MR. KOJO NNAMDIFrom WAMU 88.5 at American University in Washington, welcome to "The Kojo Nnamdi Show," connecting your neighborhood with the world. It was commissioned by Congress in the mid-1800s, an aqueduct that carries water from the Potomac River to the Del (unintelligible) Reservoir in the District of Columbia through a pipe that runs along what's now McArthur Boulevard. Today, one million people in D.C. and Virginia get their drinking water from the aqueduct, which includes a treatment operation that removes contaminants.

MR. KOJO NNAMDIAnd millions more drink Potomac River water delivered by other local agencies. In fact, one local environmentalist likes to say that since the human body is two thirds water, if you live in this region, you're probably two thirds Potomac River. But, as the aqueduct marks its 150th anniversary, there are new concerns about the quality of the water it draws from the Potomac. Agricultural runoff and new threats from human drug residues are raising questions about how to keep the river clean. Here to discuss that is Tom Jacobus. He is General Manager of the Washington Aqueduct. Tom Jacobus, thank you for joining us.

MR. THOMAS JACOBUSGood afternoon. Thank you for being -- for having me here.

NNAMDIAlso in studio with us is Stephanie Flack. She is Potomac River Project Director for The Nature Conservancy. Stephanie Flack, thank you for joining us.

MS. STEPHANIE FLACKHi Kojo. Thanks for having us.

NNAMDIAnd Matthew Logan is President of Potomac Riverkeeper. Matthew Logan, thank you for joining us.

MR. MATTHEW LOGANWell, thank you.

NNAMDIYou, too, can join the conversation. Give us a call. 800-433-8850. What environmental concerns do you have about the Potomac River? 800-433-8850. You can send us email to kojo@wamu.org or send us a tweet @kojoshow. Tom Jacobus, give us the overview. How many people in the Washington region get their drinking water from the Potomac River?

JACOBUSThe Washington Aqueduct serves about a million people, all of the District of Columbia and northern Virginia. Arlington County and the city of Falls Church service area. In addition to that, another million and a half are served by the Fairfax County Water Authority in northern Virginia. And another million and a half or so by the Washington Suburban Sanitary Commission in Montgomery, Prince George's County. All of those utilities take water from the Potomac River.

NNAMDIBy my count, that's at least about four million people.

JACOBUSAt least.

NNAMDIMatthew, you're the President of Potomac Riverkeeper. That's a nonprofit whose mission is to stop pollution and restore clean water in the Potomac. Talk about the state of the river today. We get our drinking water from it, but for some reason, it's not safe to swim it.

LOGANYeah. That's a challenge for us. The Potomac River is, in some ways, a great success story. If you were living in this region back in the 1960s and '70s, I've heard many stories of people who would, as a child, go in the water and play. And their mothers would rush them off and check their legs to make sure they had no scratches and things like that. Because that was a place where they might get an infection, they would develop rashes, and, you know, it was really a national disgrace, as Lyndon Johnson described it.

LOGANNow, thanks in large part to better sewage treatment, the river's in better shape, in some ways. But we do have a whole new set of challenges, like you mentioned in your introduction.

NNAMDIStephanie, you've describe the Potomac as one of the most wild and free rivers in the country. But a report last year also called it the nation's most endangered river. How can the Potomac be both of those things?

FLACKIt's a great question, Kojo. So, the Potomac Watershed is the source of our drinking water here, as you said, to 4.3 million people, if you add up across all the different water supply utilities in the D.C. metro region. And what we depend upon for this water is the watershed. And we're very fortunate that about 60 percent of the Potomac Watershed, the forested area that drains to the Potomac, is still forested. And that's a great thing.

FLACKAnd about 20 percent of the watershed is protected, so we have those forests in a good condition, and it's also sort of interesting historical legacy that the Potomac is relatively undammed, and wild and free, particularly compared to most other big eastern river systems. At the same time, though, there are some water quality challenges, particularly from an ecological perspective when you're looking at the health of the river in the Chesapeake Bay.

FLACKA recent report card that came out gave the Potomac a D+ from an ecological health, as it flows to the bay, contributing sediments and nutrients that are not good for the bay or for water quality for the species that live in the river.

NNAMDI800-433-8850 is the number to call. Do you know where your drinking water comes from? You can also go to our website, kojoshow.org. And ask a question or make a comment there. Tom Jacobus, can you describe what happens to the Potomac River water from the time it leaves the river until it flows out of the faucet in someone's kitchen. What's the process that makes it safe to drink?

JACOBUSThe water comes from the Potomac, whatever it's condition is. That's why it's so important to keep the pollutants out of the river to the maximum extent possible. So, if the river is muddy after a big rain, or if it's low and has algae, whatever comes through us to the Dale (unintelligible) Water Treatment Plant, or to the McMillan Water Treatment Plant that operate. And the first step is to go through sedimentation. And we add a coagulant to the water, which forces the particles to settle out. We then send that water through filters, which take out all that bacteria and viruses, all the little particles are gone.

