Environmental/sustainable mission

Dolphin water treatment device

Central's chilled water plant which provides the air-conditioning needs of the campus, incorporate heat rejecting devices commonly known as cooling towers which are located on the cooling plant's roof at the Physical Plant building. In order to control water quality in these open loop systems, chemicals are typically used to control algae, bacterial growth, and hardness in order to protect human health as well as associated mechanical equipment. As water hardness builds as a result of the evaporative cooling process, a portion of this water (called blowdown) is discharged into the city's storm sewer as "less hard" fresh city water is re-introduced back into the system. In order to be allowed to discharge this blowdown back to the local aquifers, the EPA requires a National Pollution Discharge Elimination System (NPDES) permit which is administered through the Wastewater Section of the Iowa Department of Natural Resources. This water quality arm of the DNR recently made the Central's Facilities Team aware of concerns regarding the concentration of one particular chemical that "could" be potentially harmful to aquatic life within the state's rivers and streams. Acting on this concern, Central College immediately stopped using this potentially harmful chemical and began pursuing other options. As a result, Central became the first in the state to introduce a new technology that incorporates an electrical field to sterilize bacteria and encapsulate mineral content which precipitates out in the bottom of the cooling tower sumps as a harmless powder. These new water treatment devices, called "Dolphins" developed and manufactured by Clearwater Systems Inc., are shown here after installation at the central cooling plant.
Click here to observe the lay-out, operation, and real-time performance of the plant.