As featured in Hydro Leader Magazine
Day & Zimmerman (D&Z), long recognized for executing some of the nation’s most demanding fossil and nuclear outages and maintenance work, also applies its proven planning, safety, and project execution model to keep some of the largest utilities’ hydropower assets running smoothly. In this interview, Project Manager Jay Posey and Fabrication Shop Manager Brandon Tharp tell Hydro Leader about how D&Z is leveraging its skilled craft workforce, rigorous preplanning and condition-based maintenance approach, and in-house fabrication and gate refurbishment capabilities to support hydropower projects across the full asset life cycle, from early-stage assessments to major overhauls and long-term modernization programs.
Hydro Leader: Would each of you tell us about your background and how you came to be in your current position?
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| D&Z has a talented team of skilled individuals, like this welder in D&Z’s power shop, with deep knowledge of hydro work, including maintenance, modifications, upgrades, and work on new projects. |
Jay Posey: I was hired by D&Z about two years ago. Previously, I spent around 10 years as a pipefitter, working exclusively on hydro units. We performed maintenance, modifications, rehabilitations, and upgrades to generating units, balance-of-plant equipment and facilities, and dam safety assets. I started as an apprentice, then worked my way up through journeyman, foreman, general foreman, and mechanical superintendent over those years. After that, I transitioned into estimating work for hydro projects. I spent about a year and a half doing that before moving into a project controls manager role for new builds. I currently serve as a project manager for a six-unit simple-cycle combustion-turbine generating facility.
Brandon Tharp: I started with D&Z in October 2023. I have been in the power industry for about 20 years, though I began my career as a union ironworker. I started as an apprentice on a hydropower dam, tearing apart units and getting familiar with everything. Then, I transitioned to the fabrication side. I moved up to journeyman, took on supervision, and since 2013, I have been running the fabrication shop. We do gate repairs and refurbish and sometimes replace gates, and we perform a lot of blasting and painting on gates and other parts that come off the hydro unit. Most of my crew consists of ironworkers, so I fit in managing them.
Hydro Leader: Please introduce D&Z.
Jay Posey: D&Z has a talented team of skilled individuals with deep knowledge of hydro work, including maintenance, modifications, upgrades, and work on new projects. We continuously build and improve this talent pool through ongoing training and field experience. Our simple focus is summed up in our brand promise to our customers: We do what we say.® This reflects our dedication to providing clients with dependable personnel, strict processes, and a safety culture that leads the industry in these high-risk environments. Across the power sector, D&Z oversees thousands of craft professionals, and each year, we carry out some of the most complex fossil and nuclear outages in the nation. We plan to continue expanding this work in the hydro sector.
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| Welding in D&Z's power shop |
Brandon Tharp: We aim to continue reaching out to secure more work and to retain the craft professionals we already have, keeping them happily employed. We keep succeeding by working with the same people. As we train them, we manage to keep them employed instead of having them move to different companies. Our goal is to keep them. We will remain successful in that effort.
Hydro Leader: How do you offer comprehensive support to a hydro plant throughout its life cycle?
Jay Posey: We offer comprehensive support that begins right from the conceptual stage. We handle preplanning, estimating, and permitting processes. Our goal is to get involved as early as possible. We ensure the job is properly planned and stay engaged throughout the implementation and completion phases. This focus on proper planning and effective execution allows us to provide a support model that covers the entire life cycle of a hydro plant. This approach reflects the highly effective execution model we developed primarily through fossil and nuclear work. This model positions us as a long-term partner for maintenance and modifications.
Hydro Leader: How does D&Z approach inspection, condition assessment, and the prioritization of repairs or upgrades?
Jay Posey: We always aim to have historical condition assessments of the units from previous years. This is important for planning your work and ensuring you implement the right solutions and fix the necessary components. Then, you consider the risk: Are we repairing something or performing maintenance just for the sake of doing it? Is the maintenance effective? We view condition-based planning as more essential than routine, scheduled maintenance because it benefits the assets more. It allows you to prioritize high-risk issues that could affect generation, safety, or your facilities. That methodology is also informed by our fossil industry experience. We have decades of historical data demonstrating that it reduces downtime, unknowns, cost increases, schedule disruptions, and similar issues.
Brandon Tharp: From the shop’s perspective, a lot of the gear we are receiving is older, especially gates and related equipment. Many of the gates were not built to modern code standards. We bring the gear in, assess it, and then reach out to customers to collaborate on the scope. That way, we provide what they want and ensure that their products meet code. Working closely with our clients makes a big difference.
Hydro Leader: What types of turnkey services does D&Z offer for turbine runner maintenance, generator repairs, or full unit overhauls?