JACOBUSAnd take lots of pathogens out there too. And then we go through disinfection. And once it's disinfected, it is safe to drink. And it's delivered continuously through the system. In addition to those functions which make it safe to drink, we also add chemicals to make it more palatable, so that is has a good taste and odor. And so we remove algae taste from time to time. And so the water, it goes through a purification process, and it's reliable, and we would always inform the public if there was anything disrupted about that.

JACOBUSAnd we have an excellent track record. All the public water utility have an excellent track record of making sure that water stays safe to drink and stays available for all the other uses people want to make of it.

NNAMDITom Jacobus is General Manager of the Washington Aqueduct. He joins us in studio to discuss drinking water from the Potomac River, along with Stephanie Flack, Potomac River Project Director for the Nature Conservancy. And Matthew Logan, President of Potomac Riverkeeper. We're inviting your calls at 800-433-8850. Tom, the Washington Aqueduct is federally owned and operated the Army Corps of Engineers. It treats and sells water to three retail customers. D.C. Water in the District of Columbia and Arlington County, and Falls Church in Virginia.

NNAMDIDescribe the relationship between the aqueduct as a wholesaler that makes river water drinkable and the water districts that buy the water and then sell it to retail customers.

JACOBUSOur job, and this got started, just curiosity, you said 150 years ago. There was a need for water. And we're built on a gravity system, so there's a very high probability in a storm that we would continue to have electricity, that we would not need electricity for the water to flow down. And so the production facilities are trying to give 100 percent reliability to our wholesale customers.

JACOBUSAnd the District of Columbia, D.C. Water buys water from us, and then their job is to distribute it through the pipe system, into the homes and businesses. And they take care of the distribution system maintenance and insure that it's properly built and that they have good integrated water service with all the connections that have to be out there.

JACOBUSThey flush the lines to make sure that the quality stays high in the distribution system. So, it's a partnership. It's a wholesale, retail relationship. The same things occur in northern Virginia.

NNAMDIStephanie, the Nature Conservancy is involved in protecting the natural areas along the banks of the Potomac, both here and upstream. How much agricultural runoff goes into the Potomac upstream from us before it gets to our local water treatment plants?

FLACKThat's a great question. So, the Nature Conservancy's been working in the Potomac Watershed for 60 years, working to protect important lands for water quality for nature and people. And agriculture is the top source, in terms of absolute magnitude of pollutants running into the river of nutrients. Nitrogen and phosphorous nutrients sound good when you think about food, but it's actually not. It's not good for water quality.

FLACKAnd sediments, as well. But the thing that we're concerned about, as a growing threat, is runoff from urban areas. And as this population continues to grow in this region, we have more impervious surfaces being built. Parking lots, malls, houses, and the runoff from those urban areas is more challenging and more costly to address than agricultural pollution where we have some good opportunities to use best practices on farms to reduce that source of pollution.

NNAMDIMatthew Logan, what do the laws say about what can be released into the river?

LOGANWell, we are -- pollution is basically divided into two types. There's point source pollution and non point source pollution. And point source pollution is the stuff that comes out of pipes. You think of industries, power plants, water treatment plants. That is all regulated under the Clean Water Act. And to be a discharger, you need a discharge permit. So, the states, under authority from EPA, oversee that. Potomac Riverkeeper, we take a look at every one of those discharge permits every year.

LOGANAnd make sure that polluters, that are doing it under this regulated system, are meeting the standards that have been assigned to them. In most cases, that's not a problem. With some bad actors, sometimes we have to pursue enforcement. The second type of pollution is non point source pollution, which Stephanie eluded to. You have both agricultural pollution and urban storm water. And those are very difficult, as she mentioned, to get our arms wrapped around. You know, when the rain falls on your driveway, on the sidewalk, on your neighbor's lawn, everything that's there is getting washed away.

LOGANAnd so you have this concentrated -- the water picks up all these pollutants, and then it's diffused across, you know, down the storm drains and into our waterways. Again, it's very, very challenging, with the type of infrastructure we have, to get our arms wrapped around that.

NNAMDIOn to the telephones. Put on your headphones, please, so that we can all hear Joy in Rockville, Maryland. Joy, you're on the air. Go ahead, please. Hi, Joy. Are you there? Joy, in Rockville, Maryland, can you hear me? Well, I know the question Joy wanted to raise was the question of sewage, another thing that sometimes goes into the river, Tom. Explain the history of sewage treatment in our area and what a combined sewage overflow system is. Why is raw, untreated sewage sometimes released into the river?

