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Lodi Herbicide Drift Testing Plan Secretive, Full Of Holes

The vineyard sampling in the Lodi area to determine the extent of contamination from the Bouldin Island herbicide drift is unlikely, as currently designed, to alleviate concerns about potential health consequences from wine made from exposed grapes.

Among potential shortcomings are the areas being sampled, the laboratory cut-off concentrations of imazapyr and the lack of testing for potential human health issues presented by the chemicals involved.

This article will focus on the issues with how samples are being gathered.

See Major Pesticide Drift Threatens Lodi-Area Vineyards, Lodi Pesticide Drift – Update and San Joaquin County probe into local pesticide drift for background on the contamination issues.

Ag Commissioner Gives Herbicide Supplier The Testing Lead

The San Joaquin County Agriculture Commissioner has designated the supplier of the chemicals, Wilbur-Ellis Company, as its choice for conducting sampling and laboratory testing.

Wilbur-Ellis recommended and supplied the herbicide cocktail: Roundup Custom, Polaris SP, In-Place, Cayuse and Hasten, which were aerially applied to areas in San Joaquin and Contra Costa Counties in mid-May and which  drifted north and east of the targets.

The San Joaquin County Agriculture Commissioner has been criticized by growers for his lack of transparency, slow reaction time, his failure to release information on how many growers have filed complaints and where those growers are located.

In addition, the Commissioner stated on July 11 that the investigation was close to being wrapped up even before Wilbur-Ellis had informed wineries (but not growers) of its testing plan.
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Wilbur-Ellis Grower Emails Outline Their Plans

Wilbur-Ellis executive Dan Vradenburg sent the following email  to wineries on July 14, 2014 — almost two months after the pesticide drift occurred.

The information was not sent to growers.

Winery Owner & Key Personnel,

Attached is some information that maybe beneficial to you. We have the following:

  • How Wilbur-Ellis Company is approaching testing
  • Testing processes to a recommended standard so that results can be trusted
  • Our research to address capacity and consistency in labs to get things done

We believe it is important to understand that:

  1. Some labs are not using a consistent process (it varies between lab to lab)
  2. Wilbur-Ellis committed to find and recommend the best science and we believe we did by finding the BASF process and working with BASF and getting approval to use their most current methodology
  3. We have submitted the BASF standard to 6 labs and have commitment for them to follow the BASF standard with the appropriate modifications for wine grapes (this gives us the best, most current, most relevant and most consistent testing)
  4. The BASF methodology is approved by the EPA for imazapyr in the human food chain.

We also included a sampling strategy that makes sense to us and our agronomic investigation team.

We continue to work on a map of concentric circles through the waypoints. Once we get cluster samples per the protocols we should be able to build a color gradient map using a shading system identifying the impact areas.

The goal is to give a sense of where extra precautions may need to be taken.

You will note in the slides where we suggest you plan for three weeks turnaround on samples.

Then on the lab list, it indicates what they say their turnaround time is which on all accounts is much less. We hope they can perform as indicated but I would recommend to error on the conservative side to begin with.

Hope this helps.

Dan Vradenburg

Is Testing Geographically Sufficient?

The Wilbur-Ellis map of sampling points contained in the attached (accessible here by Wine Executive News subscribers) leaves out large areas containing vineyards.

There is no way to determine from this sampling regime whether there may be areas of concern in those sectors.

We contacted Wilbur-Ellis and asked about this. Despite this being emailed last week, the Wilbur-Ellis spokesperson said it was an old map, weeks old.

They declined to provide an updated map or to explain the apparent holes in sampling this one shows.

They also said that the map was sent only to wineries and not to growers.

No other information was supplied beyond a statement at the end of this article.

The Google Earth image, below, clearly shows vineyards in the areas that are not being sampled.

Greatly enlarged map available to Wine Executive News premium subscribers.

Greatly enlarged map available to Wine Executive News premium subscribers.

In addition, no sampling is being done in non-agricultural areas because the Ag Commissioner previously stated that there was no threat to the public.

That assessment was not made on the basis of any scientific data. They could be harmful if any of the chemicals involved, their metabolites or decomposition compounds are hormone disruptors.

Greatly enlarged map available to Wine Executive News premium subscribers.

Greatly enlarged map available to Wine Executive News premium subscribers.

Inadequate Sampling Area

The Wilbur-Ellis sampling map shows a point of origin at the far eastern boundary of Bouldin Island. The aerial application — and drift — could not have begun with a single point, but would have begun with a broader front on a north-south axis. That would have created a drift pattern that should have moved the origin to a more diffused area to the west and the drift boundaries significantly north and south.


Greatly enlarged map available to Wine Executive News premium subscribers.

Greatly enlarged map available to Wine Executive News premium subscribers.

In addition, the Ag Commissioner is quoted as saying that aerial spraying also took place at Webb Tract during this same time period. Nothing has been said concerning any potential drift from that area.

Wilbur-Ellis Statement

This is the entire statement received by email at 4:17 p.m., Thursday, July 23. It does not address most issues. Unanswered questions and comments are [bold and contained in brackets].

“The map was in fact preliminary, and was prepared several weeks ago; we included it in the Winery Residue Analysis Program we provided to wineries on July 14, which was primarily focused on testing and sampling protocols for the wineries.

“The map represented our initial attempt to model the reported drift, and as I mentioned on the phone, it wasn’t intended for wide distribution. Since that map was put together all parties have focused on the actual testing, and the map no longer represents the area and crops being tested.

“This testing is being done by growers, wineries, and various independent investigators, including Wilbur-Ellis, and covers more area than shown on the initial map.

[No updated map was available, nor any specific mention of who “all the parties” are who are conducting the testing or how many are involved.]

“The good news is that the vast majority of tests we are aware of have shown no imazapyr residue in the fruit. This is consistent with the comments from the San Joaquin County Ag Commissioner in their press release. Of course, we will continue to monitor the fruit as we come closer to harvest.”

[Tests “we are aware of…” Is anyone responsible for tracking all the tests? Who is in charge? What percentage is “vast majority? Where were the positives found? In what concentrations?

We can’t really answer your questions on the application or the drift because we weren’t involved in the application, nor do we know the circumstances behind the drift.”

[This means that the area being sampled, as illustrated in the only map available, is probably not correct because this pesticide drift is not from a point source like a leaking storage tank.]


How reliance on government regulatory toxicology requirements and non-peer-reviewed science offer only a false sense of safety which may not be warranted.

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