TRE ACTIVITIES REPORT ALMATIS INC. OUTFALL 001 (NPDES PERMIT NO. AR ) 4th QUARTER 2010

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2 TRE ACTIVITIES REPORT ALMATIS INC. OUTFALL 001 (NPDES PERMIT NO. AR ) 4th QUARTER 2010 JANUARY 20, 2011

3 TRE ACTIVITIES REPORT ALMATIS INC. OUTFALL 001 (NPDES PERMIT NO. AR ) 4th QUARTER 2010 Prepared for Almatis, Inc Alcoa Road Bauxite, AR Prepared by FTN Associates, Ltd. 3 Innwood Circle, Suite 220 Little Rock, AR FTN No d January 20, 2011

4 TABLE OF CONTENTS 1.0 SUMMARY AND CONCLUSIONS INTRODUCTION TOXICITY EVALUATION FUTURE ANALYSES AND TRE ACTIVITIES REFERENCES LIST OF TABLES Table 3.1 Results of testing performed on benchtop treated samples i

5 1.0 SUMMARY AND CONCLUSIONS A benchtop evaluation of polymer dosing suggests that sporadic episodes of toxicity are due to variations in polymer dosing and/or variation in the response of the Storm Lake water to treatment. 1-1

6 2.0 INTRODUCTION The purpose of this document is to report the results of sampling and analysis conducted in support of the Toxicity Reduction Evaluation (TRE) currently being performed by Almatis, Inc. (Almatis), Bauxite Arkansas, AR (National Pollutant Discharge Elimination System [NPDES] Permit No. AR ). The objective of a TRE is to identify the means to eliminate toxicity in whole effluent toxicity (WET) tests. The technical approach to toxicity identification and control for WET in acute toxicity tests at Outfall 001 is presented in the TRE Action Plan submitted to the Arkansas Department of Environmental Quality (ADEQ) on January 19, In anticipation of a TRE requirement Almatis began investigations into potential causes of toxicity before a TRE was required. 2-1

7 3.0 TOXICITY EVALUATION Toxicity Identification Evaluation (TIE), other testing and source evaluations have indicated: 1. Likely causes of toxicity are Zinc (Zn) and treatment chemicals, and 2. A significant source of Zn was the plumbing of the sampling port used for NPDES sampling. Control measures have included: 1. Replacement of selected sections of pipe with non-metallic material, and 2. Changing the brand of polymer back to that used during previous years when toxicity excursions were uncommon. Although it is possible that toxicants are present in the collection pond (either introduced via inputs or produced in situ), the erratic nature of the toxicity suggests problems with treatment rather than lake-wide toxins that are passing through the treatment process. Testing during this quarter focused on the treatment process, particularly polymer addition rates, to determine if toxicity is occurring because of inconsistencies in the treatment process. The approach to evaluating the polymer addition procedure of the treatment process was to conduct a bench-top experiment in which the polymer addition process was simulated at various levels of polymer addition. Treated samples were then submitted to the laboratory to evaluate toxicity to Ceriodaphnia dubia in 3-brood survival and reproduction tests. Untreated Storm Lake sample was collected on November 1, In the laboratory, the treatment process was simulated by adjusting the ph of 4 separate 1 L aliquots of sample to ph 7 s.u. with industrial grade sulfuric acid (obtained from the treatment facility) along with a set dose of CaCl (51mg/L) for each sample. Nalco coagulant was added at 4 different levels (1, 4, 8, 16 mg/l by weight). The samples were stirred for about 2 minutes and allowed to settle for at least one hour. After settling, the supernatant was collected. A negative control (laboratory water treated with ph adjustment and polymer addition) was not conducted because 3-1

8 experience has shown that ph adjusted laboratory water typically performs poorly in chronic C.dubia tests. Treated samples were then submitted to American Interplex Corp. on November 3, 2010, for toxicity testing. The 4 samples were tested for chronic toxicity (3-brood reproduction and survival test per USEPA 2002) to C. dubia against a common control of laboratory water. Results of the toxicity tests on the treated samples are presented in Table 3.1. Table 3.1 shows that, although all treated samples showed significantly less reproduction than the control, there is a distinct dose-response with increasing polymer addition. Since the target polymer addition rate is 4 ppm in routine treatment, these results suggest that episodes of toxicity might be due to variations in polymer addition and/or variation in the response of the Storm Lake water to treatment. Table 3.1. Results of toxicity tests performed on benchtop treated samples. Polymer Level Replicate 1 mg/l 4 mg/l 8 mg/l 16 mg/l Control HM Mean 2.1* 0.9* 11.8* 13.8* 18.0 % survival Cell values are number of neonates produced by the end of the test; HM = handling mortality; * = Statistically less than the control (P <0.05 using Dunnet s test). 3-2

9 4.0 FUTURE ANALYSES AND TRE ACTIVITIES Future sampling and analyses will involve repeated bench-scale treatment simulations to further evaluate the treatment process based on the results reported herein. 4-1

10 5.0 REFERENCES USEPA Short-term methods for estimating the chronic toxicity of effluents and receiving waters to freshwater organisms. Fourth edition. EPA-821-R Office of Water. Washington, DC. 5-1