Environmental Project

Navigating Complexities in Leaking Underground Storage Tank Remediation

Colorado Division of Oil and Public Safety Colorado

Solution Overview

high‑pressure ozone/oxygen bio-sparge systems, used to address hydrocarbon impacts during remediation of leaking underground storage tank sites throughout Colorado.


Colorado Division of Oil and Public Safety

Business Challenge:

  • Diverse environmental challenges due to unique geological conditions
  • Large portfolio of impacted sites
  • Recognized Environmental Professional (REP) certification requirement for project managers


  • Expertise in regulations, innovative approaches to remediation, and industry guidance updates


  • Impactful outcomes through revitalized aquifers, enhanced groundwater quality, and industry‑leading environmental transformation across Colorado


Apex has been at the forefront of site assessments and cleanup efforts for orphaned leaking underground storage tanks (LUST) facilities across Colorado since 1994, operating as a contractor within the State Lead Program under the Colorado Division of Oil and Public Safety.

A distinctive feature of challenges lies in our dual role: the Colorado Department of Labor and Employment (CDLE) serves both as our client and the state regulator for our responsible party clients. This regularity context adds an extra layer of complexity to our operations, requiring us to seamlessly navigate compliance standards while ensuring effective project management and remediation outcomes.

Notably, every LUST project in Colorado mandates that the primary project manager holds a REP certification. This requirement underscores the significance of our team’s expertise and qualifications, further emphasizing the intricacies and demands of managing LUST projects in the state.


Over the years, Apex has tackled a diverse array of LUST projects, each presenting unique challenges. From petroleum impacts in clay to bedrock, we have successfully addressed complex scenarios that demand innovative solutions. At any given time, Apex supports between 20-40 active remediation projects throughout the state of Colorado, with an impressive average gross annual revenue of $1.25M.

Apex’s proven expertise and intimate familiarity with the intricate landscape of the state of Colorado underground storage tank/aboveground storage tank (UST/AST) regulations have been pivotal in our ability to manage a multitude of projects across the state. Apex’s track record includes successfully overseeing the cleanup of numerous projects, serving as a testament to our deep-rooted knowledge and ability to navigate regulatory complexities. We’ve not only managed remediation efforts but also actively contributed to refining and updating Colorado Oil and Public Safety regulatory guidance, showcasing our commitment to driving industry standards forward.

Apex’s innovative approach has been instrumental in surmounting challenging scenarios. We have employed advanced techniques such as complex aquifer tests utilizing packers in bedrock to support the remediation of methyl tertiary butyl ether (MTBE) plumes that impact groundwater supply wells. Furthermore, we’ve installed high‑pressure ozone/oxygen bio-sparge systems, effectively addressing hydrocarbon impacts in exceptionally tight clay and bedrock sites throughout Colorado. Our repertoire extends to a diverse range of in-situ remediation technologies, including but not limited to soil vapor extraction (SVE) with and without air sparging (AS), enhanced bioremediation employing various terminal electron acceptors, enhanced reductive dichlorination (ERD), pump and treat systems, and multi‑phase extraction.


Through the strategic implementation of in-situ remediation technologies, Apex has successfully rejuvenated contaminated sites, restoring environmental integrity and safeguarding community resources. The use of high-pressure ozone/oxygen bio-sparge systems and complex aquifer tests has significantly enhanced our ability to tackle hydrocarbon and MTBE plume challenges in challenging geological settings, leading to substantial improvements in groundwater quality.

Apex’s commitment to precision and technical excellence has translated into measurable outcomes, including improved aquifer health and the revitalization of impacted groundwater supply wells. Additionally, our contributions to regulatory guidance updates underscore our proactive stance in shaping industry best practices and reinforcing compliance standards. With a comprehensive toolkit of proven methodologies and a dedication to continuous improvement, we continue to drive positive transformation in the realm of environmental remediation across the state of Colorado.

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