Androscoggin Lake Update

In late September, our environmental consultants joined our staff and several algal bloom project steering committee members on Androscoggin Lake to gain a better understanding of its unique qualities. The group also visited the Dead River pollution control device (PCD), or “Dead River Dam,” to provide additional insight into how the river could be impacting the lake. 

On October 2nd, the lake reached Maine DEP’s standards for lake-wide algal bloom status, defined as clarity readings of 2m or less at the deep hole. The clarity reading was recorded as 1.8m (5.9ft). The clarity had improved to 2.34m (7.68ft) as of October 20th, ending the lake-wide algal bloom status, but the lake is still visibly green, and our monitoring buoy is still detecting high levels of cyanobacteria.

This month, sediment sampling was completed by Maine DEP with assistance from 30 Mile staff. This entailed collecting 5cm samples from 17 locations across varying lake depths and two 20cm samples from the deep hole station 1, where our bi-weekly monitoring takes place, and at a location near the Dead River’s connection to the lake. These samples will give us a better understanding of the lake’s sediment chemistry and its impact on internal phosphorus loading. 

These sediment cores will be stored until they are analyzed later this winter. This is crucial data that—alongside the increased monitoring data collected this season—will help provide the needed information to complete our Watershed-based Management Plan.