ML20212D108

Notifies of Limited Fish Kill in Circulating Water Discharge Canal on 860729.Caused by Either Thermal Shock Due to 860727 Turbine Trip or by Fish Being Trapped in Refuge Area

ML20212D108
Person / Time
Site:	Summer
Issue date:	08/06/1986
From:	Nauman D SOUTH CAROLINA ELECTRIC & GAS CO.
To:	Stanley A SOUTH CAROLINA, STATE OF
References
NUDOCS 8608120387
Download: ML20212D108 (3)

Text

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August 6,1986 i Mr. Andre G. Stanley Division of Water Quality Assessment -

and Enforcement  :

SC Department of Health and

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Environmental Control '

2600 Bull Street Columbia,SC 29201

Subject:

V. C. Summer Nuclear Station Fish Kill Report

Dear Mr. Stanley:

Attached please find the results of the fish killinvestigation initiated on 7-29-86.

This evaluation was performed in response to requests by DHEC.

Should we be of further service, do not hesitate to call, trtlly [ours, D

DCB/ DAN:jez

, Attachments pc: J. G. Connelly, Jr.

O. S. Bradham 1 W. F. Bacon W. R. Baehr S. E. Summer /P. R. Moore W. R. Higgins W. Corley (DHEC)

.H.R.'Denton i

~ 'J. N. Grace NPCF File: 814.07

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lNVESTIGATION OF ABNORMAL ENVIRONMENTAL OCCURRENCE o FISH KILL i ,m. (7-29-86) ,

At approximately d:00 p.m. on July 29,1986, a limited fish kill was discovered in the Circulating Water Discharge Canal at V. C. Summer Nuclear Station. An investigation of the fish ki I was conducted at approximately 4:30 p.m. The following observations were made:

1 Approximately 35 dead fish were found,60% of which were white catfish. The remainder of the fish were sunfish (Lepomis spp.), gizzard shad, and channel catfish.

All dead fish were seen in the discharge canal pro ser. No fish were seen in the cove Just east of the discharge canal (closest downwinc cove) orin the main body of the ake. No distressed fish were observed and no fish were seen gulping air at the surface or behaving erratically.

Water temperature in the discharge outfall was 107.3*F at 1630 hrs. The air temperature was 95*F and the wind was ENE at 3 mph. =

We telephoned SCDHEC's 24 Hour Emergency Number and left a message concerning the event. At 7:10 p.m., we received a call from Mr. Wayne Corley of DHEC's Emergency Response Team and described the situation to him. He said that given the small number of fish involved and the fact that the kill was apparently a localized, one-time phenomenon, he did not think it would be necessary to send a team of DH EC investigators. He felt, however, that it was necessary to check with Mr. Allen Trim, DHEC s fish kill expert, before giving us any further instructions. Mr. l Corley called back at 7:40 p.m. and saiti that DHEC did not feel it was necessary to send anyone, but that we should conimue to rnonitor the situation closely. He also asked that he be provided a written repor t c f findings as soon as possible.

Upon checking the Discharge Canal at 8:15 p.m., water quality measurements were as follows: discharge temperature 107'F, oissolved oxygen 6.2 mg/1, and pH 7.1. ~

OnlV three dead fish (white catfish) were seen at this time, all presumably part of the original kill.

A follow-up investigation was conducted at 7:00 a.m. on the following morning (7-30-86). One gizzard shad was found on shore nearthe concrete discharge structure and a single white catfish was floating in the discharge canal, also presumably part or the original kill. The water temperature in the discharge outfall was 105 F at this time, and dissolved oxygen levels ranged from 5.0 to 6.0 mg/1.

Winds were out of the NE at approximately 15 mph.

The condition of the dead fish discovered at 1600 7-29-86 indicated they had been

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dead for approximately somewhere between 220012 hours (6and 1000 7-29-86.6 7-28-8 These hrs). This puts fish probably the time of the kill moved into the discharge canal area after the turbine trip at 0145 on 7-27-86. This trip resulted in greatly reduced circulating water discharge temperatures. When the ,

plant went back on line (2012 on 7-27-86) and circulating water discharge temperatures rose from 86.9 F (2000; 7-27-86) to 109.7 F (0400; 7-29-86), the affected fish were either trapped in cooler " refuge" areas or lingered too long in

. the discharge, and were ultimately killed by thermal shock. During the same period, air temperatures were again in the 100's following a cooler period in the 90's prior the trip. .

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I The NPDES instantaneous discharge limit of 113'F was never exceeded and all other NPDES discharge limits were withm specifications during this entire period. Due to the small number of fish involved and the species affected, this event should be i

considered relatively insignificant.

specific additional documented visual surveillance of the discharge area will ,

continue in an effort to further define the impact of station operation on the environmentduring this current period of abnormally high temperatures and lack of precipitation.

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