JACOBUSSure. In the development of a city, you have two kinds of -- you have storm water, that when it rains, has to go down a drain. And, ideally, that would have some kind of treatment before it went back to the river. You would also have your toilets and showers and those kind of -- where your waste products go down. And those go to a sewer that goes to a waste water treatment plant to be treated and have the solid matter and the bacteria taken out before it goes back to the river.

JACOBUSIn the older cities, there was only one pipe in some areas, where you would have both the rain water and the sewage from the houses in the same pipe. And when it rained very heavily, the water could not be allowed to back up into the houses, so they built overflows. And none of those practices are approved today, or would be used today, but they exist in older cities. And there are some in the District of Columbia, and those are being taken care of through a project at the D.C. Water and Sewer Authority, D.C. Water., known as your Clean Rivers Project.

NNAMDIYeah, can you explain how that Clean Rivers Project works? It's a system of underground holding tanks that's being built to help keep raw sewage out of the river.

JACOBUSSure. And I'm on the drinking water production side, but for our colleagues at the D.C. Water, I can explain that. Instead of having the pipe have a valve that just overflows to the river, a series of large tunnels will be built. And the water will be directed to these tunnels, and it will be like underground holding tanks, so that the capacity of the pipes won't be overwhelmed.

JACOBUSAnd then they can pump water out at a lower rate that the pipes can sustain and send it to the waste water plant. So, they're building a wide spot in the process to hold the water during the major rain event and then treat it later. And that will keep in those areas where you have a combined waste water and storm water sewer, from overflowing.

NNAMDILet's see if Joy, in Rockville, Md., heard your answer and if that did indeed answer her question. Joy, can you hear me now?

JOYYes. I can. I’m sorry. Yes. You're using the future-tense to talk about building these tunnels to accommodate excessive water intake. The fact is that -- from what I heard -- raw sewage does go into the Potomac. I mean isn't that true or not?

NNAMDITom?

JACOBUSYeah, under the current circumstances that is true. These…

JOYOkay. Well, I think that's also a national disgrace.

NNAMDII know it might be a national disgrace, but would you be -- oh, hold on a second. Stephanie Flack wants to intervene in this conversation. (laugh)

FLACKWell, the water that Tom was talking about, the sewage water that flows in from D.C. is downstream of the water supply where our D.C. Metro region water is taken, but it's still a problem for the river water quality downstream of here and the Chesapeake Bay.

FLACKMost people don't realize, though, that we are actually downstream of about a dozen of these same combined sewer overflows upstream of here in older cities in western Maryland and West Virginia, but fortunately they are very far upstream and nature does it part. And the water that we get, the flows help to dilute that and also, Tom, and the aqueduct art set up to remove those problems from the water by the time it reaches us.

JACOBUSThere is no problem on the drinking water production. If there were a sewage release into the water, while that is not good for the water body itself, the drinking water plants are specifically designed and equipped to remove the material and neutralize the bacteria so that the water would be safe to drink, even if there had been a sewage spill into the river. But as Stephanie said, here in the studio, the Washington Aqueduct purification intakes are all up stream from the major combined overflow sites in the District of Columbia.

NNAMDIAnd here's Matthew Logan.

LOGANYeah, I mean, certainly drinking water quality is a concern. And I think that Tom is doing a good job to address that, but we do have a larger issue. And I agree with the caller that it is a national disgrace that we have thousands and thousands of gallons of untreated sewage that enter the Potomac River, Rock Creek, the Anacostia, every year. There is a Consent Agree that is potentially going to be opened up that would allow D.C. water to not build one of the tunnels on the Potomac. And instead use green infrastructure to try to address the capacity issue.

LOGANWe're very concerned about that because, you know, it will take years and years and years for that green infrastructure to be put in place, installed, monitored, tested, maintained. And at the end of the day I don't think it's going to be sufficient. There's very little proof that it would be sufficient to solve this issue. And so we're very concerned that D.C. water is going to backtrack on something that should have been done long, long ago.

NNAMDIStephanie?

FLACKWell, at The Nature Conservancy we come at this from a slightly different perspective. We're very concerned with both environmental health and human health, but we see that the potential to use natural infrastructure or green infrastructure solutions, as Matthew eluded to, which are things like rain gardens, porous pavement and other solutions that have storm water infiltrate on site, provide some complimentary approaches that we can tap into at lower costs, potentially, that have other social benefits.

FLACKSo we think that it's very exciting to experiment with green infrastructure as an approach to dealing with urban storm water runoff, as long as there is that monitoring and testing.

LOGANIn combination, I think it makes sense, but green infrastructure along certainly won't be able to address a problem of them scale.

