Stormwater

Go With the Flow—Green Infrastructure in Your Neighborhood

By Chris Kloss

Ten years ago, we didn’t see much green infrastructure for water resources around our neighborhoods. It was more of a novelty than a focused approach to sustainable development and construction. A few cities started using and experimenting with green infrastructure techniques such as rain gardens, permeable pavement, and bioswales which are landscape elements designed to remove silt and pollution from surface runoff water. The green was a complement to the gray infrastructure, the established system of underground tunnels and sewers. Together, green and gray infrastructure provided a holistic approach to manage stormwater for cleaner water.

Tools, Strategies and Lessons Learned from EPA Green Infrastructure Assistance Projects booklet coverAs the word spread about the early successes of these communities, a growing cadre of public works pioneers joined the movement to apply its principles and techniques to managing their water resources. EPA joined in their discussions, providing support to these pioneers through our technical assistance program. Today, EPA is releasing a summary report of the results from this program that we hope leads to even greater growth in green infrastructure.

Tools, Strategies and Lessons Learned from EPA Green Infrastructure Assistance Projects 

Many of the green infrastructure thinking and practices we see today are not new. Gardens, rain barrels and permeable pavement were standard practices for harnessing and managing water hundreds of years ago. They were old-time technology that let water do what it naturally does —seep back into the earth where it can flow back naturally to streams and rivers, replenish groundwater, or be absorbed by plants and trees.

Communities are now relearning these techniques, and green infrastructure is working for communities across the urban spectrum, from smaller cities like Clarksville, Georgia to midsized, midwestern cities like Milwaukee, Wisconsin and large metropolitan regions like Los Angeles, California.

The summary document outlines how these and other community green infrastructure projects are successful. It also highlights benefits, offering examples for city managers to think creatively about how they can design their communities for better health, abundant water resources and improved quality of life.

We can all be part of better design for our communities. It just takes a different way of looking at things. When I’m out with my kids, I talk about how when it rains the water runs off streets, parking lots and other hard surfaces and flows down the stormwater drains into the sewer systems where it can’t be used for anything else. Now armed with the information, they’re always on the lookout for the missed opportunities in our neighborhood for letting the water go where it wants to, where it can do the most good for the watershed where they live.

I hope this report contributes to a movement where green infrastructure becomes standard practice. Every time we set out to design or build, repair or remodel our water systems let’s remember to think green infrastructure and let water do what it naturally does.

Learn more at www.epa.gov/greeninfrastructure and check out the 2016 Green Infrastructure Webcast Series for in-depth presentations throughout the year.

About the Author: Chris Kloss is Acting Chief of the Municipal Branch in EPA’s Office of Wastewater Management. The branch oversees the wet-weather permitting programs (stormwater, combined sewer systems, and sanitary sewer systems) and the green infrastructure program. Chris has nearly 20 years of experience in the clean water field including time in the private and nonprofit sectors prior to joining EPA.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Waterways, wetlands, and winter wonder

by Jennie Saxe

The Schuylkill Center’s Rain Yard.

The Schuylkill Center’s rain yard

It’s true: autumn is drawing to a close. But don’t let the thought of a deeper chill in the air keep you inside all winter long! There are still some great places that you can go to experience the outdoors and learn more about the waterways right here in the Philadelphia area.

In the hilly Roxborough section of the city, on the edge of the Schuylkill River, you’ll find The Schuylkill Center. A conservation and environmental education fixture for 50 years, The Schuylkill Center is a peaceful refuge in the middle of an urban area, with miles of hiking trails. In the center’s rain garden, you can simulate a rainy day by using a functional sculpture that pulls rainwater from the roof and directs it to different types of landcover – like asphalt, lawns, and meadows – to test the infiltration of stormwater runoff. If the cold air is just too much to handle, head inside to experience an art installation inspired by a pocket of marshy land in New Jersey’s Meadowlands. The natural cedar forest habitat of the area was destroyed, but it is evolving into a unique ecosystem, ringed by shopping centers with a world-famous skyline as its backdrop.

