Blogs > Water Quality > Inspiring stewardship of ‘Trib 13’ – a beloved stream with a strange name

Inspiring stewardship of ‘Trib 13’ – a beloved stream with a strange name


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Riverkeeper helps local stewards protect the waters they care about most – like tiny Mill Brook, also known as Trib 13, in New Paltz. Sponsor a water quality sample with a donation of $10, or volunteer to sample your local waterway.


Thousands of Enterococcus samples collected by community scientists volunteering with Riverkeeper’s water quality monitoring projects have built a picture of water quality throughout the Hudson River watershed that has led to increased state funding for water infrastructure, increased awareness of sewage pollution problems, and a growing community-driven movement to improve water quality.

Of the places we sample, the Wallkill River has received a lot of attention because it’s a large river with some of the highest Entero counts we’ve observed.

In our seven years of sampling at Mill Brook, a small Wallkill tributary in New Paltz, only one sample of 41 has shown water quality safe for swimming according to EPA-recommended guidelines. Only one!

Yet, after gathering more than 937 samples, there are sites in the Wallkill Watershed where we’ve never observed swimmable water quality. With 24 sampling sites spread along 80-plus miles of the Wallkill River, tiny Mill Brook – also known as Trib 13 for its geographical sequence in watershed maps – might not seem like an obvious priority. In fact, Riverkeeper and the Wallkill River Watershed Alliance recently achieved a major milestone in prioritizing reduction in contamination from some of the Wallkill’s largest pollution sources, and Trib 13 isn’t among them.

But this small watershed includes a cherished nature preserve and an engaged community. (Trib 13 wasn’t even on Riverkeeper’s original list of sampling locations, until a passionate local advocate told us we were missing someplace important, and requested that we sample the tributary.) A fundamental idea driving community science is that communities should define priorities and scientists should work to guide and support them. That’s what Riverkeeper is trying to do with the community that cares about Trib 13.

As an environmental indicator, Entero is a starting point: where the data show that problems exist, the next step is source tracking, a process of sleuthing out where the contamination originates. The sources might be human, animal, environmental (such as street runoff), or a combination, and there are many source tracking tools and methods from which to choose.

Over the years, Riverkeeper has partnered with the Town and Village of New Paltz, the Wallkill River Watershed Alliance, Cornell University scientists, and others to do stream walks, DNA-based testing, optical brightener measurements, and additional Entero monitoring to track fecal contamination sources in Trib 13. We’ve identified stormwater and sump pump discharge pipes, investigated sewer lines and pump stations, and even found a buried stream. But despite our efforts, people were frustrated that water quality isn’t improving.

To overcome these obstacles, Riverkeeper held a workshop in Fall 2018 with the goals of educating participants about the history and scientific basis of community science done in the watershed so far, and helping the Mill Brook watershed community to define actionable next steps.

During the workshop we studied watershed maps to generate ideas about potential Entero sources. Another important component of the map study was listing research themes such as, what are the existing regulations around septic system maintenance? And, what areas of the sewer collection system has the Village recently rehabilitated? (That sometimes stinky pump station on Henry W. DuBois Drive? Not the problem!)

One exciting outcome of the workshop was the idea to form a Trib 13 Stewardship Group, with joint representation from the Village of New Paltz Environmental Policy Board and the Town of New Paltz Environmental Conservation Board, as well as other members. This group is concerned with the stream’s entire watershed, and not just the portion that flows through the Mill Brook Preserve. It’s concerned with the health of the ecosystem, and not just the concentration of bacteria in the water. The group will be in the lead moving forward, and Riverkeeper will continue to actively participate. Already, the Village has conducted dye testing of its pump station near our original test site, and found no leaks from the infrastructure in that area.

It should come as no surprise that a group with community science at its foundation also prioritized additional water sampling. This season, Riverkeeper and the Trib 13 Stewardship Group will test for fecal indicator bacteria (Entero and E. coli, a similar indicator) at nine sites in the Trib 13 watershed. The sampling sites were chosen in order to bracket small reaches of the stream where there are potential sources. We will also make other water quality measurements to provide context. With the resulting data, we will search for hotspots – stream sections with relatively high bacterial counts – and relate these back to the corresponding watershed area.

When Captain John Lipscomb started Riverkeeper’s Water Quality Program, it was his hope that providing data about something many people care about – the safety of water for recreation – would inspire concern about the range of issues that a waterway faces. The Trib 13 Stewardship Group is an example of that vision being realized.

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