As reported by the Maine Department of Environmental Protection (ME-DEP) and the Volunteer Lake Monitoring Program (VLMP), the water quality of Forest Lake is considered “above average”:
Water quality monitoring data for Forest Lake have been collected since 1974. During this period, 15 years of basic chemical information was collected in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Forest Lake is considered above average based on measures of SDT, total phosphorus (TP) and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Forest Lake is moderate.
Read the full report: ME DEP Report 3712