Community Science

On September 21, 2023, the Neshaminy Watershed Association, in collaboration with the Bucks County Master Watershed Stewards, conducted a water quality survey of creeks in Bucks County, focusing on Neshaminy Creek and its tributaries. A total of 37 samples were analyzed. The survey took place in late summer to establish base flow conditions, where stream contents originate from groundwater rather than stormwater runoff. The survey included analysis of chloride and nitrate levels in the streams. Chloride is a stream contaminant primarily derived from road salt used during winter to prevent ice formation and maintain road accessibility. Nitrate is a pollutant originating mainly from fertilizer runoff or malfunctioning waste treatment systems.

The results revealed surprisingly high concentrations of chloride in the streams. Along the main branch of Neshaminy Creek, chloride concentrations ranged from 27 to 69 ppm, while in the tributaries, concentrations ranged from 21 to 143 ppm. Particularly concerning were sites in Quakertown (Licking Run) and Little Neshaminy Creek, where chloride concentrations exceeded 80 ppm. Chloride concentrations above 50 ppm are known to impact macroinvertebrates living in the streams. These findings suggest that past road salt applications have contaminated the aquifers feeding Neshaminy Creek and its tributaries.

Nitrate levels in streams were generally low (<5 ppm nitrate), except for two locations: a section of Little Neshaminy Creek near Moland House and the West Branch of Neshaminy Creek at West Branch Park, where nitrate levels exceeded the drinking water standard of 10 ppm nitrate. To confirm these results, additional samples were taken at the concerning sites in October and November. The second set of samples confirmed high chloride and nitrate levels at Little Neshaminy around Moland House and at West Branch Park.

An additional study is currently underway to quantify areas where road salt is entering the streams and to identify the sources of nitrate contamination.

The 2023 Macroinvertebrate Survey, conducted over a nine-month period at five strategic locations along the Neshaminy Creek, aimed to assess the ecological health of the watershed through the analysis of macroinvertebrate populations. This comprehensive study, conducted from March to November, pursued two primary objectives:

1. Assessment of Stream Health: The survey aimed to determine the ecological status of the Neshaminy Creek by analyzing the diversity and abundance of macroinvertebrates present. The evaluation focused on identifying whether the stream was impaired, attaining environmental standards, or if its ecological status showed fluctuations over the survey period.
2. Establishment of Baseline Data: In anticipation of potential environmental impacts, such as contamination spills or infrastructural changes like the removal of the Spring Mill Dam, the survey sought to establish a robust set of baseline data. This foundational information is crucial for future comparative analyses to detect and quantify ecological changes within the watershed.

The separate efforts of the Neshaminy Watershed Association (NWA) and the Department of Environmental Protection (DEP) have yielded consistent findings across all surveyed sites. The collected data reveal a concerning scarcity of sensitive invertebrate species, indicating that the Neshaminy Creek does not meet the criteria for an "attaining" status under current environmental health standards. This conclusion underscores the necessity for ongoing monitoring and environmental management efforts.

Future studies and monitoring initiatives will reference the data collected through this survey to track changes in the ecological health of the Neshaminy Creek. The establishment of a comprehensive baseline dataset is a critical step in ensuring the effective stewardship of the watershed and in facilitating targeted conservation strategies to improve water quality and biodiversity in the Neshaminy Creek ecosystem.

The study document can be downloaded here.