1 

### Reducing Volatile Organic Compound Emissions from Pesticides: Analysis of Alternatives for Field Fumigation Methods

Summary

California’s ozone State Implementation Plan (SIP) for the federal Clean Air Act contains a pesticide element that requires the Department of Pesticide Regulation (DPR) to develop and maintain an emission inventory to track volatile organic compound (VOC) emissions from pesticides, and to reduce pesticide VOC emissions by 20 percent from the 1990 base year in four ozone nonattainment areas (NAA), and by 12 percent in a fifth NAA. To compile the emission inventory, DPR multiples the fraction of a pesticide product estimated to be VOCs by the amount of that product applied. The calc ulation is adjusted for fumigants to account for how emissions vary depending on fumigation method, based on monitoring data. The reduction goals have been met in all NAAs for the last two years of the inventory.

Between January 2008 and May 2011, DPR adopted a series of regulations to reduce VOC emissions from fumigant pesticides. One part of the regulations reduces VOC emissions by requiring low-emission fumigation methods in certain NAAs. The regulations include the following types of fumigation method restrictions based on monitoring data: fumigant introduction method, tarping, pre-fumigation so il moisture, post-fumigation water treatments, and application rate limits. DPR developed the re strictions based on an analysis of possible low-emission method alternatives that included VOC reduction effectiveness, technical feasibility and availability, compliance and enforceability, pest management effectiveness,

effect on other health or environmental concer ns, and cost. In general, the regulations for low-emission fumigation methods require tarping, post-fumigation water treatments, or application through drip irrigation systems. Ba sed on field monitoring data, DPR estimated that the emissions from low-emission fumiga tion methods were 9-48 percent of the amount applied, and high-emission fumigation methods were 64-100 percent of the amount applied

, except for methyl iodide . The emission inventory indicated that some growers adopted lowemission fumigation methods prior to the regulations. The remaining growers who changed fumigation methods to comply with the regulations reduced fumigant VOC emissions by approximately one-third. The estimated reduction cost was $17,000 to $70,000 per ton of VOCs, based on 2007 prices.

DPR is taking additional steps to reduce VOC emissions. The VOC regulations also include a fumigant emission limit for the Ventura NAA at least until 2012. This system is also a backstop measure in the event low-emission fumigation methods are insufficient to achieve the SIP goals for the other NAAs. DPR is working with pesticide registrants to reformulate certain pesticide products that contain hi gh amounts of solvents. DPR and others are conducting research to further reduce VOC emissions from pesticides, such as additional changes to fumigation methods, soil amendments that degrade fumigants, and growing crops without fumigants. Other measures that would reduce VOC emissions are infeasible at this time for several reasons, such as incompatibility with fumigant properties, ineffective pest control, lack of equipment or other resources, adverse health or environmental effects, or lack of legal authority. The infeasible measures include prohibiting use of fumigants, requiring the Deleted: April 2009,

Deleted: and grower allowance system2 lowest emitting fumigation method, requiring inte grated pest management or use of certain pesticides, or reducing crop oils.



### Introduction

DPR has broad authority to regulate sales and use of pesticides under various federal and state laws. DPR regulates pesticide sales through its registration process. Similar to the U.S. Environmental Protection Agency’s (EPA’s) process, pesticide manufacturers and formulators (registrants) must submit and DPR must evaluate studies on toxicity, environmental effects, chemistry, and other pesticide characteristics. DPR registers a pesticide product (approves for sale) if the studie s are acceptable and use is not anticipated to result in unacceptable risk to human health or the environment. Once registered, DPR can request additional studies and actions by registrants using the reevaluation process specified in state law. Application or use of pesticides is regulated at several levels. All pesticide products must have a U.S. EPA-approved label that describes the maximum application rate, methods of application, crops that can be trea ted, safety precautions, and other requirements. Labels are enforceable documents, and making pesticide applications contrary to label

directions is a violation of bo th state and federal law. DPR also develops and implements state regulations that can be more restrictive than the label. Under state law, county agricultural commissioners can also impose additional use requirements through the permitting process required for certain pesticides (restricted materials), based on an evaluation of local conditions. Growers and applicators are required to follow the most stringent use requirements, whether specified by labels, state regulations, or county permit conditions. County agricultural commissioners are responsible for enforcing all pesticide use requirements, under DPR oversight.

DPR has used its authority to regulate VOC emissions from pesticides. VOCs and nitrogen oxides react with sunlight in the atmosphere to create ground-level ozone, which is harmful to human health and vegetation when present at high enough concentrations. Under the federal Clean Air Act, Californ ia must meet national standards for airborne pollutants, including ozone, and must specify how it will achieve these goals in a federally approved SIP. California’s SIP contains a pesticide element that requires DPR to develop and maintain an emission inventory to track pesticide VOC emissions, and to reduce emissions by 20 percent from the 1990 base year in four ozone nonattainment areas (NAA), and by 12 percent

in a fifth NAA. These five NAAs are defined as areas that do not meet the National Ambient Air Quality Standards for ozone as designated in the Clean Air Act. The SIP specifies that DPR is responsible for tracking and reducing pesticide VOC emissions from agricultural use and commercial structural use (applications by structural pest control businesses), while the Air Resources Board (ARB) is responsible for VOC emissions from the home use of pesticides as part of their consumer products program.

To DPR’s knowledge, no other state has measures to reduce VOC emissions from pesticides, and if one did they would likely be different from DPR’s measures due to California’s unique pesticide use permit program. DPR’s VOC program is a hybrid air pollution and pesticide regulatory program. Hence, it has some commonali ties with other air pollution and pesticide programs, but differs in several respects. Pesticides are considered area sources of air3 pollution, as opposed to mobile sources (e.g., moto r vehicles), or stationary sources (e.g., oil wells). Additionally, pesticides are intentionally introduced into the environment to control harmful pests, as opposed to waste discharges (e.g., smokestacks). Most pesticide regulatory programs focus on potential toxic effects from the active ingredients in pesticide products. In contrast, DPR’s VOC program does not consider toxic effects, but does consider both active and inert ingredients in pesticide products, and generally classifies the products as fumigants or nonfumigants. Fumigant pesticide products usually contain approximately 100 percent active ingredients (some contain a small percentage of a warning agent), and the active ingredients are gases under normal environmental conditions. Nonfumigant pesticide products are liquids or solids containing both active and inert ingredients, and many such products include VOC solvents as inert ingredients, particularly products formulated as

emulsifiable concentrates.

In April 2009, DPR adopted amendments to the pesticide SIP element for the San Joaquin Valley NAA. These amendments included a commitment to implement restrictions on agricultural fumigation methods and VOC emissions of nonfumigant pesticides. In addition, DPR proposed to commit to manage pesticide VOC emissions, to ensure that they do not exceed 18.1 tons/day in the San Joaquin Valley area. The 18.1 tons/day limit is equivalent to a 12 percent reduction from the 1990 base ye ar, and “freezes” DPR’s emissions estimation methodology and pesticide emissions for 1990. The following web page contains the complete pesticide SIP and supporting documents: http://www.cdpr.ca.gov/docs/emon/vo c s/vocproj/voc_state_imp_plan.htm

Between January 2008 and May 2011, DPR adopted a series of regulations to reduce VOC emissions from fumigant pesticides. Title 3 of the California Code of Regulations (3 CCR), section 6452.2, includes specific emission ta rget levels (VOC regulation benchmarks) for each of the five NAAs, equivalent to the SIP obligation of a 12 percent or 20 percent reduction. The regulations reduce VOC emissions by requiring low-emission fumigation methods in certain NAAs. If, in spite of thes e application method requirements, pesticide VOC emissions exceed specified trigger levels, DPR is required to ensure that the benchmark is achieved by establishing a fumigant limit. The fumigant limit is determined by subtracting the estimated nonfumigant emissions from the regulatory benchmark, basing the nonfumigant emissions estimate on VOC emission inventory data from previous years. The following web page contains all of the fumiga nt VOC regulations and supporting documents: http://www.cdpr.ca.gov/docs/emon/vocs/vocproj/reg_actions.htm

In October 2009, ARB submitted DPR’s SIP amendments and three sets of fumigant VOC regulations to U.S. EPA. In July 2011, ARB submitted two additional sets of DPR fumigant VOC regulations to U.S. EPA. To assist U.S. EPA with its review, this document contains more detailed information than previously submitted on DPR’s evaluation of fumigation methods, and information on other potentia l pesticide VOC reduction measures. Additionally, this document includes more recent emission inventory data.



### Background Information on Fumigants Deleted: April 2009,

Deleted: (NOTE: DPR adopted another set of fumigant VOC regulations in April 2011, but these regula tions have not been submitted to U.S. EPA yet.)4 Fumigants are most commonly used to treat soil in agricultural fields prior to planting, but harvested commodities and other sites can also be fumigated. These other types of fumigations are not agricultural or structural uses, so they are not included in DPR’s VOC program, and are not included in the fumigant regulations. The nonagricultural uses of fumigants are very low compared to the agricultural uses.

Field fumigants include products containing one or more of the following active ingredients:

• 1,3-dichloropropene

• Chloropicrin

• Methyl bromide

• Methyl iodide (first registered in California in December 2010)

• Sodium tetrathiocarbonate (because it generate s carbon disulfide as a pesticidal agent)

• Active ingredients that generate methyl isothiocyanate (MITC) as the pesticidal agent (dazomet, metam-potassium, and metam-sodium).

Fumigants differ in several important aspects from other pesticides. As gases, fumigants are much more volatile than other pesticides. Since they disperse so readily and target large volumes of soil, fumigants are usually applied at rates of several hundred pounds of active ingredient per acre, while most other pesticides are applied at rates of a few pounds or ounces per acre. Fumigants are applied to fallow fields, prior to planting, while most other pesticides are applied to growing crops. Fumigants are applied once per year at most to any individual field, and only once for the lifetime of an orchard or vineyard. Many other pesticides are applied multiple times during the year. Most fumigant products contain only active ingredients, and no inert ingredients. Most other pesticide products contain a mixture of active and inert ingredients. Most pesticides target specific pests, such as a particular type of insect or weed. Fumigants can control a wide variety of pests in the soil, including most weeds, nematodes, insects, and diseases. However, due to the cost of the product and controls to reduce health effects, fumigant application rates are normally minimized to control only certain targeted pests. For example, MITC fumigants are primarily used to control weeds and chloropicrin primarily mitigates diseases. Because of the variable effectiveness, and to prevent pest resistance to a single pesticide, prohibiting all but the lowest emitting fumigant

is infeasible.

