EPA Survey Shows Over Half of US Streams and Rivers Are in Poor Condition

Posted March 28th, 2013
Environmental

EPA’s Comprehensive Survey Finds Little Positive About the Condition of America’s Rivers and Streams

The Environmental Protection Agency (EPA) released the results of the first comprehensive survey looking at the health of thousands of stream and river miles across the country, finding that over half — 55 percent — are in poor condition for aquatic life.

“The health of our Nation’s rivers, lakes, bays and coastal waters depends on the vast network of streams where they begin, and this new science shows that America’s streams and rivers are under significant pressure,” said Office of Water Acting Assistant Administrator Nancy Stoner. “We must continue to invest in protecting and restoring our nation’s streams and rivers as they are vital sources of our drinking water, provide many recreational opportunities and play a critical role in the economy.”

The 2008-2009 National Rivers and Stream Assessment reflects the most recent data available, and is part of EPA’s expanded effort to monitor waterways in the U.S. and gather scientific data on the condition of the Nation’s water resources, stated the release.

Findings of the assessment include:

– Nitrogen and phosphorus are at excessive levels. Twenty-seven percent of the nation’s rivers and streams have excessive levels of nitrogen, and 40 percent have high levels of phosphorus. Too much nitrogen and phosphorus in the water—known as nutrient pollution—causes significant increases in algae, which harms water quality, food resources and habitats, and decreases the oxygen that fish and other aquatic life need to survive. Nutrient pollution has impacted many streams, rivers, lakes, bays and coastal waters for the past several decades, resulting in serious environmental and human health issues, and impacting the economy.

– Streams and rivers are at an increased risk due to decreased vegetation cover and increased human disturbance. These conditions can cause streams and rivers to be more vulnerable to flooding, erosion, and pollution. Vegetation along rivers and streams slows the flow of rainwater so it does not erode stream banks, removes pollutants carried by rainwater and helps maintain water temperatures that support healthy streams for aquatic life. Approximately 24 percent of the rivers and streams monitored were rated poor due to the loss of healthy vegetative cover.

– Increased bacteria levels. High bacteria levels were found in nine percent of stream and river miles making those waters potentially unsafe for swimming and other recreation. 

– Increased mercury levels. More than 13,000 miles of rivers have fish with mercury levels that may be unsafe for human consumption. For most people, the health risk from mercury by eating fish and shellfish is not a health concern, but some fish and shellfish contain higher levels of mercury that may harm an unborn baby or young child’s developing nervous system.

EPA plans to use this new data to inform decision making about addressing critical needs around the country for rivers, streams, and other waterbodies. This comprehensive survey will also help develop improvements to monitoring these rivers and streams across jurisdictional boundaries and enhance the ability of states and tribes to assess and manage water quality to help protect our water, aquatic life, and human health. Results are available for a dozen geographic and ecological regions of the country.

Read the entire press release here.

Coal-Fired Power Plants Are One of the Worst Water Polluters

Posted March 28th, 2013
Environmental

The EPA Must Protect Our Water From Coal Pollution

by Mary Anne Hitt

Water News in a Nutshell.

 

In a Nutshell: We think of coal-fired power plants as one of our worst air polluters.  They are, but what isn’t so widely known is that they are also one of our worst water polluters. They dump more toxins into US lakes and rivers than any other industry, and a 28% increase is expected over the next 15 years.

Here’s a pretty shocking fact: While many of us know that coal-fired power plants create significant air pollution, it turns out they’re one of our biggest water polluters, too. In fact, as we’ve developed technologies that take more toxins like mercury out of coal plant smokestacks, that pollution isn’t just disappearing. Much of it is ending up in the water, instead, and those pollution levels are on the rise. Fortunately, our Environmental Protection Agency can do something about it.

