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1. What is Subsurface Utility Engineering (SUE)? 

SUE is a process to identify actual subsurface utility locations using a combination of research, geophysical methods, and non-destructive excavation/exploration. Typically it involves development of a subsurface utility map for a proposed construction site. It provides the designer and contractor with a much higher level of confidence regarding utility locations than might be available by relying on utility company records (which are often outdated and/or unreliable). For many projects, SUE saves the project significant cost and time, because it reduces the chances of unexpected utility encounters during construction.

2. Why does NTH always have a field engineer monitor drilling during geotechnical and environmental investigations? 

Unlike most of our competitors, NTH provides full time drilling inspectors during all geotechnical and environmental investigations. This ensures that the boreholes are properly logged, samples are properly collected, all necessary information is recorded, atypical conditions are noted, and if conditions are found that may adversely affect our client, we can notify that client without delay. 

3. Can I choose my own preferred analytical laboratory if I have NTH take care of my sampling and monitoring needs? 

Yes, we are happy to work with your preferred analytical laboratory. NTH has long-established and efficient working relationships with many of the finest analytical laboratories commercially available throughout the Midwest, and we are willing to establish new relationships whenever it will help our clients. 

4. Can I have my geomembrane seam tests performed on site to save shipping time and cost? I need the answers quickly! 

Yes, NTH frequently performs seam testing on site for our clients using our simple field laboratory device. This provides rapid turnaround for our test results and avoids all the problems and costs associated with sample shipment. 

5. What is "residual strength" and why does it seem to govern the choice of geosynthetic materials on my projects? 

A prudent design must sometimes be based on the residual interface shear strength of geosynthetic interfaces to address the unknown value between the peak and residual strength. "Peak strength" refers to the force it takes to cause one geosynthetic material to slide on another or on the soil. Once such sliding has occurred, it takes less force to cause further movement for many of these materials. The interface shear strength resisting the initial movement is called the peak strength, and the interface shear strength resisting subsequent movement is called the residual strength. Sometimes, we cannot depend on the peak strength occurring over the entire geosynthetic interface. In other words, some localized sections may move sufficiently, during construction and overlying fill placement, so that the remaining interface shear strength is an unknown value between the peak and the residual strength. 

6. Do I need to install a gas collection system at my landfill? 

If the landfill has a design capacity of less than 2.5 million megagrams (by mass) or 2.5 million cubic meters (by volume) you do not need to install a gas collection system. You only need to submit a design capacity report to the regulatory agency. If your landfill has a larger design capacity, you can perform modeling to estimate the maximum emissions of non-methane organic compounds (NMOCs). If the maximum NMOC emissions rate is less than 50 megagrams per year, your landfill is exempt from requirements to install a gas collection system. There are three methods ("Tiers") for estimating NMOCs, each requiring incrementally more site-specific data; contact NTH for more information. 

7. What is biotechnical engineering? 

Biotechnical engineering (also referred to as "bioengineering") refers to the combined use of engineered structures, such as riprap revetments or gabions, and live plantings to prevent soil erosion and to stabilize earthen slopes. Common applications of biotechnical engineering are slope stabilization, streambank stabilization, and erosion protection. 

8. What's the difference between a flood plain and a floodway? 

The flood plain is the area inundated by the "base flood", usually the 100-year flood. The floodway is the portion of the flood plain needed to actually convey the flood flow, while the remainder of the flood plain may be characterized by stagnant or low velocity flow. 

9. Does a 100-year flood occur once every 100 years? 

No, the 100-year flood is defined as the flood that has a 1% chance of being equaled or exceeded in any given year. 100-year floods could occur at shorter intervals or even within the same year. 

10. What is a "sunny day" dam failure? 

A "sunny day" dam failure is one that is not associated with a storm or flood wave. The Federal Energy Regulatory Commission (FERC) requires this failure mode to be evaluated for licensed dams, as well as failure during the design storm (which depends on the dam size and hazard classification). The impoundment is assumed to be at its normal elevation, and the failure mode is usually assumed to be a piping failure for earthen embankments, or a sudden gate failure for concrete dams. 

