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~ Agricultural Chemical A . ~ Compames TRADE ASSOCIATION National Agricultural Chemicals Association The National Agricultural Chemicals Association (NACA) has established an ad hoc committee on groundwater pro- tection. The committee includes representatives from eight chemical companies, and NACA's Director of Environmental Affairs serves as the staff representative. NACA is concerned that a ~chemophobia. has been build- ing in the United States because of increasing public concern about the potential health hazards of industrial and agricultural chemicals. It believes that near hysteria occurs in the public whenever pesticides are detected in groundwater at trace levels; this chemophobia is sometimes exacerbated by irresponsible reporting in the mass media. NACA asserts that pesticides rarely reach groundwater. By educating farmers about good pesticide management practices, it believes that most, if not all, problems associated with leaching of pesticides to groundwater could be avoided. The association has addressed the groundwater issue both internally and externally. A NACA-sponsored regulatory conference in April 1984 focused on During the summer of 1984, Holden visited representatives of four agr icultural chemical companies: Monsanto, FMC, Ciba-Geigy, and Union Carbide. Be also interviewed staff members of the National Agricultural Chemicals Associa- tion (NACA), the Washington, D.C., trade association representing the agricultural chemical companies. 105
106 groundwater, with presentations by representatives of the chemical companies, environmental groups, the EPA, the USDA, the American Farm Bureau Federation, and others. At that conference John Moore, the EPA'S assistant administrator for pesticides and toxic substances, encouraged the pesticide industry to Get all the data you can about pesticide products to show whether or not they have a tendency to move into groundwater.. NACA appears to be responding to this challenge; the ground- water protection committee is actively involved in the development of a sampling protocol that could be used to monitor groundwater and soils for pesticide residues. NACA believes this protocol is a critical step in ensuring that future sampling yields reliable and useful water quality data. NACA is also involved in a preventive program. to reduce the possibility of agricultural chemicals leaching through the root zone to groundwater. The association has widely circulated and promoted a paper outlining good agricultural practices to be followed to avoid contamin- ation of groundwater by pesticides. The paper is avail- able on request at no charge. ~~Hihinnallv. NACA has ~ , , sent press releases on pesticide management to the agricultural press, and the information has been published in such journals as Farm Chemicals and Agricultural Consultant and Fieldman. NACK Is aloof advocating the development of scientifically rigorous modeling approaches for delineating areas where leaching of agricultural chemicals is likely to occur. It is strongly believed by NACA that establishment of federal drinking water health advisories for agricultural chemicals is critical. Establishing health advisories for pesticides is a concrete step that NACA believes would help mitigate public panic when pesticides are detected in groundwater. The association maintains that a federally set number system that distinguishes toxic from safe concentrations by assigning a health advisory number will help put into perspective any pesticide residues that might be detected. In ~ACA's view, this number could be readily determined by using the toxico- logical data base already required for product registra- tion. NACA suggests that the acceptable daily intake (ADI) established by the EPA's OPP during the registration process be used to determine health advisories for pesticides in drinking water in the following manner:
107 Bealth advisory = ADI (mg/kg/day) x 10 kg child 1 liter of water/day NACA further believes that health advisories should be established initially for those products that have been detected in groundwater and, subsequently, for those products whose chemical properties suggest a high leaching potential. COMPANIES Monsanto At the headquarters of Monsanto Agricultural Products Company, Bolden discussed the history of groundwater problems associated with the herbicides alachlor (Lasso) and glysophate (Roundup). Alachlor is a versatile herbicide and a profitable product for Monsanto. It is used extensively for pre- emergent control of annual grasses and some broadleaf weeds in corn and soybean production. An estimated 30 percent of field corn and soybeans grown in the United States are treated with alachlor. It was first marketed in 1969 and made huge gains in the market during the 1970s. Sales of alachlor have leveled off in the 1980s, although the herbicide remains an important product for the company. Monsanto believes that alachlor does not pose a serious threat to groundwater quality. Alachlor has been detected in trace amounts (0.6-14.0 ppb) in groundwater in Nebraska, Iowa, Wisconsin, and Ontario, Canada, after normal field applications. it has also been detected in surface-water in Iowa and Ohio (as well as in eight other states) at maximum concentrations of approximately 100 ppb. m e sampling undertaken by Monsanto to quantify groundwater problems associated with the production and application of alachlor has been limited largely to monitoring at manufacturing plants and to supporting work at the Water Quality Laboratory, Heidelberg College, Tiffin, Ohio. In this work, surface-water quality in agricultural watersheds in northwestern Ohio has been monitored for specific pesticides including alachlor. However, no groundwater monitoring of agricultural lands for alachlor was reported by Monsanto despite the handful of detections of the herbicide in groundwater.
