A 100-L microbial electrolysis cell (MEC) was operated for a 12-month period fed on raw domestic wastewater at temperatures ranging from 1°C to 22°C, producing an average of 0.6 L/day of hydrogen. Gas production was continuous though decreased with time. An average 48.7% of the electrical energy input was recovered, with a Coulombic efficiency of 41.2%. COD removal was inconsistent and below the standards required. Limitations to the cell design, in particular the poor pumping system and large overpotential account for many of the problems. However these are surmountable hurdles that can be addressed in future cycles of pilot scale research. This research has established that the biological process of an MEC will to work at low temperatures with real wastewater for prolonged periods. Testing and demonstrating the robustness and durability of bioelectrochemical systems far beyond that in any previous study, the prospects for developing MEC at full scale are enhanced.

The potential benefits of applying microbial electrolysis cell (MEC) technology to wastewater treatment are clear and profound. Previous pilot studies have demonstrated a 'proof of concept' with domestic waste at ambient temperatures, but have not yet treated waste to required discharge standards, and have not reached energy neutrality. In addition, these reactors have been many orders of magnitude smaller than would be needed for full scale wastewater treatment plants. Scale-up affects many of the parameters that underpin performance; understanding its impact will be vital to further progress. Modifying a previously tested cassette-style design, we reduced the internal resistance, and increased the module size by a factor of 16, constructing an MEC with six 1 m 2 anodes. This created an anodic surface area to volume ratio of 34 m 2 m -3 . The system was operated at a hydraulic retention time of 5 hours on settled domestic wastewater for 217 days, producing more current than a scaled-down reactor, which was run in parallel. The large MEC produced 0.8 L of 93% pure H 2 d -1 at ambient winter temperatures (11.4 + 2.5°C). Chemical oxygen demand (COD) removal averaged 63.5% with an average effluent quality of 124.7 mg COD L -1 , achieving the European Urban Wastewater Treatment Directive (1991) consent.

Sustainable drainage systems (SuDS) have become a key tool in the design of water sensitive cities, due to their capacity to store and attenuate surface water, and to treat runoff. SuDS implementation requires a complex alignment of planning frameworks, engineering designs, construction practices, maintenance processes, community buy-in and ownership agreements. To understand this alignment, and build an evidence base on the implementation and management of UK SuDS, a questionnaire was distributed to 50 000 industry professionals by the Chartered Institution of Water and Environmental Management. The findings suggested that SuDS are beginning to become the norm, although 'harder' solutions tend to prevail. Additionally, design and construction remain weakly regulated, and there is a lack of clear legal framework on SuDS ownership and maintenance. Expert practitioners supported the need for a single adoption method, coordinated by the local authority and suggested policy changes to make SuDS obligatory.

The COVID-19 pandemic led to drastically altered working practices. During the UK lockdown, a questionnaire was distributed to water professionals to understand their experiences and perceptions of organisational response. Findings were evaluated on the measures of mitigation, adaptation, coping and learning. Employees' perceived there were adequate procedures to mitigate a threat, partly due to preparations for Brexit. Participants quickly adapted, with eighty-four percent working from home. Coping was experienced at an individual and sector level. IT issues and care responsibilities made it harder for individuals to cope, but good communication and signposting of support helped. Eighty percent felt able to continue their usual role, implying coping mechanisms were effective. At the sector level, coping involved the ability to meet an increased water demand with a remote workforce. Lessons learned highlight the importance of communication and collaboration. Future crisis plans should prepare for prolonged crises of international magnitude and multiple threats.

The unprecedented scale and impact of the COVID‐19 pandemic have required organizations to adapt all facets of their operations. The impact on the UK water sector extends beyond engineering and treatment processes, with social, economic and environmental consequences. Semi‐structured interviews were conducted with executives from 10 UK water companies to investigate the organizational response to the pandemic, and how their response impacted operational delivery. The Safe and SuRe framework was used to structure interview questions and analysis. Emergent themes of changes to customer behaviour, changes to operational practices and industry collaboration were mapped onto the framework and a ripple effect map developed. Lessons learnt highlight a failure to adequately prepare for the scale of the threat, the success of sector‐level collaboration and a need to embrace new ways of working.