NNAMDIGot to take a short break. Joy, thank you very much for your call. You, too, can call us at 800-433-8850 if you're interested in joining the conversation on drinking water from the Potomac River. How closely do you monitor the chemicals you use on your lawn or in your yard? We'll tell you why that's relevant when we come back. 800-433-8850. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation on drinking water from the Potomac River. We're talking with Stephanie Flack, Potomac River Project director for The Nature Conservancy. Matthew Logan is president of Potomac Riverkeeper, and Tom Jacobus is general manager of the Washington Aqueduct. We're taking your calls at 800-433-8850. One of the biggest concerns today is that people are taking medications that pass through their bodies and end up in the river. Explain the threats posed by emerging contaminants like endocrine disruptors. What are they and why are they worrisome? Matthew Logan, I'll start with you.

LOGANSure, sure. Endocrine disruptors are part of these emerging contaminants that are found in things like fragrances, pesticides, drugs, cosmetics, shampoo, the lining of canned food containers, cleaning products, basically they're everywhere. And what they do is they mimic or disrupt human hormones and the function of the endocrine system, which is responsible for things like our brain development, sexual development, things of that nature. And so the challenge with endocrine disruptors is they are effective, again because they disrupt or mimic your natural endocrine system.

LOGANThey're very effective in tiny, miniscule concentrations. We're talking about parts per billion. And we're seeing all kinds of effects, such as -- you've probably heard about some amphibians that have, you know, four legs.

NNAMDIOh, yeah.

LOGANYou know, if you remember back to the DDT issues back in the '70s when eggshells were thinned. And it really was a huge danger for the bald eagle, for instance. DDT was banned and that allowed that species to recover, but we're also seeing there were a number of fish kills in the Potomac River in the past decade. And at the time of the fish kills there were not only lesions on the fish, but they started to do pathological research and they discovered that the male fish were growing eggs in their testes, things of that nature. That's called the intersex condition.

LOGANAnd, again, you're starting to see these indications of a problem. I don't believe there's any human health effects that have been definitively linked to endocrine disrupting chemicals, but certainly to those of us who are concerned about water quality were very, very concerned about what this holds for us.

NNAMDISame question to you, Stephanie.

FLACKWell, it's very interesting and gets people's attention, this topic, because I’m a mother. I have three little children. Their body composition is even more water than grownups. I think little kids are about 75, 80 percent water. So my kids have been born and bred in the Potomac watershed. And…

NNAMDII have Potomac kids, yes.

FLACKI have Potomac children. Could have given them funny names for that. But to add to what Matthew was saying, it's a really challenging problem because we live in an industrialized society. We don't want to ask people to go without their heart medication or their, you know, antidepressants or their Advil. But at the same time I think there are some things we can do, working with our natural landscape, to reduce this problem. For example, a lot of the runoff from agriculture, they're finding things like Atrazine and other pesticides and components of these emerging contaminants are coming from our agricultural landscapes, but there are solutions there.

FLACKThere are best practices that could be done that both improve the bottom line for farmers and also help improve water quality. So we really want to look to the role of nature as filters to help get these things out of the water.

NNAMDITom Jacobus, these chemicals in the river, drug, pesticide residues that the water treatment does not remove, do those exist?

JACOBUSYes. The water treatment does an excellent job at removing the traditional bacteria, the particles. We can neutralize things with our chlorine, but the trace amounts of pharmaceuticals and other compounds, they're not effectively removed in water treatment. They're also not effectively removed at the wastewater plant. And so they can pass through the system. However, the good news is that in terms of regulatory standards, in terms of scientific studies, as Matthew said, there's no immediate indication that this is a great concern.

JACOBUSBut the concern is that we need to all of us work together to find strategies to reduce the pollutant runoff to the river and things like drug programs, where you take your pharmaceuticals that you use for your personal use -- and yes, that is excreted at a low dose in your bodily waste -- but when you have unused pills don't throw them down the toilet.

JACOBUSEither throw them in the garbage of if it's a controlled pill of some kind there are take-back programs. Because that just would add a concentration at the river that we don't need. But road salts -- there are just many, many contaminants that we want to look at and sort of change our practices, our agricultural practices we want to change.

JACOBUSThat cows don't, on the dairy farms, straddle little tiny streams because the cow waste, the manure that goes into the stream adds certain pathogens to the water. Yes, they get very well dispersed and the concentrations go down, but if we can take individual actions at the source of these activities, we can have a water shed that will be sustained for all of our benefit. And at the drinking water plants it will have us avoid putting in very expensive alternate treatment facilities to go after these compounds.

JACOBUSSo right now the water is very safe to drink. There are no immediate known human dose response situations, but there are indicators in the animal world, the fish, the frogs, that the river environment should not be allowed to become polluted and change any of the configurations of anything in the river. And we at the water treatment plants will continue to do our job to be alert to make any changes we need to make if science determines that more sophisticated kinds of treatments are required.

