On the weekends, thousands of us retreat to the various lakes surrounding our city to cool off. Lounging on boats, kayaks, tubes, noodles or anything that floats is our opportunity to find some relief from the triple digit temperatures. Lakes across the country are used for recreation use, as well as water supply. The average American uses about 80-100 gallons of water per day and some estimates go as high as 500 gallons per day. From washing dishes to watering plants, we use a lot of water, and what if the water was contaminated?
Last summer, the city of Toledo, Ohio was forced to ban the drinking of their tap water, affecting more than 400,000 residents. People drove miles to nearby towns emptying stores of bottle water. The cause of the ban on tap water was a toxin produced by an algae bloom. Late summer is the time of year when conditions are warm enough to create algae blooms even in our very own North Texas lakes. Some people in the DFW area notice a change in the taste of water this time of year. North Texas Municipal Water District has an entire web page focusing on the taste issue. “The taste and odor is a palatability issue. The palatability change that results from a naturally occurring algal bloom does not alter the quality of the water provided to the cities and the communities served.”
Algae blooms are natural, but our human activities have caused an increase in their strength leading to problems. In Toledo, the intense algae bloom was caused by the subtle effects of climate change, such as increase in rainfall, less wind and invasive species. Algae blooms intensify from an influx of enriched nutrients in fertilizers and phosphorous applied to farmlands, which flow into warm lake water. Harmful algae blooms can have various impacts on freshwater and marine ecosystems and have led to fish kills: large numbers of dead fish or marine life washed up on lake shores. In Lake Erie, near Toledo, the algae bloom produced a high level of a toxin, microcystin in the water, making it harmful for consumption.
Algae blooms in our North Texas lakes are common and haven’t reached a level to cause major damage … yet. Cities around the country are keeping a close eye on their local water supplies to monitor the algae blooms. Some cities are even taking extreme measures to maintain water quality. This past week in Los Angeles, city officials released “shade balls” destined to float on the top of lakes to block sunlight and protect area lakes from harmful algae blooms and lessen evaporation. The plastic balls will hopefully save 300 million gallons of water, are BPA free and said to have a life span of 10 years after which they will be recycled and replaced. Algae blooms are in the news right now across the country from the east coast to the west where one of the largest blooms spans 40 miles wide along the coast from California to Alaska.
So how do we reduce the harmful algae blooms? Attack the problem from the source: excess nutrient runoff. The U.S. Department of Agriculture recently said it would invest an additional $5 million in a project designed to reduce phosphorus runoff from farm fields. Cities also contribute to phosphorous runoff through lawn fertilizers. When it rains, fertilizers meant for yards and building landscapes rush onto the impervious surfaces (roads, sidewalks, parking lots) and wash into storm drains. Storm drains here in Dallas lead to our south side water treatment plant and then back into the Trinity River. We may not see that water again but the people downstream will. We need to care for our watershed, just as we hope the people upstream from us care for theirs.
An easy way to help maintain our water quality and the marine ecosystem is don’t feed the algae, meaning switch to a phosphorous free fertilizer, soaps and household cleaners. This past weekend I kayaked and swam in Tyler State Park Lake about an hour and a half east of the city. If algae blooms ravage our local lakes not only does it affect our water quality, it means we can’t continue to cool off in them either.
As seen in the Katy Trail Weekly.