A view across the impoundment at America's First Urban Refuge.

A view across the impoundment at America’s First Urban Refuge

The John Heinz National Wildlife Refuge at Tinicum is another great waterside recreation spot for hikers, bikers, and dog-walkers. The tidal marshes and native plants at America’s First Urban Refuge are critical habitat for birds, fish, turtles, and more. The trail that circles the 145-acre impoundment offers many opportunities to spot flora and fauna in this rich habitat. The refuge is open year-round; even in December you’re likely to spot a variety of wildlife, while “birds” of a different kind take off from the airport, just a stone’s throw away.

And in the heart of Center City Philadelphia, take a stroll through Sister Cities Park. The design inspiration for this park came from the nearby Wissahickon Valley. Children and adults alike can climb a trail snaking along a miniature stream that is planted with native species. The park’s café is topped with a green roof that helps cool the building and soaks up rainwater.

Grab your gloves and lace up your boots – a winter wonderland of woods, wetlands, and waterways awaits!

 

About the author: Dr. Jennie Saxe joined EPA’s Mid-Atlantic Region in 2003 and works in the Water Protection Division on sustainability programs. The gallery show, Hackensack Dreaming, will be at The Schuylkill Center until December 19.

 

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Walk your waterway today!

by Virginia Thompson

A view from the trail, high above the Schuylkill River

A view from the trail, high above the Schuylkill River

There’s nothing better than going for a walk in the fall to take in the cool, crisp autumn air.  We are fortunate that Southeastern Pennsylvania has an abundance of trails along the region’s waterways that make it fun and easy to explore a wide variety of scenic, historic, and cultural resources.

Along the Schuylkill River, the Cynwyd Heritage Trail demonstrates that these trails offer more than waterfront recreation: they also provide economic development, opportunities for regional coordination, and improved air quality.  The recently opened Manayunk Bridge, connecting the Cynwyd Heritage Trail – an abandoned portion of a rail line – to the Manayunk section of Philadelphia, now offers residents in both areas easier access to restaurants, parks, shops, and services, along with a breathtaking view from high above the river.  What used to be an area of manufacturing on both sides of the Schuylkill River (including the road that would become the Schuylkill Expressway) has given way to growing communities of residents, recreational opportunities, restaurants, and more. A weekly farmers’ market is now located on the Cynwyd side of the bridge, accessible to both city and suburban residents. Interpretive signs along the trail provide photos and descriptions of the history and geography of the area with information from the Lower Merion Historical Society.  The trail even incorporates green infrastructure: the Pennsylvania Horticultural Society will plant a rain garden of native flowers and shrubs in a striking palette of colors to help prevent stormwater run-off.

The trail provides easy access to all of these amenities without use of a car!  Perfect for walkers, bikers, and strollers, the trail is such a direct path between Cynwyd and Manyunk that it is now shorter and easier to walk or bike than drive between the two areas. Less traffic means cleaner air. And as we’ve blogged before, cleaner air contributes to cleaner water, too.

The Cynwyd Heritage Trail is one of many that connect to a large regional trail network that is part of the East Coast Greenway. Many of the Pennsylvania segments of this trail network snake along waterways like Darby Creek, Cobbs Creek, and the Delaware River. As more trails are built and connect to this network, more travelers can choose to walk or bike, further reducing the number of automobile trips and helping to clean our air.

I am looking forward to more walks–in all seasons–to explore the rich trail system and the waterways of the Philadelphia area.

 

About the Author:  Virginia Thompson works at EPA Region 3 to help protect the natural resources of our country.  She enjoys walking and biking whenever and wherever she can.

 

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

What Do a Parking Lot, Stormwater Runoff and A Rain Garden Have In Common? Happy Plants and Healthy Streams

 

By Andre Bowser

Display explaining the rain garden at EPA’s Edison, NJ facility.

