By Lisa M. Campbell, Lisa R. Burchi, and Barbara A. Christianson
On October 30, 2020, the U.S. Environmental Protection Agency (EPA) issued a final rule on the Agricultural Worker Protection Standard (WPS) regulation that revises the requirements on the pesticide application exclusion zone (AEZ), defined as an “area surrounding the point(s) of pesticide discharge from the application equipment that must generally be free of all persons during pesticide applications.” According to EPA, the targeted changes improve the enforceability and workability of the AEZ requirements, decrease regulatory burdens for farmers, and maintain critical worker protections. EPA also states the revisions made to the AEZ are consistent with the 2018 Pesticide Registration Improvement Extension Act of 2018 (PRIA 4).
The final AEZ requirements will go into effect on December 29, 2020.
EPA initially promulgated the WPS regulation in 1992 under EPA’s Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorities to protect farm workers from pesticide exposures in production agriculture. According to EPA, “WPS is a uniform set of requirements for workers, handlers, and their employers that are generally applicable to all agricultural pesticides and are incorporated onto agricultural pesticide labels by reference. Its requirements complement the product-specific labeling restrictions and are intended to minimize occupational exposures generally.”
In 2015, EPA issued significant revisions to the 1992 WPS. Of particular significance, 2015 revisions included a new provision requiring agricultural employers to keep workers and all other individuals out of the AEZ during outdoor pesticide applications. The AEZ was set at 25 feet in all directions for ground pesticide applications when sprayed from a height greater than 12 inches, and 100 feet in all directions for outdoor aerial, air blast, air-propelled, fumigant, smoke, mist, and fog pesticide applications. This provision was controversial, however, with state regulators expressing concerns with enforcing the complex AEZ requirements and farm owners expressing concerns with applying and complying with pesticide regulations.
EPA states in the final rule that it clarified and simplified the AEZ requirements based in part on input from state pesticide regulatory agencies and agricultural stakeholders after the adoption of the 2015 WPS rule. Consistent with PRIA 4, EPA is implementing changes related only to the AEZ requirements in the WPS. These targeted changes include:
- Modifying the AEZ so it is applicable and enforceable only on an agricultural employer’s property, as proposed.
- Adding clarifying language indicating that pesticide applications that have been suspended due to individuals entering an AEZ on the establishment may be resumed after those individuals have left the AEZ.
- Excepting agricultural employers and handlers from the requirement to suspend applications owing to the presence within the AEZ of persons not employed by the establishment who are in an area subject to an easement that prevents the agricultural employer from temporarily excluding those persons from that area.
- Allowing the owners and their immediate family (as defined in 40 C.F.R. Section 170.305) to shelter in place inside closed buildings, housing, or shelters within the AEZ, and allowing the application performed by handlers to proceed, provided that the owner has instructed the handlers that only the owner’s immediate family are inside the closed shelter and that the application should proceed despite their presence.
- Simplifying and clarifying criteria and factors for determining AEZ distances of either 100 or 25 feet by basing the AEZ on application method. EPA has removed the language and criteria pertaining to spray quality and droplet size, as proposed, so that all ground spray applications from a height greater than 12 inches are subject to the same 25-foot AEZ.
EPA states that many of the changes proposed in November 2019 were retained in the final rule. Changes that were made include the following:
- The final rule adds clarifications and revisions to the regulatory text regarding providing an immediate family exemption to the AEZ requirements. The final rule provides that the AEZ exemption for the immediate family members applies only when the farm owner or immediately family members are inside an enclosed building within the AEZ.
- The final rule also clarifies that owners may permit handlers to continue with applications when the owner’s family is inside an enclosed structure or home, provided that the owner has expressly instructed the handlers that only the owner’s immediate family members are inside the closed shelter and that the application should proceed despite their presence within that structure.
The final rule is available at EPA-HQ-OPP-2017-0543. Additional information on the revisions to the AEZ requirements is available here.
By Lisa M. Campbell, Timothy D. Backstrom, and James V. Aidala
On June 3, 2020, the U.S. Court of Appeals for the Ninth Circuit (Ninth Circuit) issued an opinion in National Family Farm Coalition v. EPA, No. 19-70115, vacating the U.S. Environmental Protection Agency’s (EPA) 2018 decisions to extend the conditional registrations for three reduced volatility dicamba herbicides, Bayer’s XtendiMax, Corteva’s FeXapan, and BASF’s Engenia.
