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
GENERAL WATERSHED DESCRIPTION
The Department is initiating a correction to the aquatic life use designation in the water quality standards for Blue Marsh Lake, Berks County. It currently has a Trout Stocking (TSF) 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.
Blue Marsh Lake is owned by the U.S. Army Corps of Engineers (COE) and is located in Penn, Bern, Lower Heidelberg, North Heidelberg and Jefferson Townships and Bernville Borough Berks County. Blue Marsh Lake is located on Tulpehocken Creek (stream code 01846), which is a tributary to the Schuylkill River within the Delaware River basin (drainage list F) (Figure 1). Tulpehocken Creek was impounded in 1974 creating the 1,150 surface acre, 8 mile long lake, which drains a 170 mi2 watershed consisting primarily of agricultural (68%) and forested (28%) areas. Blue Marsh Lake has a maximum depth of 53 feet with an approximate volume of 3,000 acre-feet of water at normal pool elevation. There are numerous public, non-public, and industrial discharges and withdraws upstream of Blue Marsh Lake.
Blue Marsh Lake is routinely sampled for water quality parameters by the COE. Figure 2 shows the location of their sampling sites on the main portion of the lake. Blue Marsh Lake typically stratifies during the summer with the thermocline forming between 5 and 15 feet 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 in early studies of the lake. Further, lake water temperatures often exceed levels that can support survival of cold water fish species during summer months (Figures 3-14). Water chemistry parameters are consistent with lakes that are in the meso-eutrophic state, which is typical for warm water lakes (Tables 1-6). Physical lake data for temperature and DO reveal conditions that are not supportive of trout stocking.
Blue Marsh Lake has a resident self-supporting warm water fish community. Over the history of the lake, a total of 37 species have been captured during surveys conducted by the Pennsylvania Fish & Boat Commission (PFBC)(Table 7). 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 8). Warmwater species such as largemouth and smallmouth bass, pumpkinseed, bluegill, green sunfish, white and black crappie, yellow and brown bullheads, and channel and white catfish 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. Cold water salmonids, such as rainbow and brown trout, have been collected in Blue Marsh Lake. These trout likely originated from upstream areas as salmonids are stocked or occur naturally in almost all of the tributaries to Blue Marsh Lake. Salmonids may use Blue Marsh Lake during the late fall, winter, and spring, but it is unlikely that they are present in the lake during the summer as temperatures and DO levels are usually outside normal tolerances for these cold water species. Blue Marsh Lake has always been managed by the PFBC as a warm water fishery by relying on natural reproduction and supplemental stocking of predatory warmwater fish such as walleye, tiger muskellunge, and striped and hybrid striped bass (Table 9). The PFBC has never stocked trout in Blue Marsh Lake.
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 Reading Eagle (Reading, PA) on May 30, 2003. In addition, Heidelberg, Jackson, Millcreek, North Lebanon, Bern, Jefferson, Lower Heidelberg, Marion North Heidelberg, Penn, South Heidelberg, Tulpehocken, Upper Bern, and Upper Tulpehocken Townships and the Lebanon and Berks County Planning Commissions as well as Myerstown, Bernville, Robesonia, Strausstown and Womelsdorf Boroughs were notified of the redesignation evaluation in letters dated May 29, 2003. In response, the Berks County Planning Commission submitted a report entitled “Blue Marsh Lake, Water Quality Evaluation, Assessment of Major Chemical/Physical and Biological Parameters” which was prepared by Drs. Phillip Dougherty and John Hall from Albright College. The report was reviewed and results were consistent with those presented in this report.
A review of available data indicates the existing use for Blue Marsh Lake is and has always been Warm Water Fishes (WWF). The predominance of warm water conditions and concurrent warm water fisheries found in Blue Marsh Lake 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 Blue Marsh Lake has supported a warm water fish community 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 Blue Marsh Lake is more restrictive than its existing use; 2) the designated use of TSF 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 Blue Marsh Lake are the result of limnological processes that occur naturally in impoundments and it is not feasible to restore Tulpehocken Creek to its original condition by removing Blue Marsh Lake 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 Blue Marsh Lake be changed from its current TSF designation to WWF. 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 by the PFBC. This recommendation will affect approximately 8.4 miles of the Tulpehocken Creek directly limited to Blue Marsh Lake, which approximates 1,150 surface acres. All tributaries to Blue Marsh Lake will retain their current designations.
Department of Environmental Protection. File information.
Dougherty, P and J. Hall. 2003. Blue Marsh Lake, Water Quality Evaluation,
Assessment of Major Chemical/Physical and Biological Perimeters. Albright College. Reading, PA.
PA Fish and Boat Commission. File information.
U.S. Army Corps of Engineers. File information.
Tables and Figures
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