Envco – Environmental Equipment

Landfill Gas Leaks   
Government regulations require surface level methane measurements to be regularly recorded in landfills; these are conducted in order to minimize leakage hotspots and fugitive emissions. But are these methods working? Is this data reliable? Are traditional walkovers cost effective?

Surface level methane (CH4) measurement can provide insight into the health of the landfill cap, whilst detecting unintended emissions. However sourcing the origin of these in an open environment can be difficult. In some cases a more accurate account of landfill health may be given by measuring oxygen levels within bore sites; high oxygen readings and low back pressure can be indicative of void zones or cap instability.

“We constantly search for the best solutions to help control client liability in project management, and recommendations in controlling pollutant sources.”

Case Study:
A client with a closed landfill currently generating power from landfill gas encountered decreasing CH4 values throughout the period of production; these caused a deficit within the generation scheme. This site had historically provided positive yield until 20 more extraction points were inserted into the extraction halo. Increased ambient walkovers and wellhead measurements confirmed a problem but could not locate the sources.

Envco suggested use of a FLiR device. “Forward Looking Infrared” is typically used during search and rescue, or with military devices for detection of heat sources and thermal variation. It is now commonly used for electrical and leaky home inspection. The heat escaping through pores and chasms from the degradation of refuse material can be seen via thermal imaging. Envco suggested using this system on a cold morning with the extraction system turned off for the night prior. FID techniques indicated there was a problem but could not identify specific sources. FLiR produced excellent visual images of trouble spots throughout the soil cap.  As a result over 40 fugitive leak points were located.

Technological advancements now allow fuming gas to be clearly visible in thermal images. These images illustrate the effectiveness of infrared walkovers in conjunction with FID instruments.

Envco can provide the advice and equipment needed to support your purpose.  We strive to provide timely estimates and professional “hands on” support.

Contact Envco for more information on FLiR systems or landfill walkover services.

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