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---August 28, 1997---
NEW U.S. WASTE POLICY, PT. 2: SEWAGE SLUDGE
In the mid-1980s, a citizens' organization in New Jersey--Clean Ocean Action, led by Cindy Zipf--launched an aggressive campaign to protect the oceans from the dumping of toxic sewage sludge. They were up against extraordinary power: U.S. Environmental Protection Agency (EPA) opposed them; New York and New Jersey environmental officials opposed them; nearly every municipal government opposed them. But they persevered and won.
Thus in the early 1990s, municipalities had to find other places to dump their sewage sludge.
As we saw last week, sewage sludge is the mud-like material that remains after bacteria have digested the human wastes that flow from your toilet into your local sewage treatment plant. If human wastes were the only substances entering the sewage treatment plant, then sewage sludge would contain only nutrients and should be returned to the land.
Unfortunately, most sewage treatment plants receive industrial toxic wastes, which are then mixed with the human wastes, creating a poorly-understood mixture of nutrients and industrial poisons. Furthermore, many American cities have built sewage systems that mix storm water runoff with the regular sewage; every time a rain storm scours these cities' streets, additional toxins are added to the sewage sludge.
As a result, sewage sludge contains a strange brew of nutrients laced with low levels of PCBs [polychlorinated biphenyls]; dioxins and furans; chlorinated pesticides [such as DDT, DDD, DDE, dieldrin, aldrin, endrin, chlordane, heptachlor, lindane, mirex, kepone, 2,4,5-T, and 2,4-D]; carcinogenic polynuclear aromatic hydrocarbons [PAHs]; heavy metals [arsenic, mercury, lead, selenium, cadmium, etc.]; bacteria, viruses, parasitic worms, and fungi;[1] industrial solvents; asbestos; petroleum products, and on and on. American industry uses roughly 70,000 different chemicals and any of these can be found in sewage sludge --depending on who's pouring what down the drain at any given time and place. In addition to the original chemicals, unique metabolites and degradation products develop anew in sludge. To give but one example: trimethylamine can be converted to the powerful carcinogen, dimethylnitrosamine.[2]
The U.S. produces 5.3 million metric tonnes (11.6 billion pounds) of sewage sludge each year (that's dry weight, not including the weight of the water that carries it). Today about 16% of U.S. sewage sludge is incinerated and the ashes are buried in landfills; 38% of sludge is landfilled directly; 36% is spread onto farmland or forest land or otherwise mixed into soils; and 10% is handled in other ways (piled on the land and abandoned, for example).[3]
The sewage treatment industry --and the municipal governments that employ them --represent a powerful political force in the U.S. Together in the late 1980s they figured out that the cheapest thing to do with sewage sludge is to spread it onto or into the land, preferably as close to its point of origin as possible, to minimize transport costs.
However, there were obstacles to overcome. The public thinks of sewage sludge as dirty, smelly and dangerous. Few people thought sewage sludge sounded good as fertilizer for food. So the industry hired a public relations firm, Powell Tate, and renamed sewage sludge "biosolids." They convinced U.S. Environmental Protection Agency (EPA) to go along with this verbal detoxification. The Federation of Sewage Works Associations also renamed itself --they are now the Water Environment Federation (WEF).[4]
The scientific literature on sewage sludge is large, but much of it consists of articles intended to break down public resistance to the use of sewage sludge on farm land. It is "happy literature," not necessarily honest literature. Nevertheless, there is a core of serious research that has tried to discover what the consequences might be if farmers adopted sewage sludge as fertilizer. In recent months, we have examined this literature, and here is what we found:
** Sewage sludge is mutagenic (it causes inheritable genetic changes in organisms),[5,6] but no one seems sure what this means for human or animal health. In its regulations for sewage sludge, EPA has simply ignored this information.[7,8]
** Two-thirds of sewage sludge contains asbestos. Because sludge is often applied to the land dry, asbestos may be a real health danger to farmers, neighbors and their children.[9,10,11] In its sludge regulations, EPA does not mention asbestos.[7,8]
** EPA issued numeric standards for 10 metals (arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc).[8] However, the movement of metals from soils into groundwater, surface water, plants, and wildlife --and of the hundreds of other toxins in sludge, which EPA chose not to regulate --are poorly understood.