'Free swimming', aka swimming in rivers, lakes and the sea, is gaining is popularity. With the recent publication of a consultation on designating the Wharfe as a bathing water, now seems to be a good time to offer an opinion piece on this thorny issue. This will be a data-free zone, yet one based on many years' experience dealing with bathing water issues since the original Bathing Waters Directive came into force in 1975. This piece is the personal opinion of the author and is not intended to suggest that it is the policy or opinion of the Trust.
When the original Directive came into force, the predecessors of Defra went to great lengths to minimise the number of designations. Inland waters were excluded and the criteria applied to coastal waters were so strict that only a very few were granted bathing water status. Moreover, they decided that only the minimum stadrds in the Directive needed to be applied.
The EU's Bathing Waters page offers a wealth of information on the current state of bathing waters around Europe (incuding the UK as the data were collected before Brexit). The UK currently has 644 designations, compare to the extremes of 3348 in France and 17 in Luxembourg. Unlike in the UK, many countries in the EU have designated many inland waters. Doing so in the UK would represent a major change in policy with long-lasting and complex implications, both practical and economic.
This piece explores some of those implications, albeit briefly.
The prevailing mindset when standards were first introduced was that they could be met by effective sewage treatment and/or piping effluents well out to sea beyond the possibility that they could influence bathing waters (which were generally just the few metres between high tides and into the sea at low tide). Before long, we were examining tidal flow patterns around bays and along the length opf the coast, then exploring the impact of combined sewer overflows, then misconnections into allegedly clean watercourses dischargeing onto the beach, then urban runoff, then dogs and birds defecating on the beach....
I mention these complications only to help the reader understand that meeting the standards was not as simple as it might have first appeared and that a whole lot of unexpected factors significantly delayed compliance. How might similar factors play out in the case of the Wharfe at Ilkley, or indeed any other inland water? Upstream of any sampling point on rivers are likely to be several other sewage works, a host of (generally poorly maintained) private treatment plants or septic tanks, runoff from both urban and rural roadways, field runoff containg cow/pig/sheep/chicken etc faeces, any of which could carry a substantial load of coliforms and/or enterococci.
What might meeting the standards involve? For the sake of this blog, let's just consider sewage discharges from water company assets - Combined Sewer Overflows (intermittent discharges, theoretically only after heavy rain) and Sewage Treatment works (continuous discharges). At the moment there are no bacteriological standards on these discharges and the introduction of them would inevitably lead to the need to disinfect such discharges. In order to be able to reliably disinfect, they would almost certainly need treating to a higher standard than at present (no bad thing, but in this case technically necessary to enable disinfection). I am, of course, assuming that disinfection would be by way of UV treatment, as any chemical option would be likley to lead to disinfection byproducts unlikely to be acceptable in the receiving watercourse.
For CSOs "treating to a higher standard" is likely to first mean drastically reducing the permissible discharge to river - which of course is one of the campaigners' wishes (not that it would not be welcomed by most people interested in improving water quality). But what then? CSOs do not typically have any treatment other than screening out physical debris (this could certainly be improved but it wouldn't render the deischarges disinfected). But we still have a discharge containing substantial bacteriological load, and not only from sewage but also from runoff, so what next? I don't know - do you? Perhpas we could delay the discharge until such time as the river genuinely has risen (that was the original concept behid CSOs after all) to a level where people could not realistically swim in it anyway? All of this would require significantly more sewage to be passed forward to the treatment works - and hence upgrading sewers and then additional treatment capacity at the works.
So here we are at the, now significantly bigger, sewage works. A works whose operating range has increased from a volume ranging from 1 unit to 6 units and now has to treat a range from 1 to ??? units. Now there's an interesting challenge. Any process engineer will tell you that designing a system gets harder, and more expensive, as the range of operation increases. And that bigger works will need to treat sewage to a much higher standard, typically referred to as tertiary treatment, in order that disinfection can work.
Now all of this is technically possible, so what's the challenge? Easy - money. All this has to be paid for, and who do you think will pay for it? Yes, us customers. OK, the arguments will now come out about the 'rip-off profits' of the water companies and how the owners should pay - but anyone with even a simple understanding of financing understands that owners invest in the companies and deserve a return on their investment (if they don't get one why should they invest?) and that whilst they could be financed by borrowing, that needs to have interest paid on it and be paid off as well. And please, no arguments about re-nationalisation - this is not the place for that.
So we (whoever 'we' is) spend all this money on sewers and sewage works, will it result in 'Rivers fit to Swim in'? My prediction is 'NO'. No for the reasons I have mentioned - private sewage treatment systems, urban and rural runoff etc.
Please do contribute to the discussion. Knowing how sensitive this issue is I reserve the right to moderate comments.