108 Glysophate is another important herbicide that Monsanto feels poses no threat to groundwater. The possibility that field-applied glyphosate might be chemically altered to a chemical of concern (nitrosoglysophate) has been reviewed by both Monsanto and the EPA and is considered very unlikely. EMC The main topic of discussion during interviews at the FMC Corporation concerned carbofuran (Furadan), a widely used carbonate insecticide/nematocide that has been detected in groundwater. Carbofuran was first detected in groundwater in Suffolk County, New York, in 1979. As noted in Chapter 2, some 5,100 groundwater samples have been analyzed for carbofuran. It has been detected in about 30 percent of the samples; in 5 to 6 percent the concentration equaled or exceeded the New York health standard of 35 ppb. In Wisconsin, 78 samples have been analyzed for carbofuran. and only 2 detections of the compound have been reported, with the highest concentration at 7 ppb. me sensitive hydrologic conditions of Suffolk County, which contribu- ted directly to the leaching of aldicarb, also influenced the migration of carbofuran to groundwater. FMC removed the product from the market in Suffolk County in 1980. FMC has taken partial responsibility for the degrada- tion of groundwater quality on Long Island, and, where contamination has occurred from the use of carbofuran, FMC has joined with union Carbide in installing and recharging granular activated carbon systems for domestic water supply wells. In response to the groundwater contamination on Long Island, FMC established a research area near Salisbury, Maryland, where conditions were considered worst case (that is, homogenous sandy soils, low organic matter content, shallow water table, and so on). Soil and foliar applications of carbofuran were made to plots in which corn and potatoes were planted. Monitoring wells were installed downgradient and upgradient of the plots, and vacuum lys~meters were used to take soil/water samples. After 12 to 16 months, carbofuran was detected in groundwater samples taken from the monitoring wells. me highest concentration of the compound (30 ppb) was detected in corn plots; concentrations ranging from 1 to 10 ppb were detected In potato plots. The higher
109 concentrations detected were from granular soil applications rather than from foliar applications. These findings prompted F~C to initiate a 3100,000 monitoring study in March 1984 to evaluate the leaching potential of carbofuran in various crops (corn, soybeans, tobacco, cotton, and peanuts) at two sites--one in Maryland and the other In North Carolina. The study is being supervised by O'Brien and Gere, Inc., an engineer- ing consulting firm in Syracuse, New York. The objective is to generate crop-specific data on the potential of carbofuran to leach below the root zone and impact groundwater. FMC also hired another consulting firm, Roux Associates, Inc., of Huntington, New York, to develop an environmental sensitivity assessment for pesticide application. me purpose of this assessment is to identify areas where soil, hydrogeologic, and climatic conditions may allow field-applied pesticides to be transported to groundwater. Major agricultural counties in 13 states including New York, Wisconsin, and Florida were selected for evaluation to determine areas vulnerable to groundwater contamination by pesticide applications. Ciba~Geigy Bolden visited with representatives of Ciba-Geigy's Agricultural Division to discuss the history of ground- water problems associated with the use of three herbi- cides produced by Ciba-Geigy--atrazine, shine (Princep), and metolachlor (Dual). Few detections have been reported of atrazine, shine, and metolachlor residues in groundwater samples. Atrazine has been detected in groundwater in Iowa, Nebraska, and Wisconsin, most commonly in concen- trations less than 3 ppb (an exception is the pain t source in Rusk, Wisconsin, mentioned in Chapter 3); simazine, which is considerably less mobile than a~razine, has been detected in groundwater only in California at low concentrations (3 ppb); and metolachlor has been detected only in Wisconsin's groundwater at a maximum concentration of S5 ppb at a point source. Virtually all the groundwater detections of these herbi- cides have been at concentrations below health standards established in the various states. All three pesticides have low acute toxicities (greater than 2,000 mg/kg LD50 for rats), and one of the Ciba-Geigy representatives