Field fumigant application methods are diff erent from other pesticides. Most fumigation methods either use special tractors to inject fumigant below the soil surface, or apply fumigant with water through an irrigation system (chemigation). Due to the specialized equipment required, pest control businesses rather than growers conduct most of the fumigations. Fumigant applications cost more than most other pesticides, so fumigants are economically feasible only for high-value crops. Crops that commonly use fumigants prior to planting include almonds, carrots, flowers, grapes, nursery crops, raspberries, strawberries, sweet potatoes, tomatoes, and walnuts. The Calif ornia regions with highest fumigant use are the Central Coast region between Ventura and Santa Cruz, and the San Joaquin Valley. While fumigations occur throughout the year, peak use is during the summer and fall for most crops and regions. Formatted: Bullets and Numbering

Deleted: (NOTE: In December 2010, DPR registered products containing methyl iodide for the first time and is working on a regulation to include this pesticide as a fumigant VOC.) ¶ ¶5 Like most other pesticides, fumigants are considered toxic chemicals. Since they are also volatile and applied at large rates, the risk fro m toxic exposure to fumigants is higher than most other pesticides. Due to this risk, U.S. EPA and DPR have implemented regulatory requirements to control exposures to both worker s and the public. Fumigant label revisions in 2010 include “good agricultural practices” requiring specific soil preparation and soil moisture levels, equipment calibration and equi pment safeguards, and ot her restrictions. In the early 1990s, DPR and county agricultural commissioners began implementing a series of regulatory requirements for application methods, use limits, buffer zones, and worker protections. The label and other regulatory requirements to address exposures complement the VOC regulations. When possible, DPR de veloped measures to reduce fumigant VOC emissions as well as reduce toxic exposures. All of the field fumigants are restricted materials, requiring additional scrutiny and possible permit conditions by county agricultural commissioners. Based on inspections of applications by county agricultural commissioners, compliance with the regulatory requirements is higher for fumigants than most other pesticides. Summary statistics of pesticide inspections are available by county and year at the following website: http://www.cdpr.ca.gov/docs/county/statistics/index.cfm

.

U.S. EPA plans to implement additional labe l changes for field fumigants in 2011. These changes will include buffer zones to protect bystanders. The buffer zone distances depend in part on emission estimates for various fumi gation practices. U.S. EPA’s estimates of emissions, particularly “buffer zone credits” assigned to various fumigation practices are based largely on modeling using CHAIN2D that was modified by the Chloropicrin

Manufacturers Task Force. DPR did not use U.S. EPA’s emission estimates for several reasons: 1) U.S. EPA published its emissions estimates after the fumigant VOC regulations went into effect. 2) U.S. EPA and DPR rely on peak emissions over one day or less to

determine the size of buffer zones. VOC estimates are based on total emissions over several days or weeks. 3) DPR decided not to use the modified CHAIN2D model for the reasons specified below. In brief, the modeling system is not validated. Major features of the model such as drip irrigation or the dynamic boundary layer were not tested. The testing that was done utilized an unsupported ‘shank trace’ featur e to arbitrarily make model results fit more closely to measured results. A hydraulic pa rameter estimation scheme gives incorrect estimates. The general approach, which uses average texture class hydraulic parameters, may give incorrect results. DPR relied on field m onitoring data for its emission estimates and reductions associated with various application practices. As discussed in the section on fumigation method options, some of DPR’s emission reduction estimates based on monitoring data differ from U.S. EPA’s buffer zone credits based on CHAIN2D modeling. Also discussed in a later section is DPR’s attempt to develop its own model to estimate fumigant emissions. The following document describes U.S. EPA’s em ission estimates for buffer zone purposes: http://www.regulations.gov/#!doc um entDetail;D=EPA-HQ-OPP-2007-

0350-0173

. The following document describes DPR’s review of U.S. EPA’s estimates: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2007-0350-0285.1

.

Measured in pounds, fumigants represent approximately 20 percent of all agricultural pesticides used in California. However, use of fumigants has changed dramatically since the early 1990s (Figure 3), and will likely continue to change for several reasons. Under the6 Montreal Protocol and Clean Air Act, U.S. EPA began phasing out production and importation of methyl bromide in the late 1990 s due to stratospheric ozone depletion effects. In 1990, DPR directed the county agricultural commissioners to rescind all permits for 1,3- dichloropropene due to exposure concerns. These actions caused MITC pesticides and chloropicrin use to increase. Use of 1,3-dichloropropene subsequently increased since its reintroduction in the mid-1990s, with revised regulatory requirements. However, recent decreased production of 1,3-dichloropropene due to the recession has led to decreased use of that fumigant in the last two years. DPR first registered methyl iodide in December 2010, and

its introduction could change use patterns even more. These actions, as well as other regulatory requirements, have led to increased cost for all fumigants.



### Pesticide VOC Emission Inventory

DPR prepares an annual estimate of VOC emissions from agricultural and commercial structural pesticide applications. There is an emission inventory for each year since 1990, the base year. Pesticide applications in five NAAs are included: Sacramento Metro, San Joaquin Valley, South Coast, Southeast Desert, and Ventura (Figure 1). Only agricultural and commercial structural pesticide applications are included. ARB tracks emissions from pesticides in consumer products. DPR uses data on VOC content and pesticide use to estimate emissions from reported agricultural and commercial structural applications in each NAA. The inventory focuses on May 1 through October 31, the peak ozone season in

California.

To estimate the VOC contribution of individual agricultural and structural use pesticides, DPR multiples the fraction of a pesticide product estimated to be VOCs (its “emission potential”) by the amount of that product applied.

Estimated VOC emissions = (Emission potenti al of the product) X (Pounds of pesticide product applied)

Pesticide use reports provide the amount of product used. California requires full reporting of all agricultural pesticide use and the use of pesticides by pest control businesses. The reports document the product applied, the amount applied, date applied, location (within a one square mile section), crop treated, number of acres treated, and other information.

DPR has several methods to determine the emi ssion potential. The preferred way is through laboratory analysis, using a standardized method approved by DPR (thermogravimetric analysis). When it is not available, DPR uses other approaches to decide emission potentials.

• Using the VOC emission potential already measured in TGA analysis of an identical or nearly identical pesticide product.

• Using the confidential statement of formula on file with DPR to find out the percentage of water and other inorganic chemicals in the product. This is subtracted and the remainder is assumed to produce emissions that must be included in the inventory. Deleted: The registration of methyl

iodide7 • Assigning an estimated value based on an evaluation of a product’s unique chemistry and composition. DPR takes this approach for high-use products with well-known chemical properties.

• Assigning a default emission potential at a representative level, based on measured

data that reflect the behavior of similarly formulated products.

Because DPR has monitoring data, the calculatio n is adjusted for fumigants to account for how emissions vary depending on fumigation method (Application Method Adjustment Factor, AMAF, or emission rating). AMAFs have been determined from field study data and are active ingredient and application method specific (Table 1). Since the AMAFs are based on field measured data for sp ecific application methods and fumigants, they yield more refined estimates of fumigant VOC emissions than the previous unadjusted emission

estimates.

Estimated fumigant VOC emissions = lbs of product used x EP x AMAF

Nonfumigant product emissions are not currently adju sted for application method or other field factors due to a lack of data to support such adjustments.

Usually there are several different types of application methods used for a particular fumigant in any particular NAA. Each method of use (e.g. drip, sprinkler, shank, tarp, etc.) represents a fraction of the total number of methods used and is referred to as the method use

fraction. The sum of all method use fractions fo r any particular (NAA/fumigant) combination is one. Use practices change over time so that different method use fractions are used for the base year (1990) as opposed to more recent inventory years. For 1990, 2005, 2006, and 2007, method use fractions were determined in a number of different ways. For 1,3- dichloropropene the method use fractions are determined from use data collected by the registrant in support of DPR’s township application caps; for metam sodium and metam potassium grower/applicator surveys were conducted to determine types of applications for different crops and areas. Methyl bromide and chloropicrin method use fractions are based on expert opinion and regulatory history. Finally, method use fractions for dazomet and sodium tetrathiocarbonate equal one because the AMAFs for each of these two fumigants are constant, independent of application method. See Attachment 1 a (DPR memorandum from Barry, Spurlock and Segawa to Sanders, dated September 29, 2007) for a detailed discussion

of how method use fractions and AMAFs were determined.

The 2008 fumigant VOC regulations included a change to pesticide use reports (3 CCR sections 6624 and 6626) that requires recordin g the specific application method for each fumigation within NAAs. The method use fractions for 2008 and later years are calculated using the fumigation method documented in pesticide use reports rather than the surrogate data described above. Some pesticide use reports for 2008 and later years are missing the identification of the application method. In these cases, DPR assumed that the application method with the highest AMAF allowed by the regulations for that fumigant was used. See the following web page for more details on the methodology to calculate pesticide VOC

emissions: http://www.cdpr.ca.gov/docs/emon/vocs/vocproj/voc_method_est.htm8 The 2008 fumigant VOC regulations (3 CCR section 6452.4) require DPR to publish its emission inventory annually. The annual reports are available at: http://www.cdpr.ca.gov/docs/emon/vocs/vocproj/voc_data_analysis.htm . The most recent data is for 2009, and Figure 2 shows the pesticide VOC emissions relative to the SIP goals for 2009 and earlier years. The 2009 pesticide VOC emissions for all five NAAs complied with the SIP goals, ranging from 33 to 89 percen t less than emissions in the 1990 base year. Relative to 2008, pesticide VOC emissions in 2009 ranged from a 4 percent increase to a 47 percent decrease, depending on the NAA.