That’s right – the same power plants that are causing asthma and heart attacks with their soot and wrecking our climate with their carbon are also dumping tons of toxins into our waters. And without federal standards to safeguard our water, those plants will keep on sending toxic sludge into rivers and streams, where it threatens swimmers and boaters and anglers, poisons wildlife, wrecks ecosystems, and could even contaminate drinking water. The fouled waters pouring from coal plants are laced with arsenic, mercury, and selenium: toxins that build up in ecosystems and that are dangerous even in very small amounts.

If you’re a parent like me who loves to watch your child play in the local stream or lake, this information is infuriating and scary. The same goes if you’re a wildlife lover, or some who just enjoys the outdoors and believes our waterways should remain pristine.

Believe it or not, power plants dump more toxins into our rivers and streams than any other industry in the United States, including the chemical, plastic, and paint manufacturing industries. Your drinking water should be safe, because our cities and towns do a good job of filtering and cleaning it, but those in rural areas who rely on wells don’t have as much protection. Plus, our waterways, wildlife and ecosystems aren’t so lucky. Coal plants have caused nasty fish kills and their poison builds up in fishing lakes and reservoirs.

The problem’s only getting worse as coal plants get older. The Environmental Protection Agency (EPA) estimates that the amount of toxic wastewater from these plants is going to increase 28% over the next 15 years. That means more heavy metals and more toxic sludge in more streams and rivers. More contaminated rivers, more unhealthy streams, more poisoned wildlife.

Thankfully the EPA and President Obama can protect our waterways from this toxic wastewater. The rules governing coal plant water pollution – known as effluent limitation guidelines – are more than thirty years old, and just don’t deal with most of the toxins these plants dump into our water. The good news is that EPA is now on track to propose a vitally needed update to those standards. The new safeguards are due out in mid-April – but the coal industry is already trying to block them. We need to tell the EPA and President Obama right now – before it’s too late – to give us safeguards against toxic wastewater.

Clean water is too precious to wait another day.

Enough is enough. We need these safeguards, and we ultimately need to move beyond coal. Every step we take toward clean air and water helps keep our communities and our environment healthy.

It also takes us one step closer to powering the U.S. with clean energy, as our nation realizes that coal’s real cost — in climate destruction, toxic water, and unhealthy air — is simply too high.

Source: Huffington Post.

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Water Treatment for Rainwater

Posted March 27th, 2013
Ultraviolet, Water Treatment 101

Rainwater Falls from the Sky, But It Must Be Purified For Drinking

As water becomes scarce, rainwater collection systems are becoming increasingly popular.

After water is collected and stored for later use, water treatment is essential. This usually takes the form of filtering out large particles then treating for microbiological safety. If the water is contaminated with chemicals from its collection process (for example, roofing materials if the water is collected from a roof), then a good carbon filter should be added to the treatment.

Filtering for sediment can be either with cartridge filters or, if there is a lot to be filtered out, a backwashing filter that filters down to 10 microns or so.

After elementary filtration to remove particulate, it is critical that some form of disinfection be used. This can be:

Chlorination, the old standby, followed by carbon filtration to remove the chlorine.

Ultraviolet (UV), which is probably the most popular single rainwater treatment. The water must be very clean when it passes the UV lamp to assure complete disinfection. UV has the advantage of adding no chemicals to the water. It should be the last stage in the treatment process.

Ozonation is an excellent disinfectant, but is a bit more challenging for the homeowner from the technical viewpoint.

Ultrafiltration (UF) is gaining popularity in rainwater treatment. UF filters down to about 0.02 microns—enough to remove cysts, bacteria and viruses. Again, water must be pre-filtered before the UF membrane to protect it from premature clogging of the ultrafiltration equipment.

Rainwater, with only the minimal treatment described above, can provide extremely good water. Its mineral content (TDS: Total Dissolved Solids) is very similar to that of reverse osmosis water.

Reference Source:  The Pure Water Occasional.

Modern Application of the Traditional Indian Water Wheel

Posted March 27th, 2013
Energy

The New Metal Gharat: A Simple Application of the Power of Water

A modern version of a traditional tool, the gharat, or small water-powered turbine, is part of an ecologically sustainable economic revolution that is taking place in some remote Indian villages in the Himalayas.

