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HomeMy WebLinkAboutSLOUNIFLOW_FS1 Admin iRC3926i Color_0029_001California Regional Water Quality Control Board Central Coast Region Alan C. Lloyd Ph. D. Agency Secretary Arnold Schwarzcncgger' Goventorhrtelnet Address: http://www.watelboalds.ca.gov/cenhalcoast 895 Aerovista Place, Suite 101, San Luis Obispo, California 93401-'1906 Phone (805) s49-3141 . FAX (80s) s43-0397 April 11,2006 Mr. Dana Thurman Chevron Environmental Management Company 6001 Bollinger Canyon Road,I<2236 P.O. Box 6004 San Ramon, CA 94583 -2324 Dear Mr. Thurman: UST: 151 SANTA ROSA STREET, SAN LUIS OBISPO, SAN LUIS OBISPO COIINTY; CHEVRON STATION NO. 9-1717; CASE CLOSURE TRANSMITTAL (CASE NO. 884) Central Coast Water Board (Water Board) staff has reviewed SECOR International lnc.'s March 17,2006, Monitoring Well Abandonment report for the subject site. Thank you for submitting this information. The underground storage tank case closure requirements are complete. This concludes the Water Board's regulatory oversight for the investigation and cleanup of the underground storage tank system release. This letter does not relieve you of other agency's requirements, which may continue to have jurisdiction or require further work. As with any real property, discovery of additional or previously unidentified contamination at the site may require additional investigation and cleanup. In addition, please find the enclosed case closure letter and case closure summary, which summarizes site characterization information and contaminant treatment, disposal, and concentration data for the subject site. Thank you for your diligence in addressing water quality issues and your continued commitment to the protection of water quality in the Central Coast Region. If you have any question regarding this matter, please contact Corey Walsh at (805) 542- 4787 or by e-mail at cwalsh@rvaterboards.ca.gov. S Y, Ro W Executive Officer Enclosures: Site Closule Letter Case Closure Summary S:\UST\l{egulated Sites\San Luis Obispo Co\San Luis Obispo\Santa Rosa St\151 Santa Rosa\Transmit Closule.doc cc: Next page Califo rnia Enviro nm ental P rotection Agen cy i7Oet Recycled Paper ) Mr, Dana Thutman Mr. Roger C Steiner and Barry J. Steiner Roger C. Steiner, Etal I4I7 Bridgeway, Suite 4 Sausalito, CI'94965 (Property owner) Mr. Kerry Boyle City of San Luis Obispo Fire Deparlment 2160 Santa Barbara Avenue San Luis Obispo, CA 93401-5240 Mr. Robert Jackson SECOR International Inc. 3437 Empresa Drive, Ste. A San L. uis Obispo, CA 93401 -7355 Without losure: Ms. Nancy Callsen SWRCB.DCWP UST Cleanup Fund P.O. Box 944212 Sacramento, CA 94244-2720 Mr. Scott Milner San Luis Obispo County Division of Environmental Health P.O. Box 1489 San Luis Obispo, CA 93406 Mr. Jeff M. Whitworth Shel1 Oil Products US 433 Town Center #496 Corte Madera, C494925 n April 11,2006 California Environmental Protection Agency aoet Recycled Poper California Regional Water Quality Control Board Central Coast Region Alnn C. Lloyd Ph. D Agency Secretaryt Arnold Schrvalzcncgger GoventorIntetnet Address: http://www.rvaterboarcls.ca.gor,/ccnttrlcoast 895 Aerovista Place, Suite 101, San Luis Obispo, California 93401-7906 Phone (805) s49-3147 . FAX (805) s43-0397 April 11,2006 Mr. Dana Thurman Chevron Envirorunental Management Company 6001 Bollinger Canyon Road, K2236 P.O. Box 6004 San Ramon, CA 94583 -2324 Dear Mr. Thurman: UST: 151 SANTA ROSA STREET, SAN LUIS OBISPO, SAN LUIS OBISPO COUNTY; CHEVRON SERVICE STATION NO. 9-1717; CASE CLOSURE LETTER (CASE NO. 884) This letter confirms the completion of site investigation and remedial action for the underground storage tanks formerly located at the above-described location. Thank you for your cooperation thloughout this investigation. Your willingness and promptness in responding to our inquiries conceming the former underground storage tanks are greatly appreciated. Based on the information in the above-referenced file and with the provision that the information provided to this agency was accurate and representative of site conditions, this agency finds that the site investigation and corrective action carried out at your underground storage tank site is in compliance with the requirements of subdivisions (a) and (b) of Section 25296.10 of the Health and Safety Code and with corrective action regulations adopted pursuant to Section 25299.3 of the Health and Safety Code and that no further action related to the petroleum release at the site is required. This notice is issued pursuant to subdivision (g) of Section 25296.10 of the Health and Safety Code. Please contact Corey Walsh at (805) 542-4781 of our