CORRESPONDENCE_2007 (1/07 - 6/07)

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--fx: *16-464-4775 >>> "Yekta, Gino" <GYekta@CIWMB.ca.gov> 3/23/2007 3:19 PM >>> Thank you for meeting with the operator to discuss the ponding issue. If the May 1, 2007 timeline is okay with the RWQCB, then we are okay with that as well. Here are responses to your questions (in the same order of your questions): #1 - I am not sure if there is anything that specifically constitutes a plugged probe. I suggest that you can tell if a probe is plugged by finding water and sediment in it that would keep the gas from migrating into it, filled screen levels and such, but water seems to be the culprit in making probes plugged. #2 - No, it is not. You could sample all or a few of the probes, that is up to you. #3 - I have reviewed the submittal. Our comments and suggestions are similar to RWQCB's and we would like to defer to RWQCB in regards to closure of this portion of the site. #4 - We are okay with any one of the options as long as it is designed, constructed and installed adequately. -----Original Message ----- From: Robert McClellon [EH] [mailto:RMcClellon@sjcphs.org] Sent: Tuesday, March 20, 2007 9:55 AM To: Yekta, Gino Cc: Wochnick, Michael; Todd Del Frate; Natalia Subbotnikova [EH] Subject: RE: Corral Hollow Sanitary Landfill inspection Gino, here is what I was able to find out. The ponding on Corral Hollow still remains. I spoke with Michael Carroll and met with him and his staff at the landfill on March 19, 2007. The ponding located south east of the landfill is at the toe of the slope and near the secondary storm pond. Michael Carroll disclosed that there was another area of ponding on the south west corner of the landfill that they found during the site visit (at the toe of the slope). In conversation Mike agreed to regrade the areas and eliminate the ponding (they are small area's 5ft x 20ft) by May 1, 2007. During the site visit Probe 6 was tested. We tested the probe by placing a "T" in the line between our landtec and used Public Works landtec as a magnahelic. The shallow, intermediate, and deep probes were tested and the negative pressure was the highest in probe 6 shallow (7.8 inches H2O). The landtec was shutdown and the negative pressure drifted down to zero in less than 1 minute. The other probes intermediate and deep exhibited a negative pressure around 4.0 inches of H2O. Again the machine was shutdown and the pressure drifted to zero. There was no effort on the part of Public Works to make changes to the probe. The intermediate probe register 2.6% CH4. The shallow probe registered 0.3% CH4 and Deep was 2.2% CH4. The probes are monitored quarterly by Public Works contractor SCS. The Environmental Health Department (EHD) was not trying to duplicate efforts, but merely spot check wells during our inspection. I hope this addresses your concerns. I have a few questions regarding this site and maybe you can help. 1. The probes at all of our sites seem to produce a sample with different efficiencies (some are slow producers and others seem to be fine). Is there a standard for what constitutes a plugged probe? Is there an approved methodology for determining this? 2. The sampling of the entire site is being done quarterly by SCS, is it necessary as part of our inspection to sample all the probes quarterly, or just the probes that have been a problem in the past? If you would like the EHD to sample all of the probe then we will make it a part of the quarterly. Please let me know. 3. Have you had a chance to review Public Works last proposal to determine the extent of the waste outside of the closure cap? 4. Probe #1 Deep as you know the screened interval is submersed in H2O. This probe will require relocation. There are two options regarding this. One install the probe in the closest location near the original location that is not subject to the 3