Anglian Water Research Articles

The Brettenham storm of 25 July 2021

The <scp>Brettenham</scp> storm of 25 <scp>July</scp> 2021

OxyMem MABR set to play major role in carbon reduction project

DuPont's OxyMem membrane aerated biofilm reactor (MABR) technology is being used in the Anglian Water Triple Carbon Reduction project, which has been named as one of the nine winners of Ofwat's Water Breakthrough Challenge.

Applying the wellbeing valuation method to value the costs of roadworks and flooding

ABSTRACT This study uses the wellbeing valuation method to monetise the association between water flooding or roadworks incidents and subjective wellbeing for customers served by Anglian Water in the UK. Using this method, we find that the estimated wellbeing cost per incident for flooding is considerably higher than for roadworks, that internal sewer flooding is associated with a higher wellbeing cost per property than external sewer flooding, and that internal water flooding has a lower estimated wellbeing cost per property than internal sewer flooding. The findings were used in Anglian Water’s 2019 Price Review (PR19) business planning. By providing a wellbeing valuation for events that have also been studied through stated preference models, this research also provides a case study for comparing the differences in results between the two valuation methodologies.

Toddbrook: Anglian Water's response to the incident

Anglian Water is the undertaker for 44 large raised reservoirs which fall under the Reservoir Act 1975. The reservoirs are located within the East of England between the River Humber to the north and the River Thames to the south. Anglian Water's reservoirs are predominantly filled by pumping and consequently have small natural catchments. On 1 August 2019 a major incident was declared at Toddbrook reservoir, owned by the Canal &amp; River Trust, and parts of Whaley Bridge, Furness Vale and New Mills were evacuated; 1500 residents were moved to safety after concrete slabs on the dam spillway partially collapsed following days of torrential rain. The Environment Agency (EA) issued a ‘danger to life’ warning in the area due to the possibility of the dam collapsing. Following the incident a review of Anglian Water reservoirs was undertaken to assess them. This paper describes the work undertaken by Anglian Water directly in response to the Toddbrook incident. This comprised an initial review of Anglian Water's reservoirs and then more detailed analyses for those reservoirs assessed to have greatest similarities to Toddbrook.

Priority setting for invasive species management by the water industry

The expansion of Invasive Alien Species (IAS) is a growing concern to the UK water industry because of their diverse impacts on water quality, infrastructure and eradication costs. New regulations reinforcing the industry’s responsibilities beyond operational costs, coupled with continued range expansion and establishment of new IAS will increase damages. To tackle IAS effectively, the water industry requires reliable information about which species pose the greatest risk to operations and which areas are most vulnerable to invasion. Here we assess potential biosecurity threats for the 24 water companies in the UK using well-established modelling research techniques such as risk assessment and distribution modelling. Using a consensus approach with environmental managers and water companies, we identified 11 IAS of concern for the UK water industry, including five plants, three crustaceans, two molluscs and one fish. These invaders pose important hazards in terms of water quality, flood protection, human health, integrity of infrastructures, recreational and aesthetic values, amongst others. We used distribution models to predict their potential expansion under current and future 2050 climate scenarios within each of the 24 water companies in the UK. Water companies in the South East of England (Cambridge Water, Anglian Water, Affinity Water and Thames Water) are under the highest risk of invasional meltdown from multiple IAS, both now and under future scenarios. The quagga mussel poses the most serious risk of immediate spread and may exacerbate the impacts of the widespread zebra mussel for the water industry. The information generated in this study can support the prioritization of species and regions at risk, so that funds for prevention and eradication of invasions are well allocated. Ultimately, this study demonstrates that scientific risk assessments, usually restricted to the academic and public sectors, can be extremely useful to guide decision-making by the private sector.

Keep it Clear

ANGLIAN WATER IS THE LARGEST WATER AND WASTEWATER COMPANY in England and Wales by geographic area. With the volume of waste received daily enough to fill over 300 Olympic sized swimming pools, trav...

The role of climate services in handling climate change risks: contributions of UKCP18

The role of climate services in handling climate change risks: contributions of UKCP18

Integrated catchment management for reducing pesticide levels in water: Engaging with stakeholders in East Anglia to tackle metaldehyde

In the agriculture intensive eastern region of England, plant protection products are widely applied to protect crops such as wheat and oilseed rape from pests and diseases, thus creating a risk of reaching nearby water courses through surface runoff. The EU Drinking Water Directive sets a stringent limit of 0.1 μg/l and 0.5 μg/l for individual and total pesticides respectively in treated potable water. However, peak metaldehyde levels have been persistently detected in raw water and reducing them to these limits has proven challenging and costly, in particular when using conventional treatment. In line with the EU Water Framework Directive, a more suitable approach and one adopted by the local water company, Anglian Water Services Ltd., would require moving towards mitigating pollution at source, preferably through participative action with multiple stakeholders in the agricultural industry. Initial findings demonstrate the potential of product substitution for reducing metaldehyde levels in surface waters. Reviewing Anglian Water's “Slug it Out” trial, we discuss key learnings derived from their experiences and make recommendations about the potential of the catchment approach to address the wider pesticide challenge.