NNAMDIThere are a lot of callers who want to join the conversation, so allow me to bring Julie, in Tacoma Park, Md. And, Julie, you're on the air. Go ahead, please.

JULIEHi. Thank you for taking my call. So I’m part of a group in Tacoma Park, the Safe Grow Zone Initiative, that helped to get a law passed to ban the use of weed killers, herbicides, pesticides used for cosmetic purposes. But we're just one small town. We are concerned about the threats to human and environmental health.

JULIESo I'm hearing a lot about best practices for farmlands. I'd like to know what those best practices are, but also speaking to the other point about all these individual efforts that can be made. If we don't get people, you know, beyond the town level to start taking action, our leaders to start making some restrictions on what people can put on their lawns, like 2,4-D and Glyphosate and Dicamba, I mean, all of this ultimately ends up in our air, in our drinking water.

JULIEWe do have to change individual practices and attitudes about dandelions, but we also need strong leadership to protect our health and our drinking water. So maybe if you could just talk about that.

NNAMDIStephanie Flack?

FLACKI think very few people are aware that the largest irrigated crop in the Potomac watershed and the Chesapeake watershed is grass, turf grass. So you raise some excellent points that we are all grass farmers. And this comes from Tom Schuler who did a study, along with Peter Claggett of the Chesapeake Bay Program. Tom used to be the head of the center for watershed protection. And they did an analysis of how much turf grass there is in the Potomac watershed and the Chesapeake watershed. And I think we all have a role to play, everyone who has this American dream of the manicured green lawn.

FLACKMy lawn is pretty weedy and pretty patchy and not very good looking, but I feel good that I'm not contributing fertilizer and pesticide to our waterways and to our rivers. So I think that there's a cultural change that needs to happen. I commend you and your community in Tacoma Park for taking a leadership role on this, but I think that that's the sort of effort that requires both education and people to understand these connections of where their water comes from and how our individual behaviors affect the health of our rivers and our drinking water supply.

NNAMDITom Jacobus and then Matthew Logan?

JACOBUSJust inject here that the water utilities in the region, in association with the interstate commission on the Potomac River Basin, about 10 years ago decided to voluntarily form what we call the Potomac River drinking water source protection partnership. The purpose of this is to enlist the water utilities, regulators, individuals, groups, agencies to get together and look at areas where we can collectively decide we are going to put emphasis to inform people we're not a regulatory body, but we work with regulators who do have certain regulatory ideas that could improve things.

JACOBUSSo I think that your instincts are exactly correct, that we need to work together as a community, the water producers benefit from it, and then our customers benefit from having safer water in the Potomac to pass through the treatment plants.

NNAMDIMatthew?

LOGANYeah, I wanted to bring up some activity that's happening in Maryland. There's an effort to get a pesticide reporting bill presented to the general assembly. And it would create a mandatory pesticide reporting database that would require you to report on the types of pesticides that were being applied, where they were being applied and so on.

LOGANAnd so, you know, this is largely for an agricultural setting, but I think it begins to, you know, provide a solution where we don't even know right now what is out there. And so if you're a public health researcher, if you're an advocate, if, you know, if you're trying to get your arms wrapped around this you simply can't, at this point. So that's a good starting point, at least in Maryland.

NNAMDIBack to the telephones now, here is Harriett, in Greenbelt, Md. Harriett, you're on the air. Go ahead, please.

HARRIETTYes. I am a professor of America of the University of the District of Columbia, which has been studying the Potomac River and the Anacostia River for years. We did a study published back in 1994, which was on the effect of a invasive species clam on the Potomac River. And we found that the species reached millions of numbers and essentially cleaned up the river causing an ecological change, the (unintelligible) clam (unintelligible) ecological chain in the Potomac River estuary near Washington, D.C.

HARRIETTIt cleaned up the river just like the zebra mussel has cleaned up the Great Lakes. What's happened in the last three years is that the clam is banished. The clam population has gone. Why? I don't know. This tends to happen with this clam worldwide. And we are seeing reversion of the whole Potomac River near D.C. and actually above because there's some clams up there, back to a state of pollution of, I won't say chemical pollution, but more toxic algae blooms and some plants are going to start dying because the water's not clear. And it'll be back like before it (unintelligible)…

NNAMDIOkay. Harriett, allow me to have Stephanie Flack respond.

FLACKThank you, Harriett. I have walked along the Potomac many, many times and seen the shells of that species you're talking about, the Asiatic clam or Corbicula. It's sort of a black and white shell. And you can see them littered along the edges of the Potomac where flood waters carry them up into the stream banks.