• Adjusted emissions in 2009 in the Sacramento Metro continue to decline and fell to below 1 tons/day. Nonfumigants represente d 87 percent of the total, and the total remaining well below the SIP goal.

• Emissions in the South Coast NAA also decreased slightly over 2008 values and remain well below the SIP goal. Three quarters of the total adjusted VOC emissions came from nonfumigants.

• In 2009, fumigants accounted for less than half of VOC emissions in the Southeast Desert, down slightly from 2008. Total VOC emissions in 2009 decreased by almost 50 percent from 2008 and continue to meet the SIP goal.

• 2009 VOC emissions in the Ventura NAA increased by 0.072 tons/day from the previous year but continue to meet the regulatory goal for 2010, 2011 and 2012. Seventy five percent of emissions come from fumigants.

• In the San Joaquin Valley NAA, nonfumigants accounted for approximately three quarters of the total VOC emissions in 2009. In this NAA, VOC emissions decreased from 2008 to 2009 by about 7 percent, and continue to be below the SIP goal.

As calculated for the emission inventory, fumigant emissions depend on the fumigant, fumigation method, and amount applied (application rate in pounds per acre and number of acres treated). Table 2 compares fumigant use and emissions prior to and after the 2008 fumigant regulations (2006-2007 compared to 2008-2009, annual average for May-October). May-October fumigant VOC emissions declin ed 48-81 percent where the regulationsrequired low-emission fumigation methods, depending on NAA. Some growers adopted lowemission fumigation methods prior to the regulations. The remaining growers who changed to low-emission fumigation methods to comply with the regulations accounted for a 31-32 percent decrease, and less use accounted for 17-49 percent decrease, depending on NAA. The fumigant emission limit for Ventura likely contributed to the decrease in use for that NAA.

Table 3 shows that the decrease in use was primarily due to less acreage fumigated in all NAAs after the fumigant VOC regulations were effective in 2008. Between 2006-2007 and 2008-2009, the May-October fumigated acreage decreased by 17 percent (49,242 acres to 40,862 acres) in the San Joaquin Valley NAA, by 33 percent in the Southeast Desert NAA (3,456 acres to 2,332 acres), and by 24 percent in the Ventura NAA (15,497 acres to 11,833 acres). The percentage decrease in fumigated acreage for the entire year was less than the May-October period, indicating that shifting fumigation dates outside May-October caused part of the decrease in VOC emissions.



### Evaluation of Field Fumigation Method Options9 The key provision in the fumigant VOC regulati ons that achieves emission reductions is the requirement for “low-emission” fumigation methods in the San Joaquin Valley, Southeast Desert, and Ventura NAAs during May-October. The designation of low-emission fumigation methods is based on the AMAF and maximum allowed application rate. Field monitoring has demonstrated that fumigant emissions vary with several factors, but primarily with fumigant, fumigation method, and applicati on rate. Several methods have been used to estimate fumigant emissions, including laboratory experiments, field measurements on small plots (less than one acre), field measurements of large plots (one acre or more), as well as computer modeling. DPR has relied on field me asurements of large plots for emission estimates because they are most similar to commercial fumigations. Research continues on the other methods, but comparisons so far indi cate that the other methods do not always agree with field measurements of large plots.

Most of the low-emission methods specified by the regulations were based on field studies conducted by registrants, agricultural commodity groups, the University of California, and the U.S. Department of Agriculture (USDA). They developed the fumigation methods and measured the emissions. DPR and ARB have also monitored several fumigations to confirm the emissions. The studies DPR relied upon for its emission estimates are listed in

Attachment s 1 a and 1b for each fumigant. ( Attachment 1a was peer reviewed as part of the rulemaking process.) Appendix 4 to Attachment 1 a lists other studies on fumigant emissions, but not used by DPR and the reasons for excluding the data. Attachment 1 a describes the studies available at the time the fumigant VOC regulations were first developed in 2007.

Attachment 1b describes the studies that DPR has evaluated since then. Additional studies which DPR has not yet evaluated are discussed in the Current Research on Fumigant VOC

Emission Reduction section.

The fumigant VOC regulations exempt certain small, specialized fumigations, such as individual tree-hole replant applications less than one acre. These fumigations have negligible emissions due to very low use. These applications are infrequent and small compared to other fumigations. Including these applications would have greatly complicated the regulations, with negligible reduction in VOC emissions.

DPR’s regulations for field fumigation methods are described in 3 CCR sections 6446.1 for methyl iodide; 6447.3 for methyl bromide; 6448.1 for 1,3-dichloropropene; 6449.1 for chloropicrin; 6450.1 for metam-sodium and metam-potassium; 6450.2 for dazomet; and 6451.1 for sodium tetrathiocarbonate and include the following types of fumigation method restrictions based on the monitoring data:

• Fumigant introduction method

• Tarping

• Pre-fumigation soil moisture

• Post-fumigation water treatments

• Application rate

DPR considered, but did not include the following types of fumigation method restrictions in the regulations:

• Temperature and other weather conditions Deleted: This document

Deleted: Additional

Deleted: have been conducted

Deleted: These studies10 • Soil characteristics

• Soil amendments

• Soil preparation, equipment preparation, general procedures

DPR considered the following factors in developing the fumigation method requirements:

• VOC reduction effectiveness

• Technical feasibility and availability

• Compliance and enforceability

• Pest management effectiveness

• Effect on other health or environmental concerns

• Cost

As summarized in Table 4 and described below, DPR has designated several fumigation

methods as low-emission. Based on monito ring data, the emissions from low-emission fumigation methods were 9-48 percent of the amount applied, and high-emission fumigation methods were 64-100 percent of the amount applied , with the exception of methyl iodide (Table 1). Requiring the lowest emission fumigation method is infeasible for several reasons: 1) a single method is not physically possible for all fumigants; 2) a single method is not effective in reducing VOC emissions for all fumigants; 3) a single method is not effective against all target pests for all crops; and 4) the equipment and other resources are not always available or very costly.

Evaluation of Fumigation Methods – Introduction Methods

There are two main methods to introduce fumigant into the soil: chemigation or tractor. Fumigant introduction methods vary by fumigant and crop. Some methods are feasible for some fumigants and crops, but not others. In general, drip chemigation methods have lower emissions than tractor methods (Table 1 and Attachment 1 a ). However, methyl bromide’s volatility is too high and its water solubility is too low to be retained in water, so chemigation is not technically feasible for that fumigant. Drip irrigation systems are costly to install and maintain. In general, they are economically feasible for fields where drip systems will be used for irrigation, not just a fumigant delivery system, and where the drip system can be installed prior to planting and used for fumigation. Additionally, drip chemigation is usually only effective for crops where the target pest is at shallow depths (1 foot or less). Strawberries and raspberries are the most common crops where these conditions occur and fumigations use drip chemigation. Based on th e monitoring data, all of the drip chemigation methods are designated as low-emission.

MITC-generating pesticides and sodium tetrathi ocarbonate are unusual because they can be applied using other chemigation methods, such as sprinkler or flood. The parent compounds metam-sodium, metam-potassium, and sodium te trathiocarbonate are non-volatile salts, so they are easily applied through irrigation system s. Moreover, it takes several minutes to several hours for the parent compound to convert to MITC or carbon disulfide. This delay allows MITC and carbon disulfide pesticides to be applied through irrigation systems and still minimize emissions. In many cases, non-drip chemigation fumigations are less costly and have greater pest management effectiveness than drip applications. Other irrigation Deleted: (NOTE: In April 2011, DPR adopted revisions to the fumigant VOC regulations that in clude additional lowemission fumigation methods. These regulations have not been submitted to U.S. EPA yet.)11 equipment is less costly than drip, and applications are usually more uniform. Many irrigation systems are portable and can be mo ved between fields. Like drip chemigation, other chemigation methods are suitable only for crops where the target pest is located at shallow depths. MITC sprinkler chemigations are most common for carrots and potatoes in the San Joaquin Valley and Southeast Dese rt NAAs. As discussed below, sprinkler fumigations with one post-fumigation water treatment is designated a high-emission method. Sprinkler fumigations with two or more post-fumigation water treatments are designated

low-emission methods. Sodium tetrathiocar bonate and other chemigation methods are not commonly used.

With the exception of sodium tetrathiocarbonate, all fumigants can be applied by a tractor. In most cases, fumigants applied with a tractor are injected beneath the soil surface through shanks attached to the back of the tractor. Some available data seems to support the theory that emissions may vary with depth. However, DPR’s analysis of methyl bromide applications and other fumigant data show that emissions vary significantly depending upon whether application occurs to a flat field (broadcast) or to a field that has been bedded (Attachment 2 – DPR memorandum from Barry to Sanders, dated December 2, 1999). In general, emissions are lower with flat fields. Fu migants are normally injected at 6-24 inches beneath the soil surface. The depth of crop roots and location of the target pest determines the depth of injection. Fumigants are usually injected at 6-12 inches for crops with shallow roots, such as strawberries an d vegetables. Fumigants are usually injected at 18-24 inches for crops with deep roots, such as nut orchards and grapes. Injection depth cannot be increased to decrease emissions without losing pest management effectiveness. Also, increasing depth does not always decrease emissions. The available data for methyl bromide indicates that depth has no significant effect on emissions, at least within a 10-24 inch depth (Attachment 2). This is likely due to the type of shank and tractor implements, and high soil moisture. Injection at greater depths requires wider shanks. The channel in the soil created by the shanks (shank trace) can be a pathway to the surface, so the wider the channel the higher the emissions. High soil moisture may increase this effect due to greater soil adhesiveness. Special shanks (e.g., Nobel plow) are often used for shallow injection to reduce this channeling effect. Nobel plows consist of a horizontal wing attached to the vertical shank, with fumigant released along the wings and away from the channel created by the shank. Nobel plows are usually not feasible for greate r depths because the re sistance is too high for tractors pull them through the soil. Applicators have developed other tractor implements (e.g., compaction rollers) to disrupt or close the channel created by the shanks. Broadcast fumigations are common for all crops and areas, particularly for nut orchards and grapes. Based on the monitoring data, deep injecti on is designated a low-emission method for 1,3-dichloropropene and some chloropicrin methods. Deep injection is designated a highemission method for methyl bromide, unles s accompanied with some other mitigation measure (e.g., tarping). MITC pesticides are usually not injected at deep depths because the primary target pests are we eds at shallow soil depths.

