Storm Overflows & Urban Pollution Management

WRc specialists evaluate risks and consult on environmental compliance surrounding storm overflows, in line with guidance for Urban Pollution Management (UPM).

Dr Karen Murrell is our expert in Urban Pollution Management

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Combatting storm overflow pollution

Combined sewer overflows (CSOs), storm tanks and pumping station overflows are collectively known as intermittent discharges. During periods of heavy rainfall, they serve as relief points for hydraulically overloaded sewer networks to prevent flooding of properties and buildings and to protect wastewater treatment works.

When storm overflows spill, diluted storm sewage enters the environment, impacting the chemical and microbiological water quality of receiving and downstream water bodies. Effective Urban Pollution Management (UPM) diminishes the environmental harm and ensures that water company discharges allow rivers and coasts to comply with Environment Quality Standards.

How we can help

WRc provides specialist knowledge and the development of modelling tools relied upon by water companies to help plan and target future investment. The task of assessing the quantity of pollutants discharged to receiving waters is challenging; collecting data during storm events is expensive and time-consuming, and historically not all storm overflows have been represented in sewer network models.

We can help you quantify the frequency and duration of spills, spill volume, and pollutant concentration of storm overflows. Our consultancy ensures time-effective, cost-effective compliance with UPM environmental standards.

Guiding environmental recovery

Our specialist consultants are dedicated to guiding the journey towards your environmental goals.

Sharing our knowledge for a cleaner world

Our comprehensive UPM training modules enhance beginners' understanding, confidence and practical experience.

Providing reliable tools for excellence

Our rapid but simple modelling tool, UPM-RAT, allows users to easily evaluate your wastewater performance against UPM standards.

UPM Rapid Assessment Tool

A fully integrated model of CSOs, storm tanks, WwTW and rivers

WRc's simple, rapid assessment tool evaluates the combined impact of continuous and storm overflows from small urban wastewater systems. UPM-RAT aids both Utilities and Environmental Regulators in the development and acceptability of proposals.

Interested? We'd love to hear from you. Enquire about UPM-RAT using the contact form at the bottom of this page.

  • Features tailored to the user
  • Concise on-screen outputs
  • Automatic sewer network calibration
  • Features a simple, user-friendly interface.
  • Designed for rapid repeated simulations for different assumptions, each providing a full audit trail.
  • Requires minimum data inputs, saving time.
  • Tailored for regional multi-year rainfall simulation, provided by STORMPACâ„¢.
  • Allows use of different runoff models.
  • Custom pricing to suit individual needs, including training and multi-user options. 
  • CSO spill frequencies and volumes
  • Storm tank spill frequencies and volumes
  • River reach performance against Fundamental Intermittent Standards (FIS)
  • River reach performance against WFD percentile standards.

Automatic calibration of the sewer hydraulics to agree with the information from an InfoWorks model of the catchment. 

This allows users to rapidly create a simplified sewer network from the available information.

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Can we stay in touch?

Your details will be stored within our CRM to allow us to handle your enquiry. We'd love to keep in touch and send you our newsletters and other notifications we think may be of interest to you. Please let us know if we have your permission for this.

Dr Karen Murrell

Principal Consultant

Karen's expertise lies in river impact assessment and integrated catchment management studies involving river hydraulic and quality modelling (both model application and development). This includes determining impacts of weather derived rural and urban pollution on receiving water quality. She also has extensive experience in consenting policy and application. Karen regularly works to apply deterministic and stochastic river quality models, such as SIMPOL ICM and SIMCAT/SAGIS, for WFD compliance, climate change impact assessment and Urban Pollution Management (UPM) studies.