FLACKI was not aware of your study, but I think, it's fascinating and it points to the role -- I mean, we are big proponents of native species, as opposed to invasive species, and we have a lot of mussels and native species in the river that do have that same sort of filter feeding function. We would prefer to see our native species serve that function than invasive non-native species.

FLACKI can't really speak to that study because I haven't heard of that, but I do know in the Chesapeake Bay, you know, historically we had oysters that were so abundant that in the space of eight days they could filter the enter volume of the Chesapeake Bay and we're very interested in seeing those natural functions restored through those species being robustly reintroduced, which we're working on doing, but I don't know if I could say that that non-native species was a good thing. I'd be interested in looking at your study and finding out more about that.

NNAMDIBut, Harriett, thank you very much for your call. Matthew, rainwater seems like such a natural thing to flow into the river, but how does it cause problems when it falls on man-made surfaces? Why is it better for rainwater to soak into the ground where it falls?

LOGANWell, if we think about the natural surfaces as sponges almost, that allows groundwater to recharge. It slows down runoff so that we don't have these flashy episodes in our streams. You know, when the water falls on a hard surface, it's going to pick up whatever is on that surface. And, you know, I'm looking out on a road right now and, you know, all the stuff that’s coming off the vehicles, just our industrial lifestyle, has -- there's all this contamination that comes with it.

LOGANAnd as that gets picked up by the rainwater and delivered into our rivers, we're seeing all kinds of problems with that. You know, Tom had mentioned road salts, but it happens throughout the year. And again, it's very challenging to try to contain that.

NNAMDIWe got an email from Steven, in Northwest D.C., Tom Jacobus. "Is there something new that's been added to the D.C. water supply that might explain the recent experience I've had with nozzles locking onto garden hoses? On multiple occasions recently I know of nozzles hand tightened on garden hoses being impossible to remove." Is there anything being added or is Steve just getting weaker without realizing it? (laugh)

JACOBUSI'll address the first part of that. (laughter)

NNAMDII think you're getting weaker, Steve, but go ahead.

JACOBUSNo. The drinking water characteristic that could be attributed to that is we do add conditioning agents. We add lime to the water to adjust the pH so that it doesn't act aggressively in the pipes and tries to pull materials out of the pipes. And so there could be a little calcium residue that you see, like when you boil down a cup.

NNAMDIOkay. You're not getting weaker, Steve. Go ahead.

JACOBUSOkay. But there's been no change that would have caused anything new to happen. So maybe he actually got stronger and just tightened it down a little too tight. (laughter)

NNAMDICould be. And, Matthew, we got this email from Brian. "Since runoff from parking lots is a large contributor to polluted runoff and it's easy to calculate the volume, why can't we tax building owners according to square feet of impervious surface?

LOGANWell, in Maryland there's an effort. It's been called by the opponents as the rain tax. But we're seeing efforts to begin to recognize that this is a utility. It provides a function for us, just like the delivery of water and so forth. And so asking people to pay based upon the amount of impervious cover on their property is an effort that's underway and, frankly, one that is going to be necessary. I mean society is absorbing the cost and I think this is an effort to actually distribute that cost to those who are contributing to the problem.

LOGANSo it's very controversial right now, but in places where they have gotten out in front of the issue -- for instance I've heard stories about Charlottesville, Va., where they went out and instead of letting it be driven by a regulatory requirement, they engaged the community, they engaged -- a lot of churches, for instance, have large parking lots, schools, places like that.

LOGANAnd they went out there and they talked about the benefits that were derived by healthy waterways, clean water, things of that nature. And these people became advocates for it. Whereas, in the communities in Maryland, where they've not proactively reached out, but instead allowed the regulations to drive the discussion, there's been a lot of opposition.

NNAMDIStephanie Flack?

FLACKWell, one of the biggest costs to the whole Chesapeake Bay cleanup effort is dealing with urban pollution runoff, but there's some really exciting opportunities to tap into some of these new funding mechanisms, these storm water utility fees that Maryland just mandated must be put in place for their most densely populated --what's called their MS4 jurisdictions. And there are ways, though, that -- for example, D.C. is really taking a leadership role in how they're tapping into these new storm water fees to address the runoff from urban areas.

FLACKAnd they're developing a really cutting-edge, innovative system called a Storm Water Retention Credit Trading System. And they're trying to work with market mechanisms to bring down the costs to promote the places in D.C. where they can most affordably infiltrate the storm water and allow for trades for those who must do that to either comply with their regulatory mandates, new development or redevelopment or allow it to happen in the most efficient and effective ways.

NNAMDIGot to take a short break. When we come back we'll continue this conversation on drinking water from the Potomac River. We'll talk about the possibility of fracking and its possible effect on water quality, but you can still call us at 800-433-8850. One long-time local environmentalist says that since the human body is two-thirds water, if you live in this region, you're most likely two-thirds Potomac River. How do you feel about that? 800-433-8850. I'm Kojo Nnamdi.

