NC0026441_Report_20050125

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CHARLES L. TURNER
POST OFFICE BOX 769 MAYOR
311 NORTH SECOND AVENUE
SILER CITY, NORTH CAROLINA 27344-0769 JOHN GRIMES
PROTEM
JOEL J. BROWER
TOWN MANAGER
WILLIAM C. MORGAN, JR.
TOWN ATTORNEY
Ms �Matthews
NC Division of Water Quality
Environmental Sciences Branch
Aquatic Toxicology Unit
1621 Mail Service Center
Raleigh, North Carolina 27699-1621
Dear Mr. Matthews:
PHONE: [phone]
COMMISSIONERS
FAX: [phone]
SAM ADAMS
January 25, 2005
HELEN M. BUCKNER
LARRY CHEEK
PATRICIA PERRY
TONY SILER
� CE21 t�
GUY D. SMITH
�JGOO�,Gf{41I
JAN 2 c 2005
Environmenm, Scioe-c a-- -
This is to inform you that the Town of Siler City has completed the Toxicity Identification Evaluation (TIE). We
have concluded that copper and/or zinc were not causative factors in effluent toxicity.
As required in a letter from the Division of Water Quality dated July 23, 2004, I am submitting three (3) copies of
our study evaluating the effect of copper and zinc on chronic toxicity at the Siler City Wastewater Treatment Plant.
In that letter it was indicated that the Division would consider prospective limits for copper at 15 UG/L and 116
UG/L for zinc. Our sampling has indicated that zinc is running well below this proposed limit. Our study
indicates that the concentration of copper in our plant effluent has exceeded the proposed limit of 15 UG/L on
occasion, but has not affected the chronic toxicity compliance at our plant. In fact, there seems to be no direct
correlation between the concentration of copper in plant effluent and the chronic toxicity testing. On May 5, 2004,
the concentration of copper was found to be 12 UG/L and the toxicity test failed at 82.2%. In December, the
proposed limit was exceeded but the chronic toxicity test passed. At this point, the Town feels that something
other than the presence of copper and zinc in the Town's wastewater effluent is responsible for the failure of the
chronic toxicity test.
If you have questions or need additional information regarding this situation, please advise.
Sincerely,
TOWN OF SILER CITY
VQ�.l. IiwluEt
Town Manager
JJB:ka
Attachment: (3) Copies — Copper and Zinc Evaluation Report
cc: Terry Green, Director of Public Works & Utilities
Curtis Brown, Wastewater Treatment Plant Superintendent
Bill Lester, Hobbs, Upchurch & Associates
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Siler City Wastewater Treatment Plant
Evaluation of Effluent Copper and Zinc Analysis
For Chronic Toxicity Compliance
DATE
PARAMETER
EFFLUENT(UG/L)
CT COMPLIANCE
3-17-04
Copper
14
FAILED
Zinc
32
4-7-04
Copper
9
PASSED-94.9%
Zinc
32
5-5-04
Copper
12
FAILED-82.2%
Zinc
21
5-19-04
Copper
16*
PASSED->100%
Zinc
27
6-8-04
Copper
15*
PASSED
Zinc
23
6-9-04
Copper
14
Zinc
24
6-10-04
Copper
14
Zinc
24
6-11-04
Copper
13
Zinc
24
9-13 -04
Copper
7
PASSED
Zinc
20
9-14-04
Copper
8
Zinc
22
9-16-04
Copper
13
Zinc
24
9-17-04
Copper
14
Zinc
23

4
DATE
PARAMETER
EFFLUENT(UG/L)
12-06-04
Copper
20*
Zinc
29
12-07-04
Copper
29*
Zinc
45
12-9-04
Copper
23 *
Zinc
30
12-10-04
Copper
26 *
Zinc
30
*Copper meets or exceeds proposed limit of 15 ugA.
CT COMPLIANCE
PASSED