Keeping algae blooms at bay

Aug. 25, 2014 @ 02:09 PM

What’s blue and green and slimy all over? The small but mighty Cyanobacteria, also known as blue-green algae.

These single-celled organisms brought national attention to the city of Toledo, Ohio, after residents were told to avoid the drinking water for several days earlier this month. Toxic blue-green algae in Lake Erie made the water unsafe for drinking, cooking, and washing.

Not all algae are blue-green algae, and not all blue-green algae form toxins. However, blooms from other types of algae can still occur in our water. Algal blooms can cause problems for swimming, drinking water treatment, fish and wildlife. The man-made lakes in our area are shallow, so they warm up quickly and allow light to move through the water. Add in excess nitrogen and phosphorus, and these are ideal conditions for blooms.

The City of Durham routinely tests the drinking water supply and has not found unsafe levels of the toxin-causing algae that were found in Toledo. And while there are many differences between the causes of Toledo’s water crisis and what is happening with nutrient pollution in our area, this should serve as a valuable lesson on the long-term consequences of allowing excess nutrients into our water. Laws require local governments to clean up nutrient sources, but residents and businesses can take steps to help out as well.

Fertilizing our water?

Major culprits in algal blooms often include fertilized farm fields, lawns and impervious surfaces. One of the ways that nutrients enter lakes in our area is stormwater runoff. While you may not own a farm, simply reducing the amount of fertilizer you use on your lawn can help keep nutrients out of our waterways. Have your soil tested for free to find out what type of fertilizer you need, or if you need any at all. Free test kits are available at Durham County Cooperative Extension. Look for phosphorus-free fertilizer, which you can identify by looking at the three numbers on the container. The middle number should read “0.” Contact Durham County Soil and Water Conservation District to take a pledge to reduce home fertilizer use.

Keep it neat. Leaves and grass off the street!

Grass and leaves act as natural fertilizers when they break down. On our lawns, this can be a good thing. In our waterways, this can contribute to algal blooms. You can do your part by making sure that leaves and grass clippings do not get left in the streets or on sidewalks after yard work is done. If you use a landscaper, let them know that you expect them to keep it neat also. Pass it on to your neighbors that grass clippings on the sidewalks and road are not only unsightly, but increase nutrients in stormwater runoff to our waterways.

Scoop the poop

Dog waste not only contains nutrients, but it also contains bacteria and parasites that can make us sick if the waste ends up in our water. Because of what dogs eat, dog waste by itself does not break down into natural fertilizer like cow manure. A great way to keep nutrients and other harmful things out of the water supply is to scoop, bag and can the poop.

Lesson learned?

The fact is that two of the area’s drinking water supplies, Jordan and Falls lake, are polluted from too many nutrients. As water supply issues continue to make headlines across the country, our lesson is to take responsibility now. To read more about what the City of Durham is doing to reduce nutrients and other pollutants in our water, please visit our website listed below.

 About the Public Works Department Stormwater and GIS Services Division

Emily Rhode is pollution prevention coordinator in the Stormwater and GIS Services Division of the City of Durham’s Public Works Department. The division is guided by the City’s strategic plan goals of stewardship of the City’s physical assets and well-managed city. Activities include storm drainage design and plans review; inspecting and maintaining city-owned drainage systems; enforcing stormwater ordinances and regulations; education and outreach; stream monitoring, restoration, and watershed master planning; maintaining multiple layers of the City’s geographic information system; and stormwater billing. To learn more, visit and, “like” on Facebook at and follow on Twitter @DurhamStormH2O.