The manufacturers of these dicamba products designed them to facilitate control of glyphosate resistant weeds in strains of soybeans and cotton that have been genetically modified to be dicamba tolerant (DT). Although the manufacturers intended these dicamba products to be less volatile and less susceptible to drift into adjacent non-target areas than previous formulations of dicamba, there were nonetheless many complaints that the products cause damage to non-tolerant crops and other vulnerable vegetation. The Petitioners that challenged EPA’s decision to extend the conditional registrations for these reformulated dicamba products include a group representing small farmers who claim that the new dicamba products have damaged their crops (National Family Farm Coalition) and several non-governmental organizations that routinely oppose new pesticide registrations (the Center for Food Safety, the Center for Biological Diversity, and Pesticide Action Network North America).
Although the case included some allegations by the Petitioners that EPA did not comply with the requirements of the Endangered Species Act, the court did not reach those issues. The court found unanimously that EPA’s decision to extend the conditional registrations for the three dicamba herbicides did not satisfy the requirements of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Specifically, the court found that the administrative record compiled by EPA did not include “substantial evidence” supporting EPA’s determination that registering the new uses “would not significantly increase the risk of any unreasonable adverse effects on the environment.” EPA is required under FIFRA Section 3(c)(7)(B) to make this determination to grant a conditional registration of new uses of a currently registered pesticide. The court concluded that EPA could not make this required determination because, the court stated, the record shows that EPA “substantially understated the risks that it acknowledged” and also “entirely failed to acknowledge other risks.”
According to the court, EPA made six material errors in its analysis supporting the registrations. First, the court stated that EPA understated the amount of acreage planted with DT crops in 2018, and consequently also underestimated the amount of the new dicamba products that would be applied that year, even though the decision to extend the conditional registrations for the new dicamba products was not issued until the end of the 2018 growing season. Second, in the court’s view, EPA improperly found that the number of complaints concerning damage to non-target crops and vegetation by the new dicamba products might be over-reported when the record included overwhelming evidence that non-target damage was being under-reported. Third, the court stated that EPA refused even to estimate how much damage to non-target vegetation would be caused by the new dicamba products when the record contained sufficient information for EPA to make such an estimate. Fourth, according to the court, EPA refused to acknowledge the substantial risk of non-compliance with the large number of detailed restrictions set forth in the 40-page approved label, although the court found that “there was substantial evidence that even conscientious applicators had not been able to consistently adhere to the label requirements.” Fifth, the court believes EPA failed to acknowledge the anti-competitive effect of the new technology, which encourages other growers to use DT crops even if they do not use the new dicamba products, to avoid damage from nearby applications. Sixth, according to the court, EPA failed to acknowledge the social cost being caused in small communities where damage caused by use of the new dicamba products has turned formerly amicable neighbors against each other.
Based on all of these purported deficiencies, the court held that EPA’s rationale for determining that the risk of unreasonable adverse effects would not be significantly increased by the new dicamba uses, and that the registration for the new dicamba products could therefore be extended for two additional years, was not supported by “substantial evidence” in the administrative record taken as a whole. The court also held that remanding the matter to EPA for further action without vacatur would not be appropriate because EPA did not satisfy the requirement to extend the conditional registrations. Instead, the court simply vacated the registrations and invited EPA to try again. The court acknowledged that such a decision would cause disruption, especially for those growers that have already purchased DT seeds and dicamba herbicides for this year's growing season, but concluded that no remedy other than vacatur would be appropriate given the deficiencies in the administrative record.
When FIFRA was amended to allow new pesticide products to be “conditionally” registered even though the applicants had not submitted data to satisfy all applicable requirements, the focus was primarily on allowing registration of new products that are “substantially similar” to already registered products. FIFRA Section 3(c)(7) also allows conditional registrations to be issued for new uses of existing active ingredients and for new active ingredients without all required data if EPA has sufficient information to make certain findings while it waits for additional data, but requires that EPA be able to determine that certain requirements can be met even though not all of the supporting data that will ultimately be needed are yet available.
This court’s decision illustrates the type of problems that can occur when EPA issues a conditional registration for new products that are not “substantially similar” to registered products. The court’s view of the sufficiency of the record in this case sets a high bar for the determinations that must support other types of conditional registrations. This problem was previously illustrated when a reviewing court vacated a new registration for a new nanosilver product even though there were already registered nanosilver products. In that case, because EPA chose as a matter of policy to characterize the product as a new active ingredient, it was required to make a “public interest” determination under FIFRA Section 3(c)(7)(C). When the administrative record was deemed insufficient to support this mandatory determination, the reviewing court vacated the registration.
