What are RHA’s recommendations for avoiding exposure to E. coli in our streams? When planning to swim, boat or fish in streams in the Upper Raritan, wait 2 to 3 days after significant rain or exercise sanitary precautions to avoid exposure to high levels of E. coli bacteria and other pathogens.
What data did RHA use to make this recommendation regarding recreational use and bacteria exposure? From 2017-2019 Raritan Headwaters conducted research on the levels of E. coli bacteria in our streams. We followed the NJDEP research methods to sample biologically impaired sites and popular swimming holes over a 5-week period during 3 summers. During the 5-week studies, concentrations of E.coli bacteria were measured weekly to determine whether water quality was meeting standards for safe recreational use under the federal Clean Water Act. RHA’s data are depicted in an interactive Bacterial Storymap, highlighting the major findings.
https://rha.maps.arcgis.com/apps/MapSeries/index.html?appid=fda703f4d0364144a0d3ea7ed954014a
E. coli cell. EPA
What is E. coli and why is it a cause for concern? Escherichia coli (abbreviated as E. coli) is a species of fecal coliform bacteria that live in the intestines of humans and other animals. E. coli are a large and diverse group of bacteria that are normally present at low levels in the environment. However, high levels of E. coli and other pathogens in waterways increases the risk of illness for people who come in contact with the water. Although most strains of E. coli are harmless, others can make you sick. Some kinds of E. coli can cause diarrhea, while others cause urinary tract infections, respiratory illness and pneumonia, and other diseases. Children under the age of five, the elderly, and people whose health is weakened are at greater risk of severe illness. Their presence in streams indicates the possible presence of other disease-causing pathogens (Dufour, 1977).
How do high levels of E. coli get into waterways? Common sources of E. coli in our streams include failing septic systems, farm animals, and pet waste. E. coli enters waterways with stormwater runoff from heavy rainfall, snowmelt, and through groundwater inputs. In more urban areas of New Jersey, E. coli levels in waterways spike after a major storm due to antiquated sewer systems called Combined Sewer Overflows (CSOs) that discharge raw sewage and stormwater directly into streams and rivers.
Stormwater discharge pipe on the North Branch Raritan River
Does E. coli threaten the safety of our drinking water? Yes. Public water supply is tested and treated for bacteria and other contaminants by the water purveyor, which is usually NJ American Water for those living in the Upper Raritan region. However, private well owners are responsible for testing and treating their own well water. The EPA recommends annual testing of wells for coliform bacteria and treating through chlorination or UV light systems if necessary. The acceptable amount of E. coli in drinking water is zero. See NJDEP Private Well Act testing data for E. coli here.
What are the recreational-water-quality standards for E.coli? If E. coli levels exceed a geometric mean of 126 bacteria/100 ml (recently decreased to 100 bacteria/100 ml) or a single sample maximum of 235 bacteria/100 ml then the water is deemed not suitable for recreational use. Recreational water is defined as water bodies where people engage in, or are likely to engage in, activities that could lead to ingestion of the water or immersion in the water.
Who is monitoring E. coli in our streams? Every 2 weeks, volunteer stream monitors and interns from RHA and Raritan Valley Community College visit 13 of our long-term stream sites to collect data on stream temperature, chemical parameters and E. coli bacteria levels. This study will help inform how extreme weather due to climate change (droughts and big storms) as well as land use are impacting E. coli levels in streams of the Upper Raritan region. The NJ Department of Environmental Protection also monitors E. coli levels and is responsible for addressing streams that are exceeding surface water quality standards identified in their Integrated Report.
What is RHA doing to address sources of E. coli and other contaminants in our watershed?
- Providing resources on septic maintenance for homeowners.
- Empowering homeowners and municipalities to address failing septic systems in their community with practical tools for Septic Smarts.
- Testing private well water for E. coli so homeowners can treat their well and address sources of E. coli. RHA’s Well Test Program
- Improved stormwater management through watershed planning and green infrastructure.
- Encouraging Best Management Practices (BMPs) on farms to contain animal waste and keep livestock from entering waterways.
- Restoring forested buffers to filter pollutants from stormwater runoff through our Woods and Waterways Program.
- Enlisting everyone in the watershed to do their part in being River Friendly.
