Product category:
Pressure sensors
News Release from: Burkert Fluid Control Systems | Subject: Pressure transmitters
Edited by the Engineeringtalk Editorial
Team on 21 January 2004
Pressure transmitters help clean
landfill sites
Equipment supplied by Burkert Fluid Control Systems is being used by CPS Environmental to monitor and control the pumping of leachate from landfill sites.
Equipment supplied by Burkert Fluid Control Systems is being used by CPS Environmental to monitor and control the pumping of leachate from landfill sites Put simply, a landfill site is a hole in the ground that is lined to contain commercial and household waste
As rubbish builds up, rainwater passes through it and collects in the bottom of the site as leachate.
Removing this leachate from landfill sites is a major problem for operators, who are required by the Environment Agency to maintain ground water and leachate at consent levels for the duration of the waste management process.
CPS Environmental of Nottingham designs and manufactures specialised pumping systems for some of the UK's largest waste operators, including Onyx UK, Sita, The Waste Recycling Group and Biffa Waste Services.
The systems monitor and remove leachate from landfill sites via boreholes or "wells" that are sunk through the waste down to the liner.
The boreholes, which are typically a metre wide and can be between 15 and 75m deep, are located throughout landfill sites, with smaller sites needing between three and five wells and larger sites up to 30.
Even when a site is full and capped with clay to prevent more rainwater leaching through, waste continues to decompose and leachate builds up in the boreholes.
Regulations require the leachate to be pumped out continuously until the site is completely drained, which can take between 20 and 50 years.
Until recently the monitoring of leachate levels had been performed manually using a 100m dip cane that was lowered into the well to measure the depth, but this was not particularly accurate.
Also, the pumps installed in the "wells" were switched on and off using probes.
About a year ago the CPS began looking for an alternative method of monitoring and controlling leachate levels, as spokesman Mark Latham explains: "We wanted a system that would improve the accuracy and efficiency of our service.
During the initial design stage we looked at products from eight companies and talked to their engineers".
"Burkert was chosen because its people were the most helpful and informative and the technical backup provided was the most knowledgeable".
He says the fact that Burkert equipment is also very cost effective is a bonus.
Burkert supplies pressure transmitters to accurately measure the depth of leachate in the boreholes, and controllers that turn the pumps on and off.
The pressure transmitters are lowered into the well through the dipping tubes and are located on the bottom with the pumps, where they remain for the life of the landfill site.
Controllers receive continuous information from the pressure transmitters and, when the leachate reaches a high or low-level set point (adjustable from the controller menu), the pump is switched on or off.
With real time control, leachate cannot exceed acceptable limits and pumps only run when necessary, reducing wear and increasing lifespan.
Says Latham: "Previously someone had to pay daily visits to every borehole on every site in order to check leachate levels.
The Burkert pressure transmitters allow us to monitor the depth of leachate at each site automatically by providing accurate, real-time information and data is transmitted to a computer in the site office, which can be up to a mile away from the actual landfill site".
He adds that the system also enables customers with a number of sites to access information remotely from all their boreholes.
The information is also stored in the computer, creating a complete history of leachate levels and pumping schedules to ensure that accurate documentation is available for inspection by the Environmental Agency at any time. Request a free brochure from Burkert Fluid Control Systems ...
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