ML18153B135

Ro:On 941028,total Suspended Solids Concentration in Spoil Discharge Reached 820 Mg/L.Permit Limitations Expressed as Values Exceeding Ambient Levels

ML18153B135
Person / Time
Site:	Surry
Issue date:	11/03/1994
From:	Marshall B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Gardner L NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9411070411
Download: ML18153B135 (2)

Text

J1111s/Jrook Tec/J11ical Center

' 5000 Dominion Boulevard Glen Allen, Virginia 23060 November 3, 1994 CERTIFIED MAIL RETURN RECEIPT REQUESTED VIRGINIA POWER Mr. Lance M. Gardner Water Protection Permit Program Department of Environmental Quality P. 0. Box 11143 Richmond, VA 23230-1143 RE: SURRY POWER STATION - VWP PERMIT #92-1347

Dear Mr. Gardner:

This is in follow up to our reports of high Total Suspended Solids (TSS) in the dredge spoil disposal pond discharge at Surry Power Station. Telephone notifications were made on the date of the high TSS discharge, Saturday, October 29, 1994, to the Department of Emergency Services, and to you on Monday, October 31.

On October 29, the TSS concentration in the spoil pond discharge reached 820 mg/1. The 11 ambient" TSS value at that time was 85 mg/1. The pond's discharge was stopped within 30 minutes of the high TSS occurrence by the addition of stop logs at the discharge control structure and by closing the discharge pipe valve.

No reason for the sudden lncrease in TSS of the pond discharge could be positively identified. The dredging operation is entering its last week of work, therefore a relatively large amount of dredged material has been recently placed in the facility and some of this recently moved material may still be unstable. On October 29 there were some strong winds that may have pushed silty water toward the discharge structure.

As shown in the weekly monitoring reports submitted for this operation, the TSS concentrations of this discharge are usually less than the 11 ambient 11 values measured in the river water in the station's intake. Permit limitations are expressed as values exceeding ambient levels.

As Mr. Daniel James of my staff has discussed with you previously, the spoil pond effluent does not discharge directly to state waters but enters the station's intake canal where it mixes with approximately one million gallons per minute of cooling water flow.

The relatively small flow, and any TSS content, from the spoil pond would almost instantaneously be assimilated into this flow and likely become undetectable. Although TSS in the discharge canal, which does flow to state waters, was not analyzed, station technicians did sample the discharge canal on the day of this event for other parameters and did not notice any visible impact on the J overall station discharge from the high TSS in the spoil pond effluent., - - --- --- ~ _____ --~

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Mr. Lance M. Gardner November 3, 1994 Page 2 The discharge from the pond was not continued until Monday, October 31, when enough settling had occurred to bring TSS concentrations in the effluent back down to the 20's range. The "ambient" value at that time was 42.9 mg/1. These data will be included on the weekly monitoring report for this week.

Should you need additional information or have any questions, please contact Daniel James at (804) 273-2996.

Sincerely, B. M. Marshall Manager Water Quality cc:

U.S. Nuclear Regulatory Commission Region II 101 Marietta St., NW Suite 2900 Atlanta, GA 30323 Re: Surry Units 1 & 2 Docket Nos. 50-280/50-281 License Nos. DPR-32/DPR-37 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Re: Surry Units 1 & 2 Docket Nos. 50-280/50-281 License Nos. DPR-32/DPR-37 Mr. M. W. Branch NRC Senior Resident Inspector Surry Power Station