Impact case study database

Research by UoB has led directly to: water quality improvements in drinking water catchments managed by South East Water; changes in water management policy for South East Water and Thames Water; and the development of research capacity within Southern Water to predict EU Drinking Water Directive priority contaminants. These changes have enabled the three companies (who serve a combined 13,500,000 customers across the southern UK) to provide a cleaner, more secure, water supply to households. Research outcomes have underpinned the inclusion of wastewater reuse treatment options in resource management plans for South East Water and Thames Water. UoB research is also assisting Southern Water with the selection of technology in reuse applications and being used to drive global water reuse guidance.

4.1 Improving drinking water quality

Between 2014 and 2015, Purnell, as scientific advisor on the Adur & Ouse Partnership Steering Group, formulated a new monitoring strategy for suspended sediment and metaldehyde detection. This strategy, developed in consultation with local councils, government agencies and conservation groups and in conjunction with South East Water, used evidence from MST and the water quality monitoring approach developed by Professor Huw Taylor, Ebdon and Purnell (see section 2.1). The new monitoring strategy led to the identification of priority sub-catchments in the River Ouse (Sussex) that were affecting water quality at a major drinking water intake supplying 300,000 of South East Water’s customers. In 2015, South East Water initiated a pilot project within the identified priority sub-catchments, targeting ten farms and providing advice and grants (up to GBP10,000) to reduce metaldehyde transport to surface waters [source 5.1].

The success of this project led to a roll out of the catchment management programme to four additional drinking water catchments, engaging with 90 farms to date (holdings up to 2000ha). As a result, 92% of monitoring locations (n=10) in the River Cuckmere recorded lower average concentrations (28% to 91% lower, average of 55% lower) for metaldehyde after catchment management implementation (December 2016) when compared to the long-term average (since 2011). This confirms the water quality improvement brought about by planned interventions linked directly to UoB research [5.2]. Fewer metaldehyde standard exceedances (exceedances from April 2012 to April 2016 totalled 282; and from May 2016 to April 2020 totalled 74) have: (i) eliminated any need for the shut-down of abstraction pumps and use of alternative groundwater supplies since 2015 [5.2, 5.3]; and (ii) have allowed greater time for groundwater aquifers to replenish. The Surface Water Manager at South East Water has stated that:

‘during the period from September 2019 to January 2020, water quality results taken from the River Cuckmere at our Arlington water treatment works remained below the drinking water standard of 0.1 µg/L. This is a significant improvement when compared against the long-term baseline data set’ [5.3].

Successful catchment-level implementation, leading to effective control of metaldehyde concentrations in source waters, has reduced the need for South East Water to introduce additional water treatment to remove the pesticide. If the first-choice advanced water treatment for metaldehyde removal were to be used this would necessitate building costs of GBP158,700,000 (2020 – 2025) and operational costs would increase by tens of millions of pounds [5.4]. These costs would then be passed on to consumers through higher water bills. In addition, the advanced water treatment option would have a high energy consumption and carbon footprint, making it less environmentally sustainable.

4.2 Increasing water contaminant prediction capability

The cost-effective open-source modelling approaches developed at UoB (see section 2.1) led to capacity building within the water industry to predict EU Drinking Water Directive priority contaminants (including metaldehyde). Specifically, it led to a new company data-sharing strategy for existing Southern Water-owned datasets to facilitate the use of advanced modelling techniques [5.5]. The predictive modelling research undertaken by UoB in 2015 was the first commissioned by a newly formed four-person innovation team at Southern Water. In addition to identifying a low-cost catchment-scale modelling approach, the research was designed to maximise knowledge transfer to the company. Knowledge transfer was facilitated by Purnell through the creation of a training video package for Southern Water employees that has resulted in the modelling skillset being available in-house for future predictive analyses. Outputs from the project informed and defined future research needs, including an internal assessment of Southern Water’s monitoring strategy and engagement with partners [5.5, 5.6].

4.3 Securing viable wastewater reuse options to augment water supplies

The Environment Agency (2013) has classified all water company regions in the southeast of England as operating in ‘areas of water stress’. Population increases, combined with the impact of climate change on rainfall and evapotranspiration levels, are projected to result in significant water deficits by 2050 (HR Wallingford, 2015). Treated wastewater has been recognised as a valuable and sustainable resource that can supplement conventional water supplies. UoB research has influenced wastewater reuse in the water sector by aiding the selection and deployment of technology in water reuse applications, informing global water reuse guidance, and securing viable water reuse options in water management policy.

As described in section 2.2, UoB research has verified the efficacy of a full-scale membrane bioreactor (MBR) wastewater facility to remove pathogenic microorganisms from wastewater. Data from this research underpinned the first inclusion of this treatment technology in water management policy by Thames Water for full or partial pathogen removal (Appendix L, Thames Water 2019 Water Resource Management Plan [5.7]). Published data from the research generated significant interest in the United States, and has led to collaboration between UoB, Southern Water and the global environmental engineering company Brown & Caldwell. Initial work involved UoB researchers testing and validating the performance of innovative wastewater treatment technologies for Southern Water, with technical advice provided by Brown & Caldwell based on their experience of designing full-scale wastewater recycling plants in the US. Outcomes show that the required water quality for water reuse options can be achieved using advanced treatment combinations, with a world-class water reuse bench-scale laboratory now set up at UoB to trial technologies going forward. The impact of this research on global wastewater reuse guidance is summarised by the Managing Director of Water Strategy (Brown & Caldwell) and lead developer for the most recent US Environmental Protection Agency Guidelines for Water Reuse:

‘Research from the University of Brighton (eg Purnell et al., 2015, 2016) demonstrating efficacy of technologies, such as MBR, in removal of viral indicators (phages) and pathogens have been critical in defining how these technologies can be used in water reuse. In fact, the greatest benefits of this collaboration with the University of Brighton faculty is that they are already engaged in global discussions on water reuse. Work produced by members of the University of Brighton reuse team is among the body of data that is being used globally to inform water reuse guidance, selection and deployment of technology in reuse applications’ [5.8].

As described in section 2.1, research in collaboration with South East Water investigated the public health risks associated with reused water to inform technology selection. UoB research outputs provided the data necessary to support the design and development of South East Water’s Peacehaven Reuse Scheme, a key strategic long-term water resource option. These data improved the company’s understanding of: (i) the water quality of the effluent discharge at Peacehaven; (ii) the water quality of the River Ouse at a number of locations important to the development of the scheme; (iii) potential risks to human health; (iv) the level of wastewater treatment required (to avoid any reduction in the hygienic quality of river water) at the treated wastewater discharge point and the water abstraction point; and (v) guidelines on wastewater recycling discharge distances from abstraction points by assessing ‘safest’ discharge locations. The outputs from the study formed the critical evidence-base adopted by the consultant, Jacobs, to develop the outline design for the Peacehaven Reuse Scheme and provided Jacobs with a higher level of confidence to design, cost and programme the appropriate treatment facilities. This scheme is continuing to be developed and promoted in South East Water’s future strategy as an alternative water supply option, to help reduce risk and provide adaptability and resilience in the company’s longer-term planning [5.9, 5.10].