Water Reuse OPEX & Carbon: EWSC report finds that water reuse is more cost-effective than previously assumed
About this article
The Enabling Water Smart Communities project sees the release of its latest report, led by ARUP, titled: Water Reuse Whole Life OPEX & Carbon.
The purpose of this report was to explore the operating expenditure (OPEX) of communal water reuse systems within residential settings in England. It also looked at the carbon impact these systems have over the course of their lifespan.
Enabling Water Smart Communities is a project led by Anglian Water with the goal of making integrated water management the norm in new developments. The project has been working towards this objective by collaborating with various housing associations and developers to build an evidence base demonstrating the numerous benefits of integrated water management for both the general population and the environment.
As part of this, EWSC has collaborated with leading consultants, ARUP, to produce a publication which contains a detailed outlook on how water reuse is less expensive to implement than previously thought, in addition to the positive carbon case of water reuse systems.
This short article will serve as a summary of key points mentioned in the report, a look into our thoughts, and what this means for housing developers.
Key Points
Water Reuse is more affordable than assumed
Enabling Water Smart Communities’ research stems from 12 different sites of different densities and found that the operating expenditure, per home, for a communal water reuse system, over a period of 100 years, was £130 per year for a one-bedroom dwelling and up to £220 per year for a two-bedroom dwelling.
This cost depends largely on the density (number of houses) of the development, as fewer homes will result in reduced economies of scale. It is also noted that system configuration and the type of system itself also has an influence on the whole life cost per home.
It should also be mentioned that these incurred costs look to be offset by the savings in water bills that customers and residents will experience due to these communal systems. These savings are illustrated in the report by research which shows an estimated reduction in water bills of £100-£150 for a 1-bedroom flat occupied by two residents. These savings increase for larger dwellings, with savings of £250-£375 for a 5-bedroom home occupied by 5 residents.
Water Reuse costs are comparable to Infrastructure upgrades
In this report, it was identified that the whole life OPEX for water reuse per m³ ranged from £3.00 to £7.50.
Upgrades to infrastructure conducted by water companies and their cost were also analysed, in particular, demand management options and water supply options. The cost of these solutions ranged from £3.30 to £5.70 per m³ and £3.00 to £7.50 per m³, respectively.
Whilst the costs of upgrades currently achievable are seen to be lower, the cost of water reuse is not sufficiently higher as to make it an unsuitable method of supporting infrastructure.
Labour costs are the largest contributor to operational costs
At one of the sites researched by Enabling Water Smart Communities, it was estimated that the labour behind the operation of the water reuse system accounted for over 50% of total costs.
A positive carbon impact
Due to the operational water carbon savings generated by water reuse systems, any embodied carbon generated during their entire lifecycle is offset.
Based on the type of system deployed and the type of development, the whole life carbon emissions, over a 100-year period, is estimated to be 1,000 kgCO2e – 2,100 kgCO2e per home.
Out of a range of reuse systems, Rainwater Harvesting was found to have the lowest whole life carbon, further illustrating its positive environmental impact.
Here's our take
This is another fantastic report that continues to shine the spotlight on water reuse at a critical time, where momentum around the space has been larger than ever. We believe that because of the tangible financial evidence highlighted in this report, a positive impact has been made on the public perception of communal water reuse, taking another important step towards its wider implementation in new developments.
Alongside previous research by Enabling Water Smart Communities, which highlighted the cost-effectiveness of communal-scale reuse over single-plot solutions, we have no doubt that the findings displayed in this report will provide valuable insight around communal-scale water reuse for developers across the UK.
