Water Quality Sampling on the Rock River

FNLC has been actively sampling from the Rock River for over 14 years. But what exactly does the sampling process look like?

The Rock River Basin is largely located in the town of Highgate, Vermont. FNLC's 14 sample sites are scattered across the basin on both small tributaries and on the main branch of the river. Land usage varies from site to site, as some are heavily forested while others are bordered by cropland and residential areas. Some are easy to access, while others require walking through dense brush or down steep embankments. Sampling occurs on a biweekly basis during sampling season as well as during high flow events. Extra precautions must be taken when collecting samples during high flow events, and some sites may become entirely inaccessible.

Extent of the VT sections of the Rock River Basin, shaded in yellow

The same sampling protocols are generally used for each site. An essential tool for many of our sites is a stream dipper, which is an extendable pole with a small wire cage at the end that holds a large sample bottle. The dipper allows for samples to be taken from rivers and tributaries of all different sizes without the sampler having to get too close to the water's edge. This is especially important for waterbodies that tend to be deeper or have faster currents, as well as during high flow events.

ECO Americorps member Hannah using the stream dipper in a small tributary

Project Coordinator Caroline filling a sample tube

Once collected by the stream dipper, the samples are separated into three sample tubes: total nitrogen (TN), total phosphorous (TP), and dissolved phosphorous (DP). For the TN sample, the cap of the sample tube along with the tube itself must be rinsed 3 times. For the DP sample, the water is run through a specialized filter before being put into a sample tube. All samples are later sent to the Vermont Agricultural and Environmental Lab (VAEL) for processing.

From left to right: TP and DP sample tube, TN sample tube, filter for DP

Sampling for phosphorous and nitrogen is an essential part of monitoring the health the Rock River. Excess levels of phosphorous and nitrogen can lead to events such as harmful algae blooms, as well as an overall reduction in water quality. Sampling can provide insight into what natural or man-made events are increasing levels of nitrogen and phosphorous in the watershed and help to prioritize which areas are best suited for project implementation. It's also a great way to connect with those living in the Rock River Basin and allow them to voice their concerns. Water quality monitoring has been and will continue to be a core aspect of FNLC's work in the Rock River Basin.

Images Courtesy of Caroline Foley & Hannah Mahar