is highly toxic to aquatic species such as cockles and lugworms used as water quality indicators. Incidents of serious water pollution by PFA have occurred in other countries, eg, India and USA .


Airborne dust comprising ash particles blown off the lake surfaces and nearby surroundings in dry windy weather is another cause for concern.


Concerns about Flooding

The lakes and gravel pits subject to the filling operations are on the Thames flood plain.


Since c2002, it has been a requirement that PFA be disposed of in clay-lined pits with raised bunds to contain surface water. (Why so if it is as safe as they claimed it to be?) The digging out of the clay to construct these bunds has provided the power station operators with the means of disposing of even more ash. However the result is raised structures that obstruct floodwater flow and remove volume from the floodplain.


Flap valves constructed in the walls of lakes H/I cannot compensate for volume loss due to raised levels in the lakes, and are totally ineffective if the lake has already been filled by pumping of slurry, as is believed may have occurred during the flooding of Dec 2002 - Jan 2003.


Why are Didcot not Recycling their Ash?


We believe that Didcot should recycle much more of their ash, as they have continually been promising to do since 1981. Didcot, we believe, recycles less than half of its ash production. In Germany they recycle about 95%. A contributory factor in all this is the absence of the 500,000 cu.m dry ash bund that was supposed to have been constructed on the site of Didcot Power Station in the 1980s. At that time, the CEGB argued that this facility was an essential part of the ash disposal operations at Radley, as it would allow stockpiling of PFA for recycling and permit proper regulation of ash pumping to Radley. However, this ash bund was subsequently lost, we are told, as a result of the construction of Didcot B'. The extension of the operating life of Didcot A' without this stockpiling facility was a major planning oversight that has contributed greatly to the current problem, and meant that much more ash has been pumped to Radley in recent years than should have been. We think RWE Npower should rebuild this facility. This would take the pressure off them to dump more ash at Radley while they sort out their recycling operations. There would then be no need to destroy our beautiful lakes.



Further information can be found at

Questions to be posed by the Media to Oxfordshire County Council, Politicians, Planners, Environment Agency.