Background

Polluted water contaminating the surface water and drinking water supply has been identified by the EPA as one of the most serious environmental problems facing the United States Leaking sewage collector lines, storm water drain discharges and illegal taps into storm water drainage lines can often be identified by their thermal infrared signatures during certain times of the year. As these sources of pollution leak, seep or empty into creeks, streams, rivers and lakes, their thermal signatures vary from their surroundings and they can be pinpointed accurately from the air.

This flow of liquid typically appears warm as compared to the surface water in a creek, stream, river or lake - particularly during cooler times of the year, due to the relative warmth of the ground a short distance below the surface. Leaks from nearby lines often come to the surface through lateral transfer to a creek, stream, river or lake bed, or to a slope leading down to the surface of the water. These leak areas and the warm plume of liquid joining and flowing downstream with the body of water are visible in the thermal infrared spectrum due to the difference in temperatures of the two liquids. Late fall, winter and early spring are well suited to this type of inspection because of the different water temperatures (ground and surface waters) and because the interference to view by foliage is minimized. Ground water seeps and outfalls of all types are also easily distinguishable for similar reasons.

How Can Pollution FindIR™ Help Me?

Stormwater collection systems are engineered to discharge into surface waters to efficiently drain selected areas. All too often these systems convey pollutants from illicit connections, degraded sanitary sewers and other sources.

Until now, locating these point sources has been a labor-intensive task, often relying on sampling data from sites that may be blocks or even miles from the actual source.

Let Aerial Infrared Thermographers’ Pollution FindIR™ Service do the dirty work for you… at 100 mph!

Pollution FindIR™ Reports include:

• Digital image files of selected infrared images with the name coordinated to the exact location.
• Printed list of all anomalies, indicating the location of each anomaly by latitude/longitude and by location/image number.
• Printed maps indicating the exact location of each anomaly.
• CD-ROM containing all digital files from the project.
• VHS videotape copy of the raw infrared imagery. (Original digital copy is available on request.)

Understanding Aerial Infrared Thermography

Infrared imagery is often a grayscale picture whose scales (or shades of gray) represent the differences in temperature and emissivity of objects in the image. As a general rule, objects in the image that are lighter in color are warmer and darker objects are cooler. No object in the images is detected via visible light wavelengths (400-700 nanometers) rather, only from infrared wavelengths in the 3000-5000 nanometers or in the 3-5 micrometers range (see the sample at the end of this document). Lights and other relatively hot objects are very evident, but as a result of their heat - not light emissions.
When an image is taken with infrared camera, it is often recorded on video tape and later converted to a digital image file with the help of a computer. The image may be then modified in a number of ways to enhance its value to the end user. The highest resolution infrared images are usually found on videotape, while the printed thermographs and map data may be used as a convenient reference when accompanying a report.

Advantages of Pollution FindIR™ method...

• With all system anomalies marked on a map, the system operator can prioritize areas of concern and concentrate efforts and scarce resources on problem locations first.
• The printed report and map data will allow the operator to quickly and efficiently locate and test suspect areas.
• Previously inaccessible or hard to reach areas of the system can be monitored.
• Straight down, high resolution infrared imagery provides you with accurate data.
• Fixed-wing aircraft allow AIT a cost-effective platform to obtain high quality infrared imagery, passing savings on to you!
  

Here’s how it works...

The flow of liquid typically appears warm as compared to the surface water in a creek, stream, river or lake—particularly during cooler times of the year, due to the relative warmth of the ground a short distance below the surface.

Leaks from nearby lines often come to the surface through lateral transfer to a creek, stream, river or lake bed, or to a slope leading down to the surface of the water. These leak areas and the warm plume of liquid joining and flowing downstream with the body of water are visible in the thermal infrared spectrum due to the difference in temperatures of the two liquids. Late fall, winter and early spring are well suited to this type of inspection because of the different water temperatures (ground and surface waters) and because the interference to view by foliage is minimized. Ground water seeps and outfalls of all types are also easily distinguishable for similar reasons.