Generally speaking, based on the water quality "snapshot" project described above, the Upper Pond Run Watershed did not deserve the "impaired" label in early July, 2000, which had been applied to the Pond Run drainage basin as a whole by government evaluators. Except in a few cases, chemical results were within New Jersey’s FW-2 regulatory standards and benthic macroinvertebrates near the main inlet to R.L. Martin Lake were satisfactorily diverse. On the other hand, outflow from the dam impounding Upper Pond Run most likely deserves to be labeled severely impaired. Although most water quality parameters tested there were at or exceeded of FW-2 standard, the outflow’s anoxic waters represents the biggest problem to be explained.

Given the foregoing dramatic water quality differences above and below the weir that delays initial outflow from R.L. Martin Lake, the value of this engineering structure is dubious. In the lake itself, a relative trickle of beneficial tributary waters cannot begin to mitigate the profound temperature and pH stresses to which aquatic organisms are subjected by a shallow, poorly-buffered body of water, surrounded by acid soils and the potentially nitrogen & phosphorus-overloading effects of innumerable resident geese. If periodic testing comparable to that performed during this limited investigation of the watershed can be continued until late in the summer (with correction of shortcomings apparent in hindsight), and it turns out that death and decomposition of the prodigious phytoplankton populations produce anoxic bottom waters, redevelopment of R.L.Martin Lake & its outfall should be considered along the following lines.

• Deepen the lake so that meaningful temperature stratification can occur. That change would act to limit the lake’s presently large, stressful daily temperature swings through regular turn-over of cooler bottom waters.
• Plant a wide strip of native marsh plants on the substrate of the lakeshore exposed by deepening the lake. That would deter geese from entering the water and help absorb much of the fecal nitrogen, possible parkland fertilizer, and road deposits running off into the lake (some banks of which are fairly steep).
• Retrofit the lake outfall with a biofilter wetland to improve surface water quality leaving the lake.
• Modify the weir structure at the base of the dam which backs up lake outflow, so that such waters are strongly aerated, rather than stagnated there. That would eliminate the existing "death trap" for more pollution-sensitive macroinvertebrate members of the ecosystem below the lake, not to mention creatures higher up the food chain.

Introduction

Experimental Procedure

Results and Discussion

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