Keeping cool


Aquamatic investigates the need to keep biological samples at the correct temperature to enable suitable analysis of wastewater quality


The ability of an effluent treatment plant to achieve consistent biological phosphorus removal has made sampling an increasingly important consideration – and as flow rate and wastewater quality change continuously, the need to keep samples refrigerated has never been so great. As soon as a biologically active sample is taken, for example from a brewery or a food-processing plant, its constituents must be maintained at a temperature of 0-5°C.

Biological activity such as microbial respiration, chemical activity such as precipitation or pH change, and physical activity such as aeration or high temperature must be kept to a minimum. The length of time a constituent in wastewater will remain stable is related to the character of the constituent and the preservation method used.

For a biodegradable sample, however, the number of days must be kept to a minimum, especially in warmer climes, where a sample will inevitably degrade very quickly, usually leading to a higher bill, due to its being deemed as a “typical” example of a company’s wastewater. Peter Smith, managing director of wastewater sampler manufacturer Aquamatic, says: “Not surprisingly, water companies commonly insist upon samplers with built-in refrigeration, particularly for the vast numbers of sites on which the use of portable samplers is more practical and economical. However, some industrial end-users have, until now, put up resistance to the investment of a sampler with refrigeration.”

He adds: “Keeping within the law by not breaking consent limits is of course vital, but the need to reduce one’s effluent bills – which for most have soared in recent years – has definitely sharpened the mind.” For the industrial user, says Smith, a wastewater sampler has become a very powerful conduit to financial savings because it can eliminate the lottery that is inadvertently caused when a sample is taken at a time which may not reflect a typical discharge of effluent.

“This isn’t about water companies trying to grab as much revenue as they can,” he says. “Far from it. It’s usually the water company advising their customer to invest in a sampler, so they can then take their own samples. During a longer period of regular sampling, this will give a far more representative picture, hence a fairer effluent bill, than a one-off visit by the water company.”

At minimum, taking ownership of one’s wastewater sampling develops into an opportunity to examine the plant’s overall performance, gaining a greater understanding of why the effluent is the way it is. Industrial users sometimes make the unwelcome discovery that they are pouring valuable product straight down the sewer. Samplers enable them to identify problem processes such as incorrect tank flushing, which might be contributing to the costly effluent charges they are experiencing. The variation in effluent at different times of day can sometimes manifest itself in as obvious a way as samples being totally different colours. It might be expedient for a company to take samples every hour, rather than just once every 24, in order to pinpoint where savings could be made.

New demand to rent

There are still many small and medium-sized treatment works requiring samplers by the 1 January 2006 deadline for the Urban Wastewater Treatment Directive (UWTD). Demand for portable equipment has risen significantly, with Aquamatic also reporting a trend for contractors to rent samplers because they are only needed for short-term investigations or feasibility studies.

Ease of use, with a “switch on and go” package, has made reliable, portable samplers an attractive rental proposition for work lasting less than a month, so long as there is also a good back-up service to help with tight deadlines. This, however, is on the strict proviso that the sampler is compliant with E32, the Environment Agency’s Technical Report, which represents the UK’s interpretation of the UWTD as it is applied to Automatic Keeping cool

Aquamatic investigates the need to keep biological samples at the correct temperature to enable suitable analysis of wastewater quality

The ability of an effluent treatment plant to achieve consistent biological phosphorus removal has made sampling an increasingly important consideration – and as flow rate and wastewater quality change continuously, the need to keep samples refrigerated has never been so great. As soon as a biologically active sample is taken, for example from a brewery or a food-processing plant, its constituents must be maintained at a temperature of 0-5°C.

Biological activity such as microbial respiration, chemical activity such as precipitation or pH change, and physical activity such as aeration or high temperature must be kept to a minimum. The length of time a constituent in wastewater will remain stable is related to the character of the constituent and the preservation method used.

