There are so many news articles, tweets and posts every month, that we miss some of the  good ones. NTH will be compiling the ones we think are most interesting and will re-cap them monthly on our blog. Below is the July wrap-up.


In July we saw a great deal in the news about renewable energy and the work that many companies are doing to help the environment.  Consumers Energy for example, announced it is giving away $100,000 to help communities plant trees to create sustainable urban forests and encourage responsible tree planting efforts. In a somewhat related article, a company called Carbon Engineering is building a Giant Wall that can suck carbon dioxide out of the air in areas where regrowth of trees is difficult or not possible. 


Bill Gates also got into the discussion by talking to Forbes about his latest investment in renewable energy. He will reportedly be investing in “radical, ‘wild-eyed’ energy tech companies” to help find a solution to climate change.

The Krejci dump site in the Cuyahoga Valley National Park,  historically received thousands of tons of industrial waste and was classified as a CERCLA/Superfund hazardous waste disposal site. The U.S. Department of Interior/National Park Service (NPS), who originally purchased the property, ultimately assumed the remediation oversight role from U.S. EPA.  NPS retained the Environmental Quality Company (EQ) to remediate the site and restore it to “pristine” natural conditions.

NTH Consultants, Ltd. (NTH) was involved throughout this entire project as EQ quickly retained NTH during the remedial phase of the project to assist with environmental sampling and to help assess whether contaminated soils were adequately removed.  NTH also assisted with various geotechnical matters and was involved with engineering for several activities needed to complete the restoration.  NTH worked with the NPS for EQ along with a multidisciplinary team of engineers, biologists, ecologists, geologists, and environmental scientists.  

According to the National Park Service, "the remediation of the Krejci Dump Site has benefited the Park and the public. This has become a model remediation in the NPS; by taking a contaminated former industrial site, restoring the ecology to its native condition (including three acres of wetland and wet meadow habitats) for unrestricted use by Park visitors, animals and plants alike, and transforming the additional open space that can be used for recreation ear a very urban environment."

The project was not without it's challenges however; for a more in-depth discussion of the design & construction challenges of the Krejci Dump Site restoration, please attend our free webinar on July 28, 2015. You can register here:  http://bit.ly/KrejciWebinar.  After August 1, you will be able to find the recorded version here:  http://bit.ly/NTHwebinars. 

State of Michigan Guidance
Typically, dispersion modeling is not required for sources with de minimis emissions as impacts are often negligible. As standards are ratcheted down, dispersion modeling is an increasingly important part of any permit application review.  The Michigan Department of Environmental Quality (MDEQ) has recently released new guidance addressing when air quality modeling - and in some cases, qualitative assessments of dispersion will be required.  These stringent requirements mean that modeling, and/or qualitative assessments, will be necessary for approval of most air permit applications in which the project involves installation of moderate to large industrial equipment (i.e., equipment for electrical and steam generation, gas and oil production, manufacturing, materials processing, etc.). More importantly, it is also likely that either dispersion modeling or a qualitative assessment will be necessary for those projects that involve installation of air quality control systems, replacement of equipment, and/or provide a net reduction in emissions; thereby improving local air quality. Other examples include replacing a coal boiler with a smaller natural gas boiler, or installation and operation of temporary equipment without tall stacks. 

NTH Case Study - Qualitative Assessment
NTH developed one of the first qualitative analyses under this guidance. As part of the Boiler MACT compliance plan, our industrial client decided to remove coal-firing capability from the facility boilers, convert to natural gas, and install a backup boiler to provide process steam while the facility boilers were down. Although there was a reduction in pollutant emissions as a result of removing coal capabilities, MDEQ’s guidance required further analysis regarding impacts from the new backup boiler. NTH developed a qualitative assessment demonstration to show that ambient impacts as a result of the project would not increase. The analysis included an evaluation of the existing air quality, the difference in facility actual and allowable emissions as a result of the project, and location of the backup boiler related to the facility fence line, nearby residents, and waterways. MDEQ approved the qualitative analysis and proceeded to approve the air permit without further restrictions on the backup boiler or associated stack parameters. 