[12] Their movement depends upon at least the following factors: plant species, soil type, soil moisture, soil acidity or alkalinity, sludge application rate, slope, drainage, and the specific chemistry of the toxins and of the sludge itself.[13,14]
** Soil acidity seems to be the key factor in promoting or retarding the movement of toxic metals into groundwater, wildlife, and crops.[15,16] In creating its regulations, EPA assumed that sludge-treated land would be under the perpetual care of a farmer who would lime the soil to keep it alkaline and prevent the metals from moving dangerously. For this reason, a buildup of toxic heavy metals in soils is often dismissed as irrelevant. But in the real world, farmers go out of business while acid precipitation keeps soaking soils with dilute acid year after year. A buildup of toxic heavy metals in soil today[17] seems to be a prescription for trouble 30 to 50 years down the road.[18]
The National Research Council (NRC) of the National Academy of Sciences gives sewage sludge treatment of soils a clean bill of health in the short term, "as long as... acidic soils are agronomically managed." However the NRC acknowledges that toxic heavy metals and persistent organic pollutants can build up in treated soils: "Potentially harmful trace elements and certain persistent organic chemicals in raw municipal wastewater become concentrated in the sludge during the treatment process, and, with repeated applications of sludge to the land, these chemicals may accumulate in the soil," says the NRC.[3] If such a buildup occurs and the soils are no longer "agronomically managed" but are left alone to be washed by acid rain in perpetuity, what will happen then?
** Research clearly shows that, under some conditions (which are not fully understood), toxic metals and organic industrial poisons can be transferred from sludge-treated soils into crops.[19] Lettuce, spinach, cabbage, Swiss chard, and carrots have all been shown to accumulate toxic metals and/or toxic chlorinated hydrocarbons when grown on soils treated with sewage sludge.[20,21,22,23,24]
** In some instances, toxic organics contaminate the leafy parts of plants by simply volatilizing out of the sludge.[2]
** There is good reason to believe that livestock grazing on plants treated with sewage sludge will ingest the pollutants --either through the grazed plants, or by eating sewage sludge along with the plants. Sheep eating cabbage grown on sludge developed lesions of the liver and thyroid gland. Pigs grown on corn treated with sludge had elevated levels of cadmium in their tissues.[25] Cows, goats, and sheep are also likely to eat sludge directly. In grazing, these animals may pull up plants by the roots and thus ingest substantial quantities of soil. A cow may ingest as much as 500 kg (1100 pounds) of soil each year.[26]
** Small mammals have been shown to accumulate heavy metals after sewage sludge was applied to forest lands. Shrews, shrew-moles, and deer mice absorbed metals from sludge.[27] Insects in the soil absorb toxins, which then accumulate in birds.[28]
** It has been shown that sewage sludge applied to soils can increase the dioxin intake of humans eating beef (or cow's milk) produced from those soils.[29,30] Humans in the industrial world already carry unsafe burdens of dioxin in their bodies, according to EPA. (See REHW #390, #391, and #414.) From a public health perspective, any unnecessary addition of dioxin to human food chains is unthinkable and unacceptable.
** Sewage sludge is produced in the huge quantities day after day, year after year. Sludge never takes a holiday. Municipalities find themselves under relentless pressure to get rid of the stuff, day after day after day. It is exceedingly expensive to treat it to clean it up. Towns and cities have every inducement to cut corners, skimp on tests, fudge the numbers, claim that their sludge is cleaner than it really is. Farmers have no capacity to analyze sludge independently; they must rely on the word of the sludge supplier. Only an aggressive, independent oversight agency can protect public health. Where can such an agency be found? Who has confidence that their state government, or U.S. EPA, will play that role?
EPA has acknowledged that it hasn't adequate funding to oversee the nation's sewage sludge management program.[31,32] "At headquarters, staff has been cut dramatically over the last year, and we can only do so much," one EPA official told BIOCYCLE magazine.[31] And a Washington state official said, "...with EPA cutting back from financing the sludge program, the problem will be whether state or local officials have the resources to adequately oversee every [sludge] application site."[3]
Who, then, will protect public health from the purveyors of toxic sludge? Who will protect the nation's agricultural soils from contamination, providing food security for future generations?
