ML20098C955

Forwards Summary of Util post-diversion Biological Monitoring of Aquatic Community in East Branch Perkiomen Creek

ML20098C955
Person / Time
Site:	Limerick
Issue date:	10/02/1995
From:	Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:	Garg S PENNSYLVANIA, COMMONWEALTH OF
References
NUDOCS 9510110008
Download: ML20098C955 (3)

Text

station support Oosartm2tt e.-

• A v

PECO; ENERGY = n , s om ,,e,,

965 Chesterbrock Boulevard Wayne, PA 19087 5691 October 2,1995 -

2 Mr. Sohan Garg Bureau of Water Management PA Department of Environmental Resources Suite 6010, Lee Park 555 North Lane Co,whchocken, PA 19428

Subject:

Bradshaw Reservoir Discharge NPDES Permit No. PA 0052221 Reduction in Discharge Sampling

Dear Mr. Garg:

The Pennsylvania Department of Environmental Resources (PA DER) lasued National Pollutant Discharge Elimination (NPDES) Permit No. PA 0052221 to PECO Energy Company authorizing the discharge of water, diverted from the Delaware River, to the East Branch Perklomen Creek from the Bradshaw Reservoir in support of the operation of Limerick Generating Station (LGS),

Units 1 and 2. NPDES Permit PA 0052221, Part C, "Other Requirement K," requires that PECO Energy perform post-operational biological assessments to assess the impact of the water diversion discharge on the resident aquatic communities and stocked trout population in the East Branch Perklomen Creek.

PECO Energy developed and implemented a post-operational study plan for sampling and /

monitoring aquatic life in the East Branch Perkiomen Creek and in the Perklomen Creek. This study plan was originally submitted to the PA DER by letter dated July 20,1989. The study plan

was subsequently modified as documented in our letters dated September 25,1991, and June 30,1994, in addition, we submitted " Post Diversion Aquatic Biology Assessment" reports covering the l years 1989,1990,1991, and 1992 by letters dated April 9,1991, December 18,1991, and May 19,1994, as required by NPDES Permit No. PA 0052221, Part C, "Other Requirement K.* These I reports document the effects of the first four (4) years of water diversion operation on the East Branch Perklomen Creek and Perklomen Creek. In addition, data were collected throughout 4 1993 and 1994, and are currently being analyzed. A ' Post-Diversion Aquatic Biology

i. Assessment" will be submitted for the 1993-1994 period as required by Part C, 'Other Requirement K," of NPDES Permit No. PA 0052221.

l Based on the results of the post-diversion studies conducted to date, the following conclusions

can be reached regarding the impact of the water diversion operation. l j The Perkiomen Creek fish community, as evaluated by electrofishing, has been relatively l

~

stable. The total catch-per unit-effort (CPUE) values from one year to the next have {

been consistent and there has been concordance of species rank abundances between

stations and over time. This indicates that the water diversion has had ng observable adverse effect on the Perkiomen Creek.

J n a A (%Pf. "

9510110008 951002 /

8 PDR ADOCK 05000352 -

I P PM

_ . _ . _ _ _ _ _ . _ _ _ _ __=____ _ . ._ _ _ _ _ - - _._ .._ _ _ . _ _ .

October 2,1965 Page 2 i

j Post-augmentation monitoring has shown some effects as a result of the water diversion

on the East Branch Perkiomen Creek. The most significant offects have been observed,

} as expected, in the headwaters region, where hydraulic and physical habitat changes 1 are most pronounced. The effects on the fish community structure in this region have i been evidenced by changes in cyprinid dominance (i.e., golden shiners and bluntnose j minnows have been replaced by spotfin shiners, comely shiners, common shiners, and spottal shiners) and elimination of redfin pickeral. ,

} Farther downstream, where the physical effects of the water diversion are less pronounced, pattoms of species ceiipc4 den and trends in population density have l been observed throughout the six (6) year study period. In general, both seining and

' i electrofishing have shown a spatial trend of increased abundance of smallmouth bass, rock bass, and redbreast sunfish in the lower East Branch Perklomon Creek relative to upstream prior to water diversion operation. An increased relative abundance of rock bass, falifish, shield darter, and blacknose and longnose dace have been most evident

! over the past two (2) years. In addition, a significantly decreased incidence of blackspot ,

! - parasitism at all sampling locations is an indication of improved water quality in the East .

1 Branch Perklomen Creek. .

i l Similarly, benthic' macroinvertebrate studies have demonstrated that the most significant j effects have taken place in the headwaters region. Taxa preferring a lotic environment have replaced lentic or intermittency-adapted forms. Farther downstream, lotic and 2

pollution sensitive taxa have increasingly replaced lentic and pollution tolerant taxa in response to the increased stream flow and improved water quality.

l Therefore, as result of the conclusions reached during flow-augmentation studies on the East Branch Perkiomen Creek over the past six (6) years, we plan to reduce the number of sample locations for sampling fish and benthic macroinvertebrates to four (4) locations effective January,

t. 1996. In addition, we also plan to discontinue fish sampling on the Perklomen Creek effective January,1996. PECO Energy will maintain a sample location representative of the headwaters region, and three (3) sample locations in the middle to lower reaches of the East Branch ,

I Perklomen Creek. These locations will continue to represent a gradient of increasing stream size and changes in water quality.

l The ongoing aquatic monitoring program wRl be fully effective, and will provide all the necessary data to perform an Aquatic Biology Assessment of the potential impact on the resident aquatic l

community and stocked trout fishery in the East Branch Perklomen Creek. Attachment 1 to this

letter provides a summary of our revised aquatic community monitoring program for your review.

If you have any questions or require additional information, please do not hesitate to contact us.

i Very truly yours, l

.$ Agu$ .

! G. A. Hunger, Jr.

Director - Licensing l

Attachment cc: USNRC Document Control Desk, Washington, DC [ Docket Nos. 50-352/50-353]

(w/ attachment) l T. T. Martin, Administrator, Region I, USNRC . (w/ attachment)

N. S. Perry, USNRC Senior Resident inspector, LGS

- , - . , , . , , - = - . - ,

s

= *.

ATTACHMENT 1 Summary of PECO Energy Company's Post-Diversion Biological Monitoring of Aquatic Community in the East Branch Perkiomen Creek (NPDES Permit No. PA 0052221, Part C, "Other Requirement K")

As Revised, Effective January 1, 1996 '

4 STUDY SAMPLE SITES SAMLE FREQEENCY Vater Quality Delaware River: 1 (at intake) Various: biweekly, monthly, and annually

, East Branch Perkiomen: 3 (various, including one location upstream of outfall)

Perk 1 omen Creek: 2 (one upstream of confluence with East Branch, one at intake)

Benthic Macroinvertebrate East Branch Perkiomen: 4 (various) Quarterly Fish Consnunity

- Setning (small fish) East Branch Perk 1 omen: 4 (various) Monthly (May through October) ,

- Electrofishing (large fish) East Branch Perkiomen: 4 (various) 2/ year (Spring and Fall)

. - Habitat Description' Same as electrofishing sites Annually Fish Age and Growth East Branch Perkicznen: 4 (various) Biennially l Trout Creel East Branch Perkiomen: 3 (one per stocking 2 weekends following stocking at open site) season; one per additional stocking time Perkiomen Creek Large Fish Catch-Per-Effort [ DISCONTINUE MONITORING EFFECTIVE 1996] [DISCONTINtE IGNITORING EFFECTIVE 1996] '

(Electroffshing)

• Includes depth, velocity, discharge, substrate type, overhead tree canopy and aquatic plants.

l l Page 1 of 1 -

_ - _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ - _