ML20005E543

NPDES Noncompliance Notification:On 891101 & 17,zinc Samples for Discharge Point 001 Exceeded Permit Limit.Caused by Random Error Such as Sample Contamination or Limitations in Daily Zinc Testing Probably Due to Cold Water Temps

ML20005E543
Person / Time
Site:	Limerick
Issue date:	12/21/1989
From:	Mccormick M PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Bauer R PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9001080098
Download: ML20005E543 (3)

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PHILADELPHIA ELECTRIC COMPANY  !

2301 MARKET STREET P.O. BOX 8699 l PHILADELPHI A, PA.19101 imi.....ooo e

December 21,1989 .

Hr. Robert Bauer, Jr.

Department of Environmental Resources ,

Bureau:of Water Quality Management 1875 New Hope Street  !

Norristown, PA 19401 i

SUBJECT:

' Noncompliance with NPDES permit g Limerick Generating Station NPDES Permit No. PA-0051926 l t

Dear Mr. Bauer:

DESCRIPTION OF NONCOMPLIANCE I

Discharge Point 001 was sampled'once per week for Total  !

Zine during November. Two of the five' samples taken were i above the permit limit of 1.0 mg/1. 'The results of samples taken on 11/1/89 and 11/17/89 were 1.1 and 1.5 mg/l I respectively. Station personnel were notified of this l

( noncompliance on 12/19/89. Immediate notification to DER was attempted and limited information was left with the answering service. A follow up call was made to your office ,

the morning of 12/20/89 to assure appropriate notification, t e

CAUSE OF THE NONCOMPLIANCE Station personnel perform daily zinc analysis on water from the cooling tower basins. This analysis is not an NPDES approved analytical method, but historical data shows that it traditionally yields slightly higher results than actually exist. This daily test is used to monitor and conservatively control the zine residual below our NPDES limit. Samples are then sent offsite for analysis per the EPA approved method.

Daily analysis results for the period of noncompliance

-were lower than the official values giving us no indication that a noncompliance had occurred. In addition, daily pumping rates, and weekly chemical usage logs indicate that the conditions during the apparent noncompliance were not

, significantly different from normal operating conditions, pfp 900108009s e91221 t

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These conditions have been shown to be within NPDES limitations repeatedly during the 1989 year. Therefore it is felt that the apparent noncompliance is either the result of a random error, such as sample contamination, or the result of limitations in the daily zine testing. Recently it has been discovered that this test can be negatively L biased by cold water temperatures.

DURATION OF THE NONCOMPLIANCE i

Supporting documentation indicates the zinc permit [

limit was exceeded from 10/30/89 through 11/1/89. During this 3 day period the zine concentration was between 1.0 and '

1.1 mg/1. Approximately 37 million gallons of cooling water was discharged at this concentration. The permit limit for discharge is 1.0 mg/1.

The apparent noncompliance on 11/17/89 is not supported 3 by our daily zine analysis, weekly metals analysis, chemical [

pumping rates, or chemical usage logs. Therefore it is our contention that only one release in excess of permit limitations occurred (11/1/89) for a duration of not more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

CORRECTIVE ACTION No immediate corrective actions were taken because no knowledge of the event was available at the time of the occurrence.

PREVENTION OF FUTURE OCCURRENCES A procedure revision is already in place to compensate for cold water temperatures on daily analyses, which should allow us to collect more accurate daily zine data; thus providing better control over the treatment process. In addition, our sampling process is being reviewed to identify potential sources of contamination. This review will be completed by January 15, 1990.

Both out-of-spec samples were analyzed offsite on 11/27/89. At that time the analyst was not aware of our permit limit for zine and therefore not aware that a violation had occurred. This problem has already been remedied verbally, with the analyst. To ensure timely -

notification, a copy of the permit limits will be sent under

! cover letter to the appropriate department supervision by

( December 29,1989.

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In addition, we are examining the feasibility of maintaining the zine-concentrations in the cooling towers at a slightly lower level.in order to provide additional assurance that the permit limit will not be exceeded.

Sin e ely, t i_

H.J McCormick, Jr.

Plant Manager cc U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 Administrator Region I U.S. Nuclear Regulatory Commission 475 Allendale Road l King of Prussia, PA 19406 Station Resident NRC Inspector Tom Kenny, H.C. #NRC Program Management Section (3WM52)

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

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