Terra-Petra Expands To Southwest With New Office In Phoenix Arizona

We are pleased to announce that Terra-Petra Environmental Engineering has opened a new office in Phoenix, Arizona – a significant milestone in our company’s growth.

The expansion will enable Terra-Petra to provide highly-specialized environmental engineering, waterproofing, and inspection services throughout the Southwest region.

Headed by Dan Valdez, Director of Field Operations, Terra-Petra will start its mobilization in the State of Arizona, Southern Nevada and New Mexico.

Terra-Petra’s consulting services include, but are not limited to, the following:

Environmental Division

Methane Mitigation

Vapor Intrusion Mitigation

Radon Mitigation

Phase I Environmental Site Assessment (ESA)

PHASE II Environmental Site Assessment (ESA)

Underground Storage Tanks

Oil Well

Waterproofing Division

Building Envelope Consulting

Forensic Waterproofing Consulting

Inspection Services

QA/QC Mitigation System Observation & Testing

QA/QC Waterproofing Building Envelope Observations

Electronic Leak Detection

Terra-Petra’s expansion represents a commitment to serving a greater need for more comprehensive environmental engineering services in the Southwest. We are optimistic about the new opportunities the Phoenix location offers and look forward to building strong relationships with clients in the area.

Terra-Petra Founder Hugh Avery – The Godfather Of Methane

Terra-Petra Founder Hugh Avery – ``The Godfather Of Methane``

Enjoy another amazing sketch by Terra-Petra Vice President Justin Conaway this time of Terra-Petra’s own Hugh Avery.

Hugh Avery is the Founder of Terra-Petra, and now acts as Senior Consultant. He was the first methane gas inspector in Los Angeles and he is recognized for his extensive experience and knowledge of methane mitigation, regulation, permitting, construction design, and inspection.

Hugh found his passion for his work while learning the science and engineering behind the behavior of methane gas, and he entered the field at the very beginning, when the regulations and codes on gas mitigation were being written.

Read more about Hugh

To see more of Justin’s sketches, you can visit and follow his Instagram page @justinconawaysketches

Terra-Petra Completed Successful Oil Well Leak Test

Terra-Petra Completed Successful Oil Well Leak Test

Terra-Petra completed another successful oil well leak test, this time in Placentia, CA.

We were on-site to direct the excavation contractor in an effort to locate two buried oil wells on a property scheduled for a commercial redevelopment.

Once uncovered, Terra-Petra completed in oil well leak testing activities accordance with State of California Department of Conservation, Geologic Energy Management Division (CalGEM) guidelines and the Placentia Fire & Life Safety’s Combustible Soil Gas Hazard Mitigation Guideline. The top of thw well casings were located at 11.5’ below surface grade.

Photos Of Oil Leak Test

Click any image to enlarge

Results of the emissions monitoring at the top of both well casings showed combustible gas at non-detectable concentrations (less than 1 ppmv), and background air concentration of combustible gas away from the well casings was measured at 0.1 to 0.2 ppmv.

Results of the monitoring at the top of the well casings showed non-detectable concentrations of hydrogen sulfide. Results of the bubble leak-testing activity showed no dynamic bubble formation and therefore no indication of gas pressure leakage from the top of the well casing.

All work was performed under the supervision of a CalGEM representative.

Subslab Depressurization System (SSD) Installation

Subslab Depressurization System (SSD) Installation

Terra-Petra was engaged by the attorney representing the owner of a former dry cleaner in southern California that was experiencing vapor intrusion.

Specifically, indoor ambient air was monitored and determined to have concentrations exceeding commercial screening levels for the following (as well as others):

  • Toluene
  • Tetrachloroethene
  • Dichlorodifluoromethane (CFC 12)

The attorney had requested a way to mitigate the vapor intrusion issues at the site so that the property could be commercially viable again.  As we always do with any existing building Terra-Petra completed an extensive investigation of the building of concern to gain an understanding of what type of Subslab Depressurization System (SSD) would be most effective in mitigating the issue. Terra-Petra completed the pressure field extension testing to determine how much vacuum would be required to extend a minimum sub-slab negative pressure field of -0.016 ” w.c. Understanding how much vacuum is required and where it should be applied is the objective of the permeability mapping portion of any investigation and shall serve as the foundation for our design.

The design of the mitigation plan is the most critical component in the entire process because it determines the remedial design and scope of work. This is the part that eliminates the ad hoc guess work and provides a defined plan. It also eliminates installing a system that is not effective in reducing soil borne contaminants. Additionally, the process eliminates the possibility of overdesigning the system to compensate for uncertainties. Over-designed systems result in excessive installation and operational costs. Once a plan is in place, definite implementation costs can be determined.

As such, Terra-Petra completed the design, which we permitted through the local building department and began installing the system in early February of this year. The system will be online before the end of this month after we complete the installation and run our start up testing.

