Accurate sampling and reporting for clear environmental decisions.
Contamination in the subsurface doesn't announce itself. Soil monitoring is how you find out what's present, where it has traveled, and whether conditions are improving or holding steady. At The Phoenix Group, our field teams conduct soil monitoring and soil sampling across Oklahoma following OCC, DEQ, and EPA guidelines, collecting accurate data in whatever conditions the site presents.
We sample for both LNAPL and DNAPL compounds and apply the approved sampling methods appropriate to each project. That matters because the methodology shapes the data, and the data shapes every decision that follows. Each sampling round feeds into a larger picture of what the site is doing. Our reports closely follow Oklahoma requirements and are organized so you always know where the project stands and what comes next.
Environmental soil monitoring isn't just a regulatory requirement. It's the foundation for smart remediation decisions. Whether you're working through a corrective action plan or managing ongoing compliance, you need soil contamination monitoring data you can trust. That's what we provide.
Oklahoma sites come in all shapes. Some are straightforward corrective action cases with a clear release point and a defined monitoring network. Others involve multiple source areas, varying soil types, or a regulatory history that spans years. We've worked on both kinds, and our field teams are prepared for the conditions they'll actually find on site rather than the ideal version of it. Soil sampling protocols are followed consistently regardless of how simple or complicated the location turns out to be. When the data is collected carefully and documented thoroughly, the path forward is easier for everyone involved, including the client, the consultant, and the agency reviewing the work.
Soil monitoring is most useful when it's treated as a continuous process rather than a series of isolated events. Each round of data builds on the last, and over time, the trend line tells you more than any single sample ever could.
At petroleum release sites, we typically test for BTEX compounds (benzene, toluene, ethylbenzene, and xylene), total petroleum hydrocarbons (TPH), and MTBE, along with LNAPL and DNAPL indicators depending on the product involved. The specific parameters are determined by the site history, the type of release, and the regulatory program governing the cleanup, whether that's the OCC or DEQ.
LNAPL (light non-aqueous phase liquid) floats on groundwater and typically includes petroleum products like gasoline and diesel. DNAPL (dense non-aqueous phase liquid) sinks below the water table and includes compounds like chlorinated solvents. The distinction matters because each requires different sampling strategies, screening tools, and remediation approaches. Our field teams are trained to identify and sample both.
Both agencies have oversight roles depending on the type of release and the site's regulatory history. The Oklahoma Corporation Commission (OCC) typically governs petroleum storage tank sites, while the Oklahoma Department of Environmental Quality (DEQ) handles other types of contamination. Many sites operate under one program, but some have overlapping agency involvement. We work within whichever regulatory framework applies to your site.
Monitoring frequency is generally set by the corrective action plan or the applicable regulatory program. At active remediation sites, sampling may occur quarterly, semi-annually, or on a schedule tied to specific milestones. As conditions improve and the site moves toward closure, monitoring frequency can sometimes be reduced with agency approval.
The OCC accepts several approved sampling methods, including direct push technology, split-spoon sampling, and various grab sampling techniques. The right method depends on site conditions, target depth, and the type of information needed. Our team selects the appropriate approach for each location and documents the methodology thoroughly in all regulatory submittals.
Soil data defines the lateral and vertical extent of contamination, identifies which compounds are present and at what concentrations, and establishes a baseline for measuring cleanup progress. That information directly determines which remediation technologies are appropriate, where treatment should be focused, and when conditions have improved enough to support a move toward closure.
Soil monitoring is typically required when a release is confirmed and during any active corrective action. The OCC and DEQ both require that corrective action plans include a monitoring component to track site conditions over time. Our team prepares all required documentation and submittals to keep your project in compliance and moving forward.
