Water Quality Monitoring And Assessment Section (APF)
Division of Water Quality Assessment And Standards
Bureau of Water Supply and Wastewater Management
Department of Environmental Protection
The Department is initiating a correction to the aquatic life use designation in the water quality standards for Lake Luxembourg, Bucks County. It currently has a Cold Water Fishes (CWF) and Migratory Fishes (MF) designation reflecting the condition of its source water. In most cases within Chapter 93, lakes have been classified according to the aquatic life use of their associated streams. As a result, many lakes in Pennsylvania are misclassified. Most lakes cannot and have not achieved their protected use because of natural conditions.
The water impounded within a lake, when warmed by solar radiation, often becomes too warm to support cold water fish species. Also, most Pennsylvania lakes undergo a period of stratification during summer. In early summer, solar radiation warms the surface waters more rapidly than the bottom waters, causing the upper layer to become less dense. This results in thermal stratification where the density gradient between the top and bottom layers prevents mixing of the waters. The epilimnion (surface layer) is made up of uniformly warm, circulating water and floats upon the cold and relatively undisturbed hypolimnion (bottom layer). During the period of thermal stratification, the waters of the hypolimnion are isolated from the atmosphere and cannot be replenished with oxygen. Algae and other organic debris from the epilimnion settle and decompose in the hypolimnion resulting in an increase in biochemical oxygen demand (BCOD) in the bottom waters. In many water bodies, the rate of dissolved oxygen (DO) depletion in the hypolimnion can cause anoxic conditions (DO = 0 mg/l), incapable of supporting an aquatic community. The thermal stratifications and accompanying DO responses discussed above are naturally occurring phenomena - common to cold water or warm water lakes in temperate climates. Due to stratification and anoxic conditions in the hypolimnion, many lakes cannot support cold water fish species during the summer but can support healthy warm water fish species and therefore should be reclassified.
Lake Luxembourg is owned by the Bucks County Parks Department and is located in Core Creek County Park, Middletown Township, Bucks County. Lake Luxembourg is located on Core Creek (stream code 02543), which is a tributary to Neshaminy Creek within the Delaware River basin (drainage list E) (Figure 1). Core Creek was impounded in 1975 creating the 166 surface acre lake, which drains a 15.45 mi2 watershed consisting primarily of agricultural (57%), forested (22%), and residential (17%) areas. Lake Luxembourg has a maximum depth of 26 feet with a mean depth of 10.5 feet with an overall volume of 2,149,713 m3 of water. There is one permitted industrial discharge upstream of Lake Luxembourg.
Lake Luxembourg typically stratifies during the summer with the thermocline forming between 1 and 4 meters in depth. Once stratification occurs, the DO in the hypolimnion often drops to levels not supportive of a healthy aquatic community (<2 mg/l). Conditions of stratification and an anoxic hypolimnion were evident soon after the lake was formed. Further, lake water temperatures often exceed levels that can support survival of cold water fish species during summer months (Figures 2-6). Water chemistry parameters are consistent with lakes that are in the hypereutrophic - eutrophic state with frequent algal blooms and high nutrient levels (Tables 1-2). Physical lake data for temperature and DO reveal conditions that are not supportive of cold water fishes.
Lake Luxembourg has a resident, self-supporting warm water fish community that originated from the resident fish population that occurs naturally in Core Creek and from PFBC stockings. Over the history of the lake there have been a total of 23 species captured (Table 3). Examination of catches from trap nets and electrofishing surveys indicated a healthy naturally reproducing population of warmwater species. Natural reproduction is evident upon review of length frequency data (Table 4). Warmwater species such as white perch, white catfish, pumpkinseed, bluegill, white crappie, black crappie, and brown bullheads have length frequency data showing fish lengths are represented in small and large sizes, which is indicative of natural reproduction consisting of multiple year classes. Lake Luxembourg has never supported cold water fish species throughout the summer months and has always been managed by the PFBC as a put-and-take trout fishery and warm water fishery by relying on natural reproduction and supplemental stocking of warmwater fish such as largemouth bass, channel catfish, and walleye (Table 5-6). The PFBC has stocked trout in Lake Luxembourg annually since 1979.
PUBLIC RESPONSE AND PARTICIPATION SUMMARY
The Department provided public notice of this aquatic life use evaluation and requested any technical data from the general public through publication in the Pennsylvania Bulletin on May 31, 2003. A notice was published in Bucks County Courier Times (Levittown, PA) on May 30, 2003. In addition, Lower Makefield, Upper Makefield, Middletown and Newtown townships, Newtown Borough, and the Bucks County Planning Commission were notified of the redesignation evaluation in letters dated May 29, 2003. No additional information was received in response to the publication of these notices.
A review of available data indicates the existing use for Lake Luxembourg is and has always been TSF, MF. The predominance of warm water conditions and concurrent warm water fisheries and put-and-take adult trout found in Lake Luxembourg is the consequence of impounding flowing waters. Such conditions are normal and are expected whenever flowing waters are impounded in areas with temperate climates. These warm water conditions are irretrievable since it is not feasible to remove the reservoirs. The historical data indicates that Lake Luxembourg has supported a warm water fish community and a put-and-take adult trout stocking program since it was constructed and has been managed by the PFBC as such.
It is the Department’s conclusion that: 1) the designated use of Lake Luxembourg is more restrictive than its existing use; 2) the designated use of CWF cannot be attained by implementing effluent limits required under sections 301(b) and 306 of the Federal Clean Water Act (33 U.S.C.A. §§ 1331(b) and 1316); 3) its current use designation cannot be attained by implementing cost-effective and reasonable best management practices (BMPs) for nonpoint source control; and 4) the conditions existing in Lake Luxembourg are the result of limnological processes that occur naturally in impoundments and it is not feasible to restore Core Creek to its original condition by removing Lake Luxembourg or manage it in a way that would result in the attainment of its designated use.
Based on these findings, the Department recommends that the designated use of Lake Luxembourg be changed from its current CWF, MF designation to TSF, MF. This recommendation is based on the physical characteristics of the water body, dominance of warm water fish species, and the management and stocking of warm water fish and adult trout by the PFBC. This recommendation will affect approximately 1.8 miles of the Core Creek directly limited to Lake Luxembourg, which approximates 166 surface acres. All tributaries to Lake Luxembourg will retain their current CWF, MF designations.
Coastal Environmental Services. 1993. Phase 1 Clean Lakes Study for Lake Luxembourg. May 1993, revised April 1994.
Department of Environmental Protection. File information.
PA Fish and Boat Commission. File information.
Princeton Hydro, LLC. 2002. Final Report of a Phase II Non-Point Source Pollution
Implementation Project for Lake Luxembourg/Core Creek Watershed, Core Creek Park, Bucks County, Pennsylvania.
Tables and Figures
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