Laserfiche WebLink
, <br /> ENVIRONMENTAL ���� ���� <br /> �� [� '� N �� 0[� �� Nt�� � ���� HEALTH ������f���� l������ � <br /> SAN wOrQTQN COUNTY <br /> Unit Supervisors <br /> Donna K'K'm^'R'E'R.g. ]04 I�us| �V�bnr /�vcuuo, Third Floor <br /> �or| B»/�m^n`R�E�B�S� <br /> 0//rr/o/� MikcBug-ins KC8� R.D.I. <br /> Al Olsen,R.E.H.S. �tO��ion California ��2A2-270� ` � � � ` <br /> ` ' ' � � ` Doua|u.,vv.Wilson,k.E]iS. <br /> D`*«nmMan««or Telephone: (2Ug) 468-342O w)ui potLug^ i^. DE]iS. <br /> Laurie A.Cot"Uu'BJ�B/� �ux� (209) 464-0i38 Robert O Uon,KER.S <br /> . <br /> Dognv/�avogmr ` <br /> Mark B^rcd|os.D.F.8.S. <br /> RD88EI^ CBAPI1J 6J <br /> MR »,.|\.N. 0 � ��.-. <br /> CH\PID[ BROTHERS, INC <br /> 1203 B[ CARLTON AVE <br /> 8TOCKTON CA 95303 <br /> Site �O�� ���� <br /> RE: [�H/�PIN BROTHERS '' <br /> 1766 MONTE [JI/\BLO AVENUE <br /> ST[]CKTON' C/\ <br /> The San Joaquin CountvEnvinonrnenCalHealth C)epa�rnent /EHO\ has been informed <br /> that Mr. Dennis Parfitt <br /> 'the California State Water Resources Control Board (SVVRCB) <br /> has completed the review ofyour site closure petition. The EHO understands that Mr. <br /> Parfitt does not concur with your petition at this time, and ialeaving your site under EHO <br /> oversight yWr. Parfitt shares the concern of the EHO that the plume behavior under <br /> natural conditions cannot be adequately predicted. Mr. Parfitt suggests turning off the <br /> groundwater extraction system and conducting quarterly monitoring for o year to <br /> evaluate plume behavior, while collecting additional data to demonstrate the occurrence <br /> and rate ofnatural attenuation. <br /> In order for the EHC) to concur with a site closure naquest, you must demonstrate plume <br /> stability and degradation, and make a reasonable estimate of the time required for the <br /> irnpo� d groundwater return �o background conditions. As stated in previous EHO <br /> ~^~ b| estimates of contaminant mass in soil <br /> io�era at minimum, this requires reasonable <br /> ' <br /> and groundwater, an understanding <br /> anddemonstration of the natural attenuationproc8aoeaaffe-tingthe contaninanta, and an understanding of the hydrog8o|Vgyofthe <br /> site. At this time, the E .D does not believe that you have sufficient data to meet these <br /> requirements. The - H0 notes with concern that the latest contaminant concentration <br /> data, January 205. shows total petroleum hydrocarbons, quantified as gasoline/TPH-g\' and benzene concentrations in <br /> the extraction wells either increasing or holding <br /> steady. This may indicate that the plume will not respond favorably under natural <br /> conditions. <br /> HOVYeVe[' in view Of the SVVRCB SuggeSUOD, the EHO will approve <br /> evaluation Ofplume behavior under natural conditions. <br /> Please provide the EHO with a vvOrh p|GO to evaluate plume response under natural <br /> conditions without benefit of @ctiv8, engineered remediation. The groundwater <br /> extraction vve\lS should be included as part of the quarterly monitoring pnognarn, even <br /> after the remediation system iSinactivated. The EHDrecommends including inthe work <br /> plan such S8rOp|e @O8|yS8S as are appropriate to deDl0DSt[Gt9 op8[@d0n of natural <br /> attenuation processes and toestimate theirratR(s). The work plan should also include <br />