11. What is the difference between Construction Quality Assurance (CQA) and Construction Quality Control (CQC)? 

Typically, CQC is an internal function performed by a Contractor to verify that the work being completed by the Contractor meets the requirements of the project. This function can be performed by in-house personnel or by a third-party firm, but the testing results and observations are reported first to the Contractor for his/her use and information. These results may be forwarded on to other parties (Owner, Design Team, Municipal Authority, etc.) as required by the contract documents. CQA is an independent function performed by a third-party firm engaged directly by the Owner (or the Design Team on behalf of the Owner). This firm may have had some involvement in the project prior to construction (i.e. geotechnical or structural engineer), and may have unique insights into the design itself. The purpose of CQA is to verify that the work is being constructed in accordance with the contract documents and the intent of the design. Test results and observations are reported directly to the Owner and the Design Team, and shared with the Contractor for their information. In this way, the CQA firm can become the eyes and ears of the Owner on the jobsite, and a critical advocate for the Owner's interests. 

12: How can an experienced, full time CQA construction technician save you time and money? 

An experienced CQA construction technician that maintains the necessary certifications in their field can be a valuable asset to any construction project. This technician can typically perform multiple tasks on any given jobsite, reducing the need for specialized or supplemental technicians. In addition, an experienced technician can readily review and understand complex plans, details, and specifications, and can quickly recognize deviations in the constructed product. By developing effective lines of communication with the Owner's representative and/or the Contractor, an experienced technician can notify these parties of discrepancies and in many cases provide recommendations while there is still time to correct them. To be most effective, however, such a technician should be assigned to the project site on a full-time basis so that he/she can become intimately familiar with the project and the people. The cost of this service is often a small fraction of the time and/or money that can potentially be saved from these efficiencies. 

13: Why is it important to have a trained professional on-site during a geotechnical study to witness the drilling and sampling procedure and prepare the boring logs? 

A driller is typically motivated by speed and efficiency, not necessarily accuracy. In addition, a driller may be experienced with the subsurface conditions in a given region, but they may not have received the training to understand why some information may or may not be important. A trained geotechnical professional understands the "big picture" of a test boring project, as well as the ramifications of the information being obtained. Using this perspective, the geotechnical professional can modify the parameters of the study while it is in progress to obtain the most useful data. In addition, the geotechnical professional will record the data in manner that is most appropriate for the engineering analyses to follow, and for presentation to the client. 

14: What is a roof or pavement asset management program? 

A roof or pavement asset management program is a useful tool for any facility manager to project and schedule maintenance activities and/or to allocate valuable resources. A baseline condition survey of the asset, whether at single or multiple locations, is performed by an experienced professional. The results are entered into special database software developed for this purpose, and an initial condition index is assigned to the asset. Then, various parameters are adjusted to model the projected degradation of the asset over time. Finally, projected costs are developed for various types of repair scenarios, and a 5 or 10-year maintenance plan is developed. The facilities manager can use this plan to prepare and budget for upcoming repair events before the assets need expensive emergency repairs or replacement. 

15. What is a "Brownfield"? 

"Brownfields" are properties that are under utilized, and typically abandoned, due to real or perceived environmental and/or infrastructure issues that potentially limit reuse. NTH assists public and private clients turn "real" or "perceived" problems into funding opportunities that put your site back into productive use. 

16. Is redeveloping a "Brownfield" site more expensive than developing a "Greenfield" site? 

Not necessarily. Existing legislation in Michigan has created alternative incentives to off-set typical environmental and infrastructure incremental costs that historically caused developers to look away from urban/abandoned sites. In some instances, Brownfields can be cheaper than Greenfields if the appropriate infrastructure and transportation modes already exist. NTH has successfully supported the redevelopment of residential, commercial and industrial land uses on abandoned properties that were historically over looked. 

17. Does my site have to be contaminated to be eligible for Brownfield redevelopment incentives? 

Not necessarily. If a Brownfield property is located within one of Michigan's "Core Communities", then contamination is not a prerequisite for funding eligibility. Additionally, there are other creative funding sources available to non Core Communities for infrastructure rehabilitation issues that are typically present on Brownfield sites. 

18. What is Construction Management? 

Construction Management is direction of the construction process by specialized staff for the owner. It often includes onsite inspection and review of the ongoing work, weekly (periodic) progress review and claims/change management meetings, the review of contractor pay requests and other submittals as well as coordination of multiple contractors working onsite simultaneously. This reduces daily burdens the owner, allowing them to concentrate on their main line of business.