ML20129E568

NPDES Noncompliance Notification:On 960805,geometric Mean of Fecal Coliform Concentration Calculated to Be 641 Colonies Per 100 Ml.Cause Suspected to Be Due to Malfunctioning Ozone Disinfection Sys.Adjustments to Sys Have Been Made

ML20129E568
Person / Time
Site:	Limerick
Issue date:	09/27/1996
From:	Boyce R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Oneil S PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9610030206
Download: ML20129E568 (3)

Text

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Robert W.Bryeo Plant Manager

Lmenck Generating Station

. reser PECO NUCLEAR escote . c - e, Lmerck Generating Staten A Unit of PECO Energy PO Box 2300 Sanatoga, PA 19464 0920 610 718 2000 September 27, 1996 q 4

Mr. Steven J. O' Neil, ,

Chief, Operations Section l Department of Environmental Resources Bureau of Water Quality Management Suite 6010, Lee Park 555 North Lane  ;

Conshohocken, PA. 19428

SUBJECT:

Limerick Generating Station, Bradshaw Reservoir Non-Compliance of NPDES Permit No. PA0052221

Dear Mr. O'Neil:

i DESCRIPTION OF THE NON-COMPLIANCE During the month of August 1996, the NPDES limit for fecal coliform concentration at the discharge of the Bradshaw Reservoir pumps into the East Branch of the Perkiomen Creek was not met.

The permit requires five consecutive grab samples each collected on different days, and the geometric mean of the five samples must be less than or equal to 200 colonies per 100 ml. An Ozone Disinfection System is utilized for treatment at the Bradshaw Reservoir Water Processing Facility.

On August 5, 1996, the geometric mean of the fecal coliform concentration was calculated to be 641 colonies per 100 ml, thereby exceeding the NPDES permit limit. On August 9, 1996, the fecal coliform concentration reached a geometric mean of less than 200 colonies per 100 ml, thereby re-establishing NPDES permit compliance.

CAUSE OF THE NON-COMPLIANCE:

The cause of this non-compliance was suspected to be a malfunctioning Ozone Disinfection System. Physical inspection and testing of the ozone gas diffusers and associated piping was conducted on August 22, 1996. This revealed that the seals on many of the ozone diffusers were leaking. This hampered the efficient dispersion of ozone gas in the water, which resulted in 7 inadequate disinfection performance. Additional system - ,p /

performance review is ongoing to identify other causal factors. '(

9610030206 960927 k PDR ADOCK 05000352 S PDR g.

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September 27, 1996

'Page Two CORRECTIVE ACTIONS TAKEN:

l On August 22, 1996, adjustments were made to the ozone gas flow balance to improve the performance of the system until repairs to l

the diffusers could be completed. Diffusers in the final contact chamber, which were severely leaking and causing the most ozone gas to be wasted, were isolated. Flow to the remaining diffusers in all three contact chambers was increased to establish the same total. system flow.

CORRECTIVE ACTIONS TAKEN TO PREVENT RECURRENCE:

On September 17, 1996, the Ozone Disinfection System entered a maintenance outage to replace the seals on all 32 diffusers.

Assessment of the Ozone Disinfection System is ongoing, and any additional corrective actions will be implemented to ensure NPDES Permit compliance. Currently, adjustments to the system were

- made to provide maximum disinfection capability.

If you have any questions please do not hesitate to contact Mr.

James L. Kantner at (610) 718-3400.

Sincerely, ,_

.. l, M %g -

FDL/DMS I

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i cc: U. S. Nuclear Regulatory Commission Document Control Desk Docket Nos. 50-352/353 Washington, D.C. 20555 I I

H. J. Miller Administrator, Region I, USNRC Docket Nos. 50-352/353 N. S. Perry USNRC Senior Resident Inspector, LGS Docket Nos. 50-352/353 Program Management Section (3WMS2)

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

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