Need to return call by / at/between and . Signature: Project No.: 

### 0172.08.005.607 Page 1 of 3 Project Name: 

### 2011 Prelim Cat Rev 

## CBI? Yes No TELEPHONE CALL RECORD Incoming Outgoing Date: 

### 08/24/11 Time: 

### 2:00 am pm

Company Name: 

### Horsehead Corporation ERG Staff Name: 

### Elizabeth Sabol

Contact Name: 

### David Swisher Contact Phone Number: 

### (724) 774-1020 General Subject: 

### 2009 DMR Fluoride Discharges



## TOPICS DISCUSSED AND ACTION TAKEN

I called Mr. Swisher on Wednesday, August 24, 2011, at 2:00 pm to discuss fluoride concentrations for outfall 101 in the 2009 DMR database. Mr. Swisher stated that he would work on gathering the information for fluoride concentration data and call me back.

On August 26, 2011, Mr. Swisher called me back to conf irm the fluoride concentrations for outfall 101 in the 2009 DMR database. Mr. Swisher confirme d that the outfall is later combin ed with outfall 001. Mr. Swisher stated that the fluoride concentrations reported for out fall 101 were correct. Please se e the following table of fluoride concentrations:

Monitoring Period Date DMR Loadings Tool Monthly Average Fluoride

Concentration at Outfall 101 (mg/L) DMR Loadings Tool Monthly Average Flow for Outfall 101 (MGD)
31-Jan-09 229 1.312
28-Feb-09 261 1.071
31-Mar-09 364 0.883 30-Apr-09 332 0.78 31-May-09 139 0.815
30-Jun-09 134 0.817
31-Jul-09 398 0.768 31-Aug-09 448 0.704 30-Sep-09 213 0.787
31-Oct-09 231 0.668
30-Nov-09 391 0.535
31-Dec-09 178 0.285



### Mr. Swisher stated that he would follow-up with me on how the fluoride enters the wastewater and the corresponding wastewater treatment for fluoride. Please see the following e-mail attachments.Need to return call by / at/between and . Signature: From: Swisher David <dswisher@horsehead.net> To: "elizabeth.sabol@erg.com" <elizabeth.sabol@erg.com> Date: 9/12/2011 9:21 AM Subject: Horsehead Corp. - Fluorine Sources Attachments: Fluorine Sources.doc

Elizabeth;

Sorry this took so long. I wa s away on vacation for a week.

I believe the attached write-up should answer most of your questions regarding the s ource of fluoride in our WWTP discharge. We do not treat the effluent specifically for fluoride.

Let me know if you have any further questions.

------------------------------------------------ David B. Swisher Manager, Environmental Affairs Horsehead Corporation 300 Frankfort Road Monaca, PA 15061

724.773.2284 Office 724.773.2242 Fax 724.494.8066 Mobile dswisher@horsehead.net<ma ilto:dswisher@horsehead.net>Need to return call by / at/between and . Signature: 

# M EMORANDUM

T

O

: David Swisher D ATE : 9/2/2011

F

ROM : Eric Johnson

S

UBJECT : Fluorine Sources



### Fluorine enters our process through two prim ary sources, these are crude zinc oxide (CZO) and HRD calcine (calcined CZO). Both sources bring about the same overall amount of fluorine into our process. The CZO enters our process through the CZO cl arifier system. Some of the fluorine dissolves into the water and travel s to the waste water treatment plant (wwtp) via the clarifier over flow. The CZO filter cake is then processed in the sinter plant with HRD calcine and other secondary materials. This sint er plant generates sinter , which is processed in the furnace plant, and a fume byproduct which is filtered by a bag house system.

The sinter is sent to the furnace plant where the majority of the fluorine exits our process via the discard slag. There is also an aqueous waste stream generated we call blue powder. The blue powder and sinter dust from the bag house ar e sent to the zinc sulf ate clarifier system. Similar to the CZO clarifier system some of the fluorine dissolves into the water and the overflow is sent to the wwtp.

The process water at the wwtp is processed in the wwtp clarifier. The wwtp clarifier is designed to eliminate heavy metals (zinc, cadmi um, and lead) and operates in a pH range where these metals are insoluble. However, at these pH levels the fluorine is slightly soluble and therefore the discharge from the wwtp ( 101 outfall) contains some fluorine.