The traditional wooden water turbine, widely used at one time, has been on the decline because of its inefficiency and the cost of building and maintaining it.  Newer wheels, developed and popularized by a former botany professor named  Anil Joshi, have brought significant improvements to many remote areas of rural northern India.  Joshi launched a grass-roots movement to help Himalayan villagers stop using coal-intensive power and instead turn the region’s thousands of fast-flowing streams into personal mini hydro-electric power stations.

The new gharat, a water wheel with steel blades,  grinds grain, presses oil, and generates electricity for  remote villages where electricity is otherwise unavailable.  A single steel-bladed wheel can produce electricity at night for as many as 60 homes. Usually the small turbines are used to provide hydro power for small-scale industry by day and for generating electricity by night.

A Gharat in Action.


Water wheels are a centuries-old technology in the Himalayas, but one that was becoming obsolete until Joshi and an organization he founded three decades ago taught villagers to develop alternative livelihoods by modernizing the wheels and using them for traditional industry during the day and to provide electric power for village homes at night.

Improving the technology was key to Joshi’s strategy. The old water wheels were inefficient, taking a day to crush around 10 kilos (22 pounds) of wheat. Making a single wheel was a laborious process that required the wood from an entire pine or cedar tree. And environmental considerations had led to restrictions on tree-felling, which drove up the price of timber.

Joshi did much to improve the traditional gharats by fitting them with modern gears and ball bearings, but the main innovation was the introduction of steel for the turbine blades. Wooden wheels were liable to break when torrential monsoon rains washed rocks downstream, and repairing the blades was time-consuming and costly.

The most recent improvement has been the change to the horizontal turbine to replace the traditional vertical model.

Many of the hill streams which drive the small turbines come down with tremendous force and as much as 1/5 of the generative capability is lost by the crashing of the water into the turbine vertically. Much capacity is gained with the use of the horizontal turbine.

The redesigned gharat represents an exemplary use of simple resources to improve the world without destroying it. Using the free energy from the streams rather than diesel generators or nuclear power creates a clean, sustainable power source.

Reference: The Christian Science Monitor.

Wastewater Treatment Is the “Environmental Superhero” of Our Time

Posted March 26th, 2013
Environmental

Environmental Superhero: Why Wastewater Treatment is Coming to Our Rescue

Water News in a Nutshell.

 By John Wycliffe

In a Nutshell: Wastewater treatment is a positive environmental force for it not only makes useless water useful but it takes waste, pollution, and toxins out of the environment. 

Where does the ‘sewage’ or wastewater go once you flush, wash off vegetables for cooking, and drain the bathtub?  What are the implications of efficient treatment in creating a better society and healthy environments for people in the United Kingdom?  The environment is looked after and treated by an unlikely superhero, wastewater treatment and management.

Without proper address, contamination occurs, instigated by metals, rain pollutants, oils, and urban-area runoff.  The health of people and the integrity of the environment demand efficient treatment methods.

What is Wastewater?

Sewage is a mixture of water stemming from kitchens, bathrooms, and toilets, combined with wastewater coming from industrial entities and road run-offs.  Treatment entails less filtering (less than 0.1 percent of wastewater is solid) but demands great attention and meticulous regard to an assortment of methods.

The Need for Treatment

Untreated water causes great harm to the environment and its inhabitants.  Proper wastewater management:

  • Safeguards the ecosystem, ensuring water that finds nature’s plants and animals are not depleted of rich oxygen due to biodegradation
  • Protects the ecosystem from eutrophication, a negative result of an abundance of nutrients present in water
  • Addresses water-borne pathogens that pose risks to people using waters related to public activities, such as swimming and canoeing
  • Clears obstructions to sewage flow and litter that can impact the environment (riverbed debris pose a fire hazard)
  • Ensures hotels, resorts, and all public places are not influenced by poor smells and limited usage

Benefits of Wastewater Treatment

Types and direction of water treatment take various courses depending on specific environments and sought end outcomes that are sought.  Workers seek to rid sewage of solids, excessive nutrients, metals, and pathogens.  Without the aid of water treatment processes:

  • Toxic agents and chemicals would negatively affect the well-being of wildlife and humans
  • Waste would find way into river streams and larger bodies of water, harming animals, plants, and the ecosystem
  • Particular environments would not enjoy the replenishing arrangement of recycled waters, preserving the land and recreational activities sought
  • Sewer ‘sludge’ would accumulate, creating mass sickness, marring plants and animals.

