Akcros produces additives for the plastics, detergents and rubber industries at its site in Eccles, Greater Manchester. Its discharge to a North West Water sewage works contains high levels of alkyl phenol ethoxylates (APEs), surfactants which produce persistent, oestrogenic breakdown products called alkyl phenols (APs). The compounds have been linked to reproductive disruption in fish and are highly toxic to invertebrates (ENDS Reports 246, pp 5-6 and 264, p 34 ).
APs and APEs are poorly removed by sewage treatment. Levels of the AP nonyl phenol in the Salteye Brook downstream of the sewage works far exceed a proposed environmental quality standard (EQS) (ENDS Report 263, pp 5-6 ) which is expected to come into force in July.
Akcros' IPC authorisation required it to submit plans by the end of February 1997 to render its discharge harmless, as required by law. "Harmless" was defined as a combined concentration of APEs and breakdown products "no greater than 5µg/l".
In February, Akcros asked that this definition be set aside. It said that good housekeeping measures would reduce its discharges by 90% within six months - though its releases of APs and APEs would then still be 125 times greater than the Agency's yardstick of 5µg/l (ENDS Report 266, pp 9-10 ).
In May, the Agency gave in to the firm's request. "We were putting pressure on [Akcros] because they did not have much information to give us," the site's IPC inspector, Doug Munkman, told ENDS. "Since then we have detected a change in Akcros' approach and they are doing a lot of work of their own volition."
The Agency has also eased a requirement on Akcros to take interim measures to render its discharges harmless by the end of May. A recent variation of the authorisation now requires it to submit proposals to "render harmless (by isolation or treatment)" any waste streams containing APs or APEs before the end of 1997 - but the concept of harmless is undefined.
According to the Agency, the original definition of harmless would have meant sending the site's entire effluent off-site for disposal. "The company would appeal it and then we would have a delay," Mr Munkman said. But he conceded that the receiving watercourse will not now meet the proposed EQS for nonyl phenol of 1µg/l.
If Akcros reduces its discharges by 90%, the mean concentration of APs and APEs in its discharge will be 625µg/l. The Agency's calculations suggest that this will result in levels in the sewage effluent of over 30µg/l. The effluent constitutes about 75% of the flow of the Salteye Brook and is not substantially diluted until reaching the Manchester Ship Canal several hundred metres downstream.
The Agency's most recent monitoring in March found nonyl phenol at 3,047µg/l in the sewer from the site - the second highest level since monitoring began last August. The Salteye Brook contained nonyl phenol at 21.9µg/l - over 20 times the proposed EQS.
These data are not on the IPC public register - because, Mr Munkman said, the "figures are from the sewer, not just from the site." Other minor discharges are made to the sewer, but North West Water told ENDS that it knew of "no other significant sources" of APs or APEs in the catchment.
The Agency's failure to put its results on the register runs counter to the spirit of the IPC legislation. The monitoring was designed specifically to measure Akcros' discharges. A letter from the Agency to Akcros in March indicated its intention to take the effluent samples "as confirmation of [Akcros'] own monitoring."
The Agency also told ENDS that correspondence on IPC matters is not routinely placed on the register in its North West region - based on a strict interpretation of the regulations requiring "all particulars" of applications, authorisations and variations to be included. However, it is common practice in other regions to put correspondence on the register.
Nevertheless, the Agency agreed to give ENDS copies of its correspondence with Akcros. Among the letters was a report on the firm's progress against its improvement programme which, it conceded, should have been on the register. The correspondence also includes Akcros' comments on a requested variation which the firm did not wish to see "form part of its formal reply".
The correspondence reveals that Akcros complained of unfair treatment because other companies "had not been set a definitive discharge limit" for APEs. This appears to refer to ICI Wilton, which has been given until the end of 1997 to produce proposals to render harmless its APE discharges to the Tees. Akcros has now been given an identical time scale.
IPC inspections of the Akcros works appear to be running behind schedule. In the last six months, only one of eight processes on the site has been formally inspected when, on the average national rate, eight inspections might have been expected. In May, ENDS revealed that the Agency had not carried out a single programmed inspection in six years at ICI's major Runcorn works - like Akcros, in the southern part of the Agency's North West region (ENDS Report 268, pp 23-26 ).