Abstract

A Water-quality data collected in the upper Oyster Creek drainage basin indicate that the stream has excellent water quality except for a persistently low pH (median 4.5).

The mean concentrations of the inorganic ions were all less than 6l0 milligrams per liter. Mean concentrations of total nitrogen and total phosphorus were 0.15 and 0.01 milligrams per liter and 81 percent saturation.

Low pH is typical of streams draining cedar swamps. Within the study area, pH tended to decrease downstream due to chemical and biological processes. The pH in swampy areas was half a unit or mor below the pH in the adjacent stream.

Sharp declines in stream pH were noted during runoff as the result of the mixing of poorly buffered stream water with more highly acidic water from surrounding swam areas. These pH declines severely hinder brook trout survival due to the toxic effect of highly acidic water.

The quality of ground water was similar to the quality of streamflow, except for higher iron and ammonia-nitrogen concentrations and a pH range of 4.9 to 6.5. The highest concentrations of most chemical constituents were found in the ground water within the organic muck beneath swamp areas.

The quality of precipitation on the area was also similar to the quality of streamflow. The pH of precipitation ranged from 4.2 to 7.0. Precipitation represents a major source of many chemical constituents in the water of the Oyster Creek basin.

First posted September 11, 2012