TOPICS > Science

Crumbling Pipes and Underground Waste: A Glimpse at Our Ailing Sewer System

January 3, 2013 at 12:00 AM EDT
As clean water regulations become tougher and sewer systems and water treatment plants become outdated, cities are struggling to stay compliant and safe. Science correspondent Miles O'Brien goes underground to discover the many ways America's sewer systems could be revamped to conserve water and save money.

JEFFREY BROWN: And now: the smelly depths of our aging infrastructure.

Our intrepid NewsHour science correspondent, Miles O’Brien, takes a deep dive into some very murky waters.

MILES O’BRIEN: I am suiting up for a stomach-turning trek beneath the streets of Detroit, rappelling into repelling place, a huge sewer line called the Detroit River Interceptor.

In short order, I am knee-deep in that which rhymes with it. You sure wouldn’t want to drop anything valuable in here, like my glasses.

MAN: Whoa, glasses.

MILES O’BRIEN: Oh, well. Bye-bye bifocals, right?

Well, watch this gutsy bare-handed retrieval from a river of revulsion. Sewer worker Roberto Sanchez may not be squeamish about what flows below us, but he is worried about the cracks above our heads. In Detroit, there are 3,500 miles of sewer lines, some of them dating back to the mid-19th century.

So, these are some of the things they’re really going to watch our for, these leaks coming in here. That’s a big concern.

The crumbling pipes offer a glimpse at a huge national engineering challenge that is largely unseen and unappreciated, unless you are the business of keeping the water flowing.

Sue McCormick, director of the Detroit Water and Sewerage Department, describes her profession as:

SUE MCCORMICK, Detroit Water and Sewerage Department: Silent service.

MILES O’BRIEN: What does that mean?

SUE MCCORMICK: The public took for granted that if they turned the water tap on, the water came and if they flushed the toilet, it went away.

MILES O’BRIEN: Is there a sense in the community of people of your peers across the nation that there is a crisis looming beneath the streets?

SUE MCCORMICK: Absolutely.

MILES O’BRIEN: What kind of crisis?

SUE MCCORMICK: I won’t say a crisis of epic proportions, but a crisis that is based on the belief that we have deferred replacement in the public systems, and that ultimately we’re going to see potential significant rises in failures.

MILES O’BRIEN: Unfortunately, it usually takes a big failure to get the people to pay attention.

Politicians don’t win elections by promising new sewers. And the $800 billion in federal stimulus money doled out starting back in 2009 offered lots of money for bridges and roads, but only $5 billion, or one half of 1 percent, to the pipes that lie beneath.

It’s enough to prompt the silent service to start making some noise. The American Society of Civil Engineers issued a U.S. infrastructure report card in 2009. That grade for the nation’s water and sewer systems? D-minus.

Greg DiLoreto is president of the organization.

What does a D-minus mean?

GREG DILORETO, American Society of Civil Engineers: Well, in this particular case, a D-minus would mean that we’re short $84 billion over the next eight years to bring it to a good condition over what we’re currently spending.

MILES O’BRIEN: Detroit is home to the largest wastewater treatment plant in the country. It handles as much as 700 million gallons a day. Everything that Detroiters and their neighbors flush down the drain ends up here, everything.

MILES O’BRIEN: Like what kinds of things?

SAM SMALLEY, Detroit Water and Sewerage Department: We get a lot of condoms, superhero action figures, Cheeto bags, you name it.

MILES O’BRIEN: It all ends up here?

SAM SMALLEY: It ends up here.

MILES O’BRIEN: Civil engineer Sam Smalley is the man in charge here. Here, it is a round-the-clock struggle to screen out the debris, separate the solids, let the sludge settle, and treat the water before it is dumped in the river. The sludge is dried out and then either incinerated or trucked to landfills.

Smalley must keep a creaky old plant running while adhering to a federal court mandate to meet standards set by the Clean Water Act and managing $600 million in improvements.

You’re trying to do two things at once, aren’t you?

SAM SMALLEY: Well, we’re trying to do several things at once. The regulations only get tighter or more stringent, and so that’s a challenge. And we are maintaining compliance today. Two years ago, we couldn’t say the same thing.

MILES O’BRIEN: That’s where the Baby Creek plant comes in. It is designed to stop a huge source of water pollution: combined sewage overflows. Years ago, sewer systems were built to carry runoff during a rainstorm in addition to wastewater. But when rainfall exceeds the capacity of the system, it overflows, sending an untreated mix of sewage and rainwater straight into the river.

Baby Creek is essentially a sophisticated holding tank designed to intercept the overflow so it can be treated later.

So are you testing it before it goes out, so you know what your pollution levels are?

MAN: Yes.

MILES O’BRIEN: Fifteen years ago, Detroit discharged 20 billion gallons of combined sewage overflow into the river each year. This and eight other plants have captured 94 percent of that dirty water at a cost of a billion dollars.

But a plan to eliminate the last 6 percent by building a big holding tunnel would cost $800 million. And in Detroit, where poverty is endemic and the population is declining, they are desperately trying alternatives, like building green alleys with absorb rainwater and encouraging industry to plant so-called green roofs.

