Stop 01: Cooling Towers
Highlighted Topic: Assessing Wastewater Volumes
Cooling towers can be a significant source of wastewater at a chemical plant.
The main law governing wastewater discharge is the Clean Water Act (CWA). The Clean Water Act covers discharges of wastewaters from a facility, including discharges either piped to a sewer authority or released directly to a waterway via an "outfall." The Wastewater Treatment Tour Stop a little later on this tour provides more details on CWA permitting provisions. This stop on the tour will first focus on the importance of evaluating your wastewater volumes.
One of the fundamental principles of wastewater regulation is that facility-specific limitations will be based in part on expected wastewater volume flows. Since wastewater can arise from both process and non-process activities, as well as from both ongoing and periodic activities (e.g., cooling tower blowdown), it is important to systematically map out all these potential sources of wastewater before you seek a wastewater discharge permit.
Although under normal conditions cooling water will not contact process fluids, the chance of contamination and/or leaks needs to be considered and factored into its management. In addition, cooling water may contain additives to control corrosion, bacteria buildup, etc. Therefore, even in cases when cooling water is considered "non-contact," it still represents a wastewater stream that must be managed.
Other Regulatory Issues:
Another important wastestream from cooling towers is vapor discharged to the atmosphere. This vapor might contain volatile or dispersible components of the fluid being cooled, and must be reviewed for coverage under the Clean Air Act's regulations covering hazardous air emissions.
Boilers & Furnaces