Display explaining the rain garden at EPA’s Edison, NJ facility.

On the surface, it appeared like an ordinary parking lot to me. But off to the sides, a lush wellspring of plants and flowers were bowing in the summer breeze.

Little did I know that it was the stage of a Rain Garden Demonstration Site at the U.S. Environmental Protection Agency’s Edison, N.J. installation. This of course is no secret; the EPA touts similar urban ecological models as a matter of good business, just as the Edison site had been oft-touted. But it was news to me – a newbie at EPA in New York.

During a recent summer business trip to Edison from my office in the Big Apple, I literally stumbled on a display that explained why a veritable garden surrounded the parking lot behind me. After tripping on the curb, I reached out and steadied myself on the fixture. I thought it odd that a museum-quality display would be positioned next to a nondescript parking lot.

The display detailed the multi-layered story of the parking lot behind me: how water runoff from rain is routed to nearby plants; how the gravel is waterproof to assist in efficiently shepherding the vital resource; and how the water ultimately ends up in our groundwater, underground wells and springs.   And then there’s the myriad technical benefits, such as helping EPA study “how rain gardens help mimic natural drainage processes” and how they reduce the amount of stormwater runoff that enters the storm sewage systems, according to the display. The site demonstrates how, by reducing the amount of stormwater through a natural filtration process, we reduce the amount of pollutants in our water.

Above all, it’s just plain beautiful. And that such an industrially driven edifice as a parking lot could act as a buoy for plant life – through a symbiotic relationship with nature – is ecological-poetic justice.

Rain water runoff is routed to nearby plants.

Rain water runoff is routed to nearby plants.

For the ingenuity and vision behind the site, the display gives the credit to “research efforts between EPA’s Office of Administration and Resources Management, Region 2, and the Office of Research and Development.” But let’s also give it up to the beautiful plant life at the site, including Red Maple and Dogwood trees; Switchgrass and Common Rush; Highbush, Blueberry and Beach Plum shrubs; Blue Flag, Sunflower and Golden Zizia herbs, among many others, which are all native to Mid-Atlantic rain gardens.

States like New York and New Jersey have long lauded the positive ecological effects of rain gardens. According to EPA’s New York-state counterpart, the Department of Environmental Conservation, “stormwater running off rooftops, sidewalks, driveways, and streets washes pollutants into nearby streams. As if that weren’t bad enough, as stormwater rushes over these hard-or impervious-surfaces, it picks up speed and force, causing local flooding and erosion.”  (Click on the link above to learn how to make a miniature rain garden.)

Back in Edison, N.J., the parking lot, stormwater runoff and rain garden are contributing to healthy plants, and that’s just the positive effect happening on the surface. Dig a little deeper, and you’ll find healthy groundwater finding its way to underground wells, and eventually streams.

About the Author: Andre Bowser is the director of the Public Affairs Division in EPA’s Region 2. Contact him by e-mailing bowser.andre@epa.gov.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Fresh and Clean, or Fresh and Green?

by Matt Colip

O Street NW, in DC, was revitalized to control stormwater  with 33 individual rain gardens built with native plants.

O Street NW, in DC, was revitalized to control stormwater with 33 individual rain gardens.

I’ve always enjoyed walking along new city streets.  The sidewalks are crisp and clean, free from chewing gum and spill marks.  There are no chassis-rattling potholes in the road.  It’s reminiscent of the new car feel, everything seems minted.

In Washington, D.C., and a growing number of communities in EPA’s Mid-Atlantic Region, residents and businesses are getting a bonus when it comes to new road construction – green features to control stormwater runoff.

The nation’s capital, like many older cities in the United States, is faced with the perpetual challenges of revitalizing streets and managing a combined sewer system that mixes stormwater and sewage into large underground pipes that feed the wastewater treatment plant.  The challenge for city governments is that residents want the fresh and clean feel on their streets, and a guarantee that their sewage will reach the treatment plant and not overflow into a river because too much stormwater has flooded the system.  To meet these demands, the District, under the leadership of Mayor Muriel Bowser, has chosen to build fresh and clean streets that are also fresh and “green.”

