Forest Lake Alum Treatment
Project Description & Outcomes
The Forest Lake Alum Treatment Project was a milestone project in achieving Forest Lake’s water quality goals.
The lake was treated with alum which binds to phosphorus and makes it unavailable for algae growth. Alum is a non-toxic water quality treatment that will result in a cleaner and clearer Forest Lake.
The first alum treatment took place in September 2023. The District monitored the lake in 2024 in order to calibrate the dose for the second and final phase that occurred in fall 2025.
Project Status
Completed
Project Outcomes
527 lbs/yr phosphorus removal
Financials
Clean Water Fund Grants: $513,200
CLFLWD Grant Match: $128,300
Total Project Budget : $641,500
Lifecycle cost:
$100 per pound of phosphorus removed
Timeline
Fall 2023: Alum application #1
2024: Effectiveness Monitoring
Fall 2025: Alum application #2
Project Partners