And, finally, who will lead the transition to a truly sustainable way of managing human waste?[33]
--Peter Montague
A NEW U.S. WASTE STRATEGY EMERGES, Part 1
A new strategy for disposal of hazardous materials is emerging in the U.S. After years of unsuccessful efforts to gain public acceptance of waste disposal in the oceans, in landfills, and in incinerators, frustrated environmental officials at the federal and state levels now advocate spreading hazardous materials onto and into the land, essentially dispersing dangerous toxins into the environment, leaving no fingerprints.
Typical projects include these:
** For several years, New Jersey Department of Environmental Protection (DEP) has been using monies earmarked for "recycling" to run experiments placing toxic incinerator ash in road beds. In June of 1996, the research entered the real world when toxic ash from the Warren County, N.J., municipal trash incinerator was mixed with asphalt and spread onto the streets of Elizabeth, N.J., a major city. The "ash recycling" operation took place in the dead of night, but local activists managed to videotape it.[1] New Jersey DEP officials defended the operation, saying it was completely safe and exempt from all state and federal waste management laws because it was termed "recycling."[2]
** The phosphate fertilizer industry is lobbying U.S. Environmental Protection Agency (EPA) for permission to spread radioactively-contaminated phosphogypsum onto roadbeds, or to use it as a fertilizer. Phosphogypsum is a waste product of phosphate mining, principally in Florida. By the year 2000, some 870 million cubic meters (30.7 billion cubic feet) of radioactive phosphogypsum waste will be piled up, awaiting disposition. Phosphogypsum contains 30 picoCuries of radium per gram. Radium has a half-life of 1600 years. The phosphate fertilizer industry proposes to hide this radioactive material beneath roadways. The amount of phosphogypsum available in the year 2000 would require 1.3 million kilometers (807,000 miles) of highway --about one-fifth of all the roadways under state and federal control in the U.S. Radioactive waste consultant Marvin Resnikoff says such a program would be a "major public health disaster" because it could cause thousands of cancers among unsuspecting citizens.[3]
** U.S. EPA is actively promoting the "beneficial use" of sewage sludge contaminated with industrial toxins. "Beneficial use" includes ploughing contaminated sludge into soil as fertilizer for crops intended for animal feed and for human food. Many such projects are under way across the country, to the dismay of local citizens concerned about the accumulation of toxic materials in the nation's agricultural soils.
In 1990, EPA wrote, "The Agency will continue to enthusiastically promote and encourage the recovery and reuse of sludge wherever its safe environmental use is possible."[4,pgs.47254-47255] To assure the public that almost any sewage sludge poured on crops is "safe," EPA has made exceptionally creative use of risk assessment.
Sewage sludge is the mud-like material that remains after bacteria have digested the human wastes that flow from your toilet into your local sewage treatment plant. If human wastes were the only thing entering the sewage treatment plant, then sewage sludge would contain only nutrients and should undoubtedly be returned to the land.
Unfortunately, most sewage treatment plants receive industrial toxic wastes, which are then mixed with the human wastes, creating a pernicious mixture of nutrients and industrial poisons. Furthermore, many American cities have sewage systems that mix storm water runoff with the regular sewage; every time a rain storm scours these cities' streets, additional toxins are added to the sewage sludge.
U.S. industry currently uses roughly 70,000 different chemicals. Any of these may be found in sewage sludge, depending upon what chemicals local industries and households are using. In 1988, EPA sampled sludge from 180 sewage treatment plants, but they only looked for 409 chemicals, without sampling for the roughly 69,600 others that they might have looked for. The "detection limits" for many organic chemicals were set so high that few were detected even though many were doubtless present.[5] Of the original 409, EPA narrowed the list to only 28, which were labeled "of concern," ignoring the other 381. From that list of 28, EPA then picked 10 metals that they would regulate: arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc.