Assessing filter robustness at drinking water treatment plants

AbstractThis investigation explores the use of five‐parameter logistic curve fitting in quantifying turbidity robustness and risk scoring in clarification and filtrations stages of several surface water treatment works in the Anglian Water region of the United Kingdom. The approach taken reviews different scoring systems and addresses issues of weighting, averages and variability in robustness performance using turbidity robustness indices (TRIs). It also proposes an area‐based risk scoring profile to assess performance [relative area profile for T90 (RAP90)]. The metrics produced are considered to be a logical and rational way to help prioritise where resources for water treatment operation should be deployed.

Real Time Control of Water Distribution Systems Using a Multi-criteria Decision-support Tool for Optimal Water Network Management – A Case Study

This paper addresses network management at resource zone level through the use of a real-time, multi-criteria pump scheduling tool, Miser PS. Miser PS was integrated within Anglian Water operations as a stand-alone, semi-automated, open-loop system. It is estimated that the application of Miser PS has achieved a 3.4% energy reduction on the studied system equivalent to £217000 or 428tn of CO 2eq per year and improved asset knowledge and asset management. In addition, Miser PS has facilitated scenario testing to prepare for planned and unplanned events such as drought events and improved network resilience.

Quantifying Household Water Demand: A Review of Theory and Practice in the UK

Socio-economic change, severe droughts, and environmental concerns focus attention on sustainability of water supplies and the ability of water utilities to meet levels of service. Traditionally, water management has been supply-side dominated and long-term demand forecasting has received relatively little attention. However, it is increasingly recognised that water demand management could be a ‘low regret’ adaptation measure (both financially and environmentally) given large uncertainties about future non-climate and climate pressures. This paper begins with a brief history of household water demand management in the UK. We then review approaches to water demand estimation and forecasting over the short- (daily to season) and long-term (years to decade) and note the paucity of studies on weather and climate. We discuss peak household water use behaviours identified from metering trials, micro-component diary-based studies, and statistical techniques for long-term demand forecasting. We refer to the Anglian Water Services (AWS) ‘Golden 100’ data to illustrate the significant practical and conceptual issues faced when mining household water use data for weather signals, especially when the data are noisy and originally intended for other applications. Further research is needed into the relationships between climate variables and household micro-component water use, especially for peak demands.

Monitoring and modelling of siloxanes in a sewage treatment plant in the UK

Monitoring of cyclic volatile methylsiloxanes (cVMS) carried out at Anglian Water’s Broadholme sewage treatment plant (STP) is described. The method deployed used headspace gas chromatography/mass spectrometry (HS-GC/MS) and the addition of isotopically labelled cVMS to correct for partitioning in samples containing high levels of particulate and dissolved organic carbon. The method was capable of measuring cVMS in raw sewage samples, with recoveries of 80%, 85% and 71% respectively, for D4, D5 and D6. The limit of quantification was 0.2μgL−1 for all three substances. Recoveries close to 100% were observed for all cVMS spiked into treated effluent (LOQ=0.01μgL−1). Despite the volatile nature of cVMS and its ubiquitous presence in the ambient atmosphere, the methods deployed showed excellent recoveries, reproducibility and quantification limits. A distinct diurnal variation in cVMS concentration, probably linked with the use of personal care products was observed for raw sewage but not in treated sewage effluent. The estimated per capita consumption of D5 (∼2.7mgcap−1d−1) derived for the population served by this plant was significantly lower than that derived in the Environment Agency (UK) risk assessment (11.6mgcap−1d−1). The cVMS were highly removed during sewage treatment with efficiencies greater than 98%. The methods and findings of this pilot study can be used as the basis for future studies on the fate of cVMS substances in STPs.

