9 May 2011
Brian D’Arcy begins a series of Water Reflections – blogs on the subject of water quality – with a look back to the 1970s and how old pollution problems may have been solved, then asks – what is standing in the way of tackling the remaining problems surrounding surface water management?
In the beginning, there was filth. Imagine industrial Merseyside in the 1970s-80s – a decade of depression, economic and more, a region hard hit by the Thatcher recession (anyone remember “we don’t need manufacturing industry – we have the banks”?), and much of the pollution of the estuary a consequence of still unregulated effluent discharges. It was a depressed economy and a depressing place in many ways. I was transferred there in 1975 – from the lovely English Lake District; Windermere one day, Widnes the next. Untreated sewage effluent from conurbations on both sides of the Mersey was still a major cause of pollution. Industrial sources included margarine factories, vegetable oil and mineral oil refineries, stinking rendering plants and base chemicals manufacture for the pharmaceutical industry.
The odour on approaching Widnes-Runcorn bridge was unmistakeable (the kindest way I can describe it). In the tidal swirl of the estuary, the fats and oils combined with sewage to form notorious fat balls punctuating horrible strand lines festooned with sewage debris. The salt marshes were not just tide washed turf, but tide washed t…
So it is easy to understand why, when I was sent to investigate pollution of Keckwick Brook ( a small tributary near Runcorn) and visited a new industrial estate in the headwaters, that I was looking for process effluents or untreated sewage perhaps. But those were not the sources detailed investigations revealed. Instead what is now recognised as diffuse pollution, albeit the very worst type, was the principal problem.
By an intensive programme of seeking diversion of wash bays to foul sewer, bunding oil and chemical stores, resolving a few minor trade effluent wrong connections, looking hard at loading and unloading areas and seeking more diversions to foul sewer (but we quickly ran into capacity problems), the quality in the burn was improved, visually at least. Exactly the same process was also underway on the much larger industrial estates of the River Alt catchment that drains the inland districts of Liverpool (Huyton, Knowsley for example). Similarly the car manufacturing plant at Halewood, and the copper refineries in Prescott, were also subjected to detailed investigation in response to local pollution impacts. At those extensive sites (each an industrial estate in itself) contamination of surface runoff was again the principal issue, rather than process effluent discharges.
But there is a limit to the effects of the housekeeping measures that were being formulated in the course of that work. There was a four category river classification scheme at that time whereby 4 was the poorest quality and 1 was the highest. All our best efforts, however could only take river quality, in our words from that period to ecologists and managers seeking further improvements, “from Class 10 to the bottom of class 4”. In 1984, guidance for housekeeping measures to protect surface water drainage from incidental pollution was formulated and adopted by North West Water, and similar approaches were being taken in the Clyde River Purification board in Scotland, and no doubt elsewhere in industrialised towns and cities. Yet the pollution continues. In the 2010 the regional water quality manager for Merseyside (now retired) told me there had been little change since the 1970s -80s for the industrial estates pollution problems, in marked contrast to the enormous leaps forward in addressing all the other pollution problems. At a workshop in London in 2010 (last year, run by Middlesex University) participants, with few exceptions, were still hoping housekeeping would resolve their industrial estate problems too… as if we were still in 1984. The WFD of course rightly puts ecological measures of good quality to the fore, so mere aesthetic (visual) improvements cannot be enough.
Present day answers?
What has been learned since 1984? Surely there are technical options and innovations since then, better understanding of the sources and pathways for pollution, of intervention options and regulatory regimes to bring effective measures into practice? One answer may be proprietary pollution control techniques to address the anthropogenic levels of contamination in the surface water drainage that are present even with adequate housekeeping measures in place, “the sort of techniques used for roads now” to quote one of the participants at the Middlesex workshop. Another answer is to retrofit SUDS or proprietary treatment systems to worst case problem estates – a precedent was set in Scotland that has had far more success than might have been anticipated given the size and budget constraints of the time. These issues will be the subject of the next blog and subsequent ones, offering comments on recent and new developments to address the water quality aspects of urban surface water drainage and demonstrate that the following problems need not be regarded as intractable:
A look back at the past can help us find the way forward, and avoid repeating past mistakes or flawed ideas. And a safe way of exploring ways forward is to investigate ideas and practices already tried abroad – these will also feature.
Brian J. D’Arcy
Environmental Consultant firstname.lastname@example.org