Role of Wastewater Process Control in Delivering Operating Efficiencies

Reference: 13/WW/21/16
ISBN: 1 84057 678 2
Published Date: 20/05/2013

Improved control and optimisiation of wastewater treatment processes offers the potential for significant energy, chemical and carbon savings. In recent years, Advanced Process Control (APC) technologies have been trialled and installed by water companies and it is anticipated that the use of these systems will increase in the future. Using case studies and theoretical models, this project examined the impact APC may have on the receiving water, addressing concerns by the regulator relating to discharging less variable effluent with a potential increased load.

Price: £18  

The Relationship between Per Capita Consumption and Wastewater Flows

Reference: 12/WW/21/15
ISBN: 1 84057 660 X
Published Date: 13/12/2012

Water saving measures may have an effect on per capita consumption (PCC) and hence on the volume of wastewater generated (DWF); however the relationship between PCC and DWF is not fully understood. Modification to WwTW design criteria without defining the relationship introduces environmental risk and/or potential premature expenditure by water utilities.
The aims of this study were to understand and quantify any relationship between PCC and DWF; to understand any implications for WwTW process design; and offer guidance relating to the integration of water resources and wastewater planning.
The study analysed data from two catchments during implementation of a universal metering programme (UMP). It found that the relationship between per household consumption (PHC) and flow returned to sewer (G) was a function of house type and/or socio-economic group, and season. Water demand modelling suggested that universal water metering should reduce DWF by an amount which depends upon catchment characteristics. However, no significant reduction in household water use from pre-UMP levels was observed.
Reduced catchment flows were shown by modelling to have only small effects on WwTW discharge compliance and hence, no changes to existing design criteria for wastewater treatment processes are recommended,

Price: £24  

Economic Level of Service for Sewer Blockages

Reference: 10/WW/21/14
ISBN: 1 84057 568 9
Published Date: 01/09/2010

Over 160,000 sewer blockages are reported each year in England & Wales; or about 0.5 blockages per kilometre of sewer per year. These lead to a wide range of service failures including property flooding and pollution. About 75% of the blockage management activity is in reaction to failures, although the amount of proactive work to prevent blockages has increased in recent years.
This report provides guidance in recommended reactive and proactive approaches to blockage management including newly emerging techniques. Improved reactive blockage management techniques include better blockage clearance tools and technologies for inspecting the sewer after clearance to identify residual problems. Innovative proactive techniques include programmes of regular cleansing, level monitors and automatic flushing devices. There is also a strong role for Network Protection Officers to discourage the discharge of material that can cause blockages.
The project outputs include a strategic optimisation tool (BELS) that can be used to identify how to achieve either the least cost to the company to achieve a target level of service or the best value level of service considering costs to the company, customers and other stakeholders.

Price: £18