Wastewater Forum Archive


Meeting 1st November 2012

Please note that for older reports some links will be to sites that are no longer active.

This was the Forum’s 48th meeting. It was held in CIWEM’s Boardroom in London. A roundup of members’ research included the following:

Chris Chubb told the meeting that

The EU-China report on regulation for water quality has been published “Chris Chubb, Martin Griffiths and Simon Spooner (2012) T-069 Regulation for Water Quality Management_Handbook on EU Principles and Practice Technical Report T-069 of China River Basin Management Programme. 150pp”. There has been a lot of uptake of the Chinese version. The EU/ China River Basin Management Programme website hosts the report in the Knowledge Centre, Reports.
The Bartlett School of Architecture at UCL has a project titled “New loos for London?” That will involve a 2-day workshop 8-9 November and eventually a report . It includes LooWatt dry sanitation.

Pete Vale reviewed R&D being implemented by Severn Trent Water

Hybacs has been installed at Ashbourne WwTW in anticipation of a large expansion of a chicken processing plant. It is performing well though it is not yet fully loaded. Big advantages are small footprint and rapid installation – only 2 weeks because it is mostly fabricated off site.

ANAMMOX® has been installed at Minworth and seeded; it was getting up to temperature without problems by the date of the meeting.

A full-size Blade Compressor™ from Lontra is being trialled at Worcester WwTW against 5 conventional blowers to see whether it really delivers the 20% efficiency gains claimed .

STW is researching the challenge of meeting sustainably the low P consent (0.1 mgP/L) that the EA sees as achievable. Algae, adsorption and four more technologies are being trialled.

Cranfield is assessing injecting CO2 (from biogas CHP or biomethane upgrade) into a 1 m3 AD to produce more CH4. The feasibility study suggested about 40% of the input CO2 would be used and 30% more CH4 would be produced. Four WaSCs are collaborating to measure GHG emissions (especially N2O) from wastewater treatment.

The use of membranes to upgrade biogas to biomethane is looking promising.

Richard Williams, CEH

The PROTECH family of models has been developed to simulate the in situ dynamics of phytoplankton in lakes, reservoirs and rivers. It is being used with QUESTOR to model the Thames out to 2050 for the effects of climate change and consequent changing flows on algal growth. Eleven scenarios have been modelled (the best guess at climate plus 10 perturbations). It looks as if flows will decrease, and algae will increase, limited by light not nutrients. The main grazer of algae appears to be zebra mussels. This invasive species is a voracious filter feeder that changes ecosystems by blanketing out competition, however it has been noted that water clarity in Lake Erie has increased from 15 cm to 100 cm since zebra mussels colonised.

NERC’s programme includes the changing water cycle – how urban development affects water quality and quantity. It also includes resource recovery from waste, the environmental and financial benefit.

Gordon Jones, FWR

The Revised ROCK Giardia in Water Supplies FR/R0006 was published October 2012. Summary The UPM draft is available online http://www.fwr.org/UPM3/

David Butler, Exeter University

SANITAS Sustainable and Integrated Urban Water System Management started in autumn 2012. It is a project financed by the European Union under the 7th Framework Programme (Marie Curie Initial Training Network – ITN – 289193) to meet the deficiencies in human resources in European Urban Water System (UWS) management, the need for applications of technology and for sustainability through development of an integrated technology, knowledge and action base. Exeter is hosting “Catchment based and real–time based consenting” and is modelling the activated sludge process and its emissions.

The Centre for Water Systems at Exeter has started iWIGET (FP7) aim of iWIDGET aimed at advancing knowledge and understanding about smart metering technologies in order to develop novel, robust, practical and cost-effective methodologies and tools to manage urban water demand in households across Europe. This will be achieved by reducing wastage, improving utility understanding of end-user demand and at the same time reducing customers’ water and energy costs. The main scientific challenge is managing and extracting useful information from vast amounts of high resolution consumption data.

David has been awarded a prestigious 5 year EPSRC Fellowship for 50% of his time for ‘Safe & SuRe: Towards a New Paradigm for Urban Water Management’. The water sector in the UK has been very successful up to now but increasingly is under threat as a result of climate change, increasing population, urbanisation, demographic shifts and tighter regulation. The current way of working looks increasingly out of date and out of step with emerging thinking and best practice in some leading nations. The vision is to develop a system which is sustainable and resilient focusing on the challenges of water scarcity, urban flooding and river pollution.

Nick Orman

WRc has consulted on a proposal for a “National Innovation Accelerator for Water”, which is intended “to facilitate easier entry for innovative technologies and solutions to meet its future challenges.” Having heard views on the concept itself, its operation and different funding mechanisms/models, WRc will move to produce a proposal by December 2012. [It won’t be necessary when there is less “risk avoidance” and more innovators and early adopters in the water companies. TE]

Konrad Bishop

The “Defra Water Availability and Quality - R&D Programme Project list 2010-11” had been circulated prior to the meeting and members were invited to contact KB about projects of interest.