I accompanied our EPA Regional Administrator, Shawn M. Garvin, recently as he helped cut the ribbon for one of the District’s newest green street projects – this one along the 200 block of O Street NW, a street that has been closed to traffic since 1977.

In addition to integrating green infrastructure into street rehabilitation, the revitalized O Street now includes 33 individual rain gardens along the sidewalks that are landscaped with native plants. These rain gardens capture the runoff from an area 5,732 square feet in size – about 20% bigger than a standard basketball court – and keep the water out of the sewer system.  Rainwater and sewage that flows into this part of the District’s sewer system risks overflowing into the Anacostia River.  The more stormwater that is diverted from the combined sewer system, the less likely an overflow will occur into the river.

Not only does O Street now capture rainwater, it will have a new tree canopy from the trees planted street along its sidewalks.  These trees will also slurp up stormwater, keeping it from entering the sewer system, and eventually provide shaded areas.  This shade will reduce the heat island effect of the black asphalt.  Overall, the street looks great!

This work was funded in part through the U.S. Environmental Protection Agency’s Green Streets, Green Jobs, Green Towns (G3) initiative, a program administered by EPA and the Chesapeake Bay Trust. The green infrastructure approach of the partners in this project – the District’s Departments of Energy & Environment, Transportation, and General Services – supports the G3 program goals of improving water quality, community livability and economic vitality.

 

About the author: Matt Colip is a state and congressional liaison in the region’s Office of Communications and Government Relations. He previously worked in the region’s water programs, enforcing wastewater and stormwater regulations. In addition to SCUBA diving, Matt is an avid bicyclist and enjoys riding with friends and colleagues.

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Experience history and nature on rail-trails

by Virginia Thompson

A view from the Heritage Rail Trail County Park.

A view from the Heritage Rail Trail County Park.

My husband is a huge fan of biking on rail-trails created by the conversion of unused railroad rights-of-way.  Within the past year alone, he has ridden on many trails in the Philadelphia suburbs, as well as throughout the Mid-Atlantic states.  On a recent trip, we rode on two rail-trails in southcentral Pennsylvania.

The Heritage Rail Trail County Park in York County, recently ranked by the Rails-to-Trails Conservancy as the top rail-trail in the U.S. for American history, carried President Abraham Lincoln to Gettysburg for his famous address and also carried his funeral party to Springfield, Illinois, following his assassination.  The trail follows the South Branch of Codorus Creek, connecting the City of York and many small communities with beautifully restored train stations that now serve other purposes.  The trail, next to an active rail line, also continues across the Mason-Dixon line and connects with the Northern Central Rail Trail in Maryland.

The Safe Harbor Dam as seen from the Enola Low-Grade Trail

The Safe Harbor Dam as seen from the Enola Low-Grade Trail

Another trail we biked recently was in Lancaster County—the Enola Low-Grade Trail—which parallels the Susquehanna River as it approaches the Chesapeake Bay in Maryland.  One of the interesting facets of the trail is the juxtaposition of older and new forms of electric power.  On the cliffs above the trail are several large windmills, taking advantage of the height and open space to generate electricity.  Just below the windmills sits the Safe Harbor dam, reliably providing hydroelectric power since December 1931.  The fish congregating at the dam attract bald eagles, which can be seen flying above the dam. There’s nothing quite like experiencing history and nature by biking or hiking a rail-trail. At one stop on the trail, as I looked up at the windmills and down to the river and generating station, I felt small and insignificant in one respect, but also an important part of the natural balance.

