Jul 22, 2019

Reimagining Water Use

Chicago aquarium reduced its water footprint by nearly 53% over 10 year

Chicago aquarium reduced its water footprint by nearly 53% over 10 year

Located on the lakefront of Chicago is the Shedd Aquarium, a nonprofit organization home to 32,000 animals representing more than 1,500 different species of fishes, reptiles, amphibians, invertebrates, birds and mammals, ranging from the tropical reefs of the Philippines to the open ocean of the Pacific Northwest. Since it opened May 30, 1930, the aquarium has remained a leader in innovation, from being the first inland aquarium with permanent saltwater fish exhibits to now leading the way in sustainable business operations.

From the Abbott Oceanarium habitats that serve as home for the aquarium’s Pacific white-sided dolphins and other mammals to the small habitats within the aquarium’s special exhibit Underwater Beauty, the Shedd Aquarium holds a collective 5 million gal of water, including saltwater. Even the saltwater comes from the freshwater resource in Chicago’s backyard—Lake Michigan.

beluga whales

Saltwater Situation 

Pulling water from the city of Chicago and Lake Michigan, the aquarium creates the saltwater for its saltwater habitats using a mix called Instant Ocean that contains sodium and chloride, along with smaller amounts of sulfate, magnesium, potassium, calcium, bromide and strontium. The blend is mixed with 8,000 gal of freshwater until it is the ideal blend for the animals. However, this process for manufacturing saltwater did not always exist.

As aquarists prepared for the grand opening of the world’s largest aquarium in 1930, before the creation of Instant Ocean, an obvious challenge needed to be discussed. How would an aquarium located 800 miles from the ocean get saltwater for the variety of oceanic creatures they wanted to share with the Midwest? The answer was the purchase of the Nautilus, a train consisting of 20 custom-made insulated railroad cars, and eight lengthy trips to Key West, Fla. With the Nautilus, the Shedd Aquarium siphoned 1 million gal of saltwater and transported it back to Chicago to fill exhibits for tropical fishes.

As years passed, the aquarium’s physical footprint more than doubled and so did its intake of water. The aquarium moved on to more sustainable and efficient methods for filling the exhibits with water, such as the use of Instant Ocean, which reduced energy and transportation costs. However, in the mid-2000s, the aquarium took a hard look at how much water was running through its systems in a given year—57,919,136 gal of city and lake water—and saw room for improvement. 

The Shedd linked saltwater habitats from the Caribbean Reef and Wild Reef exhibits to the Oceanarium
The Shedd linked saltwater habitats from the Caribbean Reef and Wild Reef exhibits to the Oceanarium
A researcher analyzes the aquarium’s water.
A researcher analyzes the aquarium’s water.

Conservation Measures

In 2009, the Shedd Aquarium authorized an audit of the aquarium’s water usage, resulting in a detailed assessment investigating the water consumption of all interdepartmental practices. Initially, the team predicted that animal systems were the leading consumers of water throughout the facility, but upon review it was found that animal systems only accounted for 16% of overall consumption. Rather, the cooling systems, which are used to maintain a comfortable environment for animals, guests, staff and volunteers, were the leading cause of water use.

Equipped with data and understanding of the aquarium’s water usage from the post-audit assessment, the aquarium created a Sustainability Strategic Plan (SSP), which highlighted water usage among 11 focus areas to advance sustainable practices. Among others, the SSP established a goal to reduce water consumption by 50% by 2018, with 2007 serving as the baseline year at an annual usage of 57,919,136 gal. With this goal in place, the team analyzed areas that held the greatest opportunity for improvement, such as fixing leaks and losses, and upgrading systems, such as the animal life support and chiller systems. 

Comprised of three 500-ton chillers and a 1,500-ton cooling tower, the aquarium’s cooling system is responsible for maintaining the temperatures of the 460,000-sq-ft facility and the millions of gallons of water within it. Therefore, the equipment required an exorbitant amount of water to run. 

In 2012, the facilities team upgraded and replaced the three 500-ton chillers and the cooling tower, resulting in an immediate reduction of 3 million gal of water usage. Along with the new cooling tower system, the team installed a closed condensing loop system. This system allowed the aquarium to take all the refrigeration systems that were used for animal and human food storage, and remove them from an old domestic water line that would cool the units by running straight city water through them to drain on the closed loop system. This installation saved 10.5 million gal a year. Additionally, to replenish evaporating water from the cooling towers, the team installed a rainwater collection system that saved a supplemental 708,000 gal. Collectively, the upgrades and additions to the cooling tower, chillers, closed-loop system, rainwater collection and additional efforts amount to a total of 17,908,000 annual reduced gallons.

In addition to upgrading the cooling towers, the aquarium upgraded a filtration system for water features outside, installed a tube bundle heat exchanger unit to an interactive exhibit that was condensing with city water, and more. Eventually, the team tackled bigger, aquarium-wide projects. 

At 3 million gal, Shedd’s Abbott Oceanarium presented an opportunity to reimagine the infrastructure of its water usage. As new saltwater is mixed every time exhibits in the aquarium go through a water change to maintain water quality standards, the facilities and animal health teams wondered if taking in new water every time was truly necessary for the Abbott Oceanarium, because marine mammals do not breathe their water like fishes do. They discussed the idea of recycling water by re-routing saltwater from fish systems to marine mammal systems. 

The teams discovered that not only would recycling water reduce the amount of new water pulled and drained, but the process would be favorable for the animals by providing a more diverse environment. It could potentially positively influence the microbiomes, which are a tiny living community of microbes that are essential to the health and well-being of the animals. The facilities team then began linking saltwater habitats from the Caribbean Reef and Wild Reef exhibits to the Oceanarium, resulting in the annual reduction of 2.5 million gal of water. 

These changes throughout various areas in the aquarium helped the aquarium meet and even beat its water conservation goal. At the end of 2018, Shedd’s total intake of new water was 27,461,280 gal, down from 57,919,136 gal in 2007. This was not only a 50% reduction in water intake—it was nearly 53%. 

Linking the saltwater habitats at Chicago’s Shedd Aquarium resulted in an annual reduction of 2.5 million gal of water.
Linking the saltwater habitats at Chicago’s Shedd Aquarium resulted in an annual reduction of 2.5 million gal of water.

Sustainable Mission

While cutting back on the most precious resource for building operations was daunting and challenging, operating the building sustainably through water conservation not only helped save money, which could be allocated to other important projects, but it helped the aquarium further live out its mission. As the world’s aquatic ecosystems and animals face challenges each day because of human disturbance or interference, reducing the aquarium’s environmental footprint is its responsibility. 

While not all businesses have a stake in the game quite like the Shedd Aquarium, any business or individual can make a difference. Perform water-use audits to identify the key water-consuming practices or pieces of equipment in operations. Small changes like fixing a leak, collecting rainwater to water plants around the yard, or turning off the shower head while applying shampoo, can all help conserve water as a natural resource and protect aquatic ecosystems.

About the author

Bob Wengel is senior vice president of Facilities and Security for the Shedd Aquarium. Wengel can be reached at [email protected]

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