Jay Posey: We like to begin with the planning phase. We can offer extensive assistance to clients in areas such as preplanning, scheduling, estimating, risk management, and constructability reviews for any design. Those are things we truly enjoy being involved in. For major repairs, we handle turbine repairs and replacements. Our work includes governor systems, penstocks, control gates, battery systems, and nearly any electrical system upgrade. We have also carried out some serious safety repairs. Additionally, we perform a significant amount of coating work, whether for repairs or new applications. Our team has worked on dewatering structures. Another aspect that is often overlooked is our work on plant equipment and facility upgrades. It is not just about individual units; it also involves upgrades to the entire hydro plant, including control rooms and administrative building spaces.
Brandon Tharp: In terms of fabrication, most of my work with hydro projects involves gates. We do everything from fabricating new gates and refurbishing existing ones to replacing seals. On the coating side, we also offer repairs and full coatings replacements. Some gates are in good condition and just need their seals replaced. We take them in, blast them, assess them, and replace the seals. If anything needs to be repaired, we handle that as well; then, we can coat the gates and return them to service. For tasks outside gate fabrication, we also offer balance-of-plant repairs and modifications. We also fabricate quite a few small items, such as ladders, platforms, and lifting devices, and perform pipe fabrication and steel fabrication.
Hydro Leader: How does D&Z work with clients to meet environmental, regulatory, and dam-safety requirements during upgrades or overhaul work?
Jay Posey: We support these efforts through project initiation and closure, providing any necessary documentation for permitting, licensing, and regulatory matters. Our teams are highly trained to operate in these strictly regulated environments, particularly at fossil and nuclear sites. We are well prepared to manage these challenges and have extensive experience ensuring compliance with all regulatory requirements.
Brandon Tharp: We provide various types of training to keep everyone current with their skills and work with the client to meet their expectations.
Hydro Leader: What trends is D&Z observing in hydro refurbishment demand, and how are you aligning your services to address those needs?
Jay Posey: A large portion of the hydro fleet in the United States is nearing the end of its service life. Most facilities are quite old—more than 50 years old. When equipment reaches that age, it requires ongoing rehabilitation and upgrades to keep it operational. This applies not just to the generating units but also to the facilities themselves. We are witnessing the aging of hydropower infrastructure nationwide, necessitating the modernization of units and facilities. There is a significant spike in resource demand to carry out these projects. With these rehabilitations, we are also seeing the digitalization of previously nondigital hydro units. Upgrades such as these are essential. There is a widespread workforce shortage across the industry, and hydro facilities are not exempt. Many outages tend to occur around the same time, leading to challenges in resource allocation among various clients. We are assessing this demand and exploring ways to meet it by providing the necessary labor resources.
Hydro Leader: Are there any hydropower project success stories you would like to share?
Jay Posey: Over the past two years, we have implemented two projects that were very high risk, which is out of the ordinary. Both involved replacing large existing penstock butterfly valves that were 70–80 years old—original equipment. One set of valves was 86 inches; the other was 144 inches. Both projects involved months of preplanning, since the valves were in locations that were difficult to access, and required a highly skilled team. Multiple scenarios were developed to find the best execution strategy for these projects. Both projects were completed successfully. These high-risk projects are high-priority items for us; we enjoy tackling jobs that others might avoid.
Another project, which lasted about 10 years, involved replacing and rehabbing 24 spillway gates for a client. We typically did two gates per year: removing them, taking them to an offsite facility near the plant, performing a full coating blast, making repairs, applying a new coating system, and then reinstalling them. Coordination with both the client and vendors was paramount to the success of these projects.
Hydro Leader: Why should asset owners and operators choose D&Z as a long-term partner for hydro maintenance, rehabilitation, or life-extension projects?
Jay Posey: Hydropower plant operators need partners who bring predictability, safety, and stability. We offer clients a large, dependable, scalable labor force. We have an outage management system and integrate engineering with our maintenance and modification capabilities. Additionally, we have an excellent safety culture that has been built for the most demanding environments in this industry. Our goal is to be a one-stop shop and long-term partner for all maintenance overhauls, life extensions, and other programs across the hydro industry.
Hydro Leader: Is there anything you would like to add?
Jay Posey: We aim to be known as a trusted maintenance and outage partner for hydro, just as we are known to be in the fossil and nuclear industries, supporting all client needs for modernization, reliability, and long-term stewardship. We have also expanded our capabilities beyond maintenance to engineering, construction, and other areas of project work to serve hydro clients better and strengthen our presence in that market.
Brandon Tharp: D&Z aims to focus on bringing the knowledge and experience from the fossil and nuclear sectors to the hydro sector.
Hydro Leader: What is your vision for the future?
Jay Posey: Our vision for the future is to continue supporting our fossil, nuclear, and renewables markets and to integrate hydro more fully so that we can provide the same level of support across all these markets.
For more on Day & Zimmermann, visit dayzim.com.
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| Jay Posey is a project manager at Day & Zimmermann. |
Brandon Tharp is the fabrication shop manager at Day & Zimmermann. |