The Joint Water Evidence Group (JWEG) has been established to develop closer working on R&D across the evidence teams concerned with Land Water and Management from within Defra, the Environment Agency, Natural England and the Forestry Commission, England. JWEG’s vision is to work together to help secure a healthy water and wetland environment in England, which delivers the ecosystems services required by society and helps provide resilience to climate change and other pressures.

Technical Presentations with members of CIWEM’s Wastewater Management Panel

Upper Hampshire Avon CatchmentAccounting for phosphate inputs to water – septic tanks and other sources Dr Linda May, Deputy Director, Water Programme, CEH, Edinburgh

CEH discovered that the official statistics underestimate the number of on-site sewage treatment systems (STS) including septic tanks woefully


Extrapolating from the areas that have been studied there are probably 1,400,000 in the UK but only 200,000 (14%) are registered. Many are close to watercourses, some discharge directly to the drainage network but the exact numbers and locations are unknown. In the sensitive Upper Avon catchment in Hampshire, an area of 644 km2, only 367 STS (11%) were consented and an additional 2953 were discovered.STS Locations River Conwy N Wales

In Scotland from April 2006 all new domestic discharges require authorisation and existing unconsented discharges must be registered during house sale; a 3 month amnesty was given on registration. England and Wales started a similar programme in 2012, but England suspended it after a legal challenge. The map of consented STS and STS that have only been notified since the drive to improve knowledge of on-site sewage treatment in the Conwy Valley amply demonstrates the need for the programme.

IE has been prosecuted by the EU for bad management of STS. There are probably 500,000 STS in IE. House building dispersed throughout the countryside was a feature of the “Celtic Tiger” boom. In most cases the groundwater table is too high. Many old STS take roof runoff in addition to foul sewage.

CEH found that when a stream passed an STS, the soluble reactive phosphate (SRP) in the water increased 3 or 4-fold. The boron load paralleled the phosphate and load (kg/d) in the Chittern Brook in Wiltshire which suggests the sources were the same; the only likely source of boron was detergent, which implicates discharges from STS, not diffuse pollution from farmland.

River Chew SRP concentrationThe dramatic reduction in SRP in the River Chew in Somerset, England after Wessex Water introduced first time sewerage is convincing evidence that STS had been having a significant effect which had been unrecognised previously when the conventional wisdom was that diffuse contributions from agriculture must be the balance when point sources such as wastewater treatment works had been accounted for. Ignorance of STS and their contribution has led to mistaken policy decisions.

Because of (re)development the number of STS is increasing. The evidence is mounting that STS discharges are a hitherto unrecognised problem at local and catchment scales and that discharges can occur under high and low flows. These affect stream P concentrations. Catchments with high densities of STS are the most vulnerable. Particulate-P is converted to soluble-P within an STS and therefore the P discharged from STS is very bioavailable, much more than P bound to soil particles in field runoff, consequently the risk of ecological impact is greater. When the contribution of STS is unrecognised the pollution is attributed incorrectly to agriculture and consequently attenuation strategies are ineffective. Removing or upgrading STS appears to improve water quality but technical solutions to P discharge issues are desperately needed. Iron dosing or discharging through steel slag have been found to reduce SRP concentrations.

Reinventing the toilet
Prof Andrew Wheatley, Water Engineering, Loughborough University

The Bill and Melinda Gates Foundation challenged researchers to reinvent the toilet so that developing countries could leapfrog the hard infrastructure that has served developed countries so well but which is so expensive. Gates criteria were that no grid connection should be required, it should be safe, affordable, not smell, not make a noise, be easy to use (in developing countries) and nobody should have to touch untreated toilet waste.

Eight teams qualified and developed designs. The design from Loughborough multidisciplinary team came second and progresses to further development.

Loughborough selected self-contained continuous thermal hydrocarbonisation because it satisfies the Gates’ criteria, it does not involve drying, it uses lower temperatures than direct heating, it captures VOCs and the products are safe and useful. Carbonisation takes 6 hours at 160°C or at 2 hours 180°C. Nitrogen, phosphorus and potassium are all recovered and even chlorine is recovered to disinfect the recovered water. A possible future development is to include processing of food waste, which would improve the economics by increasing the organic input.
Sewage handling in India today
Sewage handling in India today
Loughborough's CTHC product
Loughborough's CTHC product

Flow Diagram

Discussion: CIWEM’s letter to Minister Benyon and Ofwat’s reply
Stephen Palmer, CIWEM WwMP and Alison Fergusson, Ofwat

CIWEM wrote to Defra Minister Richard Benyon that it had concerns about “unintentional but significant barriers we perceive, to sustainable asset investment and development in the UK water industry.” In discussion it transpired that this perception really stemmed from the misperceptions of some water companies and that Ofwat welcomes sensitivity analyses and whole life costings in business plan submissions.

Discussion: advancing science / public interaction
Alastair Chisholm and Tim Evans, CIWEM

There was a brief discussion around the subjects of engaging with the media and public in matters of controversial science. It was agreed that much of the research commissioned and funded by the water industry is cut off from the interactive development of science because it is published behind high pay-walls and that effectively it is unavailable to the majority of researchers [and also policy makers and media] therefore it is neither part of the incremental development of science nor considered by policy makers or the media.