In the case of the new dicamba products, to grant conditional registrations for new uses of an existing active ingredient, EPA was required to determine that the new uses on DT soybeans and cotton would not “significantly increase the risk of unreasonable adverse effects on the environment” under FIFRA Section 3(c)(7)(B). The court found the record supporting this mandatory determination to be insufficient, resulting in the court’s vacatur of EPA’s decision. These two reviewing courts have taken a relatively deep dive into the administrative record supporting a conditional registration for a new use of an existing active ingredient or a new active ingredient in evaluating whether substantial evidence in the record supports the determinations required by FIFRA. Whether future decisions will maintain such a stringent evidentiary standard will be important to monitor.
By Susan M. Kirsch and Barbara A. Christianson
On October 24, 2019, the U.S. Environmental Protection Agency (EPA) announced that it is proposing narrow updates to the Worker Protection Standard’s (WPS) provision on the Application Exclusion Zone (AEZ) requirements. By narrowing updates to the WPS, EPA states that it will “improve the long-term success of the agency’s Application Exclusion Zone requirements” and “would improve enforceability for state regulators and reduce regulatory burdens for farmers.” EPA believes narrowing updates to the WPS will also continue to protect the health of farm workers and other individuals near agricultural establishments who could be exposed to agricultural pesticide applications. The proposed updates are consistent with the 2019 Pesticide Registration Improvement Act (PRIA).
EPA Administrator Andrew Wheeler states that EPA’s proposal “would enhance the agency’s Application Exclusion Zone provisions by making them more effective and easier to implement.” Wheeler states that “our proposal will make targeted updates, maintaining safety requirements to protect the health of those in farm country, while providing greater flexibility for farmers.”
EPA will hold a 90-day public comment period and seeks input on select updates that were publicly suggested to EPA by both state pesticide agencies responsible for enforcing the provision and agricultural stakeholders since the AEZ requirement was adopted in 2015. The proposed updates are also consistent with the U.S. Department of Agriculture’s comments during a May 2017 meeting of EPA’s Pesticide Program Dialogue Committee.
Specifically, EPA is proposing to:
- Modify the AEZ so it is applicable and enforceable only on a farm owner’s property, where a farm owner can lawfully exercise control over employees and bystanders who could fall within the AEZ. As currently written, the off-farm aspect of this provision has proven very difficult for state regulators to enforce. These proposed changes would enhance both enforcement and implementation of the AEZ for state regulators and farm owners, respectively. Off-farm bystanders would still be protected from pesticide applications with the existing “do not contact” requirement that prohibits use in a manner that would contact unprotected individuals.
- Exempt immediate family members of farm owners from all aspects of the AEZ requirement. This will allow farm owners and their immediate family members to decide whether to stay in their homes or other enclosed structures on their property during certain pesticide applications, rather than compelling them to leave even when they feel safe remaining.
- Add clarifying language that pesticide applications that are suspended due to individuals entering an AEZ may be resumed after those individuals have left the AEZ.
- Simplify the criteria for deciding whether pesticide applications are subject to the 25- or 100-foot AEZ.
Publication of the proposed rule in the Federal Register will begin a 90-day comment period. Comments are due on or before January 30, 2020.
When EPA included the AEZ concept in its 2015 WPS updates, of chief concern for pesticide applicators, farmers, and state departments of agriculture were the compliance and enforcement practicalities of aspects of the AEZ requirements. For example, in scenarios where the AEZ extends to nearby roads and highways, it is difficult for pesticide applicators to be aware of every vehicle that may pass by that could enter the AEZ during applications. It is unclear if the revised AEZ requirements adequately address these practical realities. Agricultural stakeholders and pesticide applicators may wish to submit comments on the proposed revisions.
Additional information on the WPS is available on EPA's website.
