Modelling solid transport and deposition in urban sewerage systems

Reference: 19/SW/01/19
ISBN: 978-1-84057-868-3
Published Date: 23/04/2019

The overall aim was to model solid transport and deposition of sediment in urban sewerage systems as a means to investigate the possible impact of water conservation measures taken in the home on the self cleansing ability of a sewerage network.

Price: £50  

FOG Control and FOG Collection: A joined-up approach

Reference: 18/SW/01/18
ISBN: 1 84057 859 9
Published Date: 07/10/2018

Sewer blockages due to discharges of fats, oils and greases (FOG) can cause flooding and pollution events. These events are unpleasant for the public, can cause property and environmental damage and can result in the Water and Sewerage Companies (WaSCs) receiving a fine. Further to this, Outcome Delivery Incentives (ODIs) have been set within the water companies in England and Wales to financially motivate, using penalties and rewards, lower occurrences of sewer flooding events (amongst other categories). Through detailed interviews with UK WaSCs, it was found that 13-31% of blockages in the UK are attributed to FOG, that uncertainties lie around WaSC legislative powers, and that the education and enforcement approaches differ. These interviews and the comprehensive literature review and interviews with global water utilities, local authorities and FOG collection/recycling solution providers gave insight into the various approaches employed across the world to control FOG discharges, and the opportunities for FOG collection and recovery in the UK. The FOG strategy, developed as part of this project clearly sets out the path to collect and recover all FOG by 2030, and achieve zero uncontrolled FOG discharges from sewers by 2050.

Price: £65  

How best to align the funding processes with the various bodies involved in resolving flooding

Reference: 16/SW/01/16
ISBN: 1 84057 820 3
Published Date: 07/10/2016

Collaborative working between water and sewerage companies is in its infancy and there is therefore a need to develop common and systematic approaches to:

- identify and prioritise collaborative funding opportunities;
- work together to identify the full set of costs and benefits to different partners;
- ensure that partnership working can save money, unlock investment, and deliver multiple benefits;
- apportion benefits of investment to each partner and hence indicate a potential funding contribution, and;
- consider appropriate delivery mechanisms, and how to manage financial and delivery risks.

Guiding principles developed for this project build upon the existing good practice and will support a common and systematic approach to unlock collaborative opportunities. 

This report is available free of charge from the Environment Agency's website.

Price: £100  

The Practicality of a PPM Approach for Managing Sewer Blockages

Reference: 16/SW/01/15
ISBN: 1 84057 806 8
Published Date: 22/01/2016

This study identifies and quantifies the features of the various Planned Preventative Maintenance (PPM) approaches for managing the 350,000 blockages that occurring in the UK each year. The effective management of blockages first required the characteristics to be understood and this included demonstrating they are not random events. The use of Multiple Factor Analysis identified both static and time varying blockage correlations factors to explain the non-randomness, and this provided the ability to target PPM activities or explain performance changes. The use of SewerBatt to repeatable survey 50 sewers over a 6 month period showed blockages form when a set of circumstances occur following cyclical process of accumulation and erosion. The financial and non-financial features of the most common PPM approaches were quantified and the economic analysis completed, with the results being presented in an Intervention Hierarchy.The outputs from the study have been used to formulate a series of recommendations to improve the management of sewer blockages.

Price: £60