Tractor fumigations to bedded fields usually have higher emissions than flat fields (broadcast fumigations). Bedded fumigations usually cost less than broadcast fumigations because the fumigation and bed forming occurs in a single tractor operation, and they use less fumigant. For broadcast fumigations, the fumigation and bed forming require separate tractor12 operations. The higher emissions with bedded fumigations are partially offset by lower application rates. The entire field is treated for a broadcast fumigation. In contrast, only the beds are treated for a bedded fumigation; the furrows are untreated. Therefore, the effective (or broadcast-equivalent) application rate is lower for a bedded field. Bedded shank fumigations are common for carrots and sweet potatoes in the San Joaquin Valley. Most bedded shank fumigation methods are designated as high-emission, unless accompanied with some other mitigation measure (e.g., tarping).

There are a few tractor fumigation methods for MITC pesticides that do not involve injection beneath the soil surface. These include rotary tiller, power mulcher, and soil capping methods. These methods involve spraying a water solution of metam-sodium or metampotassium on the surface of the soil, and then incorporating into the soil or placing untreated soil on top. The available data indicates than these methods have comparable or lower

emissions than other methods (Attachment 1 a ). These methods are most commonly used for tomatoes in the San Joaquin Valley. Based on the available monitoring data, most of the methods are designated as low-emission. The fourth set of regulations effective in April 2011 added a drench method for MITC pesticides. For this method, a tractor is used to spray a dilute solution of a MITC pesticide on the top of the soil, at very low application rates. This method is used for specialty crops, such as ci lantro, and has also been designated as lowemission (Attachment 1b, Ratto Brothers decision). The tractor fumigation methods for dazomet are unique. This MITC pesticide is granular material, applied to the soil surface, then incorporated and watered-in. The label requires multiple water treatments. This pesticide has low use for all crops. Based on the monitoring data all dazomet application methods are designated low-emission.

As shown in Table 5, for fumigations that used a high-emission method, the estimated increased cost of using a low-emission method ranged $10-$2510 per acre in 2007, depending on fumigant and fumigation method.

Other factors sometimes influence which fumi gation method is used. Water supply is sometimes a factor in the feasibility of chemigation methods. For fields that rely on surface water, irrigation canals may not have water at the time fumigations occur prior to planting. Equipment availability may also be a factor. For any one commodity, fumigations are often seasonal in nature, with most fumigations occurring in a few weeks. There may be an insufficient number of rigs to complete all fumigations using tractors. Equipment shortages can be exacerbated by weather conditions. The soil must have the appropriate moisture for fumigation. Fumigations cannot occur during or immediately after storms. Additionally,

tractors cannot enter fields that are too wet. Tractor fumigations often cannot be done in high winds due to tarpaulin considerations. If weather prevents fumigations for an extended period of time, the preferred fumigation method may not be available, so several different fumigation methods may be necessary.

Evaluation of Fumigation Methods – Tarping

Tarping reduces emissions for most fumigants and fumigation methods. Tarping is feasible for all tractor shank injection methods and drip chemigation. Tarping is physically13 impossible for most other methods, such as rotary tiller, sprinkler, and flood. The most common tarpaulin is high density polyethylene, generally 1.0-1.5 mil thick, and is sometimes referred to as the standard tarpaulin. Monitoring data indicates that the standard tarpaulin is effective in reducing emissions of chloropicrin and methyl bromide, but not 1,3- dichloropropene (Attachment 1 a ). It is rare for MITC fumigations to use a tarp because of the relatively high cost of tarping compared to the cost of the fumigant, and field monitoring data is not available. Tarpaulin costs vary and have been increasing over the last several years. In general, tarped fumigations cost at least twice as much as untarped fumigations. The tarpaulins for fumigation are used once, and disposed, creating additional landfill waste. Tarpaulin fumigations for bedded fields are more efficient than flat fi eld fumigations because less is used and the tarpaulins usually remain in place for the entire growing season, acting as a mulch. Tarpaulins for flat fields are discar ded immediately after fumigation. As discussed in the section on research, newer tarpaulins such as “virtually impermeable film” or “totally impermeable film” may have somewhat misleading names, but are more effective in reducing emissions than standard tarpaulins. Wh ile emission data is available for some low permeability tarpaulins and fumigants, data to address exposure concerns is not available for most fumigants , so these tarpaulins are not widely used and prohibited for methyl bromide. For the upcoming label changes, U.S. EPA plans to assign a buffer zone credit of 10-60 percent, depending on fumigant and type of low permeability tarpaulin. The estimatedincreased cost of changing from a high-emission untarped fumigation method to a lowemission standard tarpaulin fumigation method was $400 per acre in 2007 (Table 5).

For methyl iodide, California product labels require “highly retentive tarps” (virtually impermeable films or totally impermeable films approved by DPR and the registrant) for almost all fumigations. The highly retentive tarps are primarily required to control exposures, not reduce VOCs. To ensure that the buffer zones provide adequate protection, DPR assumes that total methyl iodide emissions are 100 percent with highly retentive tarps, as an interim assumption. Field studies on methyl iodide app lications with highly retentive tarps measured total emissions of approximately 30 percent of the amount applied, but DPR concluded that these studies likely underestimated the emi ssions (Attachment 1b, memo to John Sanders dated April 29, 2010). The registrant conducted another field emissions study to replace the earlier ones, and submitted a report to DPR in May 2011. DPR has not yet evaluated this report. Since it’s likely that actual methyl iodi de emissions are less than 100 percent with highly retentive tarps and it is applied at relati vely low application rates (maximum label rate of 100 pounds per acre), DPR has design ated these methods as low-emission.

Evaluation of Fumigation Methods – Pre-Fumigation Soil Moisture

In general, higher soil moisture reduces emissions, particularly when the moisture is higher near the soil surface (Attachment 1 a , sections on 1,3-dichloropropene and chloropicrin). However, higher soil moisture also reduces efficacy of the fumigant, by retarding dispersal. Compliance and enforcement of any soil moisture requirements are also problematic because there are no methods to easily and accurately measure soil moisture in the field. The U.S. EPA evaluated this issue in detail, and included a soil moisture requirement of 50-75 percent of field capacity as one of the revisions to fumigant labels in December 2010. This requirement is more stringent and supersedes DPR’s regulations for soil moisture of 25-5014 percent of field capacity. DPR’s regulations were based on the soil moisture levels in the field monitoring studies used to establish the AMAFs. Both the fumigant labels and DPR’s regulations specify the USDA’s “feel” method for determining moisture. (NOTE: The fourth set of regulations includes revisions that correct errors in the first set of regulations for the method of determining soil moisture.

Evaluation of Fumigation Methods – Post-Fumigation Water Treatments

Applying water after the introduction of fumi gant (post-fumigation water treatment) is effective in reducing emissions of most fumigants (Table 1 and Attachment 1 a , sections on chloropicrin and metam). Field monitoring of water treatments has not been conducted for methyl bromide, but it is likely ineffective due to methyl bromide’s higher volatility. The amount of water required and frequency of ap plication reflects the pr actices used for the monitoring studies. Post-fumigation water treatm ents are not always feasible. As discussed above, surface water may not be available prior to planting. Also, the irrigation system must cover the entire treated area. In the case of broadcast fumigations, this can only be done withoverhead sprinklers, and not all growers have access to overhead sprinkler equipment. Postfumigation water treatments are most effective for untarped applications. Water treatments are likely the least effective for broadcast fumigations where the entire field is tarped, and this type of fumigation has not been monitored. Another disadvantage for water treatments is the potential for water contamination. If too much water is applied, there is a potential for contamination of surface or ground water. The amount of water specified by the regulations is the amount and frequency used in the monitoring studies, and DPR’s evaluation concluded that surface runoff or percolation to ground water will not occur. (NOTE: The fourth set of regulations includes revisions that correct errors in the first set of regulations for the water treatment requirements.) Post-fumigation water treatments are most common for MITC sprinkler fumigations of carrot and potato fiel ds in the San Joaquin Valley and Southeast Desert NAAs. Fumigations that use at least two or three post-fumigation water treatments are designated as low-emission. The estimated increased irrigation cost of the post-fumigation water treatments was $10 per acre in 2007, assu ming the irrigation system is already in place. If the irrigation system must be rented the estimated increased cost was $240 per acre in 2007 (Table 5).

To encourage the voluntary reduction of emissions, water treatments are one of three pesticide VOC measures for which the USDA – Natural Resources Conservation Service’s Environmental Quality Incentives Program (EQIP) provides matching funds to growers in

California.

Evaluation of Fumigation Methods – Application Rates

DPR assumes that application rates and emission rates are proportional, if the application rate increases by 2x the emission rate increases by 2x. The regulations specify the maximum allowed application rate for each fumigant, when less than the rate specified on labels. The maximum application rates were based on se veral factors primarily related to exposure mitigation. 1) The rates do not exceed those used for the monitoring studies. 2) The rates resulted in buffer zone requirements (distances and field separation) that can be complied15 with and enforced. 3) The rates resulted in worker protections (e.g., respirators and work hour limits) that can be complied with and enfo rced. 4) The registrants supported the rates, indicating that they result in effective pest control. As discussed above, the effective application rate for bedded fumigations is less than broadcast fumigations because the furrows are untreated. Similarly, some growers will make “strip” fumigations, particularly for nut orchards or grapes. A strip fumigation is an application to a flat field, but every second or third tractor pass is left untreated. Trees and vines are planted only in the treated strips. Strip fumigations are less effective than normal broadcast applications, so are only feasible where the pest population is relatively low. The fourth set of regulations effective in April 2011 includes several fumigation methods for MITC pesticides that have been designated as low-emission in part due to low application rates. This includes several night fumigation methods, and the drench method (Attachment 1b, Responsible Farmers Coalition decision, Grimmway Farms decision, and Ratto Brothers decision). DPR designated some of

these methods as low-emission because the regulations include a provision for approval if theemission rate (AMAF multiplied by the application rate) is no greater than the current lowemission methods.

