A boat ride around Lake Pend Oreille will show any newcomer why people move here: great water clarity, sparse development on large portions of the shoreline, and an angler’s paradise.

But the lake is facing problems. Residents have noted an increase in shoreline algae decreasing the clarity we all enjoy. 

Algae has its place in the lake and is the food base for zooplankton who feed progressively larger fish and eventually the angler and friends. As important as algae are to the natural food chain, excessive algae causes the formation of scum, foul odors, low oxygen in water that can suffocate fish, and unpleasant views.

What does this have to do with shoreline fires? Simple answer: ash feeds algae. Wood ash contains nutrients required by any plants for growth. Burning wood creates about 8 percent ash.  The contents of ash are 1-2 percent phosphorus and 5 to 10 percent potassium. Here are some facts additional facts about phosphorus, wood, and ash.

n  One ton of wood produces 160 pounds of ash

n  160 pounds of ash produces 2.5 pounds of phosphorus

n  2.5 pounds of phosphorus produces 1,250 pounds of wet algae

You can prevent algae growth by burning at least 40 feet away from shore. A thick strip of healthy vegetation between the fire and the shore will ensure no ash blows or washes into the lake. Use a metal fire pit to limit any damage to soil and contain the ash for easy disposal. Watch your ash! A clean lake begins at your doorstep.

John Sugden is a member of the Tri-State Water Quality Council.