ML20071L176

NPDES Noncompliance Notification:On 940609,zinc Analyses Indicated That Discharge 001 Total Zinc Levels in Excess of Max Daily Limitations in Both Cooling Towers.Daily Zinc Control Limits Will Be Administratively Maintained Lower

ML20071L176
Person / Time
Site:	Limerick
Issue date:	07/27/1994
From:	Boyce R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Bauer R PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9408020248
Download: ML20071L176 (3)

Text

Rob srt W. Boyce j t

Plant Manager l Lirnenct Generating Sta:,aq l 4 1

. l T

CO ENERGY PECO Ermrgy Compar;y L1rnerick Generating S:M.

PO Box 2300 Sanatoga, PA 19464-092; 215 3271200 Ert P003 July 27, 1994 Robert Bauer, Jr.

Department of Environmental Resources Bureau of Water Quality Management Suite 6010, Lee Park l 555 North Lane Conshohocken, PA 19428 l

SUBJECT:

Limerick Generating Station, Units 1 and 2 Noncompliance of NPDES Permit No. PA-0051926, Discharge 001 Total Zinc Concentration in i Excess of Maximum Daily Limitations I

)

Dear Mr. Bauer:

Description of the Event:

On Thursday morning, June 9, 1994, routine chemical analyses ,

were performed on both cooling towers for the purpose of assessing the daily water chemistry. The zinc analyses, which are performed with an administrative non-EPA approved method, indicated total zinc levels above 1.0 mg/l in both cooling towers. Discharge 001 was the sampled and analyzed using an EPA approved method. A result of 1.2 mg/l was obtained, exceeding the daily maximum discharge limit of 1.0 mg/1. Based on additional monitoring using the administrative method, total zinc levels were within limitations by the end of the day. Since good agreement existed between the two analytical methods on that day, and based on the immediate corrective actions taken, we estimate '

the total duration of noncompliance to be 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Immediate Corrective Actions Upon receipt of the initial analytical results, the I chemistry of both cooling towers was adjusted to lower the zinc concentrction by reducing the zine addition rates.

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4 July 27, 1994 Page two cause of the Non-Compliance A review of the cooling tower chemistry trends, and operating conditions for the week of June 6, 1994, to June 10, 1994, did not indicate any system changes that could have caused an increase in zinc levels. In fact, zine was monitored at Discharge 001 04 the previous day, June 8, and the results were well withlh permit limits. While the usage rates for the zine based chem:. cal, PECO 4, were relatively elevated, they were within both NPDES permit usage limits and station administrative usage limits. The quality and concentration of zinc in the PECO 4 product has also been verified to be acceptable.

Based on the available information, we believe that the sample taken on June 9, 1994, was not affected by excess suspended solids in the sample line, and was representative of Discharge 001 effluent. At this time, no clear cause for this event can be concluded.

Actions to Prevent Recurrengg A multi-discipline task team has been assembled to re-evaluate our current program for controlling the addition, sampling, and analysis of zinc. The conclusions of this team will be reported in an August, 1994 report to the DER.

In the interim, our daily zinc control limits will be administratively maintained lower than currently practiced.

If you have any questions please contact Jim Kantner at 327-1200, extension 3400.

Sincere.'.y, 0, O ks Dl@~ -

SCD:cah cc: U.S. Nuclear Regulatory Commission Document Control Desk Docket Nos. 50-352/353 Washington, D.C. 20555 T. T. Martin Administrater, Region I, USNRC Docket Nos. 50-352/353

e JQly 27, 1994 Page three N. S. Perry USNRC Senior Resident Inspector, LGS Docket Nos. 50-352/353 Program Management Section (3WM52) ,

Permits Enforcement Branch I g Environmental Protection Agency Water Management Division Environmental Protection Agency I Water Permits Section Region III t 841 Chestnut Building Philadelphia, PA 19107 1