Project Appreciation and Objectives
There is a need to understand more fully the ability of WwTWs to meet stringent ammonia standards during periods of cold weather. These limits may not be achievable in cold weather conditions, despite relaxation clauses within existing Environmental Permits, and can be prohibitive in cost terms. Detailed advice is required to assist operators to have informed and constructive dialogue with the Environmental Regulators on the interpretation of exceptional weather conditions, particularly where they might be considered to be out of line with other European Countries.
Building on the outputs of UKWIR WW04: The Implications of Cold Weather on Nitrification Treatment Processes 2011 undertaken by WRc, this project will collect performance data from WwTWs across the UK together with experiences from other colder countries to identify which treatment processes are most resilient during cold weather conditions.
The objective is to develop a robust science base, supported with an in-depth review of European practice for regulating WwTW performance in cold weather conditions, to understand where UK and European Practice could be better aligned. This will enable fully informed and constructive discussions with the UK Environmental Regulators, who have expressed interest in this project.
Business Benefits to Clients
- Evidence and science based dialogue with environmental regulators regarding future regulatory control practice in relation to WwTW cold weather nitrification in the UK.
- An understanding of the implications of UK cold weather events and how they are likely to change in the future in order to optimise business planning processes.
- Collate regulatory practice in other European Countries and review ammonia toxicity standards for low temperatures.
- Collate and analyse water company data.
- Collate information on treatment processes most resilient to cold weather conditions;
- Analyse frequency of UK cold weather events;
- Produce guidelines in consultation with the Environmental Regulators.
- Hold workshop with participants and representatives from the Environmental Regulators.
Project Output and Implementation
- Guidance on expected performance of biological sewage treatment processes during, and after, periods of extreme low temperature, based on evidence, to support dialogue with the regulator on weather-related effects outside the control of the operator.
Related WRc Work
- UKWIR WW04: The Implications of Cold Weather on Nitrification Treatment Processes 2011.