Evaluation of Fumigation Methods – Temperature and Other Weather Conditions

The soil and/or air temperature may influence emissions. Higher temperatures may have higher emissions. However, the analyses so far have not demonstrated a significant relationship between temperature and emissions (Attachment 3 – DPR memorandum from Barry to Segawa, dated January, 29, 2010, page 6). Temperature may influence emissions, but the effect is too small to detect due to the field-to-field variability and the effect of fumigation method. Since the monitoring did not show an effect, the regulations do not include any requirements based on temperature.

With the exception of rainfall, most other weather conditions have minimal effect on emissions. However, sprinkler and tarped fumigations have label language that includes wind speed restrictions for these types of fumigations, so there are no requirements in DPR’s regulations.

Growers and applicators can only control the fumigant introduction, so any weather restrictions beyond the application period are problematic. Monitoring data indicates that emissions continue for several days or weeks after fumigant introduction, but no weather restrictions after fumigant introduction are possible.

Evaluation of Fumigation Methods – Soil Characteristics

The soil type and soil organic content may influence emissions. Soils consisting of finer particles (clay) are hypothesized to have lower emissions than coarser soils (sand). Soil with higher organic content may have lower emissions. DPR is attempting to estimate the effect of soil characteristics using the HYDRUS computer model, as discussed in Current Research on Fumigant VOC Emission Reduction section. However, it’s likely that the effect, if any, will be minor due to similar soil types for fumigations in California (Attachment 4 – DPR memorandum from Johnson and Spurlock to Segawa, dated January 23, 2009). Moreover, Deleted: No current app lication rates are designated as low-emission. However, a new fumigation method could be designated as low-emission in part due to a low ap plication rate, since16 soil type can vary within a field, so determining compliance with any requirements may be problematic. For the upcoming label changes, U.S. EPA plans to assign a buffer zone credit of 10 percent for soils with greater than 27 percent clay content, and up to 30 percent depending on soil organic content.

Evaluation of Fumigation Methods – Soil Amendments

It’s possible that fertilizers or other soil amendments affect emissions. Several studies have measured emissions comparing fu migated fields with and wit hout a thiosulfate amendment.

Most of this data was not available at th e time the fumigant VOC regulations were developed, and DPR is still reviewing the studies. For the upcoming label changes, U.S. EPA plans to assign a buffer zone credit of 15 perc ent when thiosulfate is applied with certain fumigants.

Evaluation of Fumigation Methods – Soil Preparation, Equipment Preparation, and

General Procedures

Fields with large soil clods, debris, or crop residue can exacerbate the channeling effect of tractor shanks. Labels address proper prepar ation of fields, so DPR’s regulations do not include any requirements for soil preparation. Similarly, the labels include requirements for proper equipment calibration and maintenance, as well as prevention of leaks and spills.

Evaluation of Fumigation Methods – Conclusions

Requiring the lowest emission fumigation method is infeasible for several reasons: 1) A single method is not physically possible for all fumigants. For example, methyl bromide is too volatile to apply using ch emigation systems, and tractor fumigations are not allowed by the label for sodium tetrathiocarbonate. 2) A single method is not effective in reducing VOC emissions for all fumigants. For example, tracto r injection at deeper depths reduces emissions for 1,3-dichloropropene, but not methyl bromide. 3) A single method is not effective against all target pests for all crops. For example, chemigation methods are effective against weeds and other pests at shallow depths, but usually ineffective against pests at deeper depths. 4) The equipment and other resources are not always available or very costly, particularly availability of surface water and delays due to weather.

It is also infeasible to designate the lowest emission fumigation method for individual combinations of fumigant, crop, pest, and region. This would greatly complicate and lengthen the regulations. There are approximately 50 fumigants/fumigant products, 25-60 crops for each fumigant, 4 groups of pests, a nd at least 3 regions, creating several thousand combinations. Many products contain more than one fumigant, particularly methyl bromide, chloropicrin, and 1,3-dichloropropene. The fumi gation method would need to be specified by product for these fumigants. New fumigant products or changes to labels that add crops or pests would require corresponding changes to the regulations. Additionally, specifying a single fumigation method for each of the combinations would not account for the availability of equipment and other resources.17 

### Cost of Low-Emission Fumigation Methods

ARB’s Agency-wide Economic Analysis Unit estim ated the direct cost of the fumigant VOC regulations. ARB used the information compiled by DPR in Tables 5a and 5b for the costs associated with the fumigation methods. DPR estimated that the total increased fumigation cost to growers and applicators to comply with the low-emission method requirements was$10 million to $40 million for all NAAs combined in 2007, depending on which lowemission fumigation methods growers and applicators selected. Table 2 shows that VOC emissions reduction attributed to the low-emission fumigation methods was 3.11 tons/day for all NAAs combined, or 573 tons of total VOCs during May-October. Therefore, the estimated VOC reduction cost was $17,000 to $70,000 per ton, based on prices in 2007. The cost has likely increased since 2007. Secondary economic impacts of the regulations were not considered. Secondary impacts such as loss of jobs to farm laborers, the increase in bank loan risk, or loss of income to processors and suppliers, while important to the community, do not expressly impact the grower’s profitability and were not included in the economic impact analysis. Direct impacts, such as land value losses to growers, were not considered, as estimating the impact on real estate is uncertain and highly subject to local influences.



### Other Reduction Options for Pesticide VOC Emissions

The VOC regulations include a fumigant emission limit for Ventura until at least 2012 (3 CCR sections 6452.2 and 6452.3). The regulations also include a trigger for the same system for the other NAAs in the event the reductions from low-emission fumigation methods are insufficient to achieve the SIP goals. Under this system, DPR establishes a NAA-wide fumigant emission limit each year by subtracting the estimated nonfumigant emissions from the SIP goal. County agricultural commissioners have three options to enforce the fumigant

limit : by issuing a fumigant emission allowance to each grower who plans to fumigate for the upcoming May-October period ; by tracking emissions and de nying any permit that would cause the fumigant limit to be treated; or by conditioning permits to further restrict the fumigation methods that can be used

. Agricultural commissioners may implement one or any combination of these three options. Under the fumigant allowance option, g rowers in an NAA where a fumigant limit is in effect must request an allowance from the commissioner. Allowance requests must include crop and acres . DPR or the commissioner estimates worstcase emissions by assuming the highest emitting fumigant and method by crop, for all of the requested acreage. The allowances are reduced proportionally to bring total fumigant VOC

emissions below the limit for the NAA. Commissioners issue the allowances as a condition of the restricted materials permits. Each grower must manage his/her fumigations by selecting the appropriate combination of fumigants, fumigation methods, application rates, and number of acres fumigated so the allowance is not exceeded. As restricted materials, growers or applicators must submit a Notice of Intent to the county agricultural commissioner for each fumigatio n. Commissioners check each Notice of Intent to confirm that it complies with the allowance prior to fumigation. For the Ventura NAA, Table 3 shows that the May-October fumigated acreage decreased by 24 percent in the Ventura NAA between 2006-7 and 2008-9 (15,497 acres to 11,8 33 acres). At least part of this decrease is likely due to the fumigant limit and allowances. ( Deleted: 2008

Deleted: and grower allowance system

Deleted: All of the allowances combined are equal to the fumigant limit. Near the beginning of each year, g

Deleted: the name of the product, the application rate,

Deleted:

,

Deleted: , fumigation method, and projected month of application.

Commissioners forward emission requests to DPR. If the total amount of fumigant use requested by growers is above the NAA’s emission limit, DPR imposes

Deleted: p roportionate reductions

Deleted: then

Deleted: determined by DPR

Deleted: NOTE: In April 2011, DPR adopted revisions to the fumigant VOC regulations that provid e other alternatives in addition to allowances for county agricultural commissioners to enforce a fumigant limit. These revisions have not been submitted to U.S. EPA yet.)18 Prior to implementation of the fumigant regulations in 2008, fumigants contributed 80 percent of more of the pesticide VOC emissions in the Southeast Desert and Ventura nonattainment areas and more than 40 percent of the emissions in the San Joaquin Valley. DPR implemented regulations for fumigants because their reduction was the only way to ensure the SIP goals were achieved in the Southeast Desert and Ventura NAAs. These reductions were also effective for the San Joaquin Valley. However, DPR is working on other measures to further reduce VOC emissions, particularly for the San Joaquin Valley.

In 1993, U.S. EPA published an alternative control technology document that addresses the control of VOC emissions from the application of agricultural pesticides ( http://www.epa.gov/ttn/naaqs/ozone/ctg_act/199303_voc_epa453_r-92- 011_ag_pesticides.pdf ). To DPR’s knowledge, no other state has measures to reduce pesticide VOC emissions, so there are no other evaluations to rely on. The following is DPR’s evaluation of the seven techniques the document identified as technically viable for reducing pesticide VOC emissions:

• Reformulating organic solvent containing pe sticide formulations (e.g., emulsifiable concentrates)

• Reducing fumigant usage

• Using alternative application methods

• Applying microencapsulation techniques

• Using integrated pest management

• Using alternative active ingredients

• Reducing the use of crop oils

Other Reduction Options – Reformulating Organic Solvent Containing Pesticide

Formulations

In 2005, DPR initiated a reevaluation (regul atory process to request actions by pesticide registrants) for several hundred nonfumigant products. The reevaluation required registrants to submit plans for reformulating the inert ingredients in the products to reduce VOC emissions. DPR stopped work on this reevaluation and shifted its strategy to reducing emissions with the fumigant regulations. DPR restarted work on nonfumigants in 2010 and revised the reevaluation to limit reformulation efforts to the products with the highest pesticide VOC contribution in the San Joaquin Valley NAA (Figure 4):

• Abamectin products (e.g., Agri-Mek)

• Chlorpyrifos products (e.g., Lorsban)

• Dimethoate products (e.g., Cygon)

• Gibberellins products (e.g., Gibgro)

• Oxyfluorfen products (e.g., Goal)

• Permethrin products

• Trifluralin products (e.g., Treflan)

See the following web page for more detailed information on the reevaluation for VOC emissions from nonfumigant pesticides: http://www.cdpr.ca.gov/docs/emon/vocs /vo cproj/req_reformulation_lid.htm19 Several registrants began reformulation efforts at the start of the reevaluation, most notably for chlorpyrifos. Products containing chlorpyrifos are the highest or second highest pesticide VOC contributor in the San Joaquin Valley, depending on year (Figure 4). VOC emissions from the inert ingredients in chlorpyrifos products declined 40 percent between 2008 and 2009 in the San Joaquin Valley. This decline was due to a 25 percent decrease in use, and a 15 percent decrease due to a change in products (Figure 5). DPR registered Lorsban Advanced in July 2008, and its emission poten tial is 18.45 percent. In contrast, Lorsban 4E, Lorsban 4E-HF, and similar emulisfiable concentrate products have emission potentials of approximately 50 percent. Many growers and applicators switched from the high-VOC chlorpyrifos products to Lorsban Advanced in 2009. Lorsban Advanced was the highest use chlorpyrifos product in the San Joaquin Valley during 2009 (Table 6).

