Red Dye in Water No Cause for Alarm

August 3, 2023

Over the next several weeks you may see some bright red liquid in the tributaries of the Connecticut River - do not be alarmed!

The Army Corps of Engineers (USACE), in cooperation with the Connecticut Agriculture Experiment Station (CAES), will soon begin releasing a non-toxic red dye in order to study the patterns of water flow. This study is being done as Phase I of testing that will eventually help the two groups finds ways to manage hydrilla in our waterways.

As I have reported many times before, hydrilla (hydrilla verticillata) is a pernicious invasive plant that is choking lakes, ponds, and streams - and a significant part of the Connecticut River. Management of the plant is extremely difficult, and its rapid spread is devastating to the ecosystem, recreational boaters, and businesses that depend on our environment.

Please feel free to join me and representatives from CAES, USACE, the CT River Conservancy, RiverCOG, and marina businesses at a press conference on this subject on Wed., Aug. 16 at 10 a.m. at Petzold’s Chester Boat Basin, 226 Middlesex Avenue, Chester.

Experts will address how these species cause ecological and economic harm, talk about the different research and removal projects being conducted in the Connecticut River, introduce the newly formed Office of Aquatic Invasive Species, and offer methods of prevention.



ABOUT THE DYE: In order to better understand the dynamics of water flow and exchange in the local waterways, the USACE, in cooperation with CAES, will be applying Rhodamine WT (RWT), a red tracer dye to the Chester Boat Basin, along with three other sites. This dye release and study program is preparatory to the eventual release of herbicide treatment for the control of hydrilla at each site.

According to the USACE, RWT dye is a fluorescent, xanthene dye that has been used for water tracing since at least the mid-20th century to quantify time of travel in dynamic (in this case, tidal) waters. This dye has no significant effects on aquatic organisms and has been proven to be safe to use for these studies. The dye will be applied to the sites during various environmental conditions using different application techniques at 10 parts per billion concentrations. The concentrations of the dye in the water will be collected using fluorometry equipment at certain intervals following initial dye treatment at sampling points within and just outside of the sites. There will be impacts on the color of the water at the sites and surrounding areas as the dye is bright red in color, but these are expected to be minimal and short-term as the dye will dilute and dissipate with the flow and tides of the river.

I am grateful for the combined brain power of these biologists, engineers, and advocates. We don’t want the public alarmed at the sudden appearance of red dye in the water, so we’re trying to get ahead of it by educating boaters, businesses, and residents.