office if you have any questions regarding this matter. Sincerely, Roger W. Briggs Executive Officer S:\UST\Regulated Sites\San Luis Obispo Co\San Luis Obispo\Santa Rosa St\I51 Santa Rosa\Closure letter.doc California E nviro nm ental P rote ctio 17 Ag en cy dF RecYclet! PaPet \ l UASE CLOSURE SUMMARY Leaking Underground Fuel Storage Tank Program lnformation ll. Gase lnformation lll. Tank lnformation lV. Release and Site Gharacterization lnformation EI It, Agency Name: RWQCB - Central Coast Region Address: B95Aerovista Place, Suite 101 City/State/Zip: San Luis Obispo, CA 93401-7906 Phone: (805) 542-4781 Responsible Staff person: Mr. Corey Walsh Title: Associate Engineering Geologist Site Facility Name: Chevron Service Station #9-1717 LUSTIS Case #: BB4 Site FacilityAddress: 151 North Santa Rosa Street, San Luis Obispo Responsible Parties Address Phone Number Chevron Environmental Management Company Attn: Mr. Dana Thurman 6001 Bollinger Canyon Rd., K2236 San Ramon, CA 94583 (925) 842-9559 Property Owner Roger C. Steiner Etal '1417 Bridgeway, Suite 4, Sausalito, CA 94965 Tank #Size in Gallons Gontents Glosed in Place/Removed Date 1 10,000 Gasoline Removed 10125-26195 2 10,000 Gasoline Removed 10125-26195 3 10,000 Gasoline Removed 10t25-26195 Cause and Type of Release: Piping and Dispenser leak Site Characterization Complete? Yes Date Approved by Oversight Agency: April 29, 2005 Monitoring Wells Installed? Yes Number: 4 Proper Screened interval? Yes Highest GW Depth Below Ground Surface: 3.8 ft Lowest: 7.9 ft Flow Direction : South-southeast Most Sensitive Current GW Use: Municipal (Nearest municipal well, Mitchell Park Well, located approx. 1.25 miles SE) Are Drinking Water Wells Affected? No Aquifer Name: San Luis Obispo Creek Hydrologic Subarea 3-10.24 ls Surface Water Affected? No Nearest Surface Water: Stenner Creek 600 ft. east of site Off-site Beneficial Use lmpacts (addresses/locations): None )) dASE CLOSURE SUMMARY Leaking Underground Storage Tank Program Page 2 V. TreatmenUDis osal Methods Vl. Closure a add itional information Action (Treatment or Disposal Method)DateAmount (lnclude Units) Material Removed & disposed off-site October 1995Tanks3 - 10,000 gal. USTs October 1995Removed & disposed off-sitePipingNA NAProduct Excavated and disposed off-site December 1995716 tonsSoil November 1995Not Applicable No remedial action for dewatering deemed necessary Groundwater Maximum Documented Contaminant Goncentrations--Before and After Cleanup Soil(mg/kg)Water (pg/L)Soil(ms/kg)Water (pg/L)Gontaminant Before After Before AfterBeforeAfterBeforeA,fter Gontaminant NA600<50 1,2-DCA NA NA NATPH (Gas)I 500 <0.5 NA NANANANAOil & Grease NA NATPH (Diesel)NA Lead NA NA NA NA8.'1 <0.005 4.6 0.7Benzene <0.5 MTBE NA NA 530 3.0Toluene31<0.005 <0.3 NA NA<0.3 0.8 HVO NA NAEthylbenzene21<0.005 NA NA NA<0.005 <0.6 2.0 Naphthalene NAXylenes120 Gomments: Soil samples from the excavation boundaries (side walls and bottom) did not exhibit soil hydrocarbon concentrations exceeding action levels Does completed corrective action protect existing beneficial uses per the Basin Plan? Yes Does completed corrective action protect potential beneficial uses per the Basin Plan? Yes Does corrective action protect public health for current land use? Yes Site Management Requirements: No Should corrective action be reviewed if land use changes? Yes Monitoring Wells Destroyed? Yes, on 11121105 three MWs over-drilled & MW-3 pressure grouted. Number Destroyed: 4 Number Retained: None ' -') -) CASE CLOSURE SUMMARY Leaking Underground Storage Tank Program Page 3 List Enforcement Actions Taken: Conducted remedial excavation to remove petroleum hydrocarbon impacted soil Conducted semi-annual groundwater monitoring following excavation activities (since September 1997). List Enforcement Actions Rescinded: None Vll. Local resentative Data Vlll. AdditionalComments lX. Regional Board Certification s:\ust\regulated sites\san luis obispo co\san luis 5/9/05 rosa st\151 rosa\case closure form.doc Address: 2'160 Santa Barbara AvenueAgency Name: City of San Luis Obispo Fire Department Phone: (805) 781-7383Gity/State/Zip: San Luis Obispo, CA 93401 Title: Hazardous Waste CoordinatorResponsible Staff person: Mr. Kerry Boyle See Attached Request for Closure letter Date: / 't/- 46Signature of Executive Officer X. 1 ) CASE CLOSURE SUMMARY Leaking Underground Storage Tank Program Additional lnformation (to be attached to this report) Page 4 Listinq of Reports please include a list of all investigative reports, including reports prepared for financial institutions such as phase I Environmental Assessments, all monitoring data, corrective action alternatives