ML18153B726

NPDES Noncompliance Notification:In Apr 1989,plant Experienced Two NPDES Permit Exceptions Re Operation of New Ultraviolet Sewage Treatment Sys.Corrective Actions Will Continue to Include Supplemental Wasting of Uv Tubes

ML18153B726
Person / Time
Site:	Surry
Issue date:	05/10/1989
From:	Marshall B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Ronaldo Jenkins VIRGINIA, COMMONWEALTH OF
References
NUDOCS 8905240158
Download: ML18153B726 (2)

Text

Innsbrook Technical Center f e e 5000 Dominion Boulevard Glen Al/en, Virginia 23060 May 10, 1989 Mr. R. R. Jenkins, Jr.

Virginia Water Control Board Piedmont Regional Office VIRGINIA POWER -

2201 W. Broad Street Richmond, VA 23230 Re: SURRY POWER STATION NPDES EXCEPTION - SEWAGE TREAlMENT PLANT De~r Mr. Jenkins:

During the month of April, 1989, Surry Power Station experienced two NPDES permit exceptions related to the operation of the new ultraviolet sewage treatment system. One of these violations, as measured on April 12, was equal to 1100 mpn/100 ml which exceeds the maximum permit limit of 400 mpn/100 ml. The resulting average value for fecal coliforms, equalling 282 mpn/100 ml, thus also exceeded the average permit limit of 200 mpn/100 ml.*

As you discussed with Mr. Bishop on May 10, we have directed R. Stuart Royer to begin design changes of the plant to encompass conversion of the surge tank to a true equalization tank. All influent flow will be routed to the equalization tank and then pumped to the treatment system at a more controlled rate. Their review of the system also indicated that a 0.48 inch difference in elevation existed .between the UV discharge weirs which will also be corrected. These modifications will enhance treatment and disinfection efficiency by stabilizing influent and effluent flows.

In light of the fact that wastewater color and its effect on transmittability and disinfection appears to be an inherent problem, we have also requested that design changes include the ability to provide supplemental chlorination should the proposed hydraulic modifications not result in consistently satisfactory fecal control. Our interim corrective actions as outlined by letter of February 13, 1989, will continue to include supplemental wasting and cleaning of the UV tubes.

If you have any questions or desire additional information please contact Mr. W. Glenn Bishop at 273-2988.

s ~~~aWl'°""'n B. M. Marshall, P. .,

Manager Water Quality WGB:rw/2122

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Page 2 May 10, 1989 cc: U.S.N.R.C., Atlanta George, Docket #50/280-50-281 U.S.N.R.C., Washington, DC, Docket #50/280-50-281 U.S.N.R.C., Senior Resident Inspector, Surry Power Station Ms. Jody Bryan - VWCB - Piedmont Regional Office