Monitoring the chemicals

How effective are current treatment processes in dealing with the removal of some priority substances? The Chemical Investigations Programme aims to find out.

Every wastewater treatment company in England and Scotland, including Severn Trent Water, is currently taking part in a UK Water Industry Research (UKWIR) project that aims to establish environmental quality standards (EQS) for priority hazardous substances in the water system.

Called the Chemical Investigations Programme (CIP), this initiative has been set up by UKWIR in collaboration with the Environment Agency (EA) to investigate the effectiveness of current treatment processes in dealing with the removal of some priority substances, as related to the EQS, should these be considered in the future.

Severn Trent Water has brought in West Midlands-based environmental monitoring specialist enitial to look for the presence of up to 33 chemicals potentially being released into receiving water bodies.

Some of the chemicals that are being monitored include substances found in everyday pharmaceuticals such as ibuprofen and oestrogen which, while in small concentrations pose no risk to the environment, could cause some problems in higher concentrations.

Studies have shown that high levels of oestrogen have the potential to create breeding problems for certain fish species.

The Severn Trent Water programme, being coordinated by the environment consultancy WSP, has three main components that aim to measure concentrations of priority substances to identify if trends exist and to investigate what treatment processes could manage and control their removal.

The process begins with a survey to quantify the presence of these chemicals, which is where enitial comes in. It will be collecting some 3,000 samples across 37 wastewater treatment sites over the 18-month programme. Each technician will visit five sites a day and take up to 20 samples of treated wastewater discharged into the river system.

Notes are taken at the time each sample is taken on various factors, including weather conditions, for a document which accompanies the samples to the lab, known as the “chain of custody”.

Once the samples have been collected and bottled they are sent to the National Laboratory Service (NLS) in Nottingham to identify concentrations of priority substances, such as ibuprofen, oestrogen, mercury and lead. The next stage looks to assess the various treatment options for chemicals and how well different processes affect the efficiency of their removal. enitial technicians will work at five specific Severn Trent Water sites taking samples from various points in the wastewater treatment process to analyse what is happening to the chemicals at each stage of the process.

The final stage will be undertaken by research consultancy WatStech and will analyse various source catchments and the effect different products have on these substances. This aspect of the programme is the first of its kind and will provide much needed experience and

guidance for similar programmes about to commence across the UK.

Ivor Parry, business development director at enitial and contract director for the Severn Trent Water programme, says: “This is an important programme which will look at what’s happening to these chemicals in the wastewater treatment system. It will help Severn Trent Water to understand how effective its wastewater treatment methods are at removing these substances should tighter limits be imposed in the future.”

All the data will be fed into a database to allow UKWIR to look at emerging trends across England and Scotland. Early feedback has shown that whilst older wastewater treatment works have little effect on the composition of the key chemicals, newer, more process efficient, works are having a much greater impact.

“We are pleased to be working with enitial on this programme, which will provide valuable data on the ability of various existing and more novel waste water treatment technologies to meet new river quality standards, should they be introduced in the future,” says Severn Trent Water’s Mark Jones.

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