Turning formerly used rail lines into biking and hiking trails is a great way to bring people closer to waterways in their regions. EPA’s Brownfields program has had a hand in converting unused rail lines, which often snake along picturesque rivers (our nation’s original highways), into prime recreational areas. The Harrison Township Mine Site in Allegheny County, Pennsylvania was assessed through a Brownfields grant, and is now part of the Rachel Carson trail, attracting area visitors as well as hiking and running events. Allegheny County is even acquiring additional land so that the Harrison Hills Park Mine Site will ultimately connect three trails – the Rachel Carson Trail, the Butler-Freeport Trail, and the Baker Trail.

Leave a comment below to let us know about rail-trails in your area.

 

About the author: Virginia Thompson works at EPA Region 3 and accompanies her husband on his rail-trail adventures as often as possible.

 

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

The Bottom Line: Why Permeable Pavements are Good for the Environment and Your Pocket

by Jeanna Henry

A Philadelphia Water Department parking lot includes interlocking concrete permeable pavers and other types of permeable pavements

A Philadelphia Water Department parking lot includes interlocking concrete permeable pavers and other types of permeable pavements

Are you looking for ways to reduce your environmental footprint, improve water quality, and save money?  If so, permeable pavements are a great way to green your community – and put some “green” back in your pockets.

We’ve blogged recently about the environmental benefits of permeable pavements, a green infrastructure alternative that can be used for stormwater management in urban areas.  Did you know this technology also provides a host of economic benefits?

Permeable pavements are one way take advantage of financial incentives from many state and local governments for reducing stormwater fees, and they can potentially help developers and property owners qualify for credits under the U.S. Green Building Council’s Leadership in Energy & Environmental Design (LEED) certification program.

Local economies also benefit from the use of permeable pavements because they create “green” jobs. In addition, permeable pavements serve as both a paved surface and a stormwater management system, so they can reduce the need for conventional stormwater management practices such as piping, retention ponds and swales, resulting in overall cost savings.

Permeable paving is being used across the mid-Atlantic, in places like Philadelphia, PA, Washington, DC, and Baltimore, MD. But my favorite illustration of cost savings is out of the University of New Hampshire (UNH), which happens to also be one of five recent Science to Achieve Results (STAR) grant recipients researching green infrastructure in Philadelphia.

This UNH case study compares the costs of conventional and low impact development (LID) stormwater management designs.  The LID design included the installation of two porous asphalt parking lots covering a total of 4.5 acres.  Although the paving costs for the porous asphalt drainage systems were estimated to cost an additional $884,000, the LID option provided significant cost savings for earthwork ($71,000) and stormwater management ($1,743,000). Total project cost savings were around $930,000, a 26% decrease in the overall cost for stormwater management.

The LID option doesn’t just save money, monitoring results from the case study show that porous asphalt systems are successfully treating stormwater to remove sediment and nutrients to protect local waterways, and meeting durability and permeability expectations for peak flow.

Interested in more on permeable pavements, like porous asphalt and pervious concrete? The National Ready Mix Concrete Association, the National Asphalt Pavement Association, and the Interlocking Concrete Pavement Institute have information on certified craftsmen, installers and technicians in your area as well as information on how to become certified in these green infrastructure techniques.

 

About the author: Jeanna Henry joined EPA in 2000 as an Environmental Scientist. She currently works in the Water Protection Division focusing on stormwater management through the use of Green Infrastructure. Jeanna loves nothing more than spending time outdoors with family and friends hiking, kayaking or spending a day at the beach.

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Making a Difference through Green Streets Funding

 EPA, the Chesapeake Bay Trust and MD DNR announced $727,500 in grants to 15 organizations via the Green Streets, Green Towns, Green Jobs Grant Initiative

EPA, the Chesapeake Bay Trust and MD DNR announced $727,500 in grants to 15 organizations via the Green Streets, Green Towns, Green Jobs Grant Initiative

by Tom Damm

Transforming lives is something Sarah’s Hope in Baltimore does every day as an emergency homeless shelter for families.

But this week, the focus at the safe haven was on a different type of transformation: replacing the asphalt and concrete on the property with an environmentally friendly community green space and outdoor playground area.