    Wastewater Treatment Tanks

The Future of Water Waste Management

The United Kingdom’s future is aligned with proper, present choices.  Waste management officials call for the peoples’ help, an example being the ‘Love Your River’ campaign, directing attention to the link between river and surrounding habitat health, hoping people take better care of their local rivers and neighborhoods.

Additionally, the UK has enacted (FOG) fats, oils, and grease disposal processes, ensuring pubs and restaurants properly rid the environment of collections.  Otherwise, FOGs stick to pipes and tunnels, solidifying into entities that can potentially obstruct sewer passageways, creating social complications and costing governments and municipalities a lot of money to remedy.

The next time you take a shower, flush a toilet, or leave the sink faucet running, think about what it takes to ensure the water keeps flowing without affecting your health and that of others.  Moreover, cogitate on the commitment paid to ridding rivers and flowing water of sludge and sewage-related debris.  It’s easy to forget sewage and proper water management is a production of a structured society; a lot of energy and devotion is placed upon maintaining and improving that infrastructure.

Author John Wycliffe is a researcher with an extensive background in chemistry. Her articles mainly appear on environmental blogs where she enjoys sharing her findings. Visit the chlorine analyser link for more details.

Source: Green Building Elements.

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Alum (Aluminum Sulfate) in Drinking Water

Posted March 25th, 2013
Water and Health

 How Alum Is Used in Drinking Water Treatment, and What Are Alum’s Health Effects?

One of the first of the several steps that municipal water suppliers use to prepare water for distribution is getting it as clear and as particulate-free as possible.  To accomplish this, the water is treated with aluminum sulfate, commonly called alum, which serves as a flocculant.   Raw water often holds tiny suspended particles that are very difficult for a filter to catch.  Alum causes them to clump together so that they can settle out of the water or be easily trapped by a filter.  

Usually  a mixture of water with 48 percent filter alum  is injected into the raw incoming water at a rate of 18 to 24 parts per million. The alum promotes coagulation of fine particles which helps resolve problems of color as well a turbidity. If the process is given enough time to work and is applied properly, it not only corrects problems in the water but actually results in removing most of the aluminum used in the process.  

Although concern over the safety of treating water with aluminum has often been voiced, there is no evidence that aluminum in water, whether it comes from the aluminum sulfate used in treatment or from other sources, is a health issue. Actually, most aluminum that we take in does come from other sources.  One study showed that only between 0.4% and 1.0% of our lifetime intake of aluminum comes from alum used to prepare municipal water. Most aluminum intake is from aluminum that occurs naturally in foods, aluminum used in food packaging, and from products like deodorants and vaccines.

Water treatment for aluminum is normally not needed, but aluminum is easy to remove with reverse osmosis or distillation.

See also “Simple Facts about Aluminum.”

 

Will Texas Go Without Food To Keep Their St. Augustine Lawns?

Posted March 24th, 2013
Shortage

What Drought? Just Don’t Tread on Our Green Grass

by Ross Ramsey

Water News in a Nutshell.

 

In a Nutshell: In Texas there’s a serious drought in progress, but the lawns and the golf courses are still green,  There may soon be legal battles  over the right to keep thirsty St. Augustine grass, which many feel is guaranteed us by I’ve forgotten which amendment. 

 

In big Texas cities, the state’s water shortage can seem like someone else’s problem.

Drought has been in the news a long time, but rates haven’t gone up. Water still comes out when you turn on the tap. The golf courses are still green, and so are the lawns.