NNAMDIWelcome back to our conversation about drinking water from the Potomac River. We're talking with Stephanie Flack, Potomac River Project director for The Nature Conservancy, Tom Jacobus is general manager of the Washington Aqueduct, and Matthew Logan is president of Potomac Riverkeeper. I'll go directly to the phones where Linda, in Rockville, Md., awaits us. Linda, you're on the air. Go ahead, please.

LINDAI had a question, you talked about pesticides and you talked about a dose response. And I was wondering if pesticides were being measured in the drinking water and who determines acceptable dose response? Because with the explosion of the kids with allergies and learning disabilities, I mean, is there a medical profession determining this? Also, I read something about fracking in George Washington National Forest. And I understand that's where, like, the Potomac starts. And what would that mean for the Potomac if that's allowed?

NNAMDIWell, Tom, the U.S. Forest Service, as Linda indicated, is considering whether to allow fracking in the George Washington National Park, which is part of the Potomac watershed. You should know, Linda, that Tom wrote a letter to the Forest Service saying that fracking could degrade the water quality in the Potomac River, but, Tom, what's the danger?

JACOBUSWell, the fracking is designed to release natural gas and then bring it to the surface. And using the water that is used to hydraulically expand, that water has to be reprocessed and also the concern is it's not unlike pharmaceuticals, in the sense that we are getting something into the water that wasn't being put there by design. And our position, as a water utility, and will be supported by the other water utilities in the area, is that we want to proceed very carefully so that we don't have any unintended consequences of this activity releasing substances into the drinking water, which then would have to be treated at the drinking water plants.

NNAMDIMatthew?

LOGANYeah, fracking has a number of issues that we're really concerned about. It requires millions and millions of gallons of fresh water. It poses potential to contaminate the ground water. It can contaminate surface water when it's being, you know, brought to the surface and being treated. It requires the use of thousands and thousands of pounds of chemicals, though it's only a small percentage of the total amount of liquid that is injected into these wells, it is -- the chemicals are not fully disclosed, so the public doesn't know what's being used. Of course that doesn't even being to talk about the industrial footprint on the sensitive headwater forests.

LOGANSo there's huge issues around that, but in addition there's a proposal right now to develop an export facility, a liquefied natural gas export facility on the Patuxent, right next to the Potomac. And it's called Cove Point. If that facility is approved, and there are plans underway to do that, all of a sudden you're going to see fracking in the Mid-Atlantic explode. So the places -- you know, we all know about Marcellus Shale, that's kind of the low-hanging fruit.

LOGANOnce this export facility to export our natural resources to other countries, once that is approved you're going to see more marginal places throughout our watershed begin to be exploited, which does nothing for our own energy independence and is going to leave us holding the bag with decades of cleanup.

NNAMDIStephanie?

FLACKBeyond the chemicals that are used in hydrofracking and the water that's consumed to do that, there's another issue. And that is what is happening to the areas where the fracking is being done? Often it's in headwaters areas, the areas that are the sources of our drinking water. In Pennsylvania, for example, we've worked very closely with the state and the industry to come up with better approaches to sighting and mapping that infrastructure because it can fragment important forest areas that contribute to water quality.

FLACKThe roads and all the many, many acres impacted from the above-ground infrastructure create sedimentation. So we're very concerned with trying to find ways for -- you know, everybody supports energy independence and less polluting forms of fuel for generating electricity, but are there ways for us to generate those fuels with a lesser environmental impact?

NNAMDILinda, thank you very much for your call. Tom, it seems counterintuitive, but how has the decrease in water use in recent years created new challenges for you and why should we all be taking longer showers?

JACOBUSDid I say that?

NNAMDIYep, you did. (laugh)

JACOBUSThe -- it is -- yesterday, at our treatment plants, we produced about 135 million gallons in the period of midnight from the night before until last midnight. It's fall. We expect water consumption to go down in the fall, compared to the summer. But 10 years ago, if we look back at the records we would have produced -- not 132 or whatever I said, but more like 150 to 155.

JACOBUSThe consumption is dropping very drastically. And that's both good and bad. It's good from the standpoint that then people's needs are being met. We're not wasting water through leaking pipes. We are being very efficient through the use of toilets and water-saving devices in washing machines and showerheads and those kind of things.

JACOBUSSo I'm not advising people to take longer showers, by any means. I'm advising people, though, that they should use water wisely. The economic side is that there's a certain fixed cost that goes into producing water. And so we find the situation where as you use less and less, the unit price of the water goes up a little bit because you have to recover those costs.

