ML20113A683

Requests That NPDES Permit PA0051926 Be Amended to Include Net Total Suspended Solids Calculation Worksheet for Outfall 001

ML20113A683
Person / Time
Site:	Limerick
Issue date:	06/18/1996
From:	Matty R PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Newbold J PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9606250173
Download: ML20113A683 (3)

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i PECO ENERGY "goarJ:,7" I

PO Box 8699 Philadelphia, PA 19101-8699 l 215 841 4000 June 18,1996 Mr. James Newbold i Chief, Permits Section i

Department of Environmental Protection Bureau of Water Management l Lee Park, Suite 6010 555 North Lane Conshohocken, PA 19428

Dear Mr. Newbold:

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Subject:

Limerick Generating Station NPDES Permit No. PA0051926 Total Suspended Solids Calculation Sheet This letter is being sent to request that the subject permit be amended to include the attached Net TSS (total suspended solids) calculation worksheet for outfall 001. The new worksheet has been changed to improve the accuracy of the Net TSS reported on the monthly DMRs. Two changes have been proposed:

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1) The composite sample at outfall 001 will be started on the fourth day versus the third day (see step 2). This will be done to insure that the TSS  !

levels in the four Schuylkill River samples taken are represented in the 1 outfall 001 composite sample. As currently done, the outfall 001 ,

composite sample is started on third day and collected on the fourth day.

Under this method, the water used for the " day four" Schuylkill River sample has not entered the cooling tower and is therefore not represented in the outfall 001 composite.

2) Perform a weighted composite sample of the four daily grab samples from the Schuylkill River (see step 1). The current method of compositing uses four equal aliquots of the dahy samples. This is not representative of the solids' contribution that remain in the cooling tower and ultimatelv affects

outfall 001. Assuming a relatively constant cooling tower blowdown rate, l the level of solids in the outfall 001 composite is graduated based on the j time of introduction into the cooling tower. Calculating the contribution ci solids to outfall 001 using a purification by dilution equation, the following 59192 0-l 0 YO 9606250173 960618 g DR ADOCK 050 32 )

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relationship exists between cooling tower make-up samples (Schuylkill River) and the outfall 001 composite:

Day 1 - 7% Day 2 - 15%

Day 3 - 27% Day 4 - 51%

By incorporating the proposed changes into the calculation, we believe the Net TSS concentrations at outfall 001 will be more accurately repor1ed.

A copy of this letter (including any attachments or enclosures) is being sent to the U.S. Nuclear Regulatory Commission (USNRC), in accordance with the Limerick Generating Station, Units 1 and 2, Environmental Protection Plan, Section 3.2, which stipulates that the USNRC shall receive a copy of any proposed changes to the NPDES permit at the same time that the permitting agency is notified.

If you have any questions or require additionalinformation, please contact me at (215) 841-5177, Sincerely, N

Robert M. Matty, Jr.

Engineer Environmental Affairs Attachment cc: U.S. Nuclear Regulatory Commission, Document Control Desk /

(Docket Nos. 50-352 and 50-353 & License Nos. NPF-39 and NPF-85)

T. T. Martin, Administrator, USNRC, Region 1 N. S. Perry, USNRC Senior Resident inspector, LGS Mr. Ronald Rulon Delaware River Basin Commission

DETERMINATION OF NET TSS WORKSHEET 1

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• Obtain a grab sample from Schuylkill River on 4 consecutive days and composite using the following formula:

l Day 1 -7% (35ml) / Sampled by / Date and Time Day 2 - 15% (75ml) / Sampled by/ Date and Time Day 3 -27%(135 ml) / Sampled by / Date and Time Day 4 - 51% (255ml) / Sampled by / Date and Time i

2. On the fourth day, initiate a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> composite sample of Outfall 001.

/__ Started by/ Date and Time

3. On the fifth day, retrieve the 001 composite sample.

/ Collected by / Date and Time

4. Analyze Schuylkill River composite for silica mg/l /

Analyzed by / Date and Time

5. Analyze 001 composite for silica.  :

mg/l /

Analyzed by / Date and Time

6. Determine concentration factor:

i 001 Silica = CF  ;

River Silica j l

7. Analyze River composite for TSS.

]

mg/l / I Analyzed by / Date and Time I

8. Determine background TSS.

(River Composite) X (Concentration Factor) =

( )X( )= mg/l

9. Analyze 001 composite for TSS mg/l /

Analyzed by / Date and Time l

10. Determine Net TSS (001 Composite TSS) - (Background TSS) = l

( )-( )= mg/l

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