110 pointed out that the LD50 rate for simazine (5,000 mg/kg for rats) is greater than the Logo for table salt. There was no mention by Ciba-Geigy of ongoing groundwater monitoring studies on any of these pesticides. Ciba-Geigy representatives believed health advisories were critically needed. They noted that atrazine and simazine are among the pesticides being considered by the EPA for inclusion in the National Primary Drinking Water Regulations (NPDWR). The representatives noted that if the current minimum detection limit (MDL) for a chemical were made the basis for establishing its maximum contaminant level (MCL), a company would have no motiva- tion for improving analytic capabilities. On the other hand, an MCL set below an MEL is impractical From a regulatory perspective. Ciba-Geigy officials viewed Wisconsin's preventive action limits (PALs) to be an intelligent regulatory action. Similarly to the concept of health advisory namers, PALs provide a number that can trigger a regulatory response before a crisis situation exists and decisions must be made in a highly charged political atmosphere. The Ciba-Geigy representatives believed the lead time provided by PALs could prevent the occurrence of unnecessarily harsh regulatory responses. Union Carbide The purpose of Boldents visit to Union Carbide Agricultural Products was to discuss the company's perspective on the problems caused by the leaching of its product aldicarb (Temik) to groundwater. Aldicarb has been detected in the groundwater of 15 states, with the most serious incident, as described in Chapter 2, having occurred in Suffolk County, New York. Union Carbide representatives stressed that the detection of pesticide residues in groundwater does not necessarily constitute contamination. That is, detect- able levels of certain chemicals in water do not neces- sarily mean that the water is contaminated in the sense that it is not potable. Acceptable residue levels for pesticides in food have been established by the federal government, prompting the Onion Carbide representatives to ask why such levels could not be established for pesticide residues in water.
111 Union Carbide representatives also questioned the toxicological validity of the EPA's unofficial regulatory health guideline for aldicarb of 10 ppb. The toxicology data base for aldicarb is one of the most extensive on record, according to Union Carbide. Additionally, the World Bealth Organization has established a higher ADI than the one established by the EPA. On the basis of the procedure approved by the EPA's Scientific Advisory Panel in June 1983 for deriving a health advisory from an ADI, Onion Carbide contends that the EPA'S health advisory of 10 ppb for aldicarb should be revised to between 30 and 50 ppb. Company representatives pointed out that the environ- mental data base for aldicarb is extensive and now includes approximately 20,000 water and soil samples analyzed by Union Carbide. The detection of aldicarb residues in drinking water has been limited to a few sensitive hydrologic areas and is not an extensive national problem. The label restrictions established in Wisconsin after the detection of aldicarb in the ground- water of the Central Sands region were cited as a sensible and reasonable reaction to a problem that can most likely be managed by moderate changes in agricul- tural practices. In this regard, Union Carbide said pesticide manufacturers should be directly consulted by the EPA or state regulatory agencies if pesticide residues are detected in groundwater. Cooperation between the regulated industry and the regulatory agencies, if a problem is detected, can foster the development and exploration of remedial options. Agrichemical companies are becoming more aware of environmental factors that can potentially contribute to the transport of their products to groundwater. It would appear that through responsible assessment of the poten- tial for transport of their products to groundwater, and because of a desire to limit corporate liability, such companies are becoming partially self-regulating.