Some places do have restrictions; the state keeps a long list of them. El Paso residents pay fines if the sprinklers in their front yards accidentally water the streets. Austin restricts watering to one or two days per week, depending on the level of concern over water at any given time. West Texas towns and cities operate at high levels of alert, and one medium-size city, Wichita Falls, is on a list of cities that could run out of water this year.

In the suburbs, where a lot of voters live in houses encircled by grass, and where that grass is sometimes a measure of how well or how poorly the Joneses are doing, water restrictions are a touchy subject.

Which brings us to the Battle of St. Augustine.

At some point, the realities of water in Texas will reach a point where it is impossible to lay all of the drought’s harm on someone else. Lawns — and whether to keep them in the face of a protracted water shortage — come into the argument.

Wichita Falls, home to more than 100,000 people, is on the state’s list of communities that could be without water in 180 days. Watering is restricted to once a week, and it could be tightened if things don’t improve quickly. The next level, Stage 4, would be a ban on outside watering, on filling pools and, perhaps, on industrial uses of water.

Lawns surround voters, some of whom believe the lush patches of St. Augustine grass around their noble homesteads are a God-given right, or at least an unassailable perk of owning homes in the blessed state of Texas. Threatening those lawns could make a populist issue — a loud and unstable political problem — out of the state’s water shortage.

West Texans live in the brown part of the state, where the vegetation is thin and the expectations for green landscaping are modest. But the water trouble has reached the suburbs, as have the politics.

The Texas Senate has started work on legislation that would allow a homeowner to switch to native grasses without legal retribution from their homeowners’ association.

Those associations, baked into real estate covenants when people buy homes in some areas, are set up to protect everyone’s interests against neighbors who let their properties go.

All sorts of things are prohibited, depending on the contract: weeds and overgrown plants, cracked paint, chickens, metal roofs, perpetual garage sales and, in some cases, lawns that are anything but green, well-trimmed carpets of grass.

Native grasses are tough. They use less water. They have smaller blades. They can handle summer heat. They are, in other words, adapted to Texas.

Also, they are not as socially acceptable as popular grasses, like the St. Augustine used in yards throughout the state. That grass is pretty, green, soft and thirsty.

New development is part of the problem. While new homes get more energy-efficient every year, they get less and less water-efficient, according to Luke Metzger of the advocacy organization Environment Texas. “They actually use more water,” he said.

Mr. Metzger’s group wants some of the focus that is currently on building reservoirs shifted to conservation.

Lawns aren’t the only problem with water, or even the biggest one. They are politically interesting, though, and hazardous for the average legislator or policy maker.

Lawns are at the bottom of what Tom Harrison, who is in the water business and is a director of the Central Texas Water Coalition, compares to a drug addiction, linking the Colorado River in the Texas Hill Country — where people are being asked to conserve water — to downriver on the Texas Gulf Coast — where grass for their lawns is grown.

“The sod and turf farms down there pull the same water the rice farmers use,” Mr. Harrison said. “They grow the grass there with free Colorado River water and sell it to us, and then tell us not to water it. Things like that just don’t make sense.”

Source: NY Times. 

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World Water Day Message: $25 Just Won’t Do It

Posted March 22nd, 2013
Water Issues

 Moving Beyond Basic Water Advocacy

Water News in a Nutshell.

 by Ned Breslin

In a Nutshell: The message for World Water Day is that we must move beyond the notion that sending $25 to buy a village water pump isn’t going to solve the world’s water problems of the billion inhabitants of  the planet who lack access to adequate water.

March 22nd is a noisy day across the water and sanitation sector. It’s World Water Day, and agencies working to end the global water crisis use this day to overwhelm the public, funders, and policymakers with messages related to water. The goals of this advocacy push are to raise awareness, convince people that water is essential for broad social and economic development, and ideally drive people, policymakers, and funders to engage with the water crisis.

The tactics often used on March 22nd (and throughout the year) walk a fine line and highlight real marketing and fundraising tensions among water sector professionals. Unfortunately, it is these tactics that may eventually undermine the cause we all desperately want to address.