By Lisa M. Campbell, James V. Aidala, and Timothy D. Backstrom
On October 31, 2018, the U.S. Environmental Protection Agency (EPA) announced that it is extending the registration of dicamba for two years for “over-the-top” use (application to growing plants) to control weeds in fields for cotton and soybean plants genetically engineered to resist dicamba. EPA states that the registration for these dicamba products will expire on December 20, 2020, unless EPA decides to further extend it. EPA states that the label changes described below were made to ensure that these products can continue to be used effectively while addressing potential concerns to surrounding crops and plants. EPA’s dicamba registration decisions for the 2019-2020 growing season are:
- Two-year registration (until December 20, 2020);
- Only certified applicators may apply dicamba over-the-top (those working under the supervision of a certified applicator may no longer make applications);
- Prohibit over-the-top application of dicamba on soybeans 45 days after planting and cotton 60 days after planting;
- For cotton, limit the number of over-the-top applications from four to two (soybeans remain at two over-the-top applications);
- Applications will be allowed only from one hour after sunrise to two hours before sunset;
- The downwind buffer for all applications will remain at 110 feet, but in those counties where endangered species may exist, there will also be a new 57-foot buffer around the other sides of the field;
- Clarify training period for 2019 and beyond, ensuring consistency across all three products;
- Enhanced tank clean out instructions for the entire system;
- Enhanced label to improve applicator awareness on the impact of low pH’s on the potential volatility of dicamba; and
- Label clean up and consistency to improve compliance and enforceability.
EPA states that it has reviewed substantial amounts of new information and has determined that the continued registration of these dicamba products with the specified use restrictions meets the Federal Insecticide, Fungicide, and Rodenticide Act’s (FIFRA) registration standards. EPA also determined that extending these registrations with the new safety measures will not affect endangered species. More information on this extension is available on EPA’s website; more information on other dicamba issues is available on our blog.
As expected, this decision allows the continued use of the newer dicamba formulations intended to be applied on dicamba-resistant crop varieties. Of particular note is that EPA has not granted a permanent Section 3 registration, instead granting a time-limited, two-year registration which EPA states will expire at the end of 2020. This will allow EPA more time to assess in more detail whether the new use restrictions will further reduce problems of misuse, label complexity, or unexpected drift which have been reported in past growing seasons.
The most vexing issue behind plant injury reports over the past few years is whether these reports are mostly due to misuse (e.g., applicators who do not use the new formulations designed to reduce volatility, which is a label violation since the “old dicamba” product is considered more prone to cause drift injury), or, are due to characteristics of the new formulations which are not yet fully understood and which lead to unexpected volatility and other drift problems. Some have also argued that problems are also due to the difficulty (or reluctance) in following the more prescriptive requirements for the new formulations. The two-year renewal will continue to see EPA closely monitor injury and misuse reports, as well as continued academic and registrant research into the likely cause of any reported problems.
EPA’s decision also imposes further requirements for additional training, timing, record-keeping, and stewardship when using the new dicamba formulations that are designed to reduce or to eliminate those plant injury reports that are not clearly attributable to misuse of the older dicamba products. EPA will rely on state officials to report and evaluate the experience of users in their respective states, especially concerning whether the additional training and stewardship requirements significantly reduce local injury reports.
By Margaret R. Graham
On September 20, 2018, the U.S. Environmental Protection Agency (EPA) announced it would be hosting a webinar titled “Best Practices for Ground Application” on October 25, 2018, from 2:00 p.m. to 3:30 p.m. (EDT). The announcement states that this webinar is tailored for “growers, pesticide applicators, pest management professionals, and other interested stakeholders who work in crop production.”
The webinar will be presented by Dr. Greg Kruger, a weed science and application technology specialist from the University of Nebraska-Lincoln and will cover different methods of ground application, best practices for reducing pesticide spray particle drift when using ground application equipment, and a discussion of the optimization of weed control. Registration is available online.
More information on other pesticide applicator issues, including the Worker Protection Standard, is available on our blog.
By Lisa M. Campbell and Susan M. Kirsch
On February 15, 2018, the U.S. Environmental Protection Agency (EPA) added resources to its website regarding the Worker Protection Standard (WPS) and the Application Exclusion Zone (AEZ) requirements of the WPS. As of January 2, 2018, full compliance is required with all of the AEZ-related requirements in the WPS. The new EPA website resources include:
While many welcome EPA’s guidance on the many thorny issues presented by the WPS and AEZ requirements, some believe that in places, the newly issued guidance raises additional questions and leaves some significant questions unaddressed. Given the controversy over this rule, this new guidance should be reviewed closely.
More information on the WPS, including EPA’s December 2017 announcement of its intention to revise the AEZ and other WPS provisions, and current implementation deadlines can be found on our blog under key word WPS and key phrase Worker Protection Standard.
