government
Fertilizer Concerns Prompt New Standards Increased attention is being focused on the recycling ofpotentially hazardous industrial wastes into fertilizer Bette Hileman C&EN Washington
O
ne of the Environmental Protec tion Agency's core policies is to encourage the recycling of wastes into useful products. But over the past year, more and more attention has been focused on possible hazards associated with recycling industrial wastes into fertilizer. The topic first attracted attention in the town of Quincy, Wash. There, sever al onion, potato, and hay farmers came to believe that fertilizers had caused their crops to fail, their land to become per manently barren, and their health to de cline. Last July, Duff Wilson of the Seat tle Times published a series of Pulitzer Prize-winning articles about these farm ers and surrounding issues. The articles made it widely known that some fertilizers in the U.S. are made from or mixed with industrial waste and that some have high levels of cadmium, lead, or organic chemicals such as dioxins. They also pointed out that unlike Canada and many European countries, the U.S. has no limits for toxic metals in fertilizers. Fertilizers are regulated entire ly by states, which require that labels list only beneficial plant nutrients. Before the Seattle Times articles were pub lished, few farmers or even soil scientists were aware that hazardous waste is sometimes a raw material for fertilizers. Recently, the Environmental Working Group (EWG), a Washington, D.C.-based nonprofit research organization, used the Toxics Release Inventory, an electronic database from EPA, to analyze the total amount of hazardous waste recycled into fertilizer or put directly onto farmland. The group identified more than 600 companies that sent about 270 million lb of toxic wastes to fertilizer factories and farms between 1990 and 1995. Out of this total, more than 22.5 million lb was sent directly to farms or to facilities that appear to be farms. "This includes 21 million lb 24 MAY 11, 1998 C&EN
of potentially beneficial chemicals and more than 1 million lb of toxic waste, mostly heavy metals, with no potential agricultural application," EWG says in its report. The most common waste materi als transferred to fertilizer plants or farms were zinc, copper, and sulfuric acid, but 6.3 million lb of lead and lead com pounds and 230,000 lb of cadmium also were transferred. Partly as a result of the newspaper ar ticles, EPA established a work group to look at existing data and evaluate the risks from wastes in fertilizer, says Janet Remmers, biologist in EPA's Office of Pollution Prevention & Toxics. In addition, California, Idaho, Mary land, New Jersey, New York, North Da kota, Oklahoma, Oregon, Texas, and Washington are working on new rules or laws that aim to limit toxic heavy metals and—in some states—other contami nants in fertilizers. And the American As sociation of Plant Food Control Officials (AAPFCO) recommended in February that states adopt interim standards based on the Canadian fertilizer regulations for lead, arsenic, and cadmium.
Hettenbach: K061 waste as a taw material
The Fertilizer Institute, which repre sents most of the $12 billion-per-year U.S. industry, claims that toxic waste in its products have caused no real problems, only hysteria. "We believe, based on all the scientific data available about metals in our products and in the food supply, that all of our products and all of our practices right now are absolutely safe," says insti tute spokesman Ron Phillips. He points to FDA market basket stud ies as evidence that heavy metals in food have gone down, not up, over the past few decades. However, even his group has decided that new regulations are in evitable and favors a national approach to regulation, uniformly implemented at the state level, rather than a patchwork of conflicting state rules. The institute also has begun a $1 million research pro gram on fertilizer contaminants. EWG is calling for an outright ban on the use of toxic wastes in fertilizer until enforceable standards for fertilizer con taminants have been developed. It also is calling for testing and labeling of all in gredients in fertilizers. A large variety of wastes—including ce ment kiln dust, spent acids from scrubbers and galvanizing operations, paper-mill sludge, and dust from the stacks of steel recycling plants—with a huge range of contaminants are now being incorporated into fertilizers. There is little scientific con sensus about the effects of these contami nants, even for those heavy metals that have been studied extensively. And much of the research that could establish safe levels of various chemicals has not been done. "Almost weekly, a new waste prod uct comes on the market and no one knows what it is going to do in the soil," says Murray B. McBride, professor of soil chemistry at Cornell University. Three loopholes in federal law allow hazardous wastes to be made into fertiliz er or placed directly on farm fields. One is an exemption in the Resource Conserva tion & Recovery Act that gives steel com panies the right to send ash from electric arc furnaces—technically called Κθ6ΐ waste—to facilities that manufacture a zinc fertilizer called zinc soil amendment. Otherwise, these wastes must be recycled into their pure chemical forms, taken to lined hazardous waste landfills, or sent to a developing country like India for recycling into fertilizer. Another loophole allows companies to send any hazardous waste to a fertiliz er company for recycling as long as the waste meets EPA's rule for the toxicity of wastes that can be placed in lined haz-