There are several activities to encourage the vo luntary use of low-VOC products. Purchase of low-VOC products is one of three pesticide VOC measures for which EQIP provides matching funds to growers in California. Under a U.S. EPA grant, DPR prepared a conservation management practices guide for pesticide VOCs and developed a companion website for growers and applicators that calculates and compares the VOC emissions for pesticide applications.

In conclusion, this measure is feasible because several registrants have implemented this measure, and DPR is evaluating possible additional regulatory actions for non-fumigant pesticides to require reformulation for certain pesticides. However, it may be infeasible to reformulate some products due to decreased pest control, increased toxicity of the inert ingredients, high cost, or other factors.

Other Reduction Options – Reducing Fumigant Usage

The fumigant regulations include a fumigant limit and allowance system in the Ventura NAA at least until 2012, and as a backstop measur e in the event low-emission fumigation methods are insufficient to achieve the SIP goals for the other NAAs. This measure is feasible as a backstop. It requires a reduction in fumigated acreage, and planting of less profitable crops, or no crops. Additionally it requires a new administrative program for DPR, county agricultural commissioners, and the regulated community. Low-emission fumigation methods are more compatible and less costly with the current regulatory program.

Other Reduction Options – Using Alternative Application Methods

The alternative control technology document describes this option as “improved-efficiency application equipment.” To encourage the voluntary reduction of emissions, purchase of precision pest control application equipment or “smart sprayers” is one of three pesticide VOC measures for which EQIP provides matching funds to growers in California. Priority is given to application equipment that uses phot o identification or sonar-type technologies. These technologies are primarily used for orchard sprayers, where a sensor controls the amount of spray, and turns off the spray in betw een trees. This results in less pesticide being applied. This measure is not feasible as a regulatory control because the equipment is costly and the VOC emissions due to pesticides applied with orchard sprayers are relatively low.20 Although not described in the alternative control technology document, the fumigant regulations rely primarily on low-emission fumigation methods to achieve reductions.

Other Reduction Options – Applying Microencapsulation Techniques

This measure consists of reformulating emulsifiable concentrates into microcapsules to reduce the amount of solvent in the product. DPR has grouped this measure with the reformulation option.

Other Reduction Options – Using Integrated Pest Management

The alternative control technology document de scribes integrated pest management as an “ecologically based pest management program that combines biological and nonbiological control techniques to suppress weeds, insects, and diseases. This option has been defined as a pest population management system that uti lizes all suitable techniques in a compatible manner to reduce pest populations and maintain them at levels below those causing economic injury.” DPR regulates the use of pesticides, and lacks legal authority to require integrated pest management, which includes non-pesticidal practices. However, DPR has programs that encourage the adoption integrated pest management, not only to address VOCs, but also to reduce health and environmental risks. These programs include DPR’s

IPM Innovator awards to honor California or ganizations that emphasize pest prevention, favor least-toxic pest control, and share their successful strategies with others. DPR has also funded grants and alliances that form a step-wise progression from applied research and demonstration projects to regional or stat ewide implementation of multi-disciplinary reduced-risk pest management practices. Reducing VOC emissions is one of the criteria DPR uses to judge applications for pest management grants.

Organic crop production or growing crops with no fumigants is possible in some situations, but is infeasible for all crop production. Fo r some annual crops such as strawberries, conventional crops are normally grown every year or every other year on the same field, made possible by soil fumigation. In contrast an organic crop must be rotated with other commodities and are grown on the same field once every several years. There is insufficient land in California with climate and water to support a conversion to 100 percent organic production. Growing perennial crops (orchards, vineyards) can be very risky without fumigants. These crops are subject to infestation by nematodes and nematode-borne pathogens in preplant/replant situations. In organic vineyards and orchards where soil fumigants are not allowed, the only options are nematode-resistant rootstocks and prolonged fallow periods. While nematode-resistant rootstoc ks are available for both crops, they are not always a good match for a particular soil type or local climate. The recommended fallowperiod for grapes is ten years, and this will only serve to delay the appearance of nematoderelated symptoms. Nonfumigant pesticides are not effective against these soil pests after the crop is planted. Use of fumigants for some nursery crops is essential. Many fields are planted with seedlings grown in nurseries. To preven t catastrophic failure in multiple production fields, federal and state laws require many nursery crops to be certified as pest-free prior to sales of seedlings. Fumigants are often the only alternative to obtain the certification.21 In conclusion, this measure is not feasible because integrated pest management and organic production are not always technically feasible, and DPR lacks legal authority to implement this as a requirement.

Other Reduction Options – Using Alternative Active Ingredients

This option is not feasible because DPR lacks legal authority to require certain pesticides to be used. While DPR can regulat e or prohibit sales or use of certain pesticides based on unacceptable risks, DPR cannot require growers and applicators to apply specific pesticides in place of the regulated ones.

Other Reduction Options – Redu cing the Use of Crop Oils

Crop oils have insecticidal uses, and are among the highest used pesticides in California. (Petroleum oil was ranked second and mineral oil was ranked third in pounds applied during 2009.) However, DPR disagrees that reducing crop oils is a good option to reduce VOC emissions. Based on thermogravimetric analys is data and DPR’s evaluation of 26 oil products, the emission potentials for oil products are low, with a median value of 1.53 percent. Even accounting for the high use, non e of the oils are among the top 10 pesticide VOC contributors in any of the NAAs, so any reductions would have minimal impact on emissions. Moreover, DPR and others encourage the use of oils because they have lower health and environmental risk in comparison to most other active ingredients in insecticide products, particularly organophosphates. In conc lusion, this measure is not feasible because the VOC emission reductions associated with this measure are minimal, and will likely cause an increase in use of pesticides with greater health or environmental impact. See the following for DPR’s VOC evaluation of oil products: http://www.cdpr.ca.gov/docs/emon/pubs/e ha preps/analysis_memos/2079_segawa.pdf



### Other issues

Current Research on Fumigan t VOC Emission Reduction

Another reevaluation is in progress to obtain additional data for current fumigation methods because DPR relied on surrogate data for some fumigation methods. This reevaluation requested that registrants provide monitoring da ta to confirm the accuracy of the surrogate data. The registrants included CHAIN2D computer modeling of emissions as part of their response. While the registrant modeling was re jected, DPR started its own efforts to develop a computer model to estimate fumigant emissions. Under contract to DPR, the model developer has completed modifications of HYDRUS to account for the effect of tarps, bed shape, and other fumigation parameters. Comparisons of the HYDRUS model to field monitoring data have shown good agreement in some cases, and disagreement in other cases. To assist with validating the model, DPR plans a special field study to gather data that are used for the model inputs, but were lacking in earlier studies. If validated, the model will be used to determine the parameters that affect em issions and guide efforts to reduce emissions.22 Numerous researchers are working on methods to reduce fumigant emissions. Much of this work is sponsored by USDA as part of two area-wide programs on methyl bromide alternatives. The Pacific Area-Wide program includes several multi-year projects in California to develop, demonstrate, and impl ement fumigant reduction measures. It’s likely this research will lead to additional low-emission fumigation methods. DPR is currently evaluating data for low permeability tarpaulins from this program. Field monitoring data indicates that low permeability tarpaulins can reduce peak fumigant emissions by as much as 90 percent. However, the data also indicates that relatively high emissions occur at the normal tarp removal time, and the normal ta rp removal process may cause unacceptable exposure to workers. Current research is focusing on the appropriate time period and process to remove low permeability tarpaulins. It may be possible to achieve even greater reductions by using low permeability tarpaulins in combination with lower application rates and still effectively manage pests. The Pacific Area-Wide program developed a special a global positioning system (GPS) for tractors that reduces the amount of fumigant needed by 50 percent or more. Intended for orchard and vineyard applications, tractors equipped with this system apply fumigant only at the spot where a tree or vine will be planted. Researchers are working with a major fumigant pest control business to modify the GPS system for commercial use. Research also continues on soil amendments, soil compaction techniques, and other fumigant emission reduction measures. The Pacific Area-Wide program is also conducting research on nonpesticidal alternativ es to fumigants. This includes growing strawberries in soilless substrate, anaerobic soil disinfestation, steam disinfestation, biocontrol agents, and resistant rootstocks. All research of the Pacific Area-Wide program, as well as the Southeast Area-Wide program, and other fumigant research are presented at an annual conference. Information about the research is available at the following conference

website: http://www.mbao.org/

In January 2011, U.S. EPA summarized its evaluation of the available fumigant emissions studies (Attachment 5 – U.S. EPA memorandum from Dawson, Smith, and Shelat to Leahy, dated January 11, 2011). DPR did not use all of studies used by U.S. EPA because: 1) some studies were not available when the regulations were developed in 2007 and are still under review by DPR; 2 ) some studies were conducted outsi de the state and do not reflect emissions under California conditions; 3 ) some studies measured emissions using methods unacceptable to DPR; or 4 ) some studies were insufficient to address all DPR exposure concerns. It’s likely that DPR will use the recent studies to revise the regulations and add new low-emission fumigation methods once the reviews are completed and other issues are

addressed.