By Lisa M. Campbell and James V. Aidala
On January 3, 2018, officials with the Arkansas State Plant Board (Plant Board) voted 11 to 3 to uphold its statewide ban of dicamba. The vote came after a subcommittee of the state's legislative council asked the board to reevaluate its earlier decision. The subcommittee will revisit the Plant Board's decision again on January 16, 2018. That the subcommittee plans to revisit its decision in just two weeks is noteworthy and illustrates the controversy surrounding this and other similar state bans.
Given the panel will meet again in the next few weeks, this may indicate that the legislature is urging some greater flexibility -- that is, a longer application window that would allow some growers to use the herbicide, along with consideration of any data about the newer formulations designed to reduce the likelihood of drift.
Whether any “flexibility” or additional data will be sufficient to convince the Plant Board that the product can be used without expecting drift incidents in the future is not clear, especially since the issue has become a point of intense political debate.
More information on dicamba issues is available on our blog under key word dicamba.
By James V. Aidala, Lisa M. Campbell, and Timothy D. Backstrom
On December 14, 2017, the Missouri Department of Agriculture (MDA) announced that it issued and collected the first round of fines resulting from investigations regarding the pesticide dicamba. The news release states that the first wave of civil penalties issued to applicators, all from Dunklin County, were issued as “a result of investigations of complaints during the 2016 growing season,” and the “civil penalties, ranging from $1,500 to $62,250, were issued for pesticide misuse (off label use and drift).” Further, in 2016, “Department staff conducted and completed 121 complainant investigations. Those complainants named approximately 60 applicators, who were investigated as a result of complaints. In addition, the Department investigated nearly 100 non-Dicamba related incidents.”
This is the first group of what is anticipated to be a large number of dicamba-related enforcement cases, given the extensive number of, and publicity concerning, the reported incidents involving dicamba. Reported incidents in Arkansas were even more numerous than those in Missouri. About one-third of the reported incidents in Missouri have now been attributed to only six applicators. One applicator alone was cited for 149 discrete violations, which indicates that problems with the new dicamba formulations may be less widespread than some originally feared based on the large number of reported incidents. Moreover, some of the states where the new dicamba products were widely used have reported very few incidents. In the aggregate, this data suggests that better stewardship training accompanied by rigorous enforcement may be sufficient to greatly reduce the future incidence of unexpected off-site movement of the new dicamba formulations.
More information on dicamba issues is available in our blog.
By Lisa M. Campbell, Timothy D. Backstrom, and James V. Aidala
On October 13, 2017, the U.S. Environmental Protection Agency (EPA) announced that it had reached an agreement with Monsanto, BASF, and DuPont on measures “to further minimize the potential for drift to damage neighboring crops from the use of dicamba formulations used to control weeds in genetically modified cotton and soybeans,” and “new requirements for the use of dicamba ‘over the top’ (application to growing plants) will allow farmers to make informed choices for seed purchases for the 2018 growing season.”
EPA states that in a series of discussions, it “worked cooperatively with states, land-grant universities, and the pesticide manufacturers to examine the underlying causes of recent crop damage in the farm belt and southeast,” “sought extensive input from States and [U.S. Department of Agriculture (USDA)] cooperative extension agents from across the country, as well as the pesticide manufacturers, on the underlying causes of damage,” and “reviewed all available information carefully and developed tangible regulatory changes for the 2018 growing season.”
The label changes that certain registrants of dicamba products have agreed to impose additional requirements for "over the top" use of these products next year. These new requirements include:
- Classifying products as "restricted use," permitting only certified applicators with special training, and those under their supervision, to apply them; dicamba-specific training for all certified applicators to reinforce proper use;
- Requiring farmers to maintain specific records regarding the use of these products to improve compliance with label restrictions;
- Limiting applications to when maximum wind speeds are below 10 mph (from 15 mph) to reduce potential spray drift;
- Reducing the times during the day when applications can occur;
- Including tank clean-out language to prevent cross contamination; and
- Enhancing susceptible crop language and recordkeeping with sensitive crop registries to increase awareness of risk to especially sensitive crops nearby.
