Mountaineer Power Plant Exterior of Reactor

ELG Compliance: Consider Your Equipment Options From Every Angle

Select the most effective technology for ELG compliance

This is post three of a four part series on ELG Compliance

Choosing the right ELG compliance technologies for your plant means considering your options from every angle. As you know, the ELG limits are technology-based; the EPA evaluated a number of possibilities from both a technological and an economic perspective in selecting which types of systems should form the technology-basis for each stream and in developing the new limits.

Despite all of the EPA’s research, when it comes to selecting what will work best for your plant, it isn’t as simple as checking a box. Since the EPA’s survey work was completed, various other equipment options, that have the potential to meet the ELG requirements, have come onto the market, opening the door to additional possibilities. The EPA basis is now really just a starting point for your own equipment evaluation. To determine what suits you best, you need to investigate what’s out there and consider each option from a cost, space, and schedule standpoint.

Not all costs are up front

In considering the cost impact of each technology option that you evaluate, be sure that you are looking at the whole picture. With so many variables impacting each plant, not only can the capital and installation costs of equipment vary considerably, but O&M costs can vary greatly as well. And O&M costs can be tricky to estimate accurately if you don’t ask the right questions.

Piloting equipment can give you a better understanding of not only how a given technology will perform in treating your wastewater, but also how much it will cost to operate. For instance, one treatment technology we worked with a client to evaluate looked like an optimal solution on paper — at least from a capital and installation cost perspective. It also looks great operationally — no biological system for the plant staff to learn to operate. However, once we better understood the consumables costs and the routine maintenance frequencies, at the flow rate and the level of contaminants the plant needed to treat for, the system ultimately appeared much less attractive.

While you’re evaluating equipment, consider the skills levels of your operational staff. Few power plant operators have experience running a biological system. Some systems may require a sophisticated understanding of chemistry. At the very minimum, your current staff will need additional training to operate the new systems. Depending on the equipment you choose to comply with the ELGs, you might even need to supplement your current team with additional or differently skilled operators. Bringing in outside help for commissioning and training can help close the skills gap. Hiring an outside operational group with specific skill in wastewater treatment systems to run the system on a more long-term basis is another option worth evaluating. These options can add significant dollars to your investment so be sure to factor staffing into your technology selection cost evaluation process.

Fit into your footprint

For most power plants today, expansion space comes at a premium. Equipment additions or modifications to comply with other regulations or to upgrade facilities over the years have made available space scarce, so squeezing new equipment into a tight or an irregular space is something that you very likely may have to plan for. And beyond fit, you’ll also need to leave enough space for equipment access and maintenance. With some systems as big as a small warehouse, how will you fit and integrate new equipment?

It comes down to a smart design. Get the right engineer on your team for design. Finding someone with experience working within an operating plant facility who has faced similar design challenges before can be a game changer. If you are working within tight plant space constraints, the equipment supplier’s standard design might not quite fit—you may need to look at customizing tank or clarifier design, splitting systems into parts to fit in available open space within the plant, reutilizing old foundations, demolishing abandoned equipment, and/or rehabbing areas of the site while minimizing the impact on the day-to-day plant operations. This can be quite a challenge. The engineering design is just one small piece of this balancing act— planning and scheduling deliveries, construction, tie-ins, and start-up to blend as seamlessly as possible with existing plant operations and planned outages and other work onsite (such as CCR related modifications) requires a holistic approach from a complete and smart team.

Two situations at projects we’ve worked on quickly spring to mind when I think about challenges related to space constraints. At the AEP Mountaineer facility, our engineering team worked with the equipment supplier, the constructor, and the plant team to develop a custom rectangular concrete tank approach for a biological treatment system in to fit into the minimal space available onsite for the new equipment. At another facility, we worked with the owner to take advantage of an ash pond closure and rehabilitate the space to use it as the site for the new system. It was a win-win solution for a plant that was pinched for space.

Meet your timeline

Timing your equipment installation, tie-ins and startup can be complex when you need to consider not just the timeline for the new equipment, but also coordinate the schedules of an operating plant facility and other work (such as a CCR pond closure or ash transport system replacement) as well. In addition, as I mentioned in my previous post, the lead times from suppliers for various pieces of equipment may be impacted by demand. Unfortunately, given the window for compliance and the competition for resources, being able to have the equipment onsite, in place, commissioned and treating water has to play a role in your plant’s technology selection process. Simply put—can the equipment supplier meet the delivery schedule, and can the equipment selected be installed and commissioned in a timeframe that supports plant compliance with the ELG rule? Your answer to both of those questions needs to be yes. So be sure you understand equipment lead time and how long it will take to get each system installed and operational as you are investigating your technology options.

Ask the right questions

Sometimes it’s hard to know where to start and what to ask when you’re looking at systems that you aren’t so familiar with. In general, power plant staff knows what it takes to keep a plant running, what it takes to keep the lights on across the country. But when it comes to wastewater, the knowledge base may vary. Make sure that you are talking and working with experts who know wastewater, who have experience working with the various technologies and the different suppliers. I’d love to be able to provide all my clients with a set list of questions that they should ask the technology supplier. But the truth is that there is no set list—so many of the questions you need to ask are unique to a plant based on the plant’s environment and operational characteristics. By applying lessons learned on other sites, an experienced engineer will know the right questions to ask for a technology solution that’s customized for you.