ML20117A576

NPDES Noncompliance Notification:On 921013 & 14,four of Five Samples Collected from Discharge Point 001 Exceeded Daily Max Permit Limit of 1.0 Mg/L.Caused by Heavy Rains Across Southeastern PA on 921009.Injection Rates Decreased

ML20117A576
Person / Time
Site:	Limerick
Issue date:	11/23/1992
From:	Doering J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Feola J PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9211300172
Download: ML20117A576 (3)

Text

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PIIILADELPIIIA ELECTRIC COMPANY LIMEUCK GENERATING STATION P. O. BOX 2300 SANATOGA, PA 19464-2300 (215) 3271200 EXT. 2000 J. DotnWG. JR.

gygryg,g November 23, 1992 '

Mr. Joseph A. Peola Pennsylvania Department of Environmental Resources Regional Water Quality Manager Lee Park, Suite 6010 555 North Lane Conshohocken, PA 19428

Subject:

Limerick Generating Station, Units 1 and 2 Noncompliance with NPDES Permit No. PA-0051926 Dear Mr. Foolas DESCRIPTION OF NONCOMPLIANCE During the period between October 13, 1992 and October 14, 1992 l

five samples were collected from Discharge Point 001 and Jent to our Corporate Chemistry Laboratory to be analyzed for total zinc.

Four of the five samples taken exceeded the Discharge Point 001 daily maximum permit limit of 1.0 mg/1. These four samples were all collected on October 13, 1992 and the results were 1.1 mg/l at 1100 hours0.0127 days <br />0.306 hours <br />0.00182 weeks <br />4.1855e-4 months <br />, 1.1 mg/l at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br />, 1.1 mg/l at 1530 hours0.0177 days <br />0.425 hours <br />0.00253 weeks <br />5.82165e-4 months <br />,

and 1.1 mg/1. at 2030 hours0.0235 days <br />0.564 hours <br />0.00336 weeks <br />7.72415e-4 months <br />. The fifth sample was collected at

' 1010 hours0.0117 days <br />0.281 hours <br />0.00167 weeks <br />3.84305e-4 months <br /> on October 14, 1992, and its result of 1.0 mg/l indicated that the total zine concentration was trending downward below the permit limit again.

LAUSE OF THE NONCOMPLIANCE Heavy rains across southeastern Pennsylvania on October 9, 1992 caused the pF of both the Schuylkill River and the Perkiornen l- Creek to decrease by 1.2 and 1.0 pH units respectively. This-o drop in the pH of our makeup waters to both Cooling Towers caused ~

the pH in the Circulating Water System to decrease to 8.0 in Unit 1 Cooling Tower and to 7.9 in Unit 2 Cooling Tower on October 12, 1992. The pH in this system is normally maintainad between 8.0 and 8.5 to achieve optimal chemistry conditions. This change in the system chetaistry could have centributed to a change in the solubility of the zinc in the system and caused an increase in total zinc concentration at Discharge Point 001. Additionally, we suspect that increased organic loading in the makeup water 92113,3172 921123 PDR ADOCK 050003S2 [/

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sources during this autumn season interfered with our total zinc colorimetric method that is performed daily for each unit. The interference was indic ted by approximately a G.2 mg/l difference between the reportable :otal zine results obtained by an inductively coupled plasma analyzer and the results of duplicate samples analyzed by our rout!"e colorimetric screening method. '

During the previous week, injuction rates were. increased on the pumps injecting PECo 4 due to the lower level of total zinc being detected.

DURATION OF THE NONCOMPLIANCE

-t The period of noncompliance began on October 13 1992, at approximately 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br /> when the pH in both Cooling Towers was still found to be at 8.0. The 8.0 pH in combination with increased injection of PECo 4 caused the total zine concentration to increase in the Circulating. Water Systems, thus causing the 1.0 mg/l permit limit at Discharge Point 001 to be exceeded.

Based on the zine analysis results from October 13, 1992 and October 14, 1992 the noncompliance period ended on October 14, 1992, at approximately 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> when the total zinc ,

concentration had decreased to the 1.0 mg/l permit limit. The. ,

duration of the noncompliance is e',tinated to-have occurred over a 26 hour3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br /> period during which about 9.6 million gallons of cooling water were released from the Discharge 001 Diffuser into '

the Schuylkill River. 't CORRECTIVE ACTION At approximately 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br /> on October 12, 3992, the injection rates of both the Unit 1 and Unit 2 acid injection pumps were decreased to allow the pH of the water in the Cooling Towers to q inprease towards 8.5. At 1030 hours0.0119 days <br />0.286 hours <br />0.0017 weeks <br />3.91915e-4 months <br /> on October 13, 1992, '

immediately after it was determined that the total zinc levels may have exceeded the permit limit, the PECo 4 chemical injection to both Cooling Towers was terminated. These two corrective actions reduced the total zinc concentration to the 1.0 mg/l -

permit limit by 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> on October 14, 1992.

• PREVENTION OP FUTURE OCCURRENCES _

Appropriote Chemistry procedures will be revised to require notification of Chemistry supervision if numerous chemical feed pump adjustments are required within a short time frame.

An investigation la bein, conducted to determine if there is an-interference with our total zinc colorimetric method of screening analysis. If an interference is found, corrective action.will be

. initiated. If the: interference ir found to be due to seasonal

, variations in the water, then the ' tation winterization procedure-will be revised to incorporate a cification concerning the likelihoo$ of zinc interference o. .ng the seasonal period when this procedure is implemented.

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-Until the zine analysis interference problem can be verified and corrected, pump injection rates for PECo 4 will be-maintained at 40% unless authorization to change _is granted by C.emistry Supervision.

If lower pH values are determined to have contributed to the problem, then Chemistry Supervision will institute a_setpoint change to increase the lower pH setpoint for the automated acid feed systems.

Sincerely, JLPicah cc: U.S. Nuclear Regulatory Commission Document Control Desk Docket Nos. 50-352/50-353 Washington, D.C. 20555 T. T. Martin Administrator, Region I, USNRC Docket Nos. 50-352/50-353 T. J. Keany USNRC Ser ior Resident Inspector, LGS Docket Nos. 50-352/50-353 Program Management Section (3WM52)

Permits Enforcement Branch ,

Water Management Division-Environmental Protection Agency Water Permits Section Region III 841 Chestnut Building Philadelphia, PA 19107 i

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