The Mohawk River, which begins in the Southern Adirondacks and empties into the Hudson in Cohoes, has had a new health assessment.
Riverkeeper, working with SUNY Cobleskill, began sampling the Mohawk in 2015. Taking data from various parts of the river, the team looks for the presence of a bacteria — an indicator species — to determine levels of fecal contamination.
Riverkeeper Water Quality Program Director Dan Shapley says overall the Mohawk appears in good shape. But, as he says, it’s a big river.
“And like the Hudson and what we’ve found there, we see that it’s not just one river,” said Shapley. “We see water quality really varies from place to place and over time. And that’s something that people don’t always appreciate but it’s a really important concept to understand.”
Shapley wants people to know that when they go swimming in the Mohawk, they’re not swimming in what he calls a “general river” but a particular place at a particular time.
Shapley says in general, on a lot of days and in a lot of places, the river is safe for swimming.
“Which is great news. And it tells us that the Mohawk is resilient and should be a place where we can enjoy a lot of recreation and be proud of,” said Shapley.
But the data also shows there are several spots with higher levels of contamination. According to the report, 37 percent of water samples taken on dry days failed when measured against the U.S. Environmental Protection Agency’s recommended Beach Action Value — the index used to determine if the water is safe for swimming.
After rainy weather, 48 percent of samples failed. That increase is in part due to stormwater runoff and combined sewer overflows, often in urban areas like near Utica and toward the Capital District.
Barbara Brabetz, an Associate Professor of Biology and Chemistry at SUNY Cobleskill, says tributaries that empty into the Mohawk violate the EPA standard far more often.
“So if you think of the main tributaries of the Mohawk, we have the Schoharie, which is a large contributor of material, we have the west and east Canada Creeks, and then we have a small subset of tributaries near Utica that aren’t really significant from a flow standpoint but seem to violate much more often,” said Brabetz.
As expected, high levels of contamination were found in urban areas.
“It’s surprising, though, we still see some violations on the tributaries in very rural areas, like the east Canada Creek, which if you were to look at it in a picture would be a poster child for the Adirondacks, but in reality, violates more often than we would expect,” said Brabetz.
Riverkeeper hopes the science from its sampling work can help inform policy makers to better protect the river. Next month, the organization will be presenting information on the upper Hudson in Glens Falls, Schuylerville, and Albany.