Earlier this week, EPA Regional Administrator Shawn M. Garvin was at Sarah’s Hope to join partners in announcing funding for a key phase of the project.

A $75,000 grant from the Green Streets, Green Jobs, Green Towns (G3) program will be used to tear up the hard surfaces in front of the property that during storms send rain water rushing into the street and drains, leading to flooding and pollution problems.   The surfaces will be replaced with lawn, shade trees, native plants, and other green features that will let the rain soak in and provide a welcome lift to this troubled neighborhood.

The atmosphere at the event was upbeat as the project partners, Parks & People Foundation, the City of Baltimore and St. Vincent de Paul, described their plans for the facility.

The G3 grant will tie into a larger Baltimore City project to create public open space, a playground area and a community garden at the site, which is now almost fully covered with impervious surface.  The work will improve the property for shelter residents and the community at large, and transform the appearance of the Sandtown-Winchester neighborhood.

Many of the other grantees were also on hand at the event to talk about how the G3 funds will help expand urban tree canopies, create bioretention cells to capture stormwater, and install other types of green infrastructure in neighborhoods in Maryland, Pennsylvania, and Virginia.

By keeping rain water from coming into contact with pollution in the first place, green infrastructure improves the health of our waters, while effectively reducing flooding, and helping our communities adapt to the very real challenges of climate change.

The G3 program – sponsored by EPA, and the Chesapeake Bay Trust, with assistance from the Maryland Department of Natural Resources – is in its fifth year. In this latest round of grants, 15 recipients will share in more than $727,000 in funding –  bringing the total aggregate investment in G3 grants to more than $11 million when matching funds are included over the five-years that the program has been in existence.

 

About the Author: Tom Damm has been with EPA since 2002 and now serves as communications coordinator for the region’s Water Protection Division.

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

Water Wednesday: “Mommy, Where Does It Go When I Flush?”

By Chrislyn Johnson

Last spring, when I was potty training my 3-year-old, he asked me where it goes after we flush the toilet. I thought about this before I answered him, because I have often overwhelmed the poor child with my answers. He once asked me “What is water?” and I told him it was two hydrogen atoms and one oxygen atom.

For most people, it is enough to be told that when you flush the toilet, it goes to the sewage treatment plant. Since I worked in wastewater regulation for a little while, I know it goes far beyond that, and I have trouble answering this seemingly simple question with a simple answer.

Once it goes down the drain, the water travels through a sometimes aging, sometimes modern, infrastructure of pipes to a wastewater treatment plant. Treatment options vary, from open lagoons to all-inclusive mechanical plants, all with the same goal: to treat sewage so it can be released into the environment. Many modern facilities do this with an “activated sludge” process that uses bacteria to naturally break down the waste.

As it enters the plant, the solids are separated out by a grit screen and settling basins. Heavier solids like plastics, eggshells, and intact items are settled out and removed; then taken to the landfill. The next step is the primary clarifier, where the sewage moves slowly along so heavier particles and sludge can settle out. At the same time, grease and oils dumped down the drain float to the top and are skimmed off the surface.

After the clarifier, the water is moved to the main part of the treatment: the aeration basin. Bacteria feast on the nutrients to break down the sewage and remove chemicals in the wastewater as it bubbles and roils with oxygen. Depending on the plant, an additional tank is sometimes added to help remove nitrogen. Since the treated water goes back into rivers and streams, this additional step is helpful in removing nitrogen before it can cause problems. Nitrogen can cause algal blooms that not only can be toxic, but also consume a lot of oxygen during decomposition, which kills the fish.

Following the aeration and nitrogen removal processes, the water then flows into a secondary clarifier. Water trickles out from weirs at the top of the large, circular tanks of the clarifier. The water is disinfected, either by chemical means (such as chlorination, similar to bleach), or through newer alternatives like ultraviolet (UV) lights. Once disinfected, the treated water is released into a nearby river or stream.

