Regulation of Chemigation in California:

Challenges and Changes

John Troiano: jtroiano@cdpr.ca.gov, Mark Pepple: mpepple@cdpr.ca.gov

Joy Dias: jdias@cdpr.ca.gov

California Department of Pesticide Regulation, 1001 I Street, Sacramentio, CA 95812

Potential Contamination of Ground Water

Irrigation system shutdown

causes water-chemical

mixture to flow backwards

into water source. Devices

are required to eliminate

this potential problem.

Backsiphoning of chemical into wellhead.

Each service rig and piece of application equipment that handles pesticides and draws water from an outside source shall be equipped with an air-gap separation, reduced pressure principle backflow prevention device or double check valve assembly. Backflow protection must be acceptable to both the water purveyor and the local health department.

California Code of Regulations (Title 3. Food and Agriculture)Division 6. Pesticides and Pest Control Operations

Current DPR Backflow Prevention Regulation

6610: Backflow Prevention

(G) Chemical Injection Pump

(E) Interlocking System Controls

(H) Injection Line Check Valve

(A) Mainline Single Check Valve

(C) Air/Vacuum Relief Valve

(B) Low Pressure Drain (F) Solenoid Operated Valve

(D) Pressure Switch

PR 87-1: Example of Required Components

(A)

(B)

(C) (D)

(E)

(F)

(G)(H)

1999: Cooperative contract with U.S. EPA Region 9 to provide an analysis of backflow prevention activities in California: Were DPR’s regulations in compliance with U.S. EPA label requirements?

Inception of DPR’s Chemigation Initiative

• Language in 6610 written in 1977 taken from municipal connections – not relevant to label language protecting rural irrigation/domestic wells

• General lack of awareness of label requirements amongst regulators and regulated community - education needed to explain need for and recognition of devices, enabling compliance inspections.

• Significant number of active ingredients labeled for chemigation: 109 of 420 (25%)

• Many pesticides labeled for chemigation were not restricted use materials. Posed a problem with identifying sites for inspection.

Components of DPR Chemigation Initiative

Comply with EPA Label Improvement Program PR Notice 87-1.

Comply with EPA Label Improvement Program

Issued policy letters to County Agricultural Commissioners (CAC) clarifying that they were to enforce the label instructions, thereby superceding DPR's backflow regulations.

- Handlers must comply with all chemigation requirements specified on label.

- Defined outside source – an outside water source includes all sources of water, except water that stored in a reservoir tank, that is owned or under the control of the pesticide applicator and/or property owner. (Domestic well included)

- But also issued second letter to clarify that there were acceptable alternative devices to those listed on the label.

Components of DPR Chemigation Initiative

Comply with EPA Label Improvement Program – PR 87-1.

Education/Training.

Training/Education

Contracted with irrigation specialists at Center for Irrigation Technology (CIT), CSU Fresno to provide educational materials and training.

Manuals in English and Spanish.o       English: http://www.cdpr.ca.gov/docs/gwp/chem/grower_manual.pdfo       Spanish: http://www.cdpr.ca.gov/docs/gwp/chem/120804_chemgtn_tr_man_span.pdf 

Pamphlets in English and Spanish.o       English: http://www.cdpr.ca.gov/docs/gwp/chem/chempamp_engrev2.pdfo       Spanish: http://www.cdpr.ca.gov/docs/gwp/chem/2chempamp_span0505_final.pdf

Trailer equipped for hands-on training.

Mobile Backflow Display

Training/Education

Contracted with irrigation specialists at Center for Irrigation Technology (CIT), CSU Fresno to provide educational materials and training.

Contracted with irrigation specialists at UC, Davis to provide illustrations of systems. DPR Website: http://www.cdpr.ca.gov/docs/gwp/chem/diagrams/chem_diagrams.pdf

Training/Education

Contracted with irrigation specialists at Center for Irrigation Technology (CIT), CSU Fresno to provide educational materials and training.

Contracted with irrigation specialists at UC, Davis to provide illustrations of systems. DPR Website: http://www.cdpr.ca.gov/docs/gwp/chem/diagrams/chem_diagrams.pdf

Contracted with irrigation specialists at Cal Poly SU, San Luis Obispo to develop webpage and advertise their course in trade journals. Cal Poly website: http://www.itrc.org/reports/chemigation/chemigationandfertigationforca.htm

Training/Education

Training Objectives:

CAC staff Clarify policy letters on PR 87-1.

Recognition of devices.

Awareness of alternative devices and though not listed on label are appropriate.

Training/Education

Training Objectives: CAC staff

Regulated Community. Well on property drawing ground water must be equipped with backflow prevention devices according to label requirements.

Devices required and their alternatives e.g. more than just that listed on the label.

Heads-up – DPR enforcement of policy letters and potential new regulations.

Training/Education

Training Objectives: CAC staff Regulated Community. Irrigation system specialists.

Need for devices to protect ground water.

Sources of information on devices and specs.

Components of DPR Chemigation Initiative

Comply with EPA Label Improvement Program – PR 87-1.

Education/Training.

Initiate Chemigation Inspections.

Initiate Chemigation Inspections

Contracted with irrigation specialists at CIT to provide consultation.

