Laserfiche WebLink
Op4u'N C <br />2' Z <br />c �P <br />'9C/FO'Rti <br />THOMAS M. GAU <br />DEPUTY DIRECTOR <br />MANUEL SOLORIO <br />DEPUTY DIRECTOR <br />STEVEN WINKLER <br />DEPUTY DIRECTOR <br />THOMAS R. FLINN <br />DIRECTOR <br />ROGER JANES <br />BUSINESS ADMINISTRATOR <br />March 22, 2006 <br />Mr. Robert McClellon, REHS <br />Environmental Health Department <br />304 East Weber Avenue, Third Floor <br />Stockton, California 95202 <br />n <br />P. O. BOX 1810 - 1810 E. HAZELTON AVENUE <br />STOCKTON, CALIFORNIA 95201-3018 <br />(209) 468-3000 FAX (209) 468-2999 <br />www.co.san-joaquin.ca.us <br />2006 HAR 27 PH I® I I <br />HL � L Tj-{ Drt') <rs i 11 idT <br />SUBJECT: FIRST QUARTER 2006 PERIMETER AND STRUCTURE LFG MONITORING, <br />FOOTHILL SANITARY LANDFILL <br />Dear Mr. McClellon: 1 <br />All on-site structures were found free of combustible gas. All perimeter wells were found to be <br />below the 5 percent limit for combustible gas except for monitoring well SG -4, which is located <br />near the northeast corner of unlined Module "I" (data attached). As presented in the data sent to <br />your office March 20, 2006, the concentration of methane in SG -4 was found to be 7.1 percent on <br />March 17, 2006, and 9.1 percent on March 20, 2006. Please note that the letter of <br />March 20, 2006, incorrectly identified SG -7 as the well at which this exceedance was detected. <br />We do not believe this condition threatens human health and safety at this time. The closest <br />habitable structure to this well is the on-site residence, which is over 2,500 feet from this well, and <br />which was found to be free of combustible gas in this monitoring event. Well SG -4 is also over <br />1,000 feet from the property boundary, with no structures visible for at least two miles in that <br />direction. <br />We believe that the recent heavy rains may have impeded the natural venting through the soil at <br />this well, which has shown fluctuating combustible gas concentrations in the past. We suspect <br />that we will again find the combustible gas concentrations below regulatory limits when the rains <br />have subsided. <br />As you know, installation of a landfill gas collection system is planned for completion in <br />December 2006. This system should remove the possibility of any further exceedances at well <br />SG -4. <br />