Water is an often overlooked part of lab sustainability. It pours forth from the tap and then disappears down the drain. It’s nearly invisible. But it isn’t free – it comes from somewhere and it has to be cleaned, transported, stored, and cleaned again before being returned to the environment. All of that has an enormous energy and carbon footprint.
Many laboratories require substantial amounts of water to operate. From autoclaves and glassware washers to purified water systems and faucets, the flow of water in laboratories is constant. Fortunately, there are a variety of ways you can reduce water usage. Like energy efficiency, water efficiency is possible by taking actions in the lab to become more sustainable.
Below, we’ve outlined 9 actions you can take (starting today!) to reduce water usage in the lab.
1. Retrofit autoclaves with water-saving devices
Autoclaves use a lot of water to sterilize equipment, reagens, and hazardous waste in labs. Some autoclaves, like small benchtop autoclaves, don’t use a great deal of water, but steam jacketed autoclaves are often the biggest water consumers in the lab.
There are two ways steam jacketed autoclaves use water. The first is to generate steam to heat the unit in order to sterilize equipment. The second is to cool this steam so it can be discharged. Because the steam produced is so hot, cold water is continuously added so that when discharged, it does not melt the pipes. This process can use as much as 60 gallons of water per cycle (~90 gallons if your autoclave is more than 10 years old).
To reduce this continual stream of water, water-saving devices capture steam in a closed container and use temperature sensors to help control how much water is needed to cool it down. Once appropriately cooled, it can then be flushed down the drain.
Retrofitting steam jacket autoclaves with water-saving devices can cut back water usage by 75-90%. That’s huge! Add this effective water-saving action to the top of your to-do list.
2. Consider new research grade autoclaves
If your lab is in the market for a new autoclave, consider purchasing research grade autoclaves that do not use steam jackets. These newer models use 93% less water (and help reduce energy consumption).
3. Install low-flow aerators to faucets
Low-flow aerators can help reduce faucet flow from 4.0 gallons/minute to <1.5 gallons/minute. Low-flow aerators simply screw onto the end of faucets and reduce flow without changing water pressure. It’s an easy and cheap option that will significantly reduce water usage. Your organization may even have aerators on hand and can help install them. All you have to do is ask!
In a case study conducted at UC San Diego in 2017-2018, aerators installed in labs across the campus saved a whopping 926,000 gallons of potable water per year.
4. Check for faucet leaks and report them promptly
Leaky faucets that drip once per second can waste 3,000 gallons of water per year. According to the US EPA, that’s enough water for more than 180 showers!
Check for leaks anywhere you have a line that constantly maintains water. You can find leaks on autoclaves, ice machines, and water cooled equipment. Once found, promptly report leaks, and make it a common practice to keep an eye out.
5. Eliminate single-pass cooling
Single-pass cooling is a term used to describe a process that uses water to cool something once. In contrast, a closed-loop or recirculating system reuses water continuously. The process of single-pass cooling is not only wasteful, but it can be a safety hazard in the lab, as well.
Single-pass cooling can be found in equipment such as autoclaves and ice makers, and it’s commonly used to cool reactions in chemistry. By eliminating this process from your workflow, you can save hundreds of thousands of gallons of water each year and prevent the risk of flooding.
Instead of running water continuously to cool a reaction, see if your building has a closed-loop water system that you can hook into. If that isn’t an option, you can use a recirculating water bath. If you don’t have the budget for a recirculating water bath (they can be expensive), try an ice bucket + an aquarium pump to create your own DIY option. Efficiency on a budget is still efficiency!
Find a closed loop option for fume hoods here.
6. Only run equipment that uses water when full
Ensure you’re only running equipment that uses water, like glassware washers and autoclaves, when they’re full. No half-loads allowed!
7. Only use purified water when needed
In order to make purified water, you have to clean and filter it in a process that is not 100% efficient. For instance, it takes about 3 liters of water to make 1 liter of deionized water. If you’re using purified water systems, make sure that you're only using purified water when needed.
8. Don’t let water sources run when they don’t need to be running
If you’re washing dishes or filling up containers with water, a common practice may be to walk away while the faucet is running. This can lead to unnecessary overflow. Instead, always keep your eyes on a running water source.
Alternatively, consider a timed water valve that runs for a certain amount of time or only discharges a certain amount of water. Or, install foot petals so you’re only pumping water when needed.
9. Use a vacuum pump instead of a water vacuum aspirator
Water vacuum aspirators need about 2 gallons of water per minute to work properly. Running them for just 2 hours a day wastes over 60,000 gallons of water per year. That’s the annual water usage for 750+ people!
Instead, switch to a vacuum pump that does not require water usage. Vacuum pumps offer greater control and better performance than a water vacuum aspirator, not to mention a far better alternative for the environment.
Water is essential to life. We need to think hard about how we are using water in the lab, and at home, so that we can be responsible with this most precious resource. Ensure that you’re using water when necessary, with conservation in mind, and disposing of it in ways that ensure we protect the ecosystems it will inevitably be released back into.