Let’s start with the basic “water crisis story” you have inevitably heard many times and will undoubtedly hear again this World Water Day. The story goes something like this: A girl in torn, dirty clothes walks miles and miles to fetch water from a disgustingly polluted water source, treks back with a huge bucket of water on her head, and misses school. Some will add that the girl is under threat from robbers and rapists on this journey, and others will

Women Carrying Water from a Community Tap in Cherrapunji.

use this foundational story to talk about the health problems the family will face because they drink polluted water.We all know this story and in truth, many aspects are accurate. I have taken this walk with girls for close to three decades, and it’s a miserable trek. Good friends of my daughters (who were born and raised in rural Africa) do in fact miss a considerable amount of school doing chores such as fetching water. The impact of this tragedy on girls, on families, and on societies as a whole is significant.

This story is generally followed by facts and data that try to bring the wider global crisis into view through the lens of the girl fetching water. You’ve likely heard organizations estimate that 780 million people worldwide lack access to water. Interestingly, there is a debate about this number, with new reports estimating that the figure is closer to 1.8 billion people without access to water. Others look toward the economic case, and point to losses in GDP and productivity directly correlated to poor water supply. Still others will rightly point to the deaths directly attributed to poor water supplies, effecting mostly children.

The story ends, and that’s when we as a sector get lazy. The solution to the water crisis is presented as uncomplicated and cheap. We still peddle simple “projects” as the solution. The equation here is simple:

Girl does not have water + polluted water is bad for health and development = Fund a water pump and her whole life will be changed forever.

It is literally presented that simply by both large and small agencies.

Then we say it will be cheap. The math here is equally straightforward:

Girl does not have water + water is key for economic development and health + project is needed = You pay $25 for a solution.

Claims that “$25 saves a life” ring far and wide despite the clear evidence from annual reports and financial records that $25 does not even remotely cover an organization’s costs to deliver water to a girl, let alone ensure that it lasts for a lifetime.

It’s here that marketing and fundraising cross the barrier from advocacy and education to borderline dishonesty, making it incredibly challenging to communicate and market both the crisis and the real solutions.

The saddest part of each walk I take with a girl collecting water is when we pass not only the school she is not attending, but also a broken water pump. The system was indubitably installed with the best intentions but not the impact promised by the organizations promoting cheap solutions. Getting water supply “right” is a long-term process requiring engagement well beyond laying pipes, installing taps, and taking photos of happy children. These things are important, but there is much more work to do from that point.

Everyone in the sector knows it’s more costly than commonly sold, takes more time than a simple project cycle and a bit of training, and requires a more nuanced yet compelling tale that moves us from the simplistic notion that solving the global water crisis is cheap and easy. Because the one thing we as a sector know is that while this sales pitch is compelling and has kept money flowing to support water supply, it has sadly not kept water flowing. And that is no longer good enough.

The real story for World Water Day is this: If we truly want to get girls in school and give them a chance in life, then we must create an environment where water always flows—not just temporarily, but forever. Water can’t be seen as exceptional; it must be expected. To succeed and ensure that water flows, we must focus not only on infrastructure such as water pumps, but also on ongoing monitoring and regulation, finance, water resources, supply chains, good governance, replacement equipment, and services to expand systems as the need grows.

And, as we all know, $25 can’t cover it.

Ned Breslin is chief executive officer of Water For People, an international nonprofit that supports the development of locally sustainable water, sanitation, and hygiene education programs in developing countries. He received the Skoll Award for Social Entrepreneurship in 2011.

Reference: Stanford Social Innovation Review.

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The US Is Getting Rid of Its Dams

Posted March 21st, 2013
Dams, Environmental

Sixty-Five Dams Were Removed from American Rivers in 2012

Water News in a Nutshell.

 In a Nutshell: America’s rivers are cluttered with obsolete dams.  Programs led by American Rivers in partnership with other non-profit and government agencies are steadily working to get them removed.  In 2012 65 more old dams were taken down.

