Wastewater Forum Archive


Meeting 2nd July 2012

Please note that for older reports some links will be to sites that are no longer active.

This was the Forum’s 47th meeting. It was held in CIWEM’s Boardroom in London. A roundup of members’ research included the following:

WRc had a successful “Innovation Day” attended by 145 people; it was an invitation only event.

Ofwat held a workshop on the transfer of private sewers; WaSCs (Water & Sewerage Companies), CC Water, government and Ofwat participated. The amount of extra work has been less than feared. No WaSC has yet asked for an IDoK (interim determination of K). The certainty about the number of pumping stations that will be transferred in October 2016 has improved, the estimate is currently about 20,000.

Rewriting of the UPM went rather quiet but activity resumed in May and 2012 is still the target for finalisation. Much of the work is being done in “spare time”. The users of UPM requested the update to take account of the changes in CSO design, data collection, etc. UPM aims to deliver environmental standards consistently; it does not prescribe delivery methods and as such it will not be specific about SuDS, which is a delivery mechanism.

The Nanofate EU project is about half-way with 2 years still to run. Investigators have assessed hazards and tested toxicity. Nothing has been found that is more toxic in its nano form than in its ionic form. A fear had been that nano could cross the cell wall and dissolve releasing a large dose of the ionic, but this has not been found during testing. The work has concentrated on Zn, Ag and cerium (IV) oxide, CeO2. Cranfield University has been dosing nano particles into its own WwTW to examine the fate and partitioning between water and sludge. A risk map is being produced for Europe.

CEH has launched an Information Gateway, which is a tool for finding, viewing and accessing data resources held by CEH and other data providers in the UK and beyond. People were asked to try it and give feedback.

Strass WwTW in Austria has a world recognition for its energy efficiency. The activated sludge process (ASP) has been split into ‘A’ short SRT to separate the solids and ‘B’ long SRT to denitrify. Strass is a resort town with loads varying from 60,000 in summer to 250,000 p.e. in the skiing season.

The Renewables Obligation system of incentive closes to new entrants in 2017 and since it only runs for 20 years from registration, the scheme will end entirely in 2037. The RHI and FIT will continue but there is no news on the successor to RO. For planning and investor confidence, especially in the case of new technologies, it would be useful for there to be some clarity about what happens after 2017.

The BlueTech Forum brought together innovators, investors and corporates. 2012 was the third annual event. Ecolyse Inc. won the Disrupt-o-Meter™ Award for the most disruptive technology. It aims to solve bacterial problems in processes by biocontrol. Ecolyse can identify the bacteria responsible for process problems such as bulking in activate sludge or sulphate reduction and cultures strains of bacteriophage to control them specifically [phage are like the viruses of bacteria]. This contrasts with chemical control that kills a broad spectrum of organisms, maybe all of them, including ones that are useful, phage will just take out the problematic ones.

China has got very interested in river basin management. The Pollitt Bureau has issued a No 1 Policy Document saying “we will take care of the water environment”; it might take 10 years for this to be translated through to having a major impact, but it will shape policy and strategy.

The Severn and Wye Regional Flood and Coastal Committee is aiming for cooperation with farmers, landowners, foresters as well as urban interests to tackle to problem of flooding.

NERC has launched a call worth 5 million for “Flooding from intense rainfall” Closing date for outline bids: 23 July 2012.

Severn Trent Water (STW) is installing Hybacs at Ashbourne WwTW, Derbyshire, 35,000 p.e. following three years evaluation of a containerised demonstration plant at Coleshill WwTW in Birmingham. It has installed ANAMMOX at Minworth; it is the largest ANAMMOX sludge liquor plant in the world and the first in the UK.

Minworth is also implementing gas-to-grid; 40% of the biogas will be upgraded to biomethane and 60% will be used in the CHP, the CO2 from the biogas upgrade will be fed to the AD to produce more CH4.

Siloxane monitoring has given a nearly continuous record, it costs STW 2-3 million per year; Cranfield is working on optimising GAC filters and has found that series operation is more cost effective than parallel.

STW has lots of reedbeds and is trialling aerated reedbeds and vertical flow reedbeds for improved ammonia control.

STW is trialling a real-time UV-IR sensor for BOD to give feed forward control of ASP.

This is a time of shifting standards: the Fish Directive and the Shellfish Directive both go at the end of 2013. A revised Bathing Water Directive comes in in 2015 and will use E. coli and faecal streptococci. The EA is looking at mitigating failures and “disproportionate cost analysis”.

