TWM’s field inspection services can help locate existing and potential problems before they escalate. Our technicians are well-versed in sewer and water main leak detection, closed-circuit televising (CCTV), and sewer smoke testing. These services allow us to investigate underground pipes, structures, and other spaces without the need for costly excavation.


We offer a comprehensive portfolio of field inspections and testing services to detect damages or other problems our clients may face during a project. With decades of experience, TWM can determine the right inspection method for your needs. Our professionals carry out field inspections and testing for a variety of diverse projects including roadways, bridges, building developments, water infrastructure, and utility projects.

Utility Locating

TWM’s utility locating services employ a Spar 300 unit to precisely map underground utilities. Typically mounted to a survey pole, this technology uses magnetic field sensors to measure the 3D vector to a subsurface utility. The result is highly accurate data that automatically combines with GNSS or other survey data to find the 3D coordinates of the utility.

Utility Locating

Water Inspection with Leak Detection

Water loss in municipal systems is something that has become expected and accepted. While it would be impractical to dig up and check every main within your system, our water main leak detection system uses sound waves and frequencies to listen for potential leaks and then pinpoint actual leaks. The result: it’s only necessary to dig in one specific location instead of multiple areas.

Water Inspection with Leak Detection

CCTV Inspection System

Full-color streaming video and still images are captured, and this method can be remotely steered through spaces 6” to 48” in diameter—even through debris and offsets. CCTV inspection is used for a variety of applications including sanitary and storm sewers, crawl spaces, tanks, ductwork, foundations, bridge footings, manholes, and underwater viewing. Data is provided in a digital format as quickly as possible.

CCTV Inspection System

Smoke Testing

Unwanted groundwater or stormwater (I/I) can inundate sanitary sewer systems during wet weather. This excess flow reduces system capacity, which can lead to basement backups, increased pumping and treatment costs, and excess wear and tear on system components. Smoke testing is one of the most efficient and cost-effective methods of identifying I/I sources. Our field technicians and engineers can implement a plan to eliminate I/I sources from the system.

Smoke Testing

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Our Work & Projects

Explore some of TWM’s inspections and testing projects that demonstrate our design expertise, technical knowledge, and comprehensive range of capabilities.

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The Technology To See What You Can’t

Whether your project is big or small, details matter when conducting field condition inspections and testing because each project is unique. Our team includes certified Class A Water operators as well as Class 1 Wastewater operators who have the technical knowledge and expertise to achieve the quality and results you expect. We regularly test and adopt emerging tools and technologies that are proven to provide accurate and efficient data.

  • Testing and reporting accuracy

  • Ensures proper implementation of plan design

  • Locates and identifies hidden problem sources

  • Preventive maintenance reduces the possibility of serious or costly repairs


  • Construction observation

  • Utility locating

  • Mandrel testing

  • Vacuum testing

  • Pressure testing

  • GIS/GPS data collection


As a full-service engineering consultant, we provide a broad range of design projects and related services. Besides Inspections & Testing, we also focus on many other civil and structural services as well as geospatial services. With our depth of capabilities, we can deliver cost-effective solutions to meet any need or challenge.

Our transportation group provides safe, convenient, and economical solutions for roads, trails, and traffic management.

Our large structural group delivers innovative bridge designs and associated structures that are cost-effective, safe, easily constructible, and durable.

Our land development group provides complete civil engineering services, starting with conceptual plans and ending with project approval and construction.

Our water infrastructure group is devoted to the protection of our waters, environmental responsibilities, and designing innovative wastewater facilities.

We use specialized tools that accurately evaluate and rank pavement to forecast both short- and long-term budgets for our government clients.

 TWM specializes in handling these kinds of innovative designs, with benefits that expedite schedules, control costs, and allow for greater customization.

Our construction engineering staff ensure that engineering design skills are effectively translated into the actual construction of the project.


That’s our company mission and our promise to you. Our success is built upon a solid reputation for getting the job done right. One thing we are particularly proud of is approximately 95% of TWM’s work comes from repeat business. We believe our resolution of challenges sets us apart, and based on our level of repeat business, we think our clients will agree.