Installation Progress Photos

Need Vapor Intrusion Mitigation? Contact Terra-Petra Today For Assistance

Feel free to contact Terra-Petra for any of your vapor intrusion mitigation needs.  One of our experienced and friendly team members is standing by to assist you.

A Tribute To John Conaway

A Tribute To John Conaway - Terra-Petra's Original Engineer

As a tribute to John Conaway, Terra-Petra’s original engineer, his son and Terra-Petra Vice President Justin Conaway drew this beautiful sketch seen here.  We’re proud to pay tribute to John’s legacy and his integral contributions to the success of our company.

To see more of Justin’s sketches, you can visit and follow his Instagram page @justinconawaysketches

Terra-Petra Receives 2023 Los Angeles Award For Environmental Engineering

Terra-Petra Receives 2023 Los Angeles Award For Environmental Engineering

LOS ANGELES December 5, 2023 — Terra-Petra Environmental Engineering has been selected for the 2023 Los Angeles Award in the Environmental Engineering category by the Los Angeles Award Program.  This is the 11th year in a row that Terra-Petra has received this honor.

Each year, the Los Angeles Award Program identifies companies that we believe have achieved exceptional marketing success in their local community and business category. These are local companies that enhance the positive image of small business through service to their customers and our community. These exceptional companies help make the Los Angeles area a great place to live, work and play.

Various sources of information were gathered and analyzed to choose the winners in each category. The 2023 Los Angeles Award Program focuses on quality, not quantity. Winners are determined based on the information gathered both internally by the Los Angeles Award Program and data provided by third parties.

About Los Angeles Award Program

The Los Angeles Award Program is an annual awards program honoring the achievements and accomplishments of local businesses throughout the Los Angeles area. Recognition is given to those companies that have shown the ability to use their best practices and implemented programs to generate competitive advantages and long-term value.

The Los Angeles Award Program was established to recognize the best of local businesses in our community. Our organization works exclusively with local business owners, trade groups, professional associations and other business advertising and marketing groups. Our mission is to recognize the small business community’s contributions to the U.S. economy.

SOURCE: Los Angeles Award Program

DEC 21 – Progress Photo Update Methane Mitigation Design & Inspection DTLA

Methane Mitigation Design & Inspection

Here are the latest updated progress photos from December on this development in Los Angeles.  It’s been an exciting year in 2021 to be involved on this project.  Terra-Petra provided methane mitigation design and methane inspection services for this project.

We’re very proud to be a part of this project and to see the progress as it moves forward towards completion.  Click any photo below to enlarge.

If your development project, building or home is in need of Terra-Petra’s methane services, whether it’s methane mitigation design, methane soil gas investigation, methane inspection, methane testing, methane monitoring or methane consulting then Terra-Petra is your top resource.

Contact us today to learn more.

Construction Progress Photos

UPDATED Progress Photos – Methane Mitigation Design Los Angeles

Methane Mitigation Design & Inspection

More updated progress photos on this development in Los Angeles.  Terra-Petra provided methane mitigation design and methane inspection services for this project.

We’re very excited to be a part of this project and to see the progress as it moves forward towards completion.  Click any photo below to enlarge.

If your development project, building or home is in need of Terra-Petra’s methane services, whether it’s methane mitigation design, methane soil gas investigation, methane inspection, methane testing, methane monitoring or methane consulting then Terra-Petra is your top resource.

Contact us today to learn more.

Construction Progress Photos

Oil Well Due Diligence – Uncover, Leak Test, Well Head Survey

Terra-Petra is undertaking, on behalf of a Southern California engineering firm, the task to locate uncover and leak test a single oil well in Stanislaus County CA.

The California Department of Conservation, Geologic Energy Management Division (CalGEM) requested this work to be performed as necessary oil well due diligence.

The tasks performed will encompass a geophysical survey and report, a well head excavation, a well head sniff test, a well head survey, an oil well summary report and overall project management.

Terra-Petra’s oil field services offer our clients a one-stop shop for all their oil field needs.  Our team will manage your project from start to finish, encompassing everything from initial consultation to the final report and submission of NFA (No Further Action) letter.

With the seemingly endless moving parts involved in successful oil field construction site plan reviewoil well abandonment / re-abandonmentvent cone installationconsulting and more, it’s important to have an expert by your side every step of the way to manage the process and make sure your budget and schedule stay on track.  With Terra-Petra’s hands-on expertise in ALL aspects of oil field management and consulting we stand out amongst other firms in the industry.

Methane Mitigation Design & Inspection – Construction Progress Photos

Methane Mitigation Design & Inspection

Recent drone images show construction progress on this development in Los Angeles.  Terra-Petra provided methane mitigation design and methane inspection services for this project.

If your development project, building or home is in need of Terra-Petra’s methane services, whether it’s methane mitigation design, methane soil gas investigation, methane inspection, methane testing, methane monitoring or methane consulting then Terra-Petra is your top resource.

Contact us today to learn more.

Construction Progress Photos

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