Sarah Haviland, lab manager and graduate student in the Department of Regenerative Medicine and Cell Biology at the Medical University of South Carolina, shares her experiences with contributing editor Tanuja Koppal, Ph.D., on choosing and installing a new point-of-use water purification system. Jeffrey Denoncourt, the North America custom water systems manager for EMD Millipore Corporation, discusses the importance of knowing about the type and quantity of water needed in order to make informed decisions on the design and size of the purification system.

Q: Can you tell us why and how you went about evaluating your options for a new water purification system?

A: Three and half years ago our laboratory moved from Georgetown University to the Medical University of South Carolina. When we moved, we were sort of at a loss because we didn’t have the same resources in terms of knowing people and knowing where to find everything. So it took a little bit of time to figure out where the central water system was. The system looked pretty old, and we weren’t sure who was involved with the upkeep, which made us nervous because it would cause us some delays if ever there were a problem and the purity of the water was compromised. It was really in our best interest to purchase our own system, which would support the postdoctoral fellows, graduate students, and technicians in our lab. As an electrophysiology lab, we are required to have ultrapure water because different ions in the solution can cause a lot of problems with cell patch clamp recordings. We also use ultrapure water for making stock solutions for our recordings, for molecular biology and cell culture work, or for rinsing labware after it’s cleaned.

Q: What were you looking for in a new system?

A: We needed a system that had a decent flow rate because we use a lot of water every day and sitting there waiting for the equipment to fill with water is not our favorite thing to do. We wanted something that could provide savings in terms of bench space. We also wanted something that could get rid of bacterial endotoxins for some applications. We didn’t want to have someone from the company come to install filter cartridges every few months, so we wanted a system that was user friendly, where we could replace filters ourselves. We wanted something that was reliable, because our lab will shut down completely if we don’t have pure water. Although we need water, we didn’t want to spend a fortune, and so a good price point was important too. Last, we needed something that could be moved easily, because we were in an interim space and our lab was moving to a new building. So this system was going to have to be moved as soon as our new building was completed, which took about three years. We have now moved into the new building, and we were able to easily move the water purification system and reinstall it in less than two hours. We were very nervous about this, but it actually worked out very well, and we are happy with the decision we made.

Q: Can you provide some details on what you have to do on a regular basis to maintain the system?

A: Our building provides reverse osmosis water, which is actually a lower grade than deionized water. Since the quality of the starting water is not as good, we have to watch our cartridges more carefully because they can get used up quicker. We change our cartridges probably about twice a year. We could probably get away with changing them a little less frequently, but we’d rather be safe than sorry. We have the system calibrated by the company probably once a year, and they also check the flow and output of the water. As long as the reading shows 18.2 megohms [which signifies ultrapure water], we know the quality is there and there shouldn’t be a need to change anything.

Customizing and Optimizing Water Purification Needs

Jeffrey Denoncourt, North America custom water systems manager in the lab water business field in the lab solutions business unit of EMD Millipore Corporation, says that the biggest challenge, especially for a new facility, is trying to understand the users’ requirements and needs. “I think there’s still a tendency to jump to the old solution of putting a very large system in the basement or in the penthouse and running lots of distribution pipe throughout the facility.” That can work, because common practice has been to distribute lower-quality water—a type 3 or type 2 water—throughout the building, and the researchers purify the water to type 1 quality at individual points of use. But identifying the requirements early on certainly opens up different design options. “You’re more likely to get a solution and a system design that will meet the individuals’ and the facility’s requirements in the long run and provide long-term flexibility,” he says. For instance, there might be individual users or areas that have some special needs, and their pure water requirements can be better met by smaller, individual systems. Or there might be a floor or a wing of a building that requires more water volume. A smaller central system that doesn’t have distribution piping through multiple floors but runs piping through a few laboratories may be a good design alternative.

There is also a growing trend toward installing smaller, individual point-of-use systems instead of trying to install distribution piping throughout a building, which can be expensive. These are systems that supply type 1 or type 2 purified water direct from tap water to an individual researcher or to a few researchers in a laboratory. The individual systems can be either bench-top units, installed under the bench, or wall-mounted, and they offer some advantages and more flexibility. Compared to a large central system, the individual systems provide the users with a higher level of control over the pure water. It’s easier to move or change these systems simply because they are smaller. If the user’s application changes and a different purity of water is needed, the smaller system is easier to modify without impacting the entire facility. If the demand for water increases, it’s a lot easier to add another system than to add or modify distribution piping in a building. If labs move and don’t need the water, the individual system can be shut off and moved to another location or another floor in the building. “If you have a large central system in the facility, to modify or add to it involves changing the piping in the building, and it impacts all the users in the facility,” says Denoncourt.

Whether for an individual user or a facility, Denoncourt works hard to identify the requirements for pure water by working with researchers and designers to understand their applications. “That helps us define a target for the level of purity so we can provide the purification technologies we need to design and build into the system. We also try and understand from a demand standpoint the daily usage of water and when it’s being used. Factors like these impact the size and design of the system,” he explains. He also tries to figure out where the water is going to be used within a facility, how many use points will be on each floor, and how much water will be used at each use point, and then he works with the architects and designers to create the best solution for water purification.

Table courtesy of EMD Millipore.