“Raw Sewage discharge is the big problem and will ruin fisheries – it must be stopped,” claims DBC Liberal Democrat Councillor for Tring West, Nick Hollinghurst.
Of course driver shortages are a post-Brexit symptom everywhere in the UK, but the first couple of stages of sewage settlement and treatment use few if any chemicals – the first is physical settlement and the second is trickling through a filter bed. Can it really be true that the raw sewage discharge is due to the shortage of a readily available chemical? Or
In August 2021, Fe(III) Sulphate solution for the final treatment of water from sewage works was at risk of short supply due to HGV driver issues.
The material is made from scrap iron using sulphuric acid and an oxidising agent, such as hydrogen peroxide, at chemical plants in Newcastle, Widnes and West Thurrock. There are stocks at these locations plus other stocks around the UK.
After sewage has been allowed to settle (1st stage) it is next passed through trickle filter beds (2nd stage) and finally (3rd stage) ferric sulphate is added to remove phosphorous and precipitate any remaining suspended material.
The water emerging from stage 2 might appear very slightly coloured or very slightly cloudy but the main problem is that it contains excess phosphorous which could cause algal blooms and/or oxygen reduction.
In view of the potential shortage the Environment Agency offered a temporary regulatory waiver for the 3rd (final) treatment stage.
However, applications for waivers were slow to come in and NONE had been received by 8th September, though some might have been received later. The number actually issued is not yet reported and could be very low.
The issue of raw sewage discharge is quite different and is usually a matter of insufficient capacity which shows up when rainfall is high. Both government and industry have failed to provide sufficient extra capacity to cope with climate change.
However, irrespective of any 3rd stage waivers, water companies let raw sewage into English waters more than 400,000 times in 2020 according to the Environment Agency. Raw sewage discharge is the big problem.
Only 14% of English rivers are rated as being of “good ecological standard”, i.e. close to a natural state.
Pollution of rivers and sea by raw sewage discharge has very serious implications for riverine and coastal fisheries, especially for shellfish.
There are four classes of water quality as defined by the levels of the bacteria E. coli found in shellfish; A, B, C and Prohibited.
Only shell fish from ‘A quality’ waters can be imported directly into the EU from Third Countries. Shellfish from ‘B quality’ waters can be only be imported after a period of storage for purification e.g. in clean tanks or if pre-cooked. Both these processes add to the cost.
Already there are hardly any ‘A quality’ fisheries in Great Britain, most are ‘B’. If there is further deterioration in UK water quality then shellfish exports could disappear altogether.
When the UK was an EU Member State with an agreed testing regime shellfish from ‘B quality’ waters was allowed to be imported. Now the UK is a Third Country the EU can no longer rely on adequate control in ‘B quality’ waters and so UK shellfish need a period of purification storage or to be pre-cooked.
In voting for water companies to be able to discharge raw sewage into rivers and the sea, our Conservative MPs and the Conservative Government have demonstrated just how wise the EU was to insist the UK is treated as any other Third Country.
It is clear that other countries can no longer rely on the UK testing or regulatory systems, which are either being progressively dismantled or abolished altogether.