DOT-COMPLIANT · ON-SITE EMPLOYER DRUG TESTING
Mobile Employer Drug Testing in Corpus Christi, Texas
We travel to your facility — refinery gate, port terminal, naval contractor site, or fleet yard — and administer federally compliant DOT and Non-DOT collections on-site. No clinic. No downtime.
Corpus Christi is the sixth-largest port in the United States by tonnage and a primary export hub for Permian Basin crude oil, refined petroleum products, and liquefied natural gas. Valero Energy's Corpus Christi refineries — East and West plants — are among the largest crude processing complexes in North America. Citgo and Flint Hills Resources operate additional refinery and petrochemical facilities along the La Quinta Ship Channel. The Port of Corpus Christi Authority operates a 36-mile deep-water channel with LNG export terminals, crude oil loading docks, and bulk commodity terminals whose employees work in PHMSA-regulated pipeline and terminal environments. Naval Air Station Corpus Christi — one of the Navy's primary pilot training facilities — supports a defense contractor ecosystem that requires Non-DOT testing compliance. Union Pacific serves the port and the Corpus Christi industrial corridor with freight rail under FRA jurisdiction. For employers operating in a refinery, port, or naval aviation environment, routing safety-sensitive workers to a clinic for every DOT collection is not operationally viable.
OnSite Employer Testing coordinates mobile drug testing collections at your Corpus Christi refinery, port terminal, or contractor site. We do not operate a clinic. Review how it works or browse all locations we serve.
Why Corpus Christi Employers Need Mobile Testing
The Corpus Christi refinery and port corridor operates on a continuous-process model that has no tolerance for workforce gaps. Valero's Corpus Christi refineries process hundreds of thousands of barrels per day — a PHMSA-covered pipeline or terminal employee who misses a shift because of a clinic trip cannot be replaced by an untested contractor without creating its own compliance problem. Mobile testing at the refinery gate or at the employer's designated on-site location eliminates that gap.
NAS Corpus Christi adds a defense contractor dimension that creates Non-DOT testing demand outside the refinery and port verticals. Aviation maintenance contractors, facilities operators, and construction contractors at the installation maintain drug-free workplace programs as a condition of their contracts. CDL-operating contractors at NAS Corpus Christi additionally require FMCSA DOT programs. Mobile testing at the contractor facility — not a clinic across the bay bridge — is the efficient model for a workforce split between the naval installation and commercial industrial facilities.
Program design and compliance obligations remain your responsibility under applicable law — we coordinate the collections.
Industries We Serve in Corpus Christi
Refining and Petrochemical
Valero Energy operates two refineries in Corpus Christi — the East Plant and West Plant — with a combined crude capacity that makes them among the largest refining operations in the United States. Citgo's Corpus Christi Refinery and Flint Hills Resources' facilities add additional PHMSA-regulated employer demand along the La Quinta Ship Channel. Pipeline technicians, loading rack operators, and terminal employees at these facilities are covered under PHMSA 49 CFR Part 199 anti-drug and alcohol misuse prevention programs. Turnaround contractors — the craft workforce that cycles through refinery maintenance projects — require pre-access Non-DOT testing as a condition of site entry. We coordinate both PHMSA-compliant energy and utilities collections and Non-DOT pre-access testing at refinery gates and contractor staging areas throughout the Corpus Christi industrial corridor.
Port of Corpus Christi — LNG, Crude, and Bulk Terminals
The Port of Corpus Christi is the leading U.S. crude oil export terminal by volume and a primary LNG export gateway. Terminal operators loading LNG at the Cheniere Corpus Christi LNG facility and crude oil at MODA Midstream and other dock operators are subject to PHMSA pipeline and terminal safety requirements. FMCSA-regulated drayage carriers serving the port's bulk commodity terminals and container operations require CDL driver testing programs. We coordinate logistics and transportation and energy employer collections at port terminal facilities, dock operations areas, and carrier staging zones throughout the port complex.
Naval Air Station Corpus Christi — Defense Contractors
NAS Corpus Christi is one of the U.S. Navy's primary pilot training installations, supporting T-6 Texan II and helicopter training programs. Defense contractors providing aviation maintenance, facilities management, and logistics support at the installation maintain Non-DOT company-policy drug testing programs under Drug-Free Workplace Act requirements. L3Harris Technologies and other aviation maintenance contractors at the installation represent the type of employer for whom mobile testing at their Corpus Christi facility — rather than a clinic across the Harbor Bridge — is operationally essential. We coordinate both DOT drug testing and Non-DOT workplace drug testing for NAS Corpus Christi contractors.
