Wastewater Forum
WASTEWATER RESEARCH AND INDUSTRY SUPPORT FORUM
Meeting 3rd November 2015
Please note that for older reports some links will be to sites that are no longer active.
This was the Forum’s 57th meeting and was held at CIWEM’s HQ.
Tim Evans announced his retirement and would therefore be standing down as Technical Secretary of the Forum. Steve Bungay, an independent consultant with over 25 years of experience in wastewater and sludge treatment would be taking on the task. All present thanked Tim for his service and contribution over the years.
Reports from Topic Leads
Infrastructure & Economics - Stephen Palmer
Totex – need to reduce whole-life costs sustainably. An example of this is considering retrofittable technologies such as the use of ballasted media in conjunction with activated sludge, or micro-flotation DAFs installed into existing radial flow PSTs.
Flow & Quality - Oliver Grievson
- Currently the water companies are looking to install instrumentation; YWS are currently installing telemetry; AWS spending on flow measurement; and STW have rolled out final effluent monitoring. There is currently a lot of work regarding non-contact flow meters.
- TOC and Tryptophan sensors are being considered as alternatives for BOD measurement. The validity of BOD for high-standard consents was discussed due to the inherent inaccuracy at low-level.
Peter Vale
STW are looking at on-line VFA monitors to control loadings to digesters. PV commented that the WRC are looking at non-contact organic load sensors, using infrared absorbance and reflected light. STW have also looked at nitrous oxide emissions from activated sludge, but it utilised laboratory instruments for field applications.
Biosolids - Andrew Wheatley, Tim Evans
- Loughborough University are looking at two-stage digestion regarding the release of ammonia and treating it separately to the sludge line.
- STW have early success with first recycling of CO2 back to digestion. TE stated that farmers are still uneasy using biosolids with there being concerns with odour; concerns of damage during land application; with there being a general loss of trust of the stakeholders. It was discussed about digesters being operated at their operational limits with good gas yield, good pathogen kill, but with increasingly poor digestate quality.
Resilience - David Butler
Resilience is essentially about “beyond failure”. This presents Ofwat with difficulty with how
this is regulated. Does Ofwat regulate Engineers, designs, and assets?
Legislation – Barrie Howe
- There are now new standards for bio-available metals standards. The EA has developed a tool that allows site-by-site permitting based on the DOC, calcium, and pH.
- The EA are currently undertaking a project looking at water regulation; looking at Best Practice Manual for point source and diffuse pollution.
- The EA are also looking at microbial resistance.
- There are also the on-going phosphorus trials with the water companies.
- The EA is also collecting data of upstream and downstream parameters as part of the Chemical Investigation Programme. This might add additional parameters to permits. So looking at the treatment solution to achieve the best result.
Surface Water – Nick Orman
- The UDG rainfall guide is due to be launched mid-November 2015.
- There is a big programme of replacement sewer rising mains necessary in AMP7/8. As part of this cure-in-place sewer lining technologies are being evaluated, as there might be an emerging issue of understanding the materials of construction used in sewer lining. PV commented that at WEFTEC, the profile of stormwater treatment has increased significantly.
Technical Presentations
The effects of urban growth on downstream water resources
Dr Michael G. Hutchins, Catchment Water Quality Modelling, CEH Wallingford, and Prof Steven Loiselle, Senior Freshwater Research Manager, Earthwatch
Mike presented some of the results from the research project he is leading which is looking at effects of urban growth on downstream water resources. One aspect of Mike’s research involves getting communities directly involved in water quality modelling; he is looking for End-users, Advisors, and Facilitators in the community to be involved with the project. In addition he discussed some ideas relating to forecasting water quality for which he is undertaking a scoping study and canvas opinions from a catchment partnership perspective and from water industry more generally.
FOG - forget size: it's the distribution that matters - time to reconsider separators
Martin Fairley, Research Director, ACO Technologies plc & PhD candidate Cranfield University
FOG is not simple. Particle size distribution should be a fundamental consideration in evaluating performance of separators. Considering kitchen waste, any particles smaller than 270 um will not be floated in a traditional UK separator, with most particles above this size being food and not FOG. Circumstances where there is high FOG, and high fat requires more than one treatment system due to the particle size distribution. For mitigating stormwater pollution the art is advancing rapidly with Germany and some of the US States adopting carefully considered criteria for testing proprietary products.
Date of next meeting of the Forum Tuesday, 8th March, 2016