For Metro Water Services (MWS), overseeing and maintaining Nashville’s 3,000 miles of water mains, two water plants, three wastewater treatment plants, and 35 reservoirs, are no easy tasks. And with the city of Nashville experiencing a 41 percent population growth compared to similar-sized cities within the last 25 years, MWS water demands have increased dramatically. As a result, the utility company is undergoing a major upgrade of its Omohundro Water Treatment Plant (WTP).
However, the Omohundro upgrade is a unique undertaking and is considered a once-in-a-generation project, because Omohundro isn’t a typical WTP. It is 105-year-old WTP.
At this year’s Autodesk University, team members from the Omohundro project came together during the session, “Visualizing the Future of Nashville Water: The ACC-VR Combo Hits Its Stride in a Massive Collaborative Design Effort,” to examine how cutting-edge technologies like virtual reality simulations digitally transformed the once-in-a-lifetime WTP project and set new standards for Nashville’s critical infrastructure projects in the future.
Nothing “ho-hum” about Omohundro
According to Justin Bowling, a key MSW engineer on the Omohundro project, the scale of the WTP upgrade is of the likes that Nashville water utilities have never before seen. “We are essentially building a new WTP in the footprint of our existing WTP and adding an additional treatment process,” explained Bowling. “To give you an idea of the scale of this, we’re going to pour over 136,000 cubic yards of concrete, install 46,000 linear feet of steel and ductile iron pipe…and will have almost five football fields of floor space when the plant is complete. If you were to take all the plans and specifications for this project and stack them up, it would be over nine feet in height.”
“This site is on the National Registry of Historic Places (NRHP). Anything we do on the site has to go through NRHP for approval and the State Historic Preservation Office.” –Justin Bowling
Bowling explained that in addition to keeping pace with the water demands of the growing population of Nashville, other project drivers of the Omohundro upgrade include resiliency, reliability, and service excellence. In 2018, MWS conducted a pilot plant project to explore new treatment technologies that would serve these key project drivers. “The pilot plant lasted two years and entailed 18 months of operating and collecting data, and six months of analysis for final recommendation,” said Bowling. “More than 44,000 samples were collected and analyzed, and the utility decided to implement post-filter granular activated carbon (GAC). GAC is what we are installing at Omohundro.”
The GAC system will be installed in an existing historic filter building that was constructed in the 1800s, Bowling explained. The upgrade project also includes construction of a new pre-treatment facility, a new filter facility, a new water metal storage facility to house treated water, and a new maintenance and reservoir storage facility. “[This maintenance and reservoir storage] facility will increase our capacity from 90 million gallons a day to 150 million gallons a day, to address that growth and demand put on our distribution system,” said Bowling.
In addition to the monumental undertaking of the physical upgrades, MWS must also simultaneously navigate historic preservation laws, since portions of the site upgrades were constructed in the 1800s. “There are elements that make our project unique among other WTPs,” said Bowling. “We have this historic preservation…This site is on the National Registry of Historic Places (NRHP). Anything we do on the site has to go through NRHP for approval and the State Historic Preservation Office.”
Unique projects powered by unique tech
To navigate and meet these unique demands of the Omohundro project, the teams behind the upgrade adopted new tools and state-of-the-art technologies to assist them in their reviewal and approval processes.One tool that was critical to the success of the Omohundro project was virtual reality. According to Drew Hart, a Design Manager at Carollo Engineers – one of the firms working on the WTP upgrade – virtual reality on these types of projects has traditionally been leveraged for narrow use cases.
“The first differentiator for Resolve – and the reason we selected it for this project – is we were looking for something that could handle the model size and level of detail that our federated site model had, so that we could tour the entire project in a single virtual reality environment.” –Drew Hart
“Historically, we needed powerful, dedicated laptops to run the design model on virtual reality platforms that we’ve used,” explained Hart. “We’ve also needed wire headsets to go with them. That means that we are traveling around with this equipment. And, in aggregate, all that has historically equated to virtual reality being used for one-off review events for special projects whose size really justifies an effort like this.”
Though past virtual reality use cases were limited on projects similar to Omohundro, Hart explained that the virtual reality platform the teams adopted for this particular upgrade, Resolve, was a complete gamechanger and broke the mold in how the technology could be used in WTP upgrade projects.
“The first differentiator for Resolve – and the reason we selected it for this project – is we were looking for something that could handle the model size and level of detail that our federated site model had, so that we could tour the entire project in a single virtual reality environment,” said Hart. “That ultimately led us to Resolve. Its engine for handling that model data is nothing like anything we had ever used before. We realized a lot of other benefits with it too that we didn’t even imagine when we started this.”
One of the main benefits of leveraging Resolve was that it directly integrated with BIM 360. “This means that our normal design workflow, which produces this federated Navisworks model, is sufficient to prepare the virtual reality environment,” said Hart. “The setup for Resolve is hosted on the cloud, and it’s accessible with wireless headsets. That means it can be accessed from anywhere in the world by team members. The virtual reality use case is now very different than it was historically for us. It is now a day-to-day tool for refining and simulating our design concepts and sharing them with the owner team and well beyond our design team.”
“VR is able to give us the plants in this virtual reality world, where we can see exactly how it’s going to look and how it’s going to function. It’s been huge for us.” –Justin Bowling
Hart explained that because Resolve integrates with BIM 360, each day a new Resolve model is rendered that reflects the latest design information and can be experienced virtually from anywhere at any time. He also noted that new use cases of the Resolve and BIM 360 integration are being constantly realized. “For example, when we make voice-to-text annotations in Resolve environment, those comments can manually be pushed back to the federated model’s issues, and that makes them available to the entire design team that’s interfacing with that federated model.” For Bowling, who provided the owner’s perspective of the virtual reality use cases, Resolve completely transformed how project reviews were conducted during the WTP upgrade.
“Some may ask how it’s possible for such a small team to review such a big project with 2D sets of plans,” said Bowling. “The answer is: we don’t review 2D sets of plans. I have goggles in my office and enter the virtual reality world to review the plans. With VR, we are literally looking at the ground and saying, ‘Hey, why don’t you try to give us an underground tunnel here so you can remove one of these stairwells.’ And the design team was able to do just that for us…VR is able to give us the plants in this virtual reality world where we can see exactly how it’s going to look and how it’s going to function. It’s been huge for us.”