This announcement follows two compliance advisories issued by EPA in August 2016 and July 2017 on what EPA described as the high number of complaints received regarding crop damage from the alleged misuse of herbicides containing the active ingredient dicamaba. EPA’s August 2016 compliance advisory stated that the Missouri Department of Agriculture received 117 complaints alleging misuse of pesticide products containing dicamba, and Missouri growers estimated that more than 42,000 acres of crops had been adversely affected. Further, that similar complaints alleging misuse of dicamba products were received by Alabama, Arkansas, Illinois, Kentucky, Minnesota, Mississippi, North Carolina, Tennessee and Texas. In the spring of 2016, EPA issued a proposal to register dicamba to control weeds in cotton and soybean that have been genetically engineered to tolerate dicamba. In November 2016, EPA issued a conditional registration for dicamba on dicamba-tolerant cotton and soybean to Monsanto for its Xtendimax product; and EPA recently approved a label amendment made by Monsanto for Xtendimax which includes “additional restrictions further minimizing off-field movement of the active ingredient dicamba.”
EPA’s July 2017 compliance advisory states that by early July, EPA had received reports of hundreds of complaints to state agencies in Arkansas, Missouri, and Tennessee, a significant increase from 2016; lists the three new conditional registrations issued late last year (including Xtendimax); and states that only these new registered products may be lawfully applied over-the-top of growing soybeans and cotton. It discusses what it describes as unlawful applications of dicamba products, and states that “[e]xcept for the new conditionally registered dicamba products, application of a dicamba product during either the cotton or soybean crop growing season is unlawful under FIFRA.”
EPA’s July 2017 compliance advisory further states that each of the conditionally approved dicamba herbicide products has labeling that provides mandatory directions for use, restrictions, and special precautions that must be followed, and that the labels of the new products require specific and rigorous drift mitigation measures to further reduce the potential for exposure from spray drift including:
- No application from aircraft;
- No application when wind speed is over 15 mph;
- Application only with approved nozzles at specified pressures; and
- Buffer zones to protect sensitive areas when the wind is blowing toward them.
The reports of and concerns about potential damage to crops in connection with the application of dicamba illustrate a problem that has long been discussed, which is the potential for unintended impact when a pesticide that has been specifically designed for use with one or more crops that have been genetically engineered to be tolerant to the pesticide is applied in close proximity to other crops that do not share these tolerant characteristics.
The dicamba case also illustrates the differing views on potential misuse issues. Some observers have questioned whether all of the reported dicamba incidents were due to misuse or misapplication of the product. Although the 2018 label changes are designed to mitigate the potential for damage to sensitive crops, some question whether some unanticipated or as yet not completely understood factor may be at play in some of the incident reports. One issue raised by some researchers concerns potential unexpected volatility of the product even when applied according to the label directions by well-trained applicators. The registrants have disputed this suggestion, but it is an area which will likely be more thoroughly researched over the next few growing seasons.
More information on EPA’s regulatory action on dicamba is available on EPA’s website.
By Lisa M. Campbell and Susan Hunter Youngren, Ph.D.
The California Department of Pesticide Regulation (DPR) announced on February 26, 2015, a revision to the process for evaluation of the potential for a pesticide to move off-site into surface water when the pesticide is used in an urban area. The former evaluation method followed the U.S. Environmental Protection Agency (EPA) approach with California specific parameters. This revision will continue to use the EPA approach but allow incorporation of a module specific for California urban settings.
Potential adverse impacts on surface water from use of pesticides are assessed in California by DPR’s Environmental Monitoring Branch’s Surface Water Protection Program (SWPP) using EPA methodology. The SWPP uses the EPA evaluation method for proposed agricultural pesticide registrations based on PE5 (PRZM-EXAMS version 5) and Tier 2 modeling scenarios but there have been no consistent methods for assessing potential pesticide runoff on impervious surfaces in an urban setting. The new California urban module includes the following improvements that are designed to be further representative of urban conditions in California:
* Introduction of four types of surfaces by permeability and water sources;
* Consideration of pesticide transport induced by dry-weather runoff from impervious surfaces;
* Separation of impervious and pervious portions in the modeling scenarios;
* Use of prescheduled lawn irrigation;
* Characterization of residential and commercial/industrial areas to reflect California urban conditions; and
* Aggregations of water, sediment, and pesticide yields for the urban watershed.
The urban model is designed particularly for evaluating pesticides applied outdoors in areas with large amounts of impervious surfaces such as residential areas, commercial/industrial facilities, and highway and road rights-of-way applications. Pesticide products of interest would be those that have the potential for impact to surface waters through overspray to impervious surfaces in these areas