It’s only a couple of miles in total length, and you may not know its name — or even that it’s the same stream in the various places where you encounter it. But if you’re a Paltzonian, you have certainly made the acquaintance of the Saw Mill Brook. This multibranched water body really gets around, from Cherry Hill to South Putt Corners to Jansen Road to Plains Road, as well as a meander through the SUNY campus. And now some of its admirers are joining forces to offer it some TLC.
Last week, the Saw Mill Brook Watershed Alliance (SMBWA) held its first-ever meeting. On hand were several active members of the Wallkill River Watershed Alliance (WRWA), the environmental-action group that spawned it, along with a handful of concerned residents who live along the brook. A similar spin-off group has already formed to protect the Shawangunk Kill, as part of a broad strategy by WRWA to break up the daunting task of cleaning up the Wallkill into digestible geographical chunks.
“This stream should be fine,” was the optimistic assessment of New Paltz Town Supervisor/watershed biochemist Neil Bettez, who heads up the WRWA Science Working Group. “This is small, this is bite-sized. We can do this if we get buy-in.”
The need for a special subchapter to work on the Saw Mill Brook’s problems, according to Craig Chapman of New Paltz Kayaking Tours, was established by the pattern of “consistently testing bad for bacteria levels” at the point in Sojourner Truth Park where the brook empties into the Wallkill, during the periodic water-sampling conducted by Hudson Riverkeeper. “This group’s goal is to empower people, to get ideas, to do everything we can to get the brook as clean as possible,” Chapman said.
Bettez noted that most of the area through which the brook passes is residential, suggesting that septic-field runoff may be largely to blame for the high enterococcus levels that keep registering in Riverkeeper’s samples. “I’d be curious about how it tests after my neighbor completely replaced his leachfield, which had failed,” noted John Ferro, who says that the brook “flows through my backyard” off Plains Road.
There is also some agricultural acreage abutting the brook, particularly along the branch that originates near South Putt Corners Road. Fertilizer runoff might also be a factor in the stream’s pollution levels, Bettez theorized, but more likely with respect to phosphorus saturation that stimulates algal bloom than to bacteria. This too he characterized as “not an intractable problem,” suggesting that the SMBWA should “ask farmers to do the right thing: have buffers between their fields and the stream” as part of its educational campaign.
Perhaps the most problematic stretch of the Saw Mill Brook is its course through the SUNY New Paltz campus — particularly the stagnant pond long known to students as “the Gunk,” which has never been known as an enticing spot for a dip. It’s also the only part of the brook, upstream of its confluence with the Wallkill, that has ever been systematically studied. In 2013-14, Bettez said, a buoy was placed in the Gunk that took water samples every 15 minutes, ascertaining an unacceptable level of fecal coliform bacteria in the waterway as well as “really high algae” measures. He explained that excessive algal bloom causes a “big fluctuation” in dissolved oxygen levels in water: oversaturated from photosynthesis during the day and “completely anoxic” at night and in winter due to decay of plant materials, making such a water body highly inhospitable to fish. Electrical conductivity tests of the Gunk also indicated ionization of the water that most likely resulted from road-salt runoff.
The new group decided to get its work underway by amassing more baseline data upstream of the Saw Mill Brook’s confluence with the Wallkill. After considerable discussion, the group narrowed down potential sampling sites to five, strategically chosen to isolate or rule out potential points of entry for pollutants. Future testing will move upstream of those sites if a particular branch of the brook should prove problematic. A sixth set of samples will be taken in the same spot at the stream’s mouth where Riverkeeper does its testing, for comparison’s sake. But the group agreed that it would be more informative to measure E. coli — as opposed to enterococcus, which Riverkeeper uses as its parameter for human and animal waste because it is also measurable in large water bodies like the Hudson River. WVWA president Jason West noted that the “safe level” for enterococcus is 30 cells per milliliter of water, and that, according to Riverkeeper’s sampling, “The lowest in the Saw Mill Brook is 80: more than double.”
Several members of the group volunteered to spend an afternoon gathering water samples at the assigned locations, while Chapman said that he would research prices for lab testing. The SWBWA plans to meet at New Paltz Village Hall at 7:30 p.m. on the fourth Thursday of each month, and meetings are open to the public. Residents wishing to volunteer or obtain regular updates on the group’s activities are invited to send an e-mail to firstname.lastname@example.org to be placed on the listserv.