Rail Operations
Union Pacific provides freight rail service to the Port of Corpus Christi and the industrial corridor, moving petroleum products, crude oil, grain, and chemicals throughout the South Texas network. FRA 49 CFR Part 219 applies to covered railroad employees at UP's Corpus Christi operations. We coordinate FRA-compliant DOT drug testing collections at rail facilities and crew reporting locations in Nueces County.
Construction and Turnaround Contractors
Corpus Christi's petrochemical and port construction sector employs large craft workforces on capital projects and scheduled refinery turnarounds. Construction general contractors and specialty subcontractors maintain Non-DOT pre-access testing programs required by refinery host employers. CDL crane and heavy equipment operators require FMCSA DOT programs. We coordinate both program types at contractor yards and job site staging areas throughout the Corpus Christi industrial area.
Testing Services Available in Corpus Christi
We coordinate the following collections for Corpus Christi-area employers:
DOT drug testing collections (FMCSA, FRA, FAA, FTA, PHMSA)
- Pre-employment drug and alcohol testing
- Reasonable suspicion and return-to-duty testing
Breath alcohol testing (BAT certified)
- Oral fluid drug testing
Mobile and on-site collections at your facility, yard, or job site
Communities We Serve Near Corpus Christi
In addition to Corpus Christi, we serve employers throughout Nueces County and surrounding areas including Portland, Ingleside, Aransas Pass, Gregory, Robstown, and Kingsville.
Employers at the Port of Corpus Christi industrial complex, Valero's refinery campuses, the La Quinta Ship Channel corridor, and NAS Corpus Christi contractor zones are within our mobile service range. Use our instant quote calculator to scope your collection or visit our service areas page.
Questions from employers in this region
Valero Corpus Christi requires pre-access drug testing for all turnaround contractors. Can you coordinate collections at the refinery staging area before shift mobilization?
Yes. Pre-access collections for refinery turnaround mobilizations are a standard use case. We coordinate collections at the refinery contractor staging area, gate facility, or a designated on-site location. For multi-day mobilizations with rotating craft workers, we schedule collection windows that match your workforce reporting schedule.
Cheniere's Corpus Christi LNG terminal has PHMSA-covered employees working rotating 12-hour shifts. How does mobile testing work for a 24-hour operation?
We coordinate collections at the employer's on-site designated area at a time that fits the shift structure. For PHMSA random selections, we work with your DER to schedule the collection at a shift change or break that minimizes operational disruption. Employees do not leave the terminal.
What Non-DOT testing panel is standard for contractors accessing Valero or Citgo facilities in Corpus Christi?
Host employer access requirements vary by facility. Most Corpus Christi refinery host employers require a minimum 5-panel SAMHSA-equivalent Non-DOT urine screen; some require 10-panel or expanded panels including synthetic opioids. The host employer's pre-access requirement drives the panel — your testing program must meet or exceed what the host specifies. Program design and compliance obligations remain your responsibility under applicable law — we coordinate the collections using the panel your program specifies.
Do you serve defense contractors at NAS Corpus Christi on North Padre Island Drive?
Yes. Defense contractors operating at or near NAS Corpus Christi are within our standard Nueces County service range. We coordinate Non-DOT and DOT collections at contractor facilities adjacent to or on the installation, depending on site access protocols.
Core programs: Mobile & on-site drug testing, DOT drug testing, Non-DOT drug testing, Post-accident testing, Reasonable suspicion testing, Random testing programs, Breath alcohol testing. Planning: how it works, instant quote calculator, all locations. Industries: employer industries we support. Long-form answers: Employer drug testing FAQ. Quick questions: Contact us.
For how we think about regions and feasibility, see service areas.
Nationally coordinated collection support
OnSite Employer Testing is headquartered in Illinois and coordinates mobile and on-site employer testing across selected regions and employer locations—including through partner collectors when your program, timing, and geography allow. Availability depends on location, timing, test type, site access, collector availability, and scheduling needs.
Scope collections for your Corpus Christi-area operation
Share your facility address, expected donor count, test reason, and DOT or non-DOT status — we confirm what is workable and send a written proposal.