Impact of droughts on industrial emissions into surface waters

In this paper, we examine the impact of droughts on industrial emissions into surface waters and transfers to publicly owned treatment works (POTWs). We use industrial discharges into surface waters data from the US Environmental Protection Agency's Toxics Release Inventory (TRI) database. We employ runoffs normalized using previous 61-year average runoffs as a proxy for drought. We match both the discharges into surface waters and the runoffs at the 8-digit hydrologic unit code (HUC) level. Our analysis indicates that normalized runoffs of the current and previous years positively influence industrial emissions into surface waters. We also find that the impact of uneven availability of water on emissions is higher on larger facilities. Normalized runoffs of the current and previous years do not have a statistically significant influence on transfers to publicly owned treatment works. However, normalized runoffs of the previous year do affect transfers of larger facilities. Businesses are dependent on water not only for their operations but to discharge their pollutants as well. Climate change will increase the frequency and intensity of droughts and floods. Therefore, every business that requires significant quantities of water must plan to cope with uneven availability of water.