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Public Radio's Environmental News Magazine (follow us on Google News)

Toxic Sludge: Coming to a Neighborhood Near You

Air Date: Week of

What's in a name? Whether you call it toxic sludge, or bio-solids, treated waste from America's drainpipes is being used as farm fertilizer these days and there continues to be debate on the benefits versus the possible health risks. Eric Westervelt of New Hampshire Public Radio has this report.


CURWOOD: This is Living on Earth. I'm Steve Curwood. Some call it sludge. Others call it biosolids. It's what's left over from treated waste, mainly human excreta, industrial runoff, and anything else that gets dumped into the sewers. For the last 20 years, treated sludge has been spread on farmlands as a cheap, effective fertilizer. It seemed like a great way to deal with the millions of tons of municipal sewage sludge produced every year. Recycle the organic waste while helping farmers, city hall, and the taxpayer. But there's a problem. Human waste is a great fertilizer, but sludge may be contaminated with all kinds of dangerous substances. Poisonous heavy metals like lead and cadmium. Chlorine-resistant viruses. Industrial chemicals and byproducts like dioxin. As more and more sludge gets put on farm land, more and more citizens are asking about its safety. On the other hand, the biosolids industry and the US Environmental Protection Agency say there's no cause to worry. New Hampshire Public Radio's Eric Westervelt reports.

WESTERVELT: What's in a name? When it comes to the debate over using human waste as farm fertilizer, everything. Most call it by the more traditional name: sludge. But not EPA physical scientist John Walker.

WALKER: I call them biosolids. Because I think it emphasizes the fact that these materials are usable and have a great benefit.

WESTERVELT: The semantic struggle over sludge underscores an increasingly contentious debate across America. Is sludge or biosolids as safe, beneficial, and earth friendly as Walker and others say it is?

(A car engine starts)

WESTERVELT: The answer to George and Keith Richard after more than 10 years of using sludge fertilizer on their family farm is a resounding yes.

K. RICHARD: Well, it's been beneficial in part because it saves on our chemical fertilizer bill, puts more of a natural fertilizer into the soil, builds up our organic matter.

WESTERVELT: The Richards grow foraging grain crops on their 550-acre Greengold Farm in Pembrooke, New Hampshire. The snow is still thick on their field, so George and his son Richard work on their farm truck in their grease-scarred garage next to the barn.

(A motor runs, metal scrapes)

WESTERVELT: Some consumer and citizen groups have rung health and safety alarms about the growing use of municipal biosolids. But the Richards declare it good for the town and the earth, and because they get it for free, it's good for their bank account, too.

G. RICHARD: People are afraid because of the name of the product. I think that's what they're afraid of. And it's all tested, and it's all accepted by the EPA and everybody else. So I think the sludge is as clean as anything you can put on the land.

K. RICHARD: In a landfill or incineration, it can cost anywhere from $25 to $40 a ton. This way it's a lot cheaper for the towns, but people want it to be cheaper for themselves but they don't want it in their back yard. That's half the problem right there.

WESTERVELT: But for others, including some farmers, the problem goes much deeper.

WOMAN: Did anybody from disease control go to that meeting?

MAN: The Green Line meeting? I don't know

WOMAN: No. But they were there at the open meeting.

WESTERVELT: The sun cuts through the windows of the 200-year-old Owen farmhouse in Hopkinton, New Hampshire. Seated around a long pine table are 7 local anti-sludge activists. Organizer Mary Merzi says using waste as fertilizer is a laudable idea, but it's not so simple. Merzi notes that municipal sludge isn't just processed human waste. It's also industrial waste and household materials.

MERZI: Everything that anybody puts down their drain, whether it is a chemical to get rid of mildew, or you're cleaning your bathroom bowl, or you're using ammonia or you're using Clorox all goes into the system, and is also making a waste dump. They don't know the long term effect. What's it doing to our land? We're losing our agricultural land due to development, and now, you know, due to chemical fertilizers and sludge. And I think it's just short-term gain because they don't know what to do with it , and it's the cheapest way out. It comes down to the almighty dollar once again.

WESTERVELT: The group is agitated that sludge might be pumping high levels of toxic heavy metals onto farm fields and into our food. They also fear that human pathogens, or dangerous levels of chlorinated compounds such as dioxin, might also be present. Hillary Nelson is angry that the Agency won't address the potential problem of dioxin in sludge until the turn of the century. And until then --

NELSON: You don't have to test for dioxin. That's not required right now, period. Heavy metals you have to test for, and they do allow certain levels. Now there's a big debate about whether or not those levels are appropriate. Their argument right now is if you put it into good soil and farm land, the heavy metals are bound up in the soils and they don't cause problems. But if you don't keep the farm land in good shape, 10, 20 years from now those metals are going to become active in the soil, they're going to become mobile, and they're going to wind up in people.

WESTERVELT: There's no clear evidence of that so far, but soil scientists Dr. Murray McBride with Cornell University has beenstudying decades-old sludge sites to try to determine whether heavy metals from the fertilizer remain or diminish over time. So far, Dr. McBride's results are not encouraging.

McBRIDE: There seems to be a view within EPA that one could apply these waste materials almost indefinitely and that the cumulative effect would reach some maximum and you'd never go beyond that. And I don't see any evidence for that. The availability of cadmium remains relatively high, so we think at least for that metal there could be a serious problem, and this is again 15 to 20 years after the sludge has been applied. So this problem doesn't go away.

WESTERVELT: Dr. McBride is not convinced the EPA's 1993 regulations governing sludge are tough enough. The EPA's regulations raise the acceptable levels of lead, arsenic, and mercury, above the preliminary guidelines. Citizen groups are calling for a halt to sludge spreading until more studies are conducted. But Wheelabrator, Incorporated, the nation's largest user of treated sludge, disagrees. Jane Forste is a Vice President for Wheelabrator's Biosolids Division.

FORSTE: There have been thousands of research projects conducted. Most of the people who are involved in this type of research, in fact all of the people who have been directly involved in this type of research have concluded that the only things left to do are kind of fine tuning, and that in essence we know most of what we need to know right now in order to proceed with virtually zero risk.

WESTERVELT: And EPA soil scientist John Walker, a sludge expert, says public concerns are natural, but alarmist. Walker admits the Agency's current regulations don't yet include a rigorous examination of dioxin in sludge. Still, he isn't worried.

WALKER: I don't think it's fair to ask society to pay a lot more to manage a waste than it needs to be, particularly when you have a very low risk kind of material like biosolids. And I call it a resource because that's what the data shows it to be. But it's correct to be fearful of it and everything else; I understand that. But it's also correct to understand the science that went behind this rule to say that these numbers are safe. I'm satisfied that we know enough about dioxin and the other organic constituents in biosolids that we're following prudent practice today with the rules of the United States.

WESTERVELT: The alternatives to spreading sludge as fertilizer include incineration, which is costly; and ocean dumping of sludge was recently curbed by the EPA after a long battle by environmentalists. After that fight ended, most of the nation's large environmental groups have been largely silent about land-applied sludge. Groups have to pick their battles, and taking on the Clinton Administration over sludge would be politically risky, especially since the EPA is under fire from anti-regulatory Republicans in Congress. And the future of the EPA's Biosolids Program is seriously in doubt. Walker says the Agency, hurt by budget cuts, will likely rely more and more on outside groups of stakeholders from industry and local government to establish what constitutes good practices in spreading sludge. That only bolsters concerns by citizen groups that those who produce and market sludge might play too great a role in monitoring the product. For Living on Earth, this is Eric Westervelt reporting.



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