Indiana officials regularly test the state's waters for blue green algae so they can warn people of possible harmful algal blooms like the one that recently left Toledo residents without drinking water for several days.
But how and where where is test depends on several factors. Here's a look at how it works:
What Causes Algal Blooms
On a recent weekday at an Indiana Department of Environmental Management lab in Indianapolis, workers test water samples for high concentrations of cyanobacteria-also known as blue-green algae.
Most of the tests this year show low concentrations that occur naturally. That's because of the relatively cool weather compared to previous years.
"I can tell you that during our two drought years-the official drought, which was in 2012 and the very dry summer that we had in 2013, we saw number's skyrocket," says IDEM water quality section chief Cyndi Wagner. That's just because we've got really warm water and because we haven't had any rain we've concentrated the nutrients and the algae are just really really happy."
A large portion of those nutrients comes from farms that use phosphorus and nitrogen as fertilizers that then get washed downstream into rivers and lakes like Lake Monroe. The algae use those nutrients to grow rapidly and if they get too highly concentrated, they can be toxic.
They can cause major health problems if swallowed and rashes if exposed to the skin.
Martha Miller, the district manager for the Monroe County Soil and Water Conservation District, says it would be better for everyone if all contaminants were left out of the water altogether.
"But more than anything they cost us a lot of money because they have to be removed from the water system before it can be drinkable again," Miller says. "The impurities that we add into the water actually end up costing us more in the long run than if we would just not put them in in the first place."
What Happens If There Is A Bloom
Since 2010, IDEM has been monitoring state-owned recreational areas and will close down sites if the algae levels get too high.
There are three levels.
The first triggers a warning to people who swim in the water, instructing them to take a shower afterward to remove any algae that's left on their skin.
At the second level, IDEM officials warn vulnerable people such as the elderly, children and pregnant women not to get in the water.
If blue-green algae reaches the highest level, IDEM closes down the affected area. Wagner says IDEM has never issued that alert.
But IDEM does not monitor drinking water, and utility companies are not required to monitor algae levels in drinking water.
Still, some groups such as Citizens Energy Group do regularly test for blue-green algae.
"If one of our sources of water were to be impacted, we have the ability to treat the water and shift load to another source of supply, if necessary," Jeff Willman, Executive Director Water Operations, said a statement released earlier this week.
IDEM officials say Monroe County's utilities, which get their water from Monroe Lake do not typically test for blue-green algae, but this week, they did ask IDEM for their samples, which were being taken because Monroe Lake is also a recreation area.
Testing Groundwater
But Monroe County is unique in that much of the state does not get its drinking water from surface water such as lakes, but from water under the ground, which is less susceptible to algal blooms.
That is, in part, why IDEM is trying to create a database of groundwater quality in the state.
The Ground Water Monitoring Network tests hundreds of water samples from around the state for pesticides, nitrates and other chemicals.
"So we have an idea of what areas have problems potentially and what kind of treatment might need to be done in those areas and just overall give them a report card of groundwater overall in the state," IDEM spokesman Dan Goldblatt says.
IDEM says many residents have volunteered to let IDEM test their wells, but the department still needs more information for Monroe, Lawrence, Greene, Sullivan, and Dubois counties.
Monroe County Soil and Water Conservation District's Martha Miller says routine tests, such as the kind the Ground Water Monitoring Network conducts, are important when it comes to identifying dangerous contaminants that might affect water supplies.
"Contaminants can be anything from oil and gas and debris that we leave on the roads from our cars that need to be fixed to soap suds from when we wash our cars and they go straight into a storm drain, could be fertilizer from your yard," she says.
Miller says it is important to remember all water systems are connected.
