Excessive algal growth (a.k.a. "blooms" or "population explosions") can lead to nuisance surface scums, low water clarity, noxious odors, impaired potable water supplies, low oxygen levels, and fish kills.

In addition, some types of algae produce toxins in poor water
quality lakes which have caused skin irritations, allergic reactions, gastrointestinal symptoms, and respiratory problems in humans.
Pets and livestock are more likely to drink large quantities of raw lake water, potentially resulting in negative effects, even death.

Reduced property value is another important symptom of poor
water quality. Lakefront property is highly valued for its aesthetic
and recreational assets. However, property values are significantly affected by lake water quality. A recent study in Minnesota found that the value of home lots with only 40 linear feet of lakefront property fell by an average of $24,000 when lake water clarity decreased by
3 feet!

Phosphorus! Excessive amounts of phosphorus cause nuisance algal blooms and the associated symptoms of poor water quality. Lower levels of phosphorus lead to lower levels of algae.

Common external sources of phosphorus to a lake include
septic systems, lawn fertilizer, run-off from agricultural fields and feedlots, and Stormwater inputs. Once in the lake, the phosphorus accumulates in the bottom sediments. The lake bottom then
becomes a source of phosphorus to the overlying water as the phosphorus leaches from the sediments during the summer. The process of phosphorus release from the bottom sediments (a.k.a. "internal loading") is frequently the main source of phosphorus fueling algal blooms.

Freshwater Consulting, Inc. has developed a unique, environmentally-safe alum formulation to maximize phosphorus control effectiveness. This formulation is used in both Freshwater’s In-Lake Treatment System and Freshwater’s On-Shore Treatment System. Freshwater’s In-Lake Treatment System is used to control internal phosphorus loading, resulting in less algae and better water quality. This approach is not toxic to the algae, but rather reduces
the amount of phosphorus available for algal growth by retarding phosphorus inputs from the sediment for years!

During Freshwater’s In-Lake Treatment, the alum formulation is added to the lake water from a barge where it forms a fluffy,
cotton ball-like substance known as a colloidal aluminum hydroxide floc which binds to phosphorus. The floc settles out of the lake
and forms a chemical barrier between the bottom sediments and
the water. The floc actively binds and retains phosphorus that
would otherwise escape to the overlying water, thus reducing the amount of lake algae.

Freshwater’s On-Shore Treatment System is used to control external sources of phosphorus (for example, Stormwater entering a lake from a ditch or culvert). With this approach, the chemical formulation is injected into the external water source and binds the phosphorus
to the floc before it enters the lake, thus rendering the phosphorus unavailable for algal growth.

Lake Ventura is a sandpit lake located near the Platte River in eastern Nebraska. The lake was formed by gravel mining operations which created a sand bottom pit that filled with groundwater.
Over time, large amounts of phosphorus accumulated in the lake bottom sediments and became the primary source of phosphorus to the lake.

Water quality deteriorated with increased internal loading and total phosphorus in the water column ranged well over 100 ppb. In May of 2007, Lake Ventura received Freshwater’s In-Lake Alum Treatment to control internal phosphorus loading and generally increase water quality. Phosphorus levels were monitored every month during the summer of 2007 to determine the effectiveness of the treatment in controlling internal loading and reducing the amount of phosphorus in the lake.

Dissolved phosphorus was monitored three feet above the lake bottom as an estimate of the amount of phosphorus leaving the sediments. The following graph shows Freshwater’s In-Lake Treatment reduced dissolved phosphorus near the bottom from 192 ppb (pre-treatment) to 5.9 ppb (post-treatment average). This indicates a 97% reduction in internal phosphorus loading!

Total phosphorus levels were also monitored three feet below the lake surface to determine how much phosphorus was available to
fuel algal growth. The following graph shows a reduction from 130 ppb (pre-treatment) to 27 ppb (post-treatment average). This is a 79% reduction!

Lake Leba is a sandpit lake located in eastern Nebraska and was the site of an experimental alum research project. A small portion of the lake was completely isolated from the main lake and the smaller portion received an alum treatment. The effects of the alum on water quality were then compared to the untreated main lake for a period of three years. The results of the study were published as a scientific research article in the Journal of Lake and Reservoir Management. The results of the experiment are summarized below. Click here to see the entire research article.

The treatment resulted in the following changes in water quality over the three year experiment:

• 97% reduction in internal phosphorus loading
• 74% reduction in phosphorus in the water column
• 65% reduction in chlorophyll (a measure of the
  amount of algae)
• 134% increase in water clarity

Click here to view a published scientific article documenting the effectiveness of alum.

Click here to view Freshwater’s presentation on lake water quality problems and solutions.