In short: an aluminum treatment is a way to prevent internal recycling/loading of phosphorus in lakebed sediments so it can’t become food for algae, thereby greatly reducing the chances of algae blooms. To expand: aluminum treatments involve adding a carefully measured dose of aluminum sulfate – one of aluminum’s alum forms (and yes, this is why the treatment is often referred to as an “alum” treatment) – and sodium aluminate (to keep pH levels neutral during treatment) to the water. Aluminum sulfate binds – at the molecular level – to phosphorus. Afterwards, water quality rapidly improves since there’s less phosphorus available for algae to consume.

A two-prong approach: 1. Reducing the amount of phosphorus that gets into the lake from the surrounding watershed AND 2. Conducting an aluminum (alum) treatment to stop the internal recycling/loading of phosphorus.

One of aluminum’s “alum” forms, consisting of aluminum, sulfur and oxygen. It is commonly used by water treatment plants, including Kennebec Water District to create drinkable water. The alum commonly found on grocery store shelves is a different compound – it’s potassium aluminum sulfate.

Sodium aluminate is a compound of sodium, oxygen and aluminum. It is used to balance pH levels in water, and is applied in conjunction with aluminum sulfate during an aluminum treatment.