Pa.—makes any at tempt to remove Canada's standard for fertilizers is stricter toxic heavy metals, than U.S. rule for sludge says Hettenbach. Bill Liebhardt, Maximum loading Canada's U.S. sewage (kg per hectare) fertilizer rule sludge rule director of the sus tainable agricul Arsenic 15 41 ture program at Cadmium 4 39 the University of Lead 100 300 Mercury 1 17 California, Davis, is Nickel 36 420 highly critical of Selenium 3 100 using Κθ6ΐ waste Zinc 370 2,800 as a raw material. "If I owned a com pany, I wouldn't ardous waste landfills. "If the waste is be involved in something like this. I would safe enough to be stored in these land feel I was putting myself out on a long fills, it is considered safe enough to be limb," he says. recycled into fertilizer," says Todd HetThe product made from Κθ6ΐ waste tenbach, an analyst at EWG. has another drawback. Often it is not a A third loophole allows companies to bioavailable source of zinc. Dwayne G. transfer waste directly to farms if the Westfall, professor of soil science at Col farmer can treat the waste on his or her orado State University, Fort Collins, land and render it "harmless." found that the zinc in fertilizers must be In many cases, waste loopholes al at least 50% water soluble to supply ade low benign, economically advantageous quate zinc to corn. "High correlations use of materials that would otherwise were found between the water solubility have to be landfilled. But in some frac of zinc in the fertilizer material and drytion of the fertilizers made from recy matter production," Westfall says. The cled waste, the levels of toxic metals or solubility of the zinc in the soil amend organic chemicals such as dioxins may ments made from K06l waste varies be be high, says McBride. The consumer tween 0.7 and 40% depending on pro has no way to find out what the con cessing, Liebhardt says. When purchas taminants are and therefore has no ba ing zinc fertilizer made from Κθ6ΐ sis for judging whether a fertilizer is po waste, "farmers are buying a product tentially dangerous. Nonnutritive toxic that they think will alleviate a zinc defi ingredients such as cadmium do not ciency, and it doesn't," he says. have to be listed on the fertilizer's ma Although zinc fertilizers from Κθ6ΐ terial safety data sheet unless the con waste are problematic, the recycling of centration is extremely high—at least some other types of waste into fertilizers 0.1% or 1,000 ppm. may cause much more serious contami In the ongoing fertilizer debate, zinc nation. This is because zinc fertilizers are soil amendments made from K06l waste spread so thinly that when used alone have received the most attention. Κθ6ΐ they are likely to have only a minuscule waste consists of baghouse and flue effect on toxic metal levels in the soil, dusts, much of it ZnFe204, mainly from says McBride. Other fertilizers tend to be steel recycling furnaces. Companies add used in very large volumes. sulfuric acid to the dusts primarily to cre When cement kiln dust—which can ate mixtures of ZnO, ZnS04, and iron have high levels of lead, cadmium, thalli compounds. The material is sold for use um, and sometimes dioxins—is used in on corn, sorghum, flax, and grapes. place of limestone and sometimes mixed Possible problems arise because the with sludge, and thousands of pounds dusts also may contain high levels of cad per acre of this mixture are applied, the mium and lead and in some cases diox levels of thallium, cadmium, and lead in ins. According to Washington State anal the soil could be elevated sharply, yses, zinc fertilizer can have 340 ppt of McBride says. Currently, applying mix dioxins, measured as toxic equivalents. tures of cement kiln dust and sewage Cadmium builds up in soils, is easily ab sludge to land is a fairly common prac sorbed by some plants, and may cause tice, he adds. "There needs to be a stan cancer and reproductive problems in dard for fertilizers," he says. people. Only one U.S. facility that uses Essentially, two rules now are being K06l waste as a raw material—Horse- discussed as the basis for a standard or head Resource Development, Palmerton, guideline for wastes in fertilizers. One is
the U.S. standard that stipulates the max imum levels of heavy metals allowed in sewage sludge applied to land and the maximum levels of metals that are al lowed to build up in soil from sludge applications. The other rule under consideration is the Canadian standard, which applies to both sewage sludge and fertilizer. For several toxic metals, the Canadian stan dard is about 10 times more stringent than the U.S. rule for sewage sludge. The Fertilizer Institute favors using the U.S. sludge rules as a national stan dard for toxic metals in fertilizer. But EPA and many soil scientists are highly critical of this idea. "[Sludge] has a unique pollutant-bind ing matrix, and when placed in the ter restrial environment tightly binds or se questers most of the heavy metals in the [sludge]," writes Alan B. Rubin, senior scientist in EPA's Office of Water in a let ter to the Fertilizer Institute. "No such properties have been adequately docu mented for a large majority of the inor ganic fertilizer products." David R. Bouldin, professor emeritus of soil science at Cornell University, says the sewage sludge standards are not strict enough even for sludge and are therefore totally inadequate for inorganic fertilizers. "These sludge regulations are perhaps okay for places I don't know anything about," he says. "But my expe rience with New York and the Northeast says they are not restrictive enough." The maximum levels of soil contami nation allowed under EPA's sludge rules are higher than the levels permitted in New York State for new housing devel opments, McBride says. Fertilizer legislation proposed in New York State in March is as strict as or strict er than that proposed in any other state. It prohibits the adulteration of commercial fertilizers with solid wastes, hazardous wastes, and hazardous substances, and it requires the state's Department of Agricul ture to test fertilizers for toxic materials. Washington State passed a law in March that adopts the Canadian standard for nine toxic metals in fertilizers and re quires studies of plant uptake of heavy metals in fertilizers. The bill requires that ingredients in all fertilizers sold in Wash ington be listed on the Internet. In February, AAPFCO predicted that most states will adopt rules controlling toxic materials in fertilizers. But despite intense activity at the state level, it will probably be years before EPA proposes national standards, if it ever does.^ MAY 11, 1998 C&EN 25
