The aim of this work is to improve the understanding and basis for calculating Scope 1 process greenhouse gas emissions of nitrous oxide (N2O) and methane (CH4) within the UKWIR Carbon Accounting Workbook (CAW). With reference to the Big Question: “How do we remove more carbon than we emit by 2050?”, this work provides an in-depth literature review of emission factors (EFs), methods and emission reduction concepts for water and wastewater treatment and sludge disposal.

The purpose of this UKWIR project was to review Asbestos Cement (AC) mains installed in various environments across the UK and Ireland and to develop deterioration and failure prediction models for pipes and joints in collaboration with the Water Services of Australia Association (WSAA) AC pipeline collaborative research project.

The report details the factors that were found to affect failure rates and deterioration of AC mains, and the models developed for forecasting failure rates. It also includes information on condition assessment technologies suitable for AC pipes, and recommendations for the levels of field investigation required to validate the models.

The outputs also contain a model calibration kit including Python scripts that can be used by data analysts to recalibrate the models based on individual company data.

Polyethylene (PE) potable water mains have been in widespread use for several decades. Over 30 years ago, Severn Trent Water took a far-sighted approach of laying testbeds of plastic pipe mains, which provided a unique opportunity for sections to be exhumed and studied to establish long term deterioration in typical service conditions.

Chemical and mechanical testing was backed by statistical analysis to show that PE pipes will remain in very good condition, and significantly greater than the commonly quoted 50 year lifespan, with useful information for a number of material cohorts. Focus was also given to joints and useful information provided on creep and its effect. Although butt fusion joints performed well, pipe lifetime is likely to be limited by electrofusion joints.  Causes of deterioration are explained and validated through the analysis with a view given of “end of life”.  A simple risk assessment tool for PE pipe has been developed to assist with the targeting of samples needed when assessing a particular network for asset management decisions on pipe repair and replacement.

The Urban Wastewater Treatment Directive is currently under review in 2020, with discussions being held as to whether advanced treatment for substances such as pharmaceuticals should be mandated to achieve a minimum reduction across wastewater treatment works, as is undertaken within Switzerland. This project looked at the implementation of pharmaceutical removal in Switzerland and its implications for the UK in terms of cost and effectiveness. Conclusions were drawn and recommendations made for the Water Industry and policy makers regarding pharmaceutical removal from effluent at wastewater treatment works. This knowledge will enable UKWIR and its members to inform, engage with and influence policy decision makers to ensure that any changes to the UWWTD are proportionate to the environmental benefit they will deliver.

If companies wish to address and reduce customer-side losses they need an end-to-end strategy that encompasses external supply pipe leakage and internal wastage. The strategy must address both the identification of these losses and how they will be subsequently dealt with. It is the customer who is responsible for their supply pipe and plumbing so any drive by the water company to reduce those losses needs full customer buy-in and collaboration. Customer facing policies therefore need to be in place, clearly stating the approaches the company will take and level of support that will be provided to the customer. This report and accompanying modelling framework provide guidance on different approaches to customer-side losses, the associated costs and the benefits that can be achieved. Using the guidance presented, companies will be able to develop the most appropriate policies to address their own business needs as well as customer satisfaction.