Time Period of Emission Inventory and Regulations

DPR’s emission inventory and fumigant regulations are based on the peak ozone season of May 1 through October 31 because they implement the pesticide element of the 1-hour ozone SIP. That SIP is based on seasonal inventories. Under that SIP, as approved by U.S. EPA, VOC reductions are, and always have been , measured over the 6-month ozone season. Likewise the VOC reduction goals of the pesticide element of that SIP apply, and always have been applied to that time period. The VOC reduction measures of the 1-hour ozone SIP are seasonal so that the reductions needed during the peak ozone season are required. Deleted: 2) some studies available after 2007 led to fumigant VOC regulation changes that have no t yet been submitted
to U.S. EPA; 3

Deleted: 4

Deleted: 523 Moreover, requiring low-emission fumigation methods year-round could increase fumigant emissions during the peak ozone season. Fumigants are applied prior to planting, and are not applied to prevent immediate crop damage. Therefore, the time window for application is more flexible than most other pesticides. Under the current regulations, growers and applicators have shifted some fumigations outside the May-October period to avoid the additional restrictions. It’s likely that these fumigations will shift back to the May-October period if low-emission methods are required year-round. This will result in lower emissions outside the May-October period, but greater emissions during the May-October period, defeating the overall goals of the regulations.



### Conclusions

DPR has implemented or is working to implement all feasible measures to reduce VOC emissions from pesticides. DPR has adopted regulations requiring low-emission fumigation methods in certain NAAs, usually consisting of tarping, post-fumigation water treatments, or application through drip irrigation systems. The VOC regulations also include a fumigant emission limit for the Ventura NAA at least until 2012. This system is also a backstop measure in the event low-emission fumigation methods are insufficient to achieve the SIP goals for the other NAAs. DPR is working with pesticide registrants to reformulate certain pesticide products that contain high amounts of solvents. DPR and others are conducting research to further reduce VOC emissions from pesticides. Other measures that would reduce

VOC emissions are infeasible at this time. Deleted: and grower allowance system24 Table 1. Application Method Adjustment Fact or (AMAF) and pesticide use report Field Fumigation Method (FFM) code for each fumigation method.

Regulation

Section Field Fumigation Method FFM Code AMAF (%)
6447.3. Methyl Bromide Fumigation Methods (with or without chloropicrin) 1100 series 6447.3(a)(1) Nontarpaulin/Shallow/Bed 1101 100* 6447.3(a)(2) Nontarpaulin/Deep/Broadcast 1102 74* 6447.3(a)(3) Tarpaulin/Shallow/Broadcast – Nobel Plow 1103 48 Tarpaulin/Shallow/Broadcast – Nobel Plow – Strip 1104 74* Tarpaulin/Shallow/Broadcast – Closing shoes and compaction roller 1105 100* 6447.3(a)(4 ) Tarpaulin/Shallow/Bed 1106 100* 6447.3(a)(5) Tarpaulin/Deep/Broadcast 1107 48 Tarpaulin/Deep/Broadcast – Strip 1108 74* 6447.3(a)(6) Drip System - Hot Gas 1109 100*

Other label method** 1190 ---

6448.1. 1,3-Dichloropropene Fumigation Methods (with or without chloropicrin) 1200 series 6448.1(c)(1) Nontarpaulin/Shallow/Broadcast or Bed 1201 65* 6448.1(c)(2) Tarpaulin/Shallow/Broadcast 1202 65* Tarpaulin/Shallow/Bed 1203 65* 6448.1(c)(3) Nontarpaulin/Shallow/Broadcast /Three Water Treatments 1204 44 6448.1(c)(4) Tarpaulin/Shallow/Bed/Three Water Treatment 1205 44 6448.1(c)(5) Nontarpaulin/Deep/Broadcast or Bed 1206 26 6448.1(c)(6) Tarpaulin/Deep/Broadcast 1207 26 Tarpaulin/Deep/Bed 1208 26 6448.1(c)(7) Chemigation (Drip System)/Tarpaulin 1209 19

Other label method** 1290 ---

6449.1 Chloropicrin-Fumigation Methods 1100-1300

series 6447.3(a)(1) Nontarpaulin/Shallow/Bed 1101 64* 6447.3(a)(2) Nontarpaulin/Deep/Broadcast 1102 64* 6447.3(a)(3) Tarpaulin/Shallow/Broadcast – Nobel Plow 1103 44 Tarpaulin/Shallow/Broadcast – Nobel Plow – Strip 1104 64* Tarpaulin/Shallow/Broadcast – Closing shoes and compaction roller 1105 64* 6447.3(a)(4 ) Tarpaulin/Shallow/Bed 1106 64* 6447.3(a)(5) Tarpaulin/Deep/Broadcast 1107 44 Tarpaulin/Deep/Broadcast – Strip 1108 64* 6447.3(a)(6) Drip System - Hot Gas 1109 100*

6448.1(c)(1) Nontarpaulin/Shallow/Broadcast or Bed 1201 64* 6448.1(c)(2) Tarpaulin/Shallow/Broadcast 1202 44 Tarpaulin/Shallow/Bed 1203 64* 6448.1(c)(3) Nontarpaulin/Shallow/Broadcast /Three Water Treatments 1204 43 6448.1(c)(4) Tarpaulin/Shallow/Bed/Three Water Treatment 1205 43 6448.1(c)(5) Nontarpaulin/Deep/Broadcast or Bed 1206 64* 6448.1(c)(6) Tarpaulin/Deep/Broadcast 1207 44 Tarpaulin/Deep/Bed 1208 44 6448.1(c)(7) Chemigation (Drip System)/Tarpaulin 1209 12

Other label method** 1390 ---25 Regulation

Section Field Fumigation Method FFM

Code AMAF (%)
6450.1. Metam-Sodium and Metam-Potassium Fumigation Methods 1400 series 6450.1(d)(1) Sprinkler/Broadcast or Bed/One Water Treatment 1401 77* 6450.1(d)(2) Sprinkler/Broadcast or Bed/Two Water Treatments 1402 28 6450.1(d)(3) Sprinkler/Broadcast or Bed/Three Water Treatments 1403 21 6450.1(d)(4) Nontarpaulin/Shallow/Broadcast or Bed/One Water Treatment 1404 77* 6450.1(d)(5) Nontarpaulin/Shallow/Broadcast or Bed /Two Water Treatments 1405 28 6450.1(d)(6) Nontarpaulin/Shallow/Broadcast or Bed/Three Water Treatments 1406 21 6450.1(d)(7) Chemigation (Drip System) Tarpaulin 1407 9 Chemigation (Drip System) Nontarpaulin 1408 9 6450.1(d)(8) Rotary Tiller 1409 14

Power Mulcher 1410 14

Soil Capping 1411 14 6450.1(d)(9) Flood 1412 77*

6452 Day Drench 1413 100

6452 Night 1A.M. Start/Sprinkler/Broadcast or Bed/Two Water Treatments 1452 77*

6452 Night Nontarpaulin/Shallow/Broadcast or Bed/Two Water Treatments 1455 28

6452 Night 4A.M. Start/sprinkler/Broadcast or Bed/Two Water Treatments 1472 35

Other label method** 1490 ---

6450.2. Dazomet Fumigation Methods 1500 series

Soil incorporation 1501 17 Surface application – water incorporation 1502 17

Other label method** 1590 ---

6451.1 Sodium Tetrathiocarbonate Fumigation Methods 1600 series Chemigation (Drip) 1601 10 Chemigation (mini-sprinkler) 1602 10 Chemigation (flood, basin) 1603 10 Chemigation (furrow, border) 1604 10 Chemigation (foggers, jets, misters, other) 1605 10

Other label method** 1690 ---

6446.1 Methyl Iodide Fumigation Methods 1700 Series Day Tarpaulin/Shallow/Broadcast 1701 100 Day Tarpaulin/Shallow/Bed 1702 100 Day Tarpaulin/Deep/Broadcast 1703 100 Day Chemigation (Drip)/Tarpaulin 1704 100 Day Auger-Probe 1705 100

* Method prohibited within the San Joaquin Valley, Southeast Desert, and Ventura nonattainment areas during May 1 – October 31. **For use only outside of the May 1 – October 31 time period; or areas outside of the nonattainment areas; or for exempted applicatio ns (such as described in Sections 6447, 6448, 6449, 6450, and 6451) Formatted: Not Strikethrough

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Formatted Table26 Table 2. Comparison of fumigant emissions and use prior to and after implementation of fumigant VOC regulations (2006-2007 vs. 2008-2009 May-October annual average).

Fumigant VOC Emissions and Use San Joaquin Valley NAA Southeast

Desert NAA Ventura

NAA 2006-7 Fumigant Emissions (tons/day) 6.47 0.49 3.06 2008-9 Fumigant Emissions (tons/day) 3.35 0.092 1.30

2006-7 Fumigant Use (tons/day) 14.39 0.92 8.89 2008-9 Fumigant Use (tons/day) 11.93 0.47 6.53

2006-7 vs. 2008-9 Relative Difference (percent)

Decrease in VOC emissions 48 81 57* Decrease in Amount Applied 17 49 26*

Decrease Due to Low-Emission Methods** 31 32 31

2006-7 vs. 2008-9 Mass Difference (tons/day)

Decrease in VOC emissions 3.12 0.40 1.75*

Decrease Due to Low-Emission Methods** 2.01 0.16 0.95 * Some of the decrease in use for Ventura was due to the fumigant limit and allowances required by the regulations.

** Some of the decrease may be due to changes in the procedure for determining the frequency each fumigation method is used.27 Table 3. Comparison of fumigant use prior to and after implementation of fumigant VOC regulations (2006-2007 vs. 2008-2009 annual average). Data is for all fumigants combined.