SUE MCCORMICK: That’s what’s affordable for us I think in the short term, and I think it’s the best to use of public investment in the long term.

MILES O’BRIEN: As opposed to the $800 million tunnel idea?  


MILES O’BRIEN: Detroit is looking to save money by outsourcing work to crews that line crumbling old pipes with a polymer sleeve that hardens soon after a resin is applied, much cheaper and easier than digging.

The technique is now widely used all across the nation.

MAN: This is a fiberglass mat. It’s going to be a 48-inch-long kit when we’re done.

MILES O’BRIEN: I went to San Antonio, Tex., to see how they’re managing wastewater and watched a repair crew there install a liner in short section of a small sewer pipe. They’re using a small camera on a tractor to find problems early.

Joseph Villarreal is the televising foreman.

You can’t help but think about doctors doing heart surgery, you know?

JOSEPH VILLARREAL,San Antonio Water System: Pretty much.

MILES O’BRIEN: It’s like opening up your arteries, right, using those…

JOSEPH VILLARREAL: Exactly. If I can describe a sewer main to anyone, it’s cholesterol in arteries, and grease inside a sewer main is cholesterol in arteries.

MILES O’BRIEN: But San Antonio is trying to prevent the surgery in the first place. The city is learning conservation can help solve the infrastructure dilemma, in no small part thanks to a blind salamander.

Twenty years ago, concern about the fate of the endangered species prompted a federal court ruling that limited how much San Antonio could siphon from an underground aquifer. Necessity became the mother of invention.

Robert Puente is president and CEO of the San Antonio Water Service.

ROBERT PUENTE, San Antonio Water Service: In the last 25 years, San Antonio is using the same amount of water as it did back then.

MILES O’BRIEN: With the population growth of what?

ROBERT PUENTE: Sixty-seven percent more customers.

MILES O’BRIEN: You’re doing something right?

ROBERT PUENTE: We’re doing something right, and that’s water conservation.

MILES O’BRIEN: Puente has pushed individual conservation, giving away efficient toilets, educating the public about saving water, and encouraging xeriscaping, or landscaping that doesn’t need irrigation.

EARL SMITH,San Antonio, Tex., resident: It’s been cleaned up and stuff. This is just crushed granite.

MILES O’BRIEN: Earl Smith started out not wanting to mow a lawn anymore.

EARL SMITH: Yes, this is English ivy.


EARL SMITH: Talk about maintenance.


EARL SMITH: You mow that once a year.

MILES O’BRIEN: And now his home is surrounded by a beautiful garden that needs no mowing and nothing more than rainwater.

Do you think collectively we can solve all of our water woes by planting like this?

EARL SMITH: I think — I don’t know about all. I’m not a big all-or-none person, but I think we could make a tremendous impact on taking water out of the discussion as a threatened resource.

MILES O’BRIEN: That philosophy is imbued into the way they treat their dirty water here. In fact, they call their largest wastewater treatment plant a recycling center.

GREGG ECKHARDT, San Antonio Water System: This is the only plant in the country that recycles or reuses all of the processed residuals that come out of this plant.

MILES O’BRIEN: Scientist and senior analyst Gregg Eckhardt gave me a tour.

GREGG ECKHARDT: We’re recycling this water. We’re recycling the solids and the gas. No other place is doing that. And so — and we have got the solar farm out here.

MILES O’BRIEN: Just for good measure.

GREGG ECKHARDT: Between all those things, there’s no other place in Texas that’s any greener than this plant.

MILES O’BRIEN: Really? A green sewage treatment plant? Eckhardt showed me how they handle water here: clarifying, scrubbing with bacteria and microorganisms fed by oxygen, and then clarifying again.

GREGG ECKHARDT: After this, we also do a filtration process. We can meet all the standards without that, but we do that just to polish the water, to give it that extra shine.

MILES O’BRIEN: Polish the water?

GREGG ECKHARDT: Polish, that’s what you call it?


GREGG ECKHARDT: You polish the water.

MILES O’BRIEN: Extra shine.



MILES O’BRIEN: Thirty percent of that polished water goes into the San AntonioRiver. The remaining 70 percent is captured and reused. The polished, yet non-potable water in the purple pipes supplies manufacturers and irrigates golf courses and even keeps the famous River Walk from becoming a dry riverbed-walk.

ROBERT PUENTE: The water that you don’t use, you don’t have to treat. So there’s also savings in our wastewater treatment plants, so much so that we close one of our plants, instead of expanding, although, during this growth, we actually closed one of our four plants.



MILES O’BRIEN: The city is growing and you can shut down plants.

ROBERT PUENTE: Tremendous amount of savings.

MILES O’BRIEN: So maybe the best way our aging water systems can avoid flunking the grade is by finding ways to use them less. And it wouldn’t hurt if we stopped taking for granted the unsung heroes who keep the stuff flowing.

JUDY WOODRUFF: Miles blogs about his plunge into Detroit’s sewer system. You can read about it on our Science page.