Sewage sludge regulations --known as the Clean Water Act Part 503 regulations --were published in the FEDERAL REGISTER February 19, 1993.[6] The regulations were based on a "comprehensive"[4,pg.47252] risk assessment of a "highly exposed individual."[4,pg.47249] In other words, EPA asked how much of each of the 10 pollutants a highly-exposed individual would be exposed to in various scenarios. If their risk assessment showed that this individual would not be harmed by a particular level of pollutants, EPA declared that level safe.
There are several serious flaws in such a procedure. First, no risk assessment is ever "comprehensive" (especially not one based on only 10 out of 70,000 possible chemicals) and to label it such is misleading. Tomorrow's science will very likely prove today's science wrong, so no risk assessment is ever "comprehensive." Secondly, EPA assumed that the "highly exposed individual" did not have any other exposures to toxins besides the exposures created by the sewage sludge. Clearly, this is a false assumption because each of us is exposed to tobacco smoke, automobile exhaust, pharmaceutical preparations, pesticides, and a host of other pollutants in our daily air, water, and food.
Third, and most importantly, concern for the "highly exposed individual" omits the major category of dangers inherent in "beneficial use" of sewage sludge: the slow but steady buildup of toxins in soils and in food-chains that begin in the soils (such as earthworms or insects to birds).[7] As Robert Goodland of the World Bank and waste consultant Abby Rockefeller have recently written, "Land application [of sludge] was implemented in Sweden in the early 1980s with disastrous results, which to date the U.S. EPA seems to be ignoring. Such a practice must lead to accumulation in living tissues of heavy metals and persistent organic chemicals: first they accumulate in the soil, then in decomposer microbes and soil-conditioning invertebrates. Other life forms are damaged as thousands of non-biocompatible substances move up the food chain. The toxic effect on crops, as well as on the consumers of such crops, is buying risks for the future."[8] It has been shown, for example, that sewage sludge applied to soils can increase the dioxin intake of humans eating beef (or cow's milk) produced from those soils.[9]
The fundamental problem with sewage sludge is that its four main categories of potential pollutants --nutrients, pathogens, toxic organics, and heavy metals --behave differently and cannot all be managed by any single kind of treatment.[8] The goal of "safe management" of such a complex toxic mixture simply cannot be met at any reasonable cost. Ploughing it into cropland doesn't change that fact.
** In Pennsylvania, state environmental officials are promoting the "beneficial use" of coal ash and incinerator ash as a soil amendment, to rehabilitate coal mines and strip-mined lands.[10] A private firm, Beneficial Ash Management, in Morrisdale, Pa., reportedly supplies the ash, which it gets from "power plants, mid-sized industries, and paper manufacturers." Professor Barry Sheetz of Pennsylvania State University, funded by U.S. EPA, is providing the engineering know-how to harden the toxic ash into a cement-like material, which is then placed in mines and onto strip-mined land. The cement-like material is then covered with "synthetic soil" and left. Professor Sheetz says he hopes this provides a permanent solution to the problem of acid mine drainage. More likely, it promises to provide a cheap, permanent solution for toxic wastes generated by coal-burning power plants and incinerators as far flung as the American Ref-Fuel incinerator in Essex County, N.J.; International Paper Company's plants in Erie, and Lock Haven, Pa.; and the Tobyhanna (Pa.) Army Depot, saving each of these facilities large sums of money that would otherwise be spent on toxic waste disposal, and absolving them of liability because their wastes will never again be identifiable or traceable.
** In Washington state, the SEATTLE TIMES recently published a series titled "Fear in the Fields," which documented the disposal, nationwide, of industrial wastes on farmers' fields as "fertilizer." The TIMES reported, "Manufacturing industries are disposing of hazardous wastes by turning them into fertilizer to spread around farms. And they're doing it legally...."
The TIMES gave this typical example:
"A dark powder from two Oregon steel mills is poured from rail cars into the top of silos attached to Bay Zinc Co. under a federal permit to store hazardous waste. "The powder, a toxic by-product of the steel making process is taken out of the bottom of the silos as a raw material for fertilizer.
"'When it goes into our silo, it's a hazardous waste,' said Bay Zinc President Dick Camp. 'When it comes out of the silo, it's no longer regulated. The exact same material. Don't ask me why. That's the wisdom of the EPA.'"[11]
--Peter Montague
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