NTH Case Study - A Unique Solution
NTH recently assisted one of our waste-to-energy clients with a compliance demonstration related to health-based screening levels for formaldehyde emissions using dispersion modeling. In order to more accurately account for how formaldehyde reacts and breaks down in the atmosphere, NTH recommended use of a Gaussian puff modeling system called CALPUFF. CALPUFF was ideal for this project as it includes pollutant removal due to wet scavenging, dry gas deposition, and reactive decay. It also allows the use of more sophisticated meteorology that incorporates multiple weather stations, topography, water temperatures and precipitation. CALPUFF is not a conventional model, and therefore, approval from MDEQ was required prior to using it. 

As part of this project and modeling demonstration, NTH performed an extensive scientific assessment in order to demonstrate that the source would not cause or contribute to injurious effects to human health or safety. All available information on the health effects of formaldehyde exposure based on the level of emissions and duration of exposure were reviewed. This included a description on how formaldehyde is formed, how it reacts in the atmosphere, how it is present in the atmosphere, its half-life, and methods of exposure (i.e., inhalation, ingestion, dermal). An evaluation of toxicological affects from exposure, both acute and chronic, was performed after an extensive review of available documents and studies. 

Finally, NTH reviewed the distance of the facility to nearby residents and current and future land use to more accurately determine exposure from actual emissions from the facility. This information, coupled with the CALPUFF modeling analysis, was used to demonstrate that the existing facility will not result in adverse impacts. MDEQ approved the analysis and the facility could continue operating without restrictions or changes to the equipment configuration and stack heights. 

From baseball to football to hockey and more, NTH Consultants, Ltd. (NTH) has been involved with Detroit area sports and entertainment facilities since the company’s inception.  NTH’s involvement began when in the 1970s NTH was hired to consult on Pontiac Stadium to provide an optimal solution for foundation design. Since this time, NTH has been called on to provide its engineering talents on other entertainment and events venues, such as the Fox Theater, Motor City Casino, Greektown Casino, Comerica Park, Ford Field, and Cobo Center and more.

Knocking it Out of the Park

NTH has been involved in the two significant projects for the Detroit Tigers over the years. NTH was retained by Economic Development Corporation of Detroit to provide environmental consulting services and supplemental air monitoring during the asbestos and hazardous materials abatement and demolition of Tiger Stadium. The site is now prepared for future use and according to some reports, there are plans for an athletic complex that could host 15,000-20,000 youths a year in addition to other planned retail and residential structures.

The Detroit Tigers Organization also retained NTH to provide engineering services that formed the backbone for building Comerica Park, a 40,000-seat baseball stadium in the heart of Detroit. Our professionals provided full-time, on-site observation during earthwork and foundation installation to verify that subsurface conditions were consistent with those defined during the geotechnical investigation. We remained on site throughout the project, providing construction monitoring of steel erection, concrete and earthwork aspects, as the last details were completed. All work was done according to an aggressive schedule to be ready for Opening Day as planned.

Tackling a Fast-Tracked Project

Settled into the City of Detroit landscape, Ford Field, home to the Detroit Lions, is a magnificent addition to the City’s revitalization efforts. NTH was there every step of the way, providing environmental, construction materials testing, supplemental testing and inspection services to keep the project on track and structurally sound for visitors to enjoy for years to come.

Coming Off the Bench

Most recently, NTH was called off of the engineering “bench” long before the first construction equipment rolled on-site at the new Detroit Entertainment & Events Center. NTH role has been to assist with pre-acquisition due diligence studies as well as pre-engineering data collection and evaluation. Now that the construction of the new indoor arena for the Detroit Red Wings has begun, an NTH crew is working on-site overseeing and monitoring the hazardous materials removal, building demolition, mass excavation as well as caisson installation and substructure construction activities.

NTH is thrilled to have an important role in these historic projects that are helping Detroit become a premiere sports and entertainment destination as the city makes its rebound. 

(This blog post does not express the views of Olympia Development of Michigan and the views expressed here are only the views of NTH Consultants, Ltd.) ​