Water Quality: Cyanotoxin Monitoring

FB Environmental, Maine/New Hampshire

Tracking Weather Conditions for Cyanotoxin Monitoring

Heavy summer rains combined with warm, sunny days create ideal conditions for cyanobacteria blooms on Lake Waukewan, the primary drinking water source for thousands of Meredith, New Hampshire residents. These blooms can release harmful cyanotoxins, posing risks to public health and making a strong monitoring and response strategy essential for decision makers.

To address this challenge, the Town of Meredith partnered with FB Environmental to develop a thorough Cyanobacteria Monitoring and Response Plan.

A key component of the plan was securing a reliable weather station to monitor blooms following certain weather events. With support from an Environmental Protection Agency grant, FB Environmental installed a Pulsar 700 Weather Station on the roof of a treatment facility building and documented its application in the official response plan:

MONITORING SOURCE WATER FOR EARLY WARNING SIGNS 3.1 Routine Lake Monitoring

Year-round deployment and maintenance of the weather station at the Meredith Water Treatment Facility. Remote data checks will be conducted weekly by MWD to ensure proper functioning of the weather station. Alarms may be set to alert MWD to parameters surpassing thresholds determined as high risk for cyanobacteria blooms...

3.2.4.2 Weather and Water Temperature Blooms are anticipated to occur within the weeks after a heavy rain event followed by or preceding hot, sunny conditions or a period of several warm, calm days during peak thermal stratification or around fall turnover at the end of the season...

MWD may set up an automated alert to be emailed to both MWD and volunteers for the following weather conditions: more than three consecutive “calm” days (winds <2 mph and precipitation <0.1 inches), particularly warm (air temperature >26.7ºC) and sunny (solar radiation >600 W/m2) days, and after storm events with precipitation >0.5 inches and/or sustained wind speeds >10 mph, particularly for winds coming from the northwest or southeast direction . . . Over time and with proper statistical data analysis, specific thresholds that are precursors to a cyanobacteria bloom may be discovered for weather and temperature data."

By integrating accurate, real-time Weather Data into its monitoring plan, the Town of Meredith can better anticipate when cyanobacteria blooms are most likely to occur. This improves the town’s ability to protect its drinking water supply through earlier detection, more precise response actions, and stronger safeguards for public health.

“Year-round deployment and maintenance of the weather station at the Meredith Water Treatment Facility. Remote data checks will be conducted weekly by MWD to ensure proper functioning of the weather station. Alarms may be set to alert MWD to parameters surpassing thresholds determined as high risk for cyanobacteria blooms.”

All photos courtesy of FB Environmental