ML20045G553

NPDES Noncompliance Notification for Apr 1993 for SONGS, Unit 2.Discrepancy in Analytical Technique Used to Determine Total Residual Chlorine Concentration.Amperometric Titration Method for Total Residual Chlorine Analysis Reinstated

ML20045G553
Person / Time
Site:	San Onofre
Issue date:	06/02/1993
From:	Newton H SOUTHERN CALIFORNIA EDISON CO.
To:	Coe A CALIFORNIA, STATE OF
Shared Package
ML20045G550	List: ML20045G549 ML20045G553
References
NUDOCS 9307140116
Download: ML20045G553 (2)

Text

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June 2, 1993 California Regional Water Quality Control Board San Diego Region 9771 Clairemont Mesa Boulevard, Suite B San Diego, California 92124-1331 Attention: Mr. Arthur L. Coe

Subject:

NPDES Monitoring Report San Onofre Nuclear Generating Station, Unit 2 The NPDES Discharge Monitoring Report (DMR) for San Onofre Unit 2 covering the month of April is submitted in accordance with the requirements of Order No. 85-11 (NPDES Permit No. CA0108073). A l

l summary of the generating unit's status and significant I analytical results is provided below.

The unit was in operation all month and all sampled water sources were found to be within permit limits.

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! An investigation was recently conducted in which a discrepancy in analytical technique was found. The current method used to determine total residual chlorine concentration per 40 CFR part 136 is the Environmental Protection Agency (EPA)-approved Hach N-diethyl-p-phenylenediamine (DPD) colorimetric test. During the investigation it was noted that 40 CFR 432.11 Steam Electric Power Generating Point Source Category requires a different EPA-approved method, stating:

"The term total residual chlorine (or total residual. oxidants for intake water with bromides) means the value obtained using the amperometric method for total residual chlorine described in 40 CFR part 136."

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California Regional Water

-Quality Control Board -

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June 2, 1993 Upon discovery of the discrepancy, we took immediate actions to reinstate the amperometric titration m'ethod for total residual chlorine analysis for future NPDES re jorting. Edison believes the DPD test is equivalent or better than the amperometric test (due to greater reliability and reproducibility of results).

This issue also applies to Unit 3 and the requirements of Order No. 85-13 (NPDES Permit No. CA0108181).

Pursuant to Order No. 85-11, Reporting Requirement 12, the following representative has prepared and is authorized to sign the reports required by this order: Robert K. Heckler, Environmental Engineer.

I certify under penalty of law that I have personally examined and am familiar with the information submitted in the attached document, and based on my inquiry of those individuals immediately responalble for obtaining the information, I believe the submitted information is true, accurate, and complete. I am aware that there are significant penalties for submitting falso information, including the possibility of fino and imprisonment.

. W. Newton Manager, Site Support Services ,

rkh:U2apr93NPD Enclosure cc: Environmental Protection Agency, Region IX 1

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