Fumigant Use San Joaquin Valley NAA Southeast

Desert NAA Ventura

NAA

Amount of Fumigant Used

May-Oct 2006-7 7,005,537 lbs 490,624 lbs 3,283,589 lbs

Jan-Dec 2006-7 16,225,657 lbs 1,029,983 lbs 3,538,332 lbs May-Oct as fraction of 2006-7 43% 48% 93%

May-Oct 2008-9 5,805,199 lbs 317,963 lbs 2,453,000 lbs

Jan-Dec 2008-9 15,710,197 lbs 950,877 lbs 3,018,515 lbs May-Oct as fraction of 2008-9 37% 33% 81%

Size of Area Fumigated

May-Oct 2006-7 49,242 ac 3,456 ac 15,497 ac

Jan-Dec 2006-7 146,872 ac 6,906 ac 16,766 ac May-Oct as fraction of 2006-7 34% 50% 92%

May-Oct 2008-9 40,862 ac 2,332 ac 11,833 ac

Jan-Dec 2008-9 139,861 ac 6,403 ac 14,967 ac May-Oct as fraction of 2008-9 29% 36% 79%

Average Application Rate

May-Oct 2006-7 175 lbs/ac 199 lbs/ac 216 lbs/ac Jan-Apr & Nov-Dec 2006-7 164 lbs/ac 190 lbs/ac 241 lbs/ac

May-Oct 2008-9 167 lbs/ac 205 lbs/ac 291 lbs/ac Jan-Apr & Nov-Dec 2008-9 167 lbs/ac 189 lbs/ac 199 lbs/ac28Table 4. Summary of the evaluation ofpossible fumigation method restrictions.Possible Restriction1,3-DichloropropeneChloropicrinMethyl BromideMethyl IodideMITCSodiumTetrathiocarbonateIntroduction - DripLow-emissionLow-emissionNot allowed by labelsLow-emissionLow-emissionLow-emissionIntroduction - OtherChemigationNot allowed by labelsNot allowed bylabelsNot allowed by labelsNot allowed bylabelsSeveral methodsallowed, additionalrequirements forlow-emissionSeveral methodsallowed, all lowemissionIntroduction -Tractor ShankSeveral methodsallowed, deep shankis low-emissionSeveral methodsallowed, additionalrequirements forlow-emissionSeveral methodsallowed, additionalrequirements for lowemissionSeveral methodsallowed, additionalrequirements forlow-emissionSeveral methodsallowed, additionalrequirements forlow-emissionNot allowed by labelTarpingIneffectiveLow-emissionmethodLow-emissionmethodHighly retentivetarp low-emissionNot testedIncompatible withchemigationSoil MoistureRegs superseded bylabelsRegs supersededby labelsRegs superseded bylabelsLabel requirementRegs supersededby labelsRegs superseded bylabelWater Treatments3 or more for low-emission3 or more for low-emissionNot testedNot tested2 or more for low-emissionLabel requirementsApplication RateMax based on highestrate testedMax based onhighest rate testedMax based on highestrate testedMax based onhighest rate testedMax based onhighest rate testedMax based on highestrate testedWeather RestrictionsInsufficient dataInsufficient dataLittle or no effect onemissionsInsufficient dataInsufficient dataInsufficient dataSoil CharacteristicsInsufficient dataInsufficient dataLittle or no effect onemissionsInsufficient dataInsufficient dataInsufficient dataSoil AmendmentsVariable results,possible odorVariable results,possible odorVariable results,possible odorNot testedNot testedNot testedSoil and EquipmentPrepLabel requirementsLabel requirementsLabel requirementsLabel requirementsLabel requirementsLabel requirementsFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted TableFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 ptFormatted:Font: 10 pt29 Table 5a. Standard fumigation costs in 2007.

Fumigant $/lb. Active Ingredient Per acre costs**

Methyl Bromide $3.50 $2100 (350 lbs/ac, broadcast shank injection, tarped Chloropicrin $3.00 $1400 (200lb/ac, broadcast shank injection, tarped)
1,3-D tractor $1.40 $550 (35 gal/ac, broadcast shank injection, untarped) 1,3-D drip $2.40 $640 (25 gal/ac, drip application) Metam Sodium $1.00 $400 (75 gal/ac, shank injection, water seal)

* Tom Trout, USDA-ARS, Fumigant use trends in California; Response to MeBr PhaseOut.

Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions, 2006. **Includes both fumigant and application costs

Table 5b. Costs of conversion to low-emission fumigation methods in 2007.

Fumigant application

method Fumigant Increased $/ac* Acres (average 2003-2005)* Estimated total cost

of conversion

SJV = 124,750 $63,622,500

SE Desert = 4,280 $2,182,800 Convert to drip application from shank injection (drip system already in place)* 1,3-dichloropropene Chloropicrin

Metam $510 1

Ventura = 6,408 $3,268,080
SJV= 124,750 $313,122,500
SE Desert = 4,280 $10,742,800 Convert to drip application from shank injection (including installation of drip system)** 1,3-dichloropropene Chloropicrin

Metam $2510 2

Ventura = 6,408 $16,084,080

SJV= 124,750 $1,247,500
SE Desert = 4,280 $42,800 Post-application water treatments (sprinkler system already in place)** 1,3-dichloropropene Chloropicrin

Metam $10 3

Ventura = 6,408 $64,080
SJV= 124,750 $29,940,000

SE Desert = 4,280 $1,027,200 Post-application water treatments (including rental of sprinkler system** 1,3-dichloropropene Chloropicrin

Metam $240 4

Ventura = 6,408 $1,537,920

SJV= 16,898 $6,759,200

SE Desert = 30 $12,000 Tarping – methyl bromide Trees & Vines Only ** Methyl Bromide $400 5

Ventura = 32 $12,800 * Increased costs per acre: To m Trout, USDA-ARS, Fumigant use trends in California; Response to MeBr PhaseOut. Annual Internatio nal Research Conference on Methyl Bromide Alternatives and Emissions Reductions, 2006. ** Increased cost per acre estimates provided by Husein Ajwa, Ext Specialist, UC Davis Dept. of Plant Sciences, Salinas, CA +1 831 755 2823.

1 Materials and installation costs: tarp + drip tape = $500, water = $10 for 3 x 1⁄4 inch applications within two days after fumigation

2 Materials and installation costs: tarp + drip tape $500, water = $10, Install drip system $2000

3 Water: $10/ac in. for 3 x 1⁄4 inch applications within two days after fumigation

4 Sprinkler rental = $200 and setup = $40; (purchase sprinklers about $2000/ac).

5 Tarp and application = $40030 Table 6. Use of major chlorpyrifos products and liquid low-VOC alternatives in the San Joaquin Valley NAA.

Product Use May-Oct (lbs) Product Emission Potential (%) 2008 2009

Nufos 4E 52.30 176,922 190,975

Lorsban 4E 50.00 500,314 188,032

Govern 4E 50.00 185,234 141,313

Lorsban 4E-HF 48.68 423,639 116,953

Lorsban Advanced 18.45 2,323 386,662
Lock-On 20.90 305,620 176,50531 Figure 1. Nonattainment areas included in the pesticide element of the ozone state implementation plan.

CALIFORNIA CALIFORNIA

Sacramento

Metro

San Joaquin Valley

Southeast

Desert

South Coast

Ventura * Sacramento Metro NAA - all of Sacramento and Yolo counties, and parts of El Dorado, Placer, Solano and Sutter counties.

* San Joaquin Valley NAA - all of San Joaquin, Stanislaus, Merced, Madera, Fresno, Kings, and Tulare counties, and the valley portion of Kern County.

* South Coast NAA - all of Orange County, and part of Los Angeles,
Riverside and San Bernardino counties.

* Southeast Desert NAA - the desert portions of Riverside (Coachella Valley), Los Angeles (Lancaster/Palmdale), and San Bernardino (Barstow) counties.

* Ventura NAA - all of Ventura County. 

# ® FEDERAL NON-ATTAINMENT AREAS
AFFECTED BY CALIFORNIA REGULATIONS
TO REDUCE EMISSIONS
FROM
FUMIGANT PESTICIDES

January 200832 Figure 2. Pesticide VOC emission inventory for 1990-2009. The emissions using fumigant Application Method Adjustment Factors cannot be calculated for 1991-2004 due to lack of data on the frequency each fumigation method was used (method use fractions).

NAA 1 Sacramento Metropolitan

Year 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0 2 0 1 5Emission Rate (tpd)

0.0 0.5 1.0 1.5 2.0 2.5 3.0 NAA 2 San Joaquin Valley

Year 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0 2 0 1 5Emission Rate (tpd)

0 5 10 15 20 25

NAA 3 Southeast Desert

Year 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0 2 0 1 5Emission Rate (tpd)

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 NAA 4 Ventura

Year 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0 2 0 1 5Emission Rate (tpd)

0 1 2 3 4 5

NAA 5 South Coast

Year 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0 2 0 1 5Emission Rate (tpd)

0 2 4 6 8 10 12



## • Adjusted Emissions

(1990, 2004, 2005, 2006, 2007, 2008 & 2009)

SIP Goals33Figure 3. Statewide use of field fumigants.05,000,00010,000,00015,000,00020,000,0001988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Statewide Use (lbs)1,3-DChloropicrinMethyl BromideMITC pesticidesSodium Tetrathiocarbonate34 Figure 4. VOC emissions from pesticide products used in the San Joaquin Valley during May-October 2009, by active ingredient. Emissions from glyphosate products are likely overestimated due to the lack thermogravimetric analysis data for one high-use product and the assignment of a high default emission potential.

1,3-D

9%

Glyphosate

8%

Glufosinate

3% Methyl bromide

2% Dimethoate

4% Abamectin

5% Gibberellins

5% Oxyfluorfen

5% Metam

11%

Acrolein

2% Fenpyroximate

2% Trifluralin

2% All other pesticides

32% Chlorpyrifos

10%35 Figure 5. Chlorpyrifos use and product VOC emissions in the San Joaquin Valley during May-October.



### 0 250,000 500,000 750,000 1,000,000

Active ingredient VOC emissionsAmount (lbs)



## 2008 2009