Restricted materials – available as technical consultant during CAC staff inspections of devices used for chemigation of soil fumigants.

Respond through e-mail to questions from staff.

Available for request of visits to wellheads.

Initiate Chemigation Inspections

Contracted with irrigation specialists at CIT to provide consultation.

Provided funding for focused to CAC for interested counties to:

Develop method to identify growers using chemigation.

Conduct site inspections on a percentage of growers they identified as using chemigation as a method of application.

Components of DPR Chemigation Initiative

Comply with EPA Label Improvement Program – PR 87-1.

Education/Training.

Initiate Chemigation Inspections.

Create Chemigation Task Force.

Create Chemigation Task Force

CIT contracted to head a chemigation task force comprised of diverse personal - agricultural engineers, irrigation specialists, participating growers, irrigation manufacturers, registrants, EPA Region 9 staff, and DPR field staff

Provide an integrated approach for further regulatory actions by acting as a forum for input from the group.

Task Force Issues/Actions

Review educational manuals.

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Provide expertise in questions on system design.

Equivalency in design of sand filters to gooseneck.

Use of hydraulic cut-off in remotely located injections.

Equivalency of hydraulic positive displacement pumps.

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Provide expertise in questions on system design.

Is certification necessary, how to do it?

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Provide expertise in questions on system design.

Is certification necessary?

Should components be tested, how to do it?

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Provide expertise in questions on system design.

Is certification necessary?

Should components be tested, how to do it?

Groups to train – irrigation system designers.

Task Force Issues/Actions

Review educational manuals.

Advise and review proposed revisions to DPR’s regulation.

Provide expertise in questions on system design..

Is certification necessary?

Should components be tested, how to do it?

Groups to expand training to – irrigation system designers.

Develop guidance on application methodology (emerging issues).

Components of DPR Chemigation Initiative

Comply with EPA Label Improvement Program – PR 87-1.

Education/Training.

Initiate Chemigation Inspections.

Create Chemigation Task Force.

Update regulations to clarify requirements.

Clarify Requirements in California’s Regulations

Issue: California irrigation systems are diverse with a constant stream of new improvements/ideas/designs.

Problem: How can a regulation be written that will be flexible and allow for implementation of new devices.

Clarify Requirements in California’s Regulations

Proposed Approach: Indicate in regulation the engineering principle to be

controlled and then refer to a website/manual that contains acceptable devices. The manual can be updated according to the Director’s policy.

Example Language: 1)Backflow prevention equipment on irrigation systems that draw water from an outside source shall functionally accomplish the following objectives: (A) Keep irrigation water containing pesticides from contaminating the outside water source. (B) Keep irrigation water from entering the chemical supply

tank and causing the tank to overflow. (etc)

Clarify Requirements in California’s Regulations

Chemigation Safety Devices That Meet the Requirements of 3CCR Section 6610

For Direct Chemical Injection into a Pressurized Water System with No Air Gap with an Outside Water Source

Publication/Internet Site:

I. To Keep Irrigation Water Containing Pesticides From Contaminating The Water Source.

Install one of the following three devices:

Original Device*: A main water line check valve and main water line low pressure …..

or Alternative Device *: Standard gooseneck pipe loop.

or Alternative Device *: Irrigation system media filter “gooseneck .

and install one of the following two devices:Original Device: Vacuum relief valve

orAlternative Device: Combination vacuum relief and air release valve

Emerging Issues

Complexity of irrigation systems in CA raise questions of appropriate devices – current required statements on label not reflective of majority of systems.

• Approach in PR 87-1 part A for VI-IX needs to be revisited to incorporate protective language but flexibility. Example of micro systems: though positive displacement pump listed on label, a venturi injector is easiest and most common method used to inject pesticides into a system.

Emerging Issues

Complexity of irrigation systems in CA raise questions of appropriate devices.

Greater emphasis/research on appropriate application methodology.

• Human exposure from chemigating fumigants.Incident: Monterey County 2005

• Drip application of chloropicrin• Injection point ‘far’ from field• Lines flushed after application• Water switched to sprinklers• Early evening, people began calling

• Off-gassing from puddles caused by leaks in line?

• Line was not really fully flushed due to length of feed?

• Blind laterals? – Pipes/tubing placed in line with no emitters.

Causes of Exposure

Emerging Issues Complexity of irrigation systems in CA raise questions of appropriate devices.

Greater emphasis on application methodology.

• Human exposure from chemigating fumigants.

• Bird kill from chemigating nematicide

- Chemigation in early November, overcast, rain forecast.

- Conducted by vineyard management company.

- Fertigated in morning.

- Chemigated in afternoon (on a schedule).

- Cut short, county rules allow for rain to incorporate.

- Left ponds in field that song birds were exposed to.

Emerging Issues Complexity of irrigation systems in CA raise questions of appropriate devices.

Greater emphasis on application methodology.

• Human exposure from chemigating fumigants.

• Bird kill from chemigating nematicide

• Exact application method to assure efficacy.

- Conducted co-operative research that promoted chemigation of pre-emergence herbicides for 24C

- Issues have arisen as to the best method to apply: short, fast burst vs longer, slower injections