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Subject: CWS AMP & Frequency of Monitoring Meeting with Syng enta Date/Time: December 15, 2010 – 1:30-2:00 PM Meeting Requestor: Syngenta Meeting Notes Preparer: Melanie Biscoe, EPA/OPP/PRD

Meeting Summary:

During this meeting, Syngenta indicated that it wil l be sending a decommissioning request to EPA for 69 Community Water Systems (CWS) that have had 8 seasons of monitoring and will start the 9 th season of monitoring in 2011 (see slide 2 in Synge nta’s associated slide set). Syngenta also indicated tha t it could voluntarily increase the frequency of monitoring in a select number of CWS, particularly focusing on 13 CWS that are flowing drinking water sources and therefo re have lower dilution of atrazine compared to static water sources as well as higher variability in atrazine exposures. Syngenta thought that this may be useful for any mo del validation that EPA is doing in its frequency of monitoring work, or for acquiring addi tional statistical comfort in the Agency’s work. EPA indicated that it had not decid ed on whether it will be using modeling to determine peak exposures. EPA also ind icated that more frequent data is always beneficial. EPA indicated that data collect ed during the 2011 growing season could not be analyzed in time for the 2011 SAP, but may be useful as EPA and the registrants think about the registration review tha t commences in 2013. EPA also noted that on slide 2 of Syngenta’s slide set that they l ist 88 CWS as being currently enrolled in the monitoring program, EPA’s count is 101; Syngent a and EPA discussed how this could be the result of multiple sampling measuremen ts at individual CWSs, but that Syngenta and EPA should hold follow-up discussions to ensure that our lists of sampling sites are in agreement.

Syngenta also discussed how it has been conducting other water quality measurements, such as turbidity, in other monitoring it is doing. Syngenta indicated that it would be able

to conduct such additional measurements in a subset of AMP sites should EPA find such measurements helpful in understanding the watershed s and their water quality issues in a more comprehensive way.

One EPA employee wanted some clarification on who c onducts the monitoring and what the relationship is between Syngenta and that parti cular party. Syngenta explained that employees of the water systems themselves typically take the samples and send the samples directly to Syngenta for analysis by Adpen labs. Syngenta also indicated that some of the CWSs in the AMP have refused to partici pate in the AMP after 5 years of monitoring or as a result of increased scrutiny res ulting from media inquiries; Syngenta

indicated that in those circumstances it hires a th ird party to take the required samples.

Note that on slide 5 of Syngenta’s slide set, the e xposure values/rolling averages are for raw water, not water that has already gone through the treatment process. Also on slide 5, samples from CWSs are only taken every 7 days an d, as a result, Syngenta’s 4-day rolling average concentrations of atrazine were cal culated using linear interpolation.Page 2 of 2

Meeting Attendees:

Janis McFarland Syngenta Dan Campbell Syngenta

Melanie Biscoe PRD/OPP/EPA

Nelson Thurman EFED/OPP/EPA

Jack Arthur HED/OPP/EPA Dana Spatz EFED/OPP/EPA Don Brady EFED/OPP/EPA Mary Frankenberry EFED/OPP/EPA

Anna Lowit HED/OPP/EPA