Algae growth in our lakes and reservoirs can really explode when weather conditions are primed just right. Warm temperatures and low turbidity create the perfect breeding ground for the photosynthetic bacteria all over the country.

Here in Indiana, the algae bloom season usually lasts from May to October. Dry days and excessive amounts of fertilizer runoff encourage new algae growth all summer long. So once August rolls around, our water supplies are usually right in the thick of it.

About Blue-Green Algae

The cyanobacteria that flourish this time of year are commonly referred to as blue-green algae. When their levels are high, they can make floating layer of scum or film on a water body’s surface. As the name suggests, the algae colors can range from green to blue. They might even be a mix of brown, reddish-purple, or white depending on the algae type.

Of all the different blue-green varieties, about one-third of cyanobacteria can be toxic. (Kind of important to know before you dive into any algae lake water!) The algal toxins microcystin and cylindrospermopsin have certain, specific health concerns for recreational waters because people can exposed to them while swimming, motor boating, or water skiing.

Contact with contaminated water (or accidentally swallowing it) can cause rashes and irritate the skin and eyes. In some cases, exposure can even result in stomach aches, nausea, or a tingling feeling in fingers and toes. That’s why the Indiana Department of Environmental Management (IDEM) takes samples from certain water bodies to alert us to the possible algae risks.

Every year, state parks and other state water recreation areas are tested to make sure the cyanobacteria and cyanotoxin counts remain relatively low. Indiana currently follows the recreational water guidelines set by the World Health Organization. (The EPA plans to release their own set of Ambient Water Quality Criteria for cyanotoxins in Fall 2016.) When cyanotoxin risks start to increase, the park will post warnings and limit access. The Indiana Department of Natural Resources (DNR) also lists the current Recreation Advisory and sampling results on their website.

Algae in Drinking Water Supplies

Even at “low counts,” it’s important to realize that algae growth can still have some significant impacts on local water supplies—especially those that are used as drinking water sources. In Central Indiana, some of those main water supplies include Geist Reservoir, Morse Reservoir, and Eagle Creek Reservoir. Because these surface water sources are susceptible to blue-green algae, Citizens Water takes samples on a weekly basis. This informs the treatment plants about the source water quality, so they can take the appropriate measures to clean it during the treatment process.

Unfortunately, the effects of algae often remain in our tap water long after treatment. Sure, the process is designed to make the water safe enough to drink (by the Safe Drinking Water Act standards), but it can’t always remove the foul tastes and odors left behind by algae blooms. If the source water has blue-green algae, it tends to have an earthy or musty smell. So while the tap water might be considered “safe” for consumption, the smelly water can still be very unpleasant to drink.

For the full water treatment and cleaning process, many families opt for in-home filtration. Taste and odor aren’t mandatory water quality features for city treatment. So as long as the water source toxins are removed, the tap water is considered good enough—even if it’s smelly! Homeowners who prefer to have odorless, clean-tasting water tend to go with in-home water filtration. It’s the best way to get safe drinking water that meets your own high-quality standards.

Managing Algae Blooms

There’s plenty we can do at home to curb new algae growth in the years ahead. Simple steps can reduce the amount of phosphorus runoff to our water supplies. This helps keep excessive blue-green algae growth to a minimum.

Limiting home fertilizer usage (or stopping to use it altogether) can greatly reduce the influx of nutrients our waterways get every summer. If you are using fertilizers, it’s best to choose a phosphorus-free fertilizer. Look for bags with a zero (0) as the middle number on the nutrient content label—that’s how you’ll know it’s phosphorus-free.

All over the country, the more we can prevent algae blooms, the better off of our water supplies will be. On a local scale, Indiana has recently awarded nearly $1.3 million in grants to 33 different water projects all throughout the state. It’s all thanks to the DNR’s Lake and River Enhancement (LARE) program. A grand total of 36 lakes and streams will be impacted, and several of them are specifically concerned with reducing nutrient runoff. Fingers crossed that we can keep this algae problem down in the upcoming years!