For a biodegradable sample, however, the number of days must be kept to a minimum, especially in warmer climes, where a sample will inevitably degrade very quickly, usually leading to a higher bill, due to its being deemed as a “typical” example of a company’s wastewater. Peter Smith, managing director of wastewater sampler manufacturer Aquamatic, says: “Not surprisingly, water companies commonly insist upon samplers with built-in refrigeration, particularly for the vast numbers of sites on which the use of portable samplers is more practical and economical. However, some industrial end-users have, until now, put up resistance to the investment of a sampler with refrigeration.”

He adds: “Keeping within the law by not breaking consent limits is of course vital, but the need to reduce one’s effluent bills – which for most have soared in recent years – has definitely sharpened the mind.” For the industrial user, says Smith, a wastewater sampler has become a very powerful conduit to financial savings because it can eliminate the lottery that is inadvertently caused when a sample is taken at a time which may not reflect a typical discharge of effluent.

“This isn’t about water companies trying to grab as much revenue as they can,” he says. “Far from it. It’s usually the water company advising their customer to invest in a sampler, so they can then take their own samples. During a longer period of regular sampling, this will give a far more representative picture, hence a fairer effluent bill, than a one-off visit by the water company.”

At minimum, taking ownership of one’s wastewater sampling develops into an opportunity to examine the plant’s overall performance, gaining a greater understanding of why the effluent is the way it is. Industrial users sometimes make the unwelcome discovery that they are pouring valuable product straight down the sewer. Samplers enable them to identify problem processes such as incorrect tank flushing, which might be contributing to the costly effluent charges they are experiencing. The variation in effluent at different times of day can sometimes manifest itself in as obvious a way as samples being totally different colours. It might be expedient for a company to take samples every hour, rather than just once every 24, in order to pinpoint where savings could be made.

New demand to rent

There are still many small and medium-sized treatment works requiring samplers by the 1 January 2006 deadline for the Urban Wastewater Treatment Directive (UWTD). Demand for portable equipment has risen significantly, with Aquamatic also reporting a trend for contractors to rent samplers because they are only needed for short-term investigations or feasibility studies.

Ease of use, with a “switch on and go” package, has made reliable, portable samplers an attractive rental proposition for work lasting less than a month, so long as there is also a good back-up service to help with tight deadlines. This, however, is on the strict proviso that the sampler is compliant with E32, the Environment Agency’s Technical Report, which represents the UK’s interpretation of the UWTD as it is applied to Automatic

Sampling Equipment.

Dave Crisp, Thames Water’s team leader for audit and compliance, believes E-32 is still very much the main driver for purchases of portable samplers: “We have the peace of mind that we have E32-compliant equipment and we are complying with urban waste water regulations,” he says. This is echoed by another Aquamatic customer, Dwr Cymru Welsh Water’s Environmental Scientist, Alan Smith: “We have the benefit of reliable, E-32 compliant samplers, which continue to serve our needs very well indeed.”

Service recognised

In addition to the upturn in rental of wastewater samplers,

maintenance contract uptake has also grown significantly, demonstrating the value now placed upon a piece of equipment formerly considered with much less regard. Aquamatic’s Peter Smith adds: “Problems with samplers tend to be quite minor, but as with anything mechanical, preventative maintenance is best, and by creating a dialogue with customers via regular site maintenance visits, we gain a better understanding of their needs.”

Sampling Equipment.

Dave Crisp, Thames Water’s team leader for audit and compliance, believes E-32 is still very much the main driver for purchases of portable samplers: “We have the peace of mind that we have E32-compliant equipment and we are complying with urban waste water regulations,” he says. This is echoed by another Aquamatic customer, Dwr Cymru Welsh Water’s Environmental Scientist, Alan Smith: “We have the benefit of reliable, E-32 compliant samplers, which continue to serve our needs very well indeed.”

Service recognised

In addition to the upturn in rental of wastewater samplers,

maintenance contract uptake has also grown significantly, demonstrating the value now placed upon a piece of equipment formerly considered with much less regard. Aquamatic’s Peter Smith adds: “Problems with samplers tend to be quite minor, but as with anything mechanical, preventative maintenance is best, and by creating a dialogue with customers via regular site maintenance visits, we gain a better understanding of their needs.”

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