DOT-COMPLIANT · ON-SITE EMPLOYER DRUG TESTING
Mobile Employer Drug Testing in San Antonio, Texas
We travel to your facility — military-adjacent contractor site, fleet yard, manufacturing plant, or distribution center — and administer federally compliant DOT and Non-DOT collections on-site. No clinic. No downtime.
San Antonio is Texas's second-largest city and one of the most military-concentrated metro areas in the United States. Joint Base San Antonio — encompassing Lackland AFB, Randolph AFB, and Fort Sam Houston — supports a massive ecosystem of defense contractors, logistics providers, and federal contractors who maintain Non-DOT company-policy drug testing programs as a condition of their contracts. Toyota Motor Manufacturing Texas operates its full-size truck assembly plant in San Antonio, generating significant CDL-heavy inbound supply chain and outbound vehicle logistics demand. Union Pacific and BNSF both serve San Antonio with freight rail operations. San Antonio International Airport (SAT) hosts Southwest Airlines operations and air cargo tenants under FAA 14 CFR Part 120. CPS Energy, the nation's largest municipally owned energy utility, serves San Antonio with natural gas and electric infrastructure under PHMSA jurisdiction. For employers in a city where defense, manufacturing, and logistics intersect, mobile testing at the facility is the only model that keeps safety-sensitive workers at the worksite.
OnSite Employer Testing coordinates mobile drug testing collections at your San Antonio-area facility, contractor site, or fleet yard. We do not operate a clinic. Review how it works or browse all locations we serve.
Why San Antonio Employers Need Mobile Testing
San Antonio's defense and federal contractor ecosystem creates persistent Non-DOT drug testing demand that most testing pages ignore entirely. Contractors supporting JBSA operations — IT services, facilities management, logistics support, and construction — maintain drug-free workplace programs as a condition of their contracts. Many of those contractors also operate CDL vehicles for equipment and material transport, layering FMCSA DOT obligations on top of their federal contractor Non-DOT requirements.
Toyota's San Antonio truck plant runs tightly sequenced just-in-time supply chain deliveries from dozens of tier-one and tier-two suppliers. Each inbound CDL driver and each supplier's logistics fleet requires a compliant FMCSA random testing program. The plant's own outbound vehicle haulaways add finished-unit CDL logistics demand. Mobile collection at supplier yards, carrier terminals, and the Toyota campus itself keeps that workforce compliant without disrupting production timelines.
Program design and compliance obligations remain your responsibility under applicable law — we coordinate the collections.
Industries We Serve in San Antonio
Defense Contractors and Federal Employers
Joint Base San Antonio is the largest joint base in the Department of Defense, encompassing three installations with a combined workforce of over 250,000 military, civilian, and contractor personnel. Defense contractors providing logistics, facilities, construction, IT, and aviation support services at JBSA installations are subject to the Drug-Free Workplace Act and maintain Non-DOT company-policy programs. Contractors with CDL-operating employees additionally require FMCSA 49 CFR Part 382 programs. We coordinate both DOT drug testing and Non-DOT workplace drug testing for defense and federal contractors operating in the greater San Antonio area.
Automotive Manufacturing and Supply Chain
Toyota Motor Manufacturing Texas operates its Tundra and Sequoia full-size truck and SUV assembly plant in San Antonio. The facility employs thousands of production workers and relies on just-in-time supply chain logistics from Tier 1 and Tier 2 suppliers throughout Texas and the Midwest. Inbound CDL drivers, yard hostlers, and outbound vehicle transport operators require FMCSA-compliant testing programs. Toyota's supplier base in the San Antonio metro — including stamping, injection molding, and sub-assembly manufacturers — maintains Non-DOT company-policy programs for plant employees. We coordinate manufacturing and logistics and transportation collections at the Toyota campus and at supplier facilities throughout Bexar County.
Rail Operations
Union Pacific operates through San Antonio on a primary mainline connecting Houston, Laredo, and El Paso — one of the busiest freight rail corridors in Texas. BNSF provides additional freight rail service in the region. FRA 49 CFR Part 219 requires covered railroad employees at both carriers' San Antonio operations to participate in random, post-accident, and reasonable suspicion programs. We coordinate FRA-compliant collections at rail yards and crew reporting facilities in Bexar County.
Energy and Utility
CPS Energy is the nation's largest municipally owned combined gas and electric utility, serving over 900,000 electric customers and 350,000 natural gas customers in the San Antonio area. Natural gas distribution and pipeline workers employed by CPS Energy are subject to PHMSA 49 CFR Part 199 anti-drug and alcohol misuse prevention requirements. Field technicians dispatched from CPS Energy depots on emergency call-outs cannot stop at a clinic mid-response. We coordinate PHMSA-compliant energy and utilities collections at utility depots, maintenance facilities, and field staging locations throughout the San Antonio service territory.
Aviation
San Antonio International Airport hosts Southwest Airlines operations, multiple cargo carriers, and a significant military and charter aviation presence tied to JBSA. FAA 14 CFR Part 120 applies to air carriers and operators with safety-sensitive employees at SAT. We coordinate FAA-compliant aviation and airline employer collections at the airport and at employer facilities in the SAT business corridor.
Testing Services Available in San Antonio
We coordinate the following collections for San Antonio-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 San Antonio
In addition to San Antonio, we serve employers throughout Bexar County and surrounding areas including New Braunfels, Schertz, Seguin, Boerne, Converse, Universal City, and Lackland AFB.
Employers at the Toyota truck plant, JBSA contractor zones, CPS Energy depots, and the Union Pacific mainline corridor are within our standard mobile service range. Use our instant quote calculator to scope your collection or visit our service areas page.
Questions from employers in this region
Toyota Manufacturing Texas suppliers need pre-employment testing before their drivers begin deliveries to the San Antonio plant. Can you serve both Toyota and its Tier 1 suppliers?
Yes. We coordinate collections for Toyota and for Tier 1 and Tier 2 suppliers operating in the San Antonio metro. Each employer's collection is managed separately with their designated employer representative. We travel to supplier facilities, carrier terminals, and the Toyota campus as needed.
Our company provides facilities management services at a JBSA installation. Does the Drug-Free Workplace Act require specific drug testing procedures?
The Drug-Free Workplace Act of 1988 requires covered federal contractors to maintain a drug-free workplace policy and program, but it does not mandate specific testing procedures, panels, or frequencies — those are employer-defined under Non-DOT policy. If your employees also operate CDL vehicles, FMCSA 49 CFR Part 382 adds specific procedural requirements for those roles. Program design and compliance obligations remain your responsibility under applicable law — we coordinate the collections.
CPS Energy dispatches gas utility crews across Bexar County on emergency calls. Can you reach field crews at multiple depot locations?
Yes. PHMSA-regulated utility employers with crews at multiple depots are a standard use case. We coordinate collections at each depot or staging location you designate. You provide facility addresses and expected donor counts; we confirm logistics for each site.
Union Pacific's San Antonio mainline handles border-crossing traffic from Laredo. Do cross-border operations change the FMCSA testing requirements for UP crews?
FRA employees working on Union Pacific's San Antonio mainline are governed by FRA 49 CFR Part 219, regardless of whether trains originate from or proceed to the Mexican border. FMCSA requirements for motor carriers operating across the U.S.-Mexico border involve additional FMC Safety regulations beyond the standard Part 382 drug and alcohol testing program. Program design and compliance obligations remain your responsibility — we coordinate the collections.
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 San Antonio-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.