JACOBUSSo the challenge then comes to us to operate more and more efficiently. And we strive to do that so you get good value. Our motto is safe, reliable and cost effective. And we work on all three of those, in that order. And we have never forgotten the cost effective nature of trying to produce the best water we can as inexpensively as we can.

NNAMDIStephanie?

FLACKIf I can just add to that. We know that the highest quality water comes from forests, forests that act as natural filters. They're basically our Brita filters on the landscape. And there are ways that we can invest in that natural infrastructure, those forests, the wetlands that help filter and clean water to potentially reduce the costs that the aqueduct and other water treatment facilities have to provide. So we're hoping that into the future that we can help people understand the connection between where their water comes from and the quality of that water.

NNAMDIThere goes my longer shower. According to the Interstate Commission on the Potomac River Basin we'll be fine for about 20 more years, but by the year 2040, we could be looking at water shortages, Matthew. Why?

LOGANYou know, that's probably a better question for Tom. If he wants to respond.

NNAMDISure.

JACOBUSWell, as the population grows and there's more and more demand for water, even though the unit use is going down, there will be an aggregate increase over time. The good news is that through the planning since the late 1960s, the Jennings Randolph Reservoir and the Little Seneca reservoir have been very effective at allowing us to have water in storage, in the flow of the river, that can be released to augment the flow. We're also looking at not building more dams, but there are a lot of quarries in the area, especially in Virginia. There's the Travilah Quarry in Maryland.

JACOBUSIf those quarries were owned by the water utilities, they could be filled from the river and then in periods of low flow we could withdraw from there and send that water to the treatment plants. So we're looking at innovative ways, inexpensive ways as possible, to conserve the water resources in the area and make sure that people have the water they need to go about their daily lives, assuming there's going to be population growth and further development. And then we want to do that development wisely.

NNAMDIStephanie?

FLACKSome of the latest study that talks about looking out to 2040 and that we will have a need for either more storage capacity or mandatory water use restrictions in that year, that's due to, in part, climate change and projections that we're going to have more drought periods, coincident with more demand during those hot, dry periods.

FLACKAnd so one of the things to look at into the future, as we're planning to make sure that we have plenty of adequate and safe drinking water, is what is the role of nature as an insurance policy in guarding against both the more floods and during those periods of droughts what is the role of nature in helping to provide adequate and secure water to our city?

NNAMDITom, you've said that you can clean any water and make it drinkable, but the best-case scenario is when the water is clean to begin with. What are the greatest challenges for you right now in making the water drinkable?

JACOBUSRight now we have a very abundant and reliable source in the Potomac. Getting the bacteria out of the water and making sure we remove any of the pathogens through having very, very tight filtrations standards, and then using chemicals to make the water pleasant to smell and so that it's not hard and it doesn't cause any damage to your pipes.

JACOBUSSo we just need to make sure that we continue -- every day keep our eye on the ball, look to the future at what may be required to augment treatment a little bit and work collaboratively with our friends in the resource agencies, the regulators, the public, advocacy groups. All of us are in this together for safe water in the community, safe water in the environment.

NNAMDIPaul, in Washington, D.C., we only have about a minute left, Paul, but go ahead, please.

PAULCongratulation on your 15th anniversary at WAMU.

NNAMDIThank you, Paul.

PAULAnd thanks to the panelists, who I know all, on the great wheel of intent, are trying to do the right thing for people on the planet. But the central 35-second problem I want to bring up is that we have tens of billions of dollars being invested in water infrastructure really focused on an accreted 19th century and 20th century platform. And there's a justice issue which is that lots of people -- for lots of people in D.C. and around the region, it's their fastest growing bill. And the money that's being spent is being spent backwards on old approaches. When are we going to adopt a 21st century approach that uses (unintelligible) .

NNAMDII'm glad you raised that question, Paul, because with our final answer from Stephanie, you've said all eyes will be on the Potomac going forward. What makes our river a national benchmark for water quality and climate change, even as you answer Paul's question in 30 seconds?

FLACKPaul, you raised a fascinating point. I would direct you to an article that George Hawkins, the head of D.C. Water recently wrote, talking about the need for a reformed Clean Water Act. It's in National Democracy Journal and it's a fascinating look at how we can bring the Clean Water Act into the 21st century to have more cost effective interventions, many of which will depend on investing in nature and natural approaches and using buffers and other things that will help keep our water cleaner.

NNAMDIStephanie Flack is Potomac River Project director for The Nature Conservancy. Stephanie, thank you for joining us. Matthew Logan is president of Potomac Riverkeeper. Matthew, thank you for joining us.

LOGANYou're welcome.

NNAMDITom Jacobus is general manager of the Washington Aqueduct. Tom, thank you for joining us.

JACOBUSThank you.

NNAMDIAnd thank you all for listening. I'm Kojo Nnamdi.