SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Mr. Curt Richards • - 4 - • 9 June 2008 Olin Chlor Alkali Products On 23 October 2007, Joe Hofbauer, Eva Hey, and James Brownell met to specifically discuss these items. No. 4. Pioneer asked the Regional Board to reconsider the quarterly sampling frequency requirement for the Homestead, Reed, and Medina domestic wells because monitoring had been performed for over four years with no detections of VOCs. However, Regional Water Board staff found that the wells had not been tested since August 2000. Apparently, Pioneer was referring to four years of testing of nearby monitoring wells. Therefore, due to the uncertainty of well screen depth intervals in the domestic wells, staff found that it could not be know if the monitoring wells were screened within the zones from which the domestic wells were pumping water. As a result, the participants of the 23 October meeting agreed that the quarterly monitoring of the domestic wells would be performed. As specified in the enclosed final MRP, if analyses of water samples from a domestic well collected during four consecutive quarters does not detect VOCs, the sampling frequency of that well would be changed to annual, and would continue at that frequency until or if a detection of VOCs occurred. No. 5. Pioneer asked that water level measurements not be required from onsite, industrial water supply wells AP-1, Banta #1, and Banta #2. Although the draft MRP did not require these measurements, for clarity, a footnote has been added to Table 2 of the final MRP that indicates water level measurements from Pioneer production well AP-1, Banta #1, and Banta #2, as well as the Homestead, Reed, Medina, and Pombo domestic wells are not practical. No. 7. Pioneer asked that the frequency of water level measurements in the shallow monitoring wells be changed from quarterly to semiannually. The participants of the 23 October meeting agreed that quarterly measurements from only three of these wells would be necessary: MW-1, MW-7, and MW-13. Measurements from MW-1 and MW-13 will allow vertical gradient calculations at the locations of deep wells AP-2 (nested with MW-1) and MW-15 (nested with MW-13). The purpose for measuring MW-7 is to obtain a third measurement from the shallow zone, which will allow the option of checking shallow zone horizontal gradient on a quarterly rather than semiannual basis. No. 8. Pioneer requested changes to the types and frequencies of monitoring reports, specifically GeoTracker reports, monthly wellhead treatment system reports, semiannual groundwater monitoring reports, and annual groundwater monitoring reports. At the 23 October meeting, the Regional Water Board staff stated that the types of required reports could not be changed. However, the frequency and content of some reports could be modified. The final MRP summarizes the following final MRP requirements discussed at the meeting: 1) GeoTracker. Reports must be submitted to satisfy the requirements of Title 23 of the California Water Code. 2) Monthly wellhead treatment system reports. Apparently, Pioneer has replaced the contaminated Pombo domestic well instead of installing a wellhead treatment system on the contaminated well. However, in the event that such a system becomes necessary for this well or other domestic wells, the treatment system report requirements will remain in the final MRP. 3) Semiannual reporting requirements. Item (a) of the semiannual reporting requirements in the final MRP requires only a brief statement in each report that