PROJECT

Water Quality Testing Resumes

The Newtown Creek Coalition has resumed water quality testing of Newtown Creek. Regular sampling will be scheduled several times a year at three locations: in Newtown Grant, below Hidden Lake Dam, and at Barclay Street. Special attention will be given to elevated water quality parameters that may pose risks to aquatic life, particularly sensitive species.

Test Results Updated October 4, 2025

The Newtown Creek Coalition is collecting baseline water quality data for the creek. Water samples are being collected from three locations on Newtown Creek under baseflow conditions, when groundwater is the primary source of streamflow. Sampling sites included:

  • South Drive, Newtown Grant (headwaters)
  • Below Hidden Lake Dam, Washington Crossing Road (mainstem)
  • Barclay Street (mainstem, furthest downstream)

In-field measurements are being taken for chloride (Cl−), nitrate, nitrite, electrical conductivity, and temperature. Results from the sampling on October 9, 2024, July 24, 2025 and October 4, 2025 are summarized below:

Table 1. Water Quality Results – October 9, 2024
Table 2. Water Quality Results – July 24, 2025
Table 3. Water Quality Results – October 4, 2025

At all three sites, nitrite was not detected, and nitrate was only present at the most downstream site (Barclay Street). Chloride was detected at all locations. The observed chloride (1 2 3) and electrical conductivity (4) data indicate stressful/harmful conditions for biota, especially sensitive taxa.

The Coalition has now established a long-term monitoring program to track changes in water quality, detect pollution, and identify potential pollution sources. Special attention will be given to elevated water quality parameters that may pose risks to aquatic life, particularly sensitive species. Regular sampling is planned several times per year as part of this ongoing effort. Additional pilot studies could incorporate additional sites to test out the process for identifying sources of pollution.

1 R. Miltner, Assessing the Impacts of Chloride and Sulfate Ions on Macroinvertebrate Communities in Ohio Streams, Water, 2021, 13, 1815

2 S. Miess and A.R. Dzialowski, Salt Belt Index (SBI): A biotic index for streams within the North American “salt belt,” with proposed baseline chloride thresholds, 1 September 2024, Science of the Total Environment, 941, 173726

3 Maryland Department of the Environment, Maryland Biological Stressor Identification Process, BSID Process Report, June 2009, p. 19 – 20

4 W.H. Clements and C. Kotalik, Effects of major ions on natural benthic communities: an experimental assessment of the US Environmental Protection Agency aquatic life benchmark for conductivity, Freshwater Science. 2016. 35(1):126–138

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