SITE INFORMATION AND CORRESPONDENCE

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Mr. Arnold Hof - 3 - 30 April 2003 our 23 April 2003 telephone conversation, you stated that MW-8 is located on the adjacent property and the owner has denied access for sampling. Since MW-8 is no longer needed for your monitoring program, this well should also be destroyed. Please provide a schedule to abandon these wells by 23 May 2003. Nitrate Trends Since upgradient well MW-9 was installed in late 1997,the concentration of nitrate (as nitrate) climbed from 20 mg/1 to 550 mg/l in 1998, and then steadily declined to 5 mg/1 in October 2002., (The water quality limit for nitrate is 45 mg/l.) The proximate well, MW-4, is downgradient of MW-9 and on the upgradient boundary of the Cal Farm Supply facility. In mid-1998, the nitrate concentration in MW-4 climbed from 40 mg/l to 244 mg/l,before declining to 71 mg/l in October 2002. This concentration spike and steady decline in these two upgradient wells shows that a slug of nitrate is passing beneath the Cal Farm Supply facility unrelated to former site activities. On-site, monitoring wells MW-2 and MW-3 contain nitrate at concentrations of 300 and 170 mg/1,respectively, MW-5 contains about 71 mg/1, and MW-1 does not contain detectable nitrate. The comingling of an off-site nitrate source with the on-site nitrate source presents difficulty in estimating a reasonable background concentration for nitrate at this site. Continuing to monitor nitrogen in MW-4 will detect if another nitrate slug moves on-site. You are not required to remediate contaminants coming onto your property from an off-site source. Replacement for Monitoring Well MW-6 In 1997, Cal Farm Supply installed monitoring well MW-6 in a seasonally ponded area in the southern portion of its former property. This well consistently showed nitrate concentrations greater than those ever observed in the operations area before it was inadvertently destroyed in 1999. In our 23 April conversation you stated that all the adjacent facilities and residences had on-site septic systems up until last year,which could be contributing to the nitrate concentrations observed in MW-6. In our October 2001 meeting, you agreed to install a monitoring well to replace MW-6,but since you did not own the portion of the former facility where MW-6 had been located, we agreed that you could install the well on the southern boundary of your property in order to avoid property ownership and access issues. In our 2 April 2003 telephone conversation, you stated that you recently purchased the southern property. Since you now own the southern property,we prefer to have a replacement well re-established near its former location, about 200 feet south of MW-3. In our 23 April conversation,you stated that you intend to install a replacement well in the near future,but must wait until funds are available. You advised me that you would have a better idea of when you could install the replacement well in a few weeks. Therefore, by 23 May 2003, please submit a schedule to provide a monitoring well installation work plan and to install the monitoring well. Replacement well MW-6R needs to be installed not later than 30 August 2003. The replacement well should be sampled for nitrate and ammonium when it is installed, in the third quarter when the other wells are sampled, and again in the first quarter of 2004. Then it should be sampled annually in the third quarter along with the other wells. This provision is included in the draft MRP.