1. Metal Finishing Pretreatment in Connecticut SNEATP Tech Talk Presentation Mariana Miller February 10, 2015

2. What is Metal Finishing? ‘Finish’ a metal off by: – Depositing coatings of one metal on to another – Coating metals, based on specific requests from customers – Producing specific designs or appearances on part surfaces Metal finishers – 47% of regulated CT industry

3. Pollutants generated Metals Hexavalent chromium Cyanides Oils Toxic organic compounds Solids

4. Pretreatment Treatment plants are not designed to handle pollutants in raw wastewater Wastewater must be treated prior to discharge to sewer Prevents: – Interference with processes at the treatment plant – Pass through of pollutants

5. Common types of Pretreatment Metals precipitation prior to discharge – Neutralization – Flocculation/coagulation – Sludge dewatering Hexavalent chromium reduction Cyanide destruction Filtration Oil/water separation Haul wastewater

6. Without Pretreatment… EPA NPDES Permit Writers’ Course Workbook – Bottom left: Hexane explosion – Top right: Manhole cover blown off after gas explosion – Bottom right: Buildup of hydrogen sulfide/buildup of solidified oil Other effects…

7. How is this regulated? Local, state, federal regulations CT DEEP permits Effluent limitations Treatment plant’s review/approval Inspections Monthly reporting Enforcement actions

8. Questions?