An artificial intelligence approach for optimizing pumping in sewer systems

This paper presents details of a fuzzy logic system developed for the control of sewer pumping stations for energy costs savings. This is part of an ongoing collaborative project between Anglian Water and the University of Sheffield. The model rules and operation are developed for one representative pumping station in order to enable the identification of potential benefits and inhibitors to Anglian Water. Results are included that demonstrate the potential for energy cost-savings by application to a single pumping station for dry weather flow conditions and through comparison to current on/off switching rules. The fuzzy system is shown to be robust to changes in flow pattern (using both modelled inflow data and real data from a flow survey), but sensitive to changes in price structures. Application of a genetic algorithm (GA) search technique was used to adjust the parameters that define the membership functions in the fuzzy rules, in order to provide automated minimization of the energy costs towards an optimal solution. The GA system is shown to be transferable to another pumping station with different pump sizes, wet well capacity and inflow pattern. The GA solution outperformed the base case in terms of energy costs and switching totals.

EDC DEMONSTRATION PROGRAMME IN THE UK - ANGLIAN WATER?S APPROACH

The environmental impact of endocrine disrupting chemicals (EDC) has been intensively researched over the last 10 years in the academic field. One of the observations highlighted has been the relationship between feminization of male fish (known as intersex) and the discharge of steroid estrogens from sewage treatment works (STWs). Compounds that act like estrogens found in certain industrial chemicals have also been blamed for such an effect. Given the long-term effect this may have on fish population, it is anticipated that EDC removal may be imposed in the future discharge consent to ensure the concentration not exceeding a Predicted No Effect Concentration (PNEC), taking into account the dilution capacity in the receiving water. Currently, there is a lack of understanding as to how the steroid estrogens and other EDCs are removed through various wastewater treatment processes. To ensure that future policy decisions are well founded, the Environment Agency (EA) and Department for Environment Food and Rural Affairs (Defra) have instigated a Demonstration Programme, which involves collecting baseline data at 17 STWs across the UK and investment to achieve EDC reduction at 2 full-scale STWs. This paper focuses on the baseline data element of the Demonstration Programme. Given the complexity of the programme, and the technical issues to be resolved it was seen as beneficial to trial the protocol at one or two sites to inform the remainder of the Demonstration Programme. Having a strong analytical capability, Anglian Water Services (AWS) has agreed to take this leading role.

Assessing the robustness of adaptation decisions to climate change uncertainties: A case study on water resources management in the East of England

Projections of future climate change are plagued with uncertainties, causing difficulties for planners taking decisions on adaptation measures. This paper presents an assessment framework that allows the identification of adaptation strategies that are robust (i.e. insensitive) to climate change uncertainties. The framework is applied to a case study of water resources management in the East of England, more specifically to the Anglian Water Services’ 25 year Water Resource Plan (WRP). The paper presents a local sensitivity analysis (a ‘one-at-a-time’ experiment) of the various elements of the modelling framework (e.g., emissions of greenhouse gases, climate sensitivity and global climate models) in order to determine whether or not a decision to adapt to climate change is sensitive to uncertainty in those elements. Water resources are found to be sensitive to uncertainties in regional climate response (from general circulation models and dynamical downscaling), in climate sensitivity and in climate impacts. Aerosol forcing and greenhouse gas emissions uncertainties are also important, whereas uncertainties from ocean mixing and the carbon cycle are not. Despite these large uncertainties, Anglian Water Services’ WRP remains robust to the climate change uncertainties sampled because of the adaptation options being considered (e.g. extension of water treatment works), because the climate model used for their planning (HadCM3) predicts drier conditions than other models, and because ‘one-at-a-time’ experiments do not sample the combination of different extremes in the uncertainty range of parameters. This research raises the question of how much certainty is required in climate change projections to justify investment in adaptation measures, and whether such certainty can be delivered.

Design of environmentally and socially conscious water metering tariffs for the UK

England is one of the few industrialised countries where water metering is not compulsory. Most households instead pay a fixed charge regardless of use. Yet water consumption is already at the limit of resources and beyond them in some regions. Despite the need to control demand, compulsory water metering has not been implemented largely because of concerns about the regressive impact on poorer households. This research analysed new data from Anglian Water on household water consumption and income to examine the distributional impacts of ten different hypothetical tariff designs. It was found that it was possible to design revenue-neutral metered tariffs that would cause only a small percentage of low-income households to lose and most to gain. With sensitive design, the social concerns about compulsory water metering can be dealt with.