Whereas the water treatment is nearly finished in the secondary clarifier, the sludge often has a few more steps to completion. The bacteria slowly settle to the bottom of the clarifier into what is called the sludge blanket. Some of the sludge blanket from the clarifier is recycled and added back into the incoming wastewater to begin the treatment reaction in the aeration basin. Depending on the type of plant, the remainder of the sludge travels to the digesters for either aerobic or anaerobic digestion (where the bacteria eat each other).

Aerobic digestion uses oxygen to further break down the sludge. It is nearly odorless, but also costly since the process has to be manually oxygenated. The other common alternative is anaerobic digestion, which is not so odorless since it produces methane. However, the methane can be captured and used to generate electricity to operate the plant. The waste heat from the generators even can be used to keep the anaerobic digesters at the correct operating temperature. After leaving the digesters, water is removed from the sludge, which can then be disposed of or used as a soil conditioner. With clean water going back to the stream or river, and sludge going back to the earth, the cycle is complete.

I thought about this intricate series of steps that mimics the breakdown processes wastes would undergo in nature, given sufficient time and space. I thought about how fortunate we are to live in a country where water quality is a high priority, and we can make a daily difference to protect our local waterways (see graphic below).

I also thought about my son’s level of understanding, as he impatiently asked me again, “Where it go?” With all of this in mind, I looked down at my innocent little boy and told him, “It goes to the sewage treatment plant, honey.”

Click image to see larger version.

Click image to see larger version.

About the Author: Chrislyn Johnson is a Life Scientist with EPA Region 7’s Water, Wetlands, and Pesticides Division. She holds degrees in biology and photography from the University of Central Missouri and loves all things nature. She also enjoys access to flush toilets.

Sources:
Scientific American
U.S. Census Bureau
World Health Organization

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

The Promise of Permeable Pavement

by Jeanna Henry

Permeable pavement products can be used together with other green infrastructure.

When it rains, or as snow and ice melt, I frequently notice streams of water running off of my lawn, onto the street, into the storm sewer, and ultimately to a local waterway. I’ve also noticed an increase in flooded roadways and neighborhoods in my area even after a moderate to heavy rain. Unfortunately, stormwater is not just a localized issue, it is a problem across the country. As the saying goes: when it rains, it pours.

Flooding results in economic costs, human health impacts, and environmental damage in its wake. A major factor in more frequent flooding events is the increasing cover of impervious surfaces, such as roadways, parking lots and rooftops. Since these hard surfaces do not allow stormwater to naturally seep into the ground, most rainfall turns into runoff. With continuing development and growth, what options are available to minimize the effects of impervious surfaces? A more sustainable solution is to replace or substitute conventional pavements with permeable pavements – a green infrastructure tool.

Porous asphalt allows water to drain through it.

Porous asphalt allows water to drain through it.

Permeable pavements include pervious concrete, porous asphalt, and permeable interlocking pavers that mimic nature by capturing, infiltrating, treating, and/or storing rainwater where it falls. EPA considers these materials a Best Management Practice (BMP) for the management of stormwater runoff. Permeable pavements also provide multiple benefits beyond stormwater management and reducing localized flooding: they also have the ability to improve water quality; reduce the “heat island” effect in urban areas; reduce roadway hazards like ponding water and icing; create green jobs; and can increase the livability and resiliency of communities and increase property values when used with other green infrastructure. In fact, these benefits are already being realized throughout EPA’s Mid-Atlantic Region.

Permeable pavements along with green infrastructure are effective ways to address flooding as well as supporting green, sustainable growth. So the next time it rains, think about where permeable pavements and other types of green infrastructure could fit into your community.

 

About the author: Jeanna Henry joined EPA in 2000 as an Environmental Scientist. She currently works in the Water Protection Division focusing on stormwater management through the use of Green Infrastructure. Jeanna loves nothing more than spending time outdoors with family and friends hiking, kayaking, or spending a day at the beach.

 

 

 

 

 

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.