STI Engineering has been performing in-situ landfill investigations since 1984. We have developed a method to locate and profile gas pressure, liquid pressure and vacuum zones in landfills and in the vadose zone. The process involves the use of the side-sensing piezo-penetrometer cone (PPT) which is pushed into a landfill. The data is continuously recorded the full depth of the landfill and inputted into a computer. A 3-D profile of the conditions inside the landfill is created from this data.

This profile is used to perform the following:

• Design and construct landfill gas collectors
  
• Map out the daily cover layers
  
• Project pathways for subsurface gas migration and surface emmissions
  
• Avoid installing collectors through pockets of liquid
  
• Screen sections are installed only where the gas is located
  
• Map out the vacuum influence of existing collectors

The above 3-D Profile was performed at a landfill in Southern California. This profile was able to identify the cause of the impacted perimeter monitoring probe by LFG. Note the lack of vacuum (pink) in the foreground of the profile. The LFG is migrating straight to the probe which is to the right of the profile. Push-in 2" diameter steel collectors should be installed in the LFG (yellow) area to collect this LFG. This process eliminates a lot of the guess work in placing collectors.

By clicking on the above buttons you will find the following:

Landfill Compliance - This page will describe an innovative method to keep your landfill in compliance with regulatory agencies. It will also describe the use of Internal Conduits to increase the extraction of LFG without installing another collector.

The Procedure - This page will describe the procedure (PPT Landfill Gas Profiling)used to obtain and interprete the data used for landfill engineering.

Push-In Collectors - This page will describe the advantages of installing Push-in collectors compared to conventional drilling methods. There is also a cost comparison of both methods of installing collectors.

Clients & Projects - This page contains a list of some of the past clients and projects.

Feedback - STI invites you to provide questions and comments on the contents of this website.

Steam Injection - This page will describe the advantages of injecting steam into a landfill instead of liquid, to enhance the biodegradation of MSW.

STI appreciates you taking the time to review this information and is looking forward to discussing your landfill issues in the near future.

Reg Renaud
President