Case Study


Chemical investigations programme - phase 2

UKWIR was engaged by the water industry, the Environment Agency and other UK Regulators to manage The Chemical Investigation Programme (CIP) comprising of £25m of research into the management and control of a range of emerging substances of concern that are likely to be found in all stages of the wastewater treatment process.

The five year programme, begun in 2010, provided the necessary evidence base to inform future policy decisions regarding measures (both catchment management and treatment) to regulate these substances. This can be by using ‘upstream’ source controls or by investment in existing and novel treatment processes. It provided evidence for consideration of the technical feasibility and proportionality of the costs of such measures.

The success of the programme has led onto a second £140m phase which is now well underway and due to finish in 2020.

The project links in well with UKWIR’s Big Questions Programme, looking how to turn all wastes we receive into products by 2030 and how to achieve zero uncontrolled discharges from sewers by 2050.

UKWIR hosted a workshop at the Institution of Civil Engineers last November to disseminate the progress and initial findings of this second phase.

The workshop was chaired by UKWIR Programme Lead, Howard Brett of Thames Water with sixty delegates from water companies, consultants, government, Regulators, academia and NGOs in attendance.

Mike Gardner and Arthur Thornton from the main contractor, Atkins, gave presentations and outlined the scale of the research and presented the initial findings.

Seventy four substances, not including pesticides, were extensively monitored at over 600 wastewater treatment works, an exercise which often tested the analytical limits of detection.

Many of the chemicals have a domestic origin and therefore present issues across the whole country. They include fire retardants, pharmaceuticals, artificial hormones and personal care products that all manage to enter the sewerage system.

The wastewater treatment works investigated have been chosen to represent the range of plants nationally. There was a focus on locations where the dilution of effluent in the receiving water is low and hence where there is a high risk of elevated concentrations of substances.

Samples of river water upstream and downstream of the wastewater discharge, as well as samples of effluent, have been analysed and the results compared with proposed water quality standards.




Initial Findings

• the principal source of many of these emerging substances of concern is domestic. As there is considerable similarity between effluent quality at different wastewater treatment works, substances identified as problematic at one location are likely to be so at others.

• river water quality is not solely determined by concentrations of these substances in the effluent in the immediate locality. This means that water quality upstream of a discharge can have a bearing on downstream compliance.

• eight chemicals have been identified as posing the greatest risk. They include several fire retardants that are used in materials, an insecticide (that is relatively harmless to humans) and a group of substances that are generated by combustion processes.

• comparisons of data with that from the first phase of work provides evidence of reductions in concentrations of some substances. This indicates the emerging success of control measures that have been put in place since 2010 (eg. bans on usage).

• several novel treatment techniques have been examined that could be used to supplement existing processes. The option of using these techniques more widely is under consideration, while bearing in mind the cost and likely effectiveness of the different available approaches. However, no single treatment process can remove all substances of concern.

Potential concern

Whilst pharmaceuticals are not at present regulated in surface waters, data from CIP2 suggests that, as new legislation is developed, of the twenty compounds examined, some analgesics, antibiotics and steroid hormones (natural and synthetic) are of potential concern.

The presenters stressed that the conclusions summarised above represent an initial assessment of results from a programme that still has nearly three years to run. Hence they must be regarded as provisional inputs to the process of identifying pollution control measures that are necessary, worthwhile and justifiable.