Chicago Zoological Society

Because the Brookfield Zoo is concerned for the safety and well-being of animals and human visitors alike, we pay scrupulous attention to the variety of environments we establish.

Creating and maintaining the many bodies of water found in habitats around the zoo is no small challenge. Our Water Quality Monitoring Program shoulders this responsibility. The program takes the quality of our water very seriously—with good reason.

Water is essential to life, a fact we humans tend to take for granted. But any visit to the zoo reinforces the crucial role that water plays for all living creatures.

We maintain nearly fifty different aquatic systems throughout the zoo, from simple ponds to complex salt-water coves, and create special effects environments ranging from basic rain to humid rain forests.

Along with all this, we also maintain pools and fountains to provide an optimal environment for our human guests.

For all our bodies of water, we apply rigorous testing and safety standards that meet and often exceed regulatory standards, including those set by the EPA. All our aquatic systems are tested on a regular basis. We test older established systems at least weekly, and newer systems and those our guests come in contact with more frequently, sometimes as often as twice a day.

Besides ensuring that our water systems are safe and sufficient for the needs of the animals who depend on them, the Water Quality Monitoring Program also looks beyond our own confines. In keeping with CZS’s strong commitment to conservation, the Program also plays a leading role in developing conservation-minded models for zoo water-quality control worldwide.

Quality of Life

At any zoological facility with closed live animal aquatic systems, it is important to provide a safe and healthy environment for animals to thrive. This environment should closely reflect the natural environment from which the animals originate thus promoting natural behaviors such as feeding, courtship, and breeding. At Brookfield Zoo, the Chicago Zoological Society continually strives to improve the lives of all animals through the use of leading edge environmental monitoring equipment and methods, while setting the standard for animal care and welfare in the zoo and aquarium community.

A Water Quality Laboratory at the zoo is responsible for a number of animal systems and public water contact areas. The current lab was constructed in 1993 within the Animal Hospital to provide a central location for water testing of many of the buildings around the zoo that house animal enclosures that incorporate water, such as the Living Coast, Seven Seas and the Swamp.

Led by John Kanzia, Environmental Quality Manager, there are currently almost fifty different aquatic systems that are sampled and tested at least once weekly to monitor the general health of the system and make sure that parameters in the environment reflect conditions in nature as much as possible. Older, more stable systems are tested once each week, while new systems, such as quarantine, are tested daily. While in operation, interactive water features (spray pad, pad stream) are tested up to twice per day to ensure that state regulations are met.

Mobile instrumentation is taken to Indian Lake twice each month to monitor dissolved oxygen at various depths and to determine the status of the lake. Surface and bottom samples are collected and brought back to the lab for bench-top analysis. We work closely with the Northeastern Illinois Planning Commission and the Chicago Forest Preserve District to manage the lake and maintain it as a waterfowl sanctuary and a stocking source for public lakes in the county. The zoo has multiple “satellite” water quality labs located at the Living Coast, Swamp, and Seven Seas, and these smaller facilities are used for basic monitoring by Keeper or Life-Support staff on days when the Environmental Manager is not on-grounds.

The main Water Quality Laboratory is equipped with instrumentation and chemical reagents to perform temperature, pH, salinity/conductivity, free or total chlorine, free or total bromine, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, copper, iron, alkalinity, calcium hardness and dissolved oxygen tests. Wet chemistries are performed with Hach reagents designed for a 25 mL sample and read with a DR 4000 spectrophotometer. Tests routinely performed on aquatic exhibits include temperature, pH, salinity/conductivity, ammonia-nitrogen, nitrite-nitrogen, and nitrate-nitrogen. Husbandry staff has the option to request other tests as they find appropriate. Tests performed on interactive water features include pH, free chlorine, total chlorine, alkalinity, and conductivity. Data are entered into a networked Water Quality Database which is maintained by the Environmental Quality Manager. Daily reports are sent via email with a brief summary of the findings for each area. Every two weeks, the Environmental Quality Manager meets with lead keepers from aquatic areas to discuss water quality data, trends, and to address any system-wide problems.

Microbiological samples are an integral part of the water testing schedule. Samples are currently collected weekly from marine mammal pools, non-human primate water systems, and interactive water features. Total bacterial counts, total coliform and total fecal coliform counts are monitored.

During the summer season when interactive water features are in operation, they are tested at least twice daily to ensure EPA compliance and provide a safe environment for guests who would like to use them. Also, samples from some of the larger systems are sent to an outside laboratory for more thorough analysis (metals, trace elements, etc.) on a quarterly basis.

The Chicago Zoological Society’s Water Quality Laboratory has established a program that has been developed from published standards and accepted ‘best practices’ from aquatic life support professionals.

By continuously monitoring the environments we provide for our animals with an array of bench-top, in-line and field equipment, closely studying the results, and communicating regularly with the staff that interacts with the animals on a daily basis, it becomes possible to recognize inconsistencies in water quality and/or behavior and deal with potential issues proactively rather than reactively.