Technical Presentations with members of CIWEM’s Wastewater Management Panel

Pipe lining to reduce plumbosolvency - an alternative to phosphate dosing or pipe replacement
Keith Walker, Morrison Utility Services
Section of epoxy lined lead pipeePIPE technology is a cost effective and sustainable solution to control dissolution of metal pipes and fittings and leakage. It was established in 1998 in the USA and is approved for contact with potable water in the USA, Canada, Spain, Belgium and Finland. WRAS and DWI are still in the process of approving ePIPE products for the UK. The blown in place epoxy lining was originally developed to solve pinhole leaks resulting from cuprosolvancy; the fact that it could also solve plumbosolvancy was realised later. The approx. 0.1mm coating will probably last in excess of 70 years. It is difficult to simulate long term stability but certainly there has been no deterioration in the 12 years that it has been deployed so far. Pipes can be lined through valves provided the valve is simply closed and reopened before the lining has cured. If there are several properties in vicinity they can be lined in parallel, which reduces the on-site time per property. Return to service time is only 3 hours. Lining would not only guarantee freedom from lead in the drinking water and curing pinhole leaks, it would also obviate the need for dosing phosphate (which is standard practice in UK) and of subsequently removing this phosphate during wastewater treatment. The UK uses about 15,000 tP2O5/y for dosing. To put this in context, the total fertiliser use in UK is [only] about 200,000 tP2O5/y. Phosphate is a non-substitutable, finite resource that is being exploited excessively fast.

Pharmaceuticals in water
Richard Williams, CEH

Routes to the environment for pharmaceuticalsThe subject of pharmaceuticals in water is emotive and it is important to understand the real exposures and risks through the chain of wastewater treatment, river, water treatment and into supply. A range of chemicals was chosen (non-steroidal anti-inflammatories, beta-blocker, anti-epileptic, hypolipidemic, antibiotic, antidepressant, anti-obesity, diuretic and an illicit drug). They were monitored for 12 months at 4 sites that had been selected on the basis of previous work. Although the compounds were detectable in the rivers, drinking water treatment removed them. None of the drugs that were studied are likely to be of concern in drinking water, nor even in the raw (pre-treatment) water. The possible human intake from drinking water was 10-5 or less than the therapeutic doses.

Preparing for the 2nd cycle of the WFD - the twin challenge of phosphorus and iron
Pete Vale, Severn Trent Water, Senior Strategist - Wastewater R&D

The majority of UK WwTWs employ chemical precipitation (with iron or occasionally aluminium) to remove P. Bio-P is used where possible but generally wastewater lacks sufficient carbon to feed the process; even where bio-P is feasible, it is usually backed-up with chem-P. In AMP 5 between 360,000 and 572,000 tonnes Fe products are used per annum at a cost of about 50 million. About 12,000 tonnes Fe /y are discharged to the aquatic environment. Only the UK and two other Member States have iron Consents, none of the other 24 or the USA has seen fit to classify Fe as a specific pollutant. Fe2+ (ferrous) iron is toxic but Fe3+ (ferric) is not; Fe2+ converts rapidly to Fe3+ in aerated water. If the oxygen level were so low in a water body that Fe2+ persisted, it would be dead because of lack of oxygen irrespective of the Fe content. Oxides and hydrous oxides of iron are abundant in soil; they are a cause of red and brown colours in soil. Maybe classifying Fe as a specific pollutant should be reappraised. Recently, UKTAG published proposals to tighten the EQS for Fe from 1 mg/l dissolved to 0.73 mg/l total. In a double Biological P removal reactorwhammy it is likely that standards for P will also be tightened, which inevitably would require dosing more Fe. The water industry faces the twin challenge of needing to meet tighter P standards while at the same time needing to meet tighter iron standards. However P chemistry is complex and maybe the case for tightening P standards is also equivocal.

Severn Trent Water is already implementing Enhanced Biological P Removal (EBPR) at 10 WwTW serving a total of 4 million p.e. and is researching further P removal processes. In addition it is reducing P recycling within WwTWs by capturing P as struvite from dewatering liquor. Struvite is a good fertiliser ingredient and this initiative will contribute to conserving this vital resource.

Attached to the presentation are 4 informative, authoritative and unbiased briefing notes have been prepared for STW by Atkins. They summarise the situations for phosphorus, ammonium, iron and aluminium and are intended to move the debate forward.

The Principal Global Macroeconomic Risks to 2050 and their consequences for UK water industry Investment and Operations
Steve Palmer, MWH

Global macroeconomic risks to 2050Steve identified the principal global macroeconomic trends to 2050 and how they affect the global, and UK, economy. He discussed the interrelationships between water and energy and explained why UK inflation has been so ‘sticky’ because of its origins in non-core inflation elements, food and energy. This is probably a long term economic problem relating to strategic resource demand generated by a growing global population and projected global GDP growth.

The effects of global risks on UK policy development and its effects on the UK water industry were presented using a model water and sewerage company to demonstrate the effect of these apparently distant global pressures on the WaSC’s bottom line, arising from significant operating cost increases, which reduce operating margin, return to shareholders and retained profit by 50% between 2010 and 2030. The presentation identified an investment strategy that allows both climate change and GHG emissions targets to be met by UK water companies while simultaneously delivering a lower operating cost asset base that holds the losses in margin to only 10 - 15% of 2010 levels. The presentation described how little variation there is available in pursuing the right strategy to hit government carbon reduction targets and a significant concomitant reduction in operating costs at minimal capital cost.