Maximising biogas in anaerobic digestion by using engine waste heat for thermal hydrolysis pre-treatment of sludge

Dublin's Ringsend WWTP was designed to serve a population of approximately 1.2 million p.e. with a sludge production of 37,000 dry tonnes per year after upgrading to full secondary treatment. Several technical solutions were put forward as part of a design, build, finance and operate (DBFO) competition, with the chosen solution being a proposal by Black and Veatch for a combination of sequencing batch reactor (SBR) technology and anaerobic digestion with Cambi thermal hydrolysis pre-treatment (THP). The THP plant was built by Cambi and handed over to B&V in 2002. The plant is now operated by Celtic Anglian Water. In September 2004 a test was carried out on the mass and energy balance of the plant following 2 years of operation and is detailed in this paper. The process enables digestion at very high dry solids feed and low hydraulic retention time. The plant was built with three digesters of 4250 m3 each and is fed with hydrolysed sludge at 11% DS. There are four no. 1 MW Jenbacher engines operating mainly on biogas. Each pair of engines is fitted with a waste heat boiler with a capacity of one tonne steam per hour. These boilers have sufficient capacity to provide 80% of the steam required for the THP, which in turn provides all the heat for the subsequent digestion in the form of hydrolysed feed. There are two main biogas boilers for top up steam and other uses of the biogas including thermal oxidation of concentrated odours.

WATER RE‐USE ‐ CAPTURING A WASTE RESOURCE

ABSTRACTThe east and south‐east of England has the lowest rainfall in the UK, water resources are limited and under pressure through increased demand and population growth. In the late 1990’s AW Innovation (the AW R&amp;D group) developed a process that could produce high purity water from sewage effluent using membrane technology. In late 1999 Texas Utilities (TXU) signed a contract with Alpheus Environmental for the supply of high purity water for Peterborough Power Station. The novel treatment plant was built in 1999 ‐ 2000 and opened in July 2000 by the Mayor of Peterborough. This paper is a review of the plant design, the technology used for the treatment process and a summary of the first four years of operation.Changing from potable water to high purity water produced from sewage effluent has brought significant benefits for the power station resulting in higher purity steam generation while reducing chemical, power and effluent discharge costs. In addition Anglian Water is now saving 1,000 m3/day of potable water.

ADVANCED LEACHATE TREATMENT AT THE STEWARTBY LANDFILL SITE

Landfill liquor (leachate) is produced by complex microbial processes within a landfill site. The long retention period, typically in excess of many years, ensures that easily-biodegradable materials disappear rapidly, whereas intractable (hard) Chemical Oxygen Demand (COD) substances decay slowly. The resultant liquor is often difficult to treat biologically due to high concentrations of Ammoniacal N (amm.N) and low concentrations of nutrient Phosphorus (P) and Biochemical Oxygen Demand (BOD). The advanced treatment process adopted at the Stewartby landfill site has been based on extensive laboratory trials by WRG Ltd (formerly Shanks Ltd), with technical input from Birse Process Engineering Ltd. This has significantly reduced the risks involved in plant scale-up. The particular choice of treatment process reflects the stringent discharge consent and the wide variety of waste received at the site, in particular, the presence of hazardous waste producing a leachate which is especially difficult to treat. Treatment is based on the activated sludge process, assisted by Powdered Activated Carbon (PAC) dosing. The leachate is heated to improve oxidation of amm.N and the process stream also includes Dissolved Air Flotation (DAF) and Sand Filtration to remove suspended solids (SS) and P. Odour control is provided by a two-stage activated carbon unit. Results from the full-scale treatment plant have been excellent, averaging 70% COD removal and almost 100% amm.N removal and fully satisfying the sewer discharge consents imposed by Anglian Water and the Environment Agency. This paper describes the laboratory trials, process design and commissioning of the leachate treatment plant at the Stewartby landfill site.

SBR Performance with an Excessive Long Sludge Age

In the UK water industry, the sequencing batch reactor (SBR) has been seen as a technically-economically advantageous option as an alternative to the continuous flow activated sludge process (ASP). The technology has enjoyed a booming period over the last decade, with many installations now operational. These installations appear to have achieved various degrees of success, but not without operational and performance issues. This paper reviews the typical design practices of SBR, and focuses on one particular SBR supplied by Biobubble Ltd within the spectrum of various SBR technologies. Biobubble SBR is designed as a true SBR with discrete phases of fill, aerate, settle and decant. It often guarantees an effluent quality of 15: 10: 2 (TSS : BOD : AmmN) and a low sludge production. Its main operating parameters are distinct in comparison with continuous flow ASP, and indeed other 'mainstream' SBRs. Differentiation can be seen on plant sizing, sequence control and equipment configuration. Studies have been carried out by Anglian Water Services Ltd to gain a better understanding of this type of SBRs. It has been found that the reliable performance is due to the long hydraulic retention time (HRT) of about 70 hours (aerated), which provide high tolerance against shock loadings. The good settlement is a result of a long settling phase of 1.5 hours and a low fill time ratio (FTR) of about 0.05, creating a feast/famine condition similar to a plug-flow ASP. The low sludge yield of 0.33 kgSS·kgBOD−1 is a result of a long sludge retention time (SRT) of about 200 days, which enables aerobic sludge digestion in the SBRs.