In line with a strong trend away from dams,  communities in 19 states, working in partnership with non-profit organizations and state and federal agencies, removed 65 US dams in 2012.

Dams were removed from rivers in California, Connecticut, Georgia, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oregon, Pennsylvania, Vermont, Washington and Wisconsin  In total, the dam removal project restored 400 miles of streams for the benefit of fish, wildlife and people across the country.

Nearly 1,100 dams that have been removed across the country since 1912. Nearly 800 were removed in the past 20 years. American Rivers is the only organization maintaining a record of dam removals in the United States and uses the information to communicate the benefits of dam removal, which include restoring river health and clean water, revitalizing fish and wildlife, improving public safety and recreation, and enhancing local economies.

Removing a dam from a creek in North Carolina.

American Rivers is the leading organization working to protect and restore the nation’s rivers and streams. “The river restoration movement in our country is stronger than ever. Communities nationwide are removing outdated dams because they recognize that a healthy, free-flowing river is a tremendous asset,” said Bob Irvin, President of American Rivers.The top three states for river restoration through dam removal in 2012 are:1. Pennsylvania – 13 dams removed

2. Massachusetts – 9 dams removed

3. Oregon – 8 dams removed

The complete list of dam removals in 2012 is available at http://www.americanrivers.org/2012damremovals.

 

Source Reference: Water Efficiency

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Water and Sinkholes

Posted March 20th, 2013
Environmental, Shortage

Unseen Connections

by Janice Kaspersen,  Editor,  Stormwater

Water News in a Nutshell.

 

In a Nutshell:  The strange, frightening and sometimes tragic phenomena called sinkholes, aka sinks, snake holes, swallow holes, dolines, and more, are natural depressions or holes in the Earth’s surface whose causes are shadowy and  whose occurrence is usually unexpected. They are closely related to water and its mysterious ways.

Sinkholes are in the news these days, both for their sudden and frightening appearances and for the implications they have for surface- and groundwater quality.   This article from the New Yorker has a detailed and fascinating history of how and where they occur. It recounts, among other events, the 1999 disappearance of Florida’s Lake Jackson; the 4,000-acre lake emptied “like a bathtub emptying into a drain,” although the drain in this case was an 8-foot-wide sinkhole. Sometimes the lake would partially refill as water cam back up through the hole.

Where did the water go? And where was it returning from when it refilled the lakebed? The vast underground limestone caverns that underlie Florida and parts of several other states.

A famous sinkhole in Belize.

A sinkhole is what happens when a breach occurs between the underground realm and the surface—as it did in Lake Jackson, as it did several weeks ago underneath a house in a Tampa suburb, and as it does in hundreds of other cases, large and small, wherever such karst topography exists. The occurrence of sinkholes can be exacerbated by too much water—they tend to open more frequently during tropical storms, for example—as well as by too little water. In 2010, heavy irrigation (actually, the constant spraying of water on strawberry crops to keep them from freezing during a cold snap) lowered the water table in an area near Tampa by 60 feet in a week, and 140 sinkholes appeared.The porosity of the underground terrain, and the free movement of water through it, has some serious implications for water quality. Something that infiltrates the ground in one place can show up miles away.  This article from Stormwater describes how the process works in West Virginia and how the Department of Agriculture monitors water quality there, in part to gauge what effect farming operations and crop fertilization are having on the water supply.) Urban pollutants in stormwater runoff are entering the aquifer, too. The New Yorker article says that Tallahassee used to recycle its treated wastewater by using it for farm irrigation, until it discovered several years ago that doing so was causing elevated nitrogen levels far to the south, in the Wakulla River, where no one had expected the irrigation to have an effect. The nutrients reach the river through the ground. Florida’s Department of Environmental Protection has taken to injecting dye into some sinkholes—much the same procedure, on a larger scale, that we use to detect illicit storm sewer connections—and seeing where it shows up downstream.

Source:  Stormwater

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