If your shoreline neighborhood is anything like mine, July 4th and your favorite lake go together like baseball and apple pie.  Setting off fireworks along the shoreline is a ritual in my neighborhood every July 4th.  It goes something like this...

On July 3rd, all the neighborhood dads pool their money together and buy a truckload full of fireworks from the local retailer—sparklers, black snakes, ground spinners, smoke bombs, pinwheels, screamers, fountains, bottle rockets, sky rockets, roman candles—practically one of everything the store is selling that year.  The dads then spend the morning of the 4th painstakingly rigging up the explosives along the beach, trying to recount the arrangement from the previous year while contemplating how to “make it even better” this year so that they can be sure to win the competition for most impressive (and loudest!) display with the neighborhood across the cove.  The afternoon is spent moving boats to “safe” locations and, as dusk approaches, as if by magic, a ring of brightly illuminated flares outlines the curvy shoreline.  Soon the show begins—and so does the polluting of the lake.  

Fireworks pollute our lakes.
It wasn’t until recently that I learned exactly how fireworks pollute the lake.  Of course I remember spending many mornings after July 4th picking up the refuse strewn across the beach from the dazzling pyrotechnic display the night before—small bits of brown cardboard tubes partially blackened by soot, plastic caps and cylinders of all shapes and sizes and in various stages of being melted, and thin metal rods burnt to a crisp. During the next week or two, I would find more bits of refuse in the lake while snorkeling around searching for critters.  But, I never realized what else, besides litter, our firework fun was contributing to our lake.

Fireworks are composed of many different elements and each element contributes to the propellant, color or sound of the display. Not surprisingly, some of these elements are dangerous and even toxic to human health.  What I didn’t know is that fireworks often contain trace amounts of phosphorus—the element that aquatic plants and algae in our lakes need to grow.  While each individual firework may contain only a small amount of phosphorus, every little bit of phosphorus added by humans into a lake, whether it is from fertilizers, detergents, septic systems, and, yes, even fireworks, adds to the problems associated with “phosphorus pollution” in our lakes.  And, just think of all the fireworks that each shoreline neighborhood may shoot out over their lake throughout an entire summer.  All the phosphorus from each of the thousands of individual fireworks shot over your favorite lake this summer could become a significant source of pollution!

Phosphorus pollution hurts our lakes and our wallets.
Too much phosphorus accelerates the natural aging process of a lake, and can result in unsightly and smelly algal blooms and even toxic bacterial blooms!  (You may have heard that toxic cyanobacteria blooms have already occurred in a few New Hampshire lakes this summer.)  When algal and cyanobacteria blooms decompose, the oxygen in the lake can be used up, causing fish and other aquatic organisms that rely on this vital compound to perish. 

Not only do algal and cyanobacteria blooms negatively affect the lake ecosystem, these types of blooms can also result in economic problems for lakeside communities.  Algal and cyanobacteria blooms can cause taste and odor problems in drinking water which results in increased water treatment costs, decreased shoreline property values which negatively affects the local economy (and, as a result, may cause the property taxes on non-shoreline properties in the community to increase!) and negatively affects tourism. 

You can enjoy fireworks and protect your lake!
Being the lake-protectionist that I am, as soon as I found out about the detrimental impact that fireworks can have on our lake, I have been trying to convince my shoreline neighbors to ban the annual event. Not surprisingly, old habits die hard, and my neighbors continue to carry on the tradition, but it has changed, just a bit.  Now, instead of shooting off the display over the lake, the rockets and missiles are aimed away from the lake.  And, while the flares are still placed around the shoreline as dusk nears, they are now placed a few feet back from the water’s edge and a metal pan is placed below to catch the ashes. 

Yes, my neighbors still enjoy the firework display on July 4th, but I’d like to think that perhaps we all enjoy the tradition a little bit more now that we know we are making efforts to protect the lake while appreciating the beautiful spectacle.

For more information on the effects of fireworks on lakes, please visit the New Hampshire Department of Environmental Services’ website at des.nh.gov/organization/commissioner/pip/factsheets/bb/documents/bb-60.pdf.