analyses, and other consultant reports. lf a report on the list has not been previously submitted to the Regional Board, please submit the report with this form. On or attached to the list must be the following statement, with itre dated signature of the responsible party or his agent: "l attest, under penalty of perjury, in accordance with Water Code section 13267, the following documents constitute the complete list of documents pertaining to waste discharged, hydrogeology and other information directly relevant to the characterization and cleanup of the waste discharged at the subject site." Extent of Soil Contamination a) Maps showing the extent of soil degradation by chemicals of concern in excess of guidelines, before and after remediation. b) Geologic log of the most highly degraded soil boring or monitoring well showing sample points with a list of contaminant concentrations. c) Summary table of all historic soil sampling results. Extent of Ground Water Contamination a) Maps showing the extent of ground water degradation in excess of detection limits for chemicals of concern, before and after remediation. '' b) Geologic logs, including construction, for allwells' c) Representative geologic log identifying all aquifers. d) Two intersecting cross-sections of the site. e) Summary table of all historic ground water analyses and water levels. 2. 3 CASE CLOSURE SUMMARY Leaking Underground Storage Tank Program I attest, under penalty of perjury, in accordance with Section 19267 of the California Water Code, the following documents constiiute the complete list of documents pertaining to waste discharged, hydrogeology and other information directly relevant to the character and cleanup of the waste discharged at the subj ect site. A1r'.t rlrJosF"- 6htq'a"r Signature of Res Party (or Designated Agent's)Date Signed *foJ t f,Jr*- Pi'int Name Page 5 TABLE 1 : LIST OF HISTORICAL ENVIRONMENTAL OVERSIGHT REPORTS CHEVRON SERVICE STATION 9-1717 151 NORTH SANTA ROSA ROAD, SAN LUIS OBISIPO, CALIFORNIA Repoft Date Title and Author of rePort 11t27 t1995 for Site Assessment SECOR for advancement of 5 hand-a ered borin 1t11t1996 Resu//s of Srte Assessme nt and Corrective Action Plan SECOR 2t1t1996 Soil Excavation SECOR 1At1612001 Quarler 2001 G roundwater Monitorin SECOR 4t1812002 Quafter 1 2002 Groundwater SECOR 10t1412002 Third Quarter 2002 Groundwater SECOR 4t1512003 First Quarter 2003 Groundwater SECOR 10t6t2003 Third QuarTer 2003 Groundwater SECOR 412012004 First Quarter 2004 Groundwater ort b SECOR 101512004 Third Quarter 2004 Groundwater Monitorin SECOR 4t20t2005 First Quafter 2005 Groundwater SECOR 7t1912005 Second Quarler 2005 Groundwater b SECOR 811712005 st for Closure with attached Case Closure Summa b SECOR Note: QuarTerty Groundwater Monitoring Repofts written by BlaineTech Services between 1997 and 20A1 are not available for review. ', Chevron Service Station 9-1717, San Luis Obispo, California List of Historical Repofts ,.-) California Regional Water Quality Control Board Central Coast Region Arnold Schwat'zencggcr Got entorAlan C, Llol'd Ph. D. Agettcy $sa'e.14t'1t lnternet Address: http://www.waterboards.ca.gov/cetrtralcoast 895 Aelovista Place, SLrite 101, San Luis Obispo, Calilolnia 93401'7906 Phone (805) 549-3147'FAX (805) 543-0391 September 1,2005 Mr. Dana Thunnan Chevron Envirorunental Management Cornpany 6001 Bollinger Canyon Road K2236 San Ramon, CA 94583 Dear Mr. Thunnan: UST: 151 SANTA ROSA STREET, SAN LUIS OBISPO, SAN LUIS OBISPO COUNTY; CHEVRON SERVICE STATION NO. 9-t717; MONITORING WELL DESTRUCTION (CASE NO. 884) Central Coast Water Board (Water Board) staff has reviewed the SECOR lrternational, Ittc,'s (SECOR) Augnst 17,2005, Request for Closure reporl and attached Case Closure Summary infonnatiol. Thank you for the submittals. The data indicate all gtoundwater monitoring results were below cleanup goals for total petroleum hydrocarbons as gasoline (TPH-g), benzene, toluene, ethylbenzene, xylenes and methyl tertiary butyl ether (MTBE). Groundwater sample results from May 18, 2005, indicate TPH-g, benzene, and MTBE maximum concentrations are <50 micrograms per liter QtglL), 0.7 p,glL and 3.0 pgll., respectively. Therefore, based on the infonnation provided, we have no further requirements for groundwater investigation or cleanup of the site. However, pursuant to the California Health and Safety Code, Section 25296.20, the Water Board shall not consider comective action or issue a closure letter, unless all curent record fee title owners of the subject site have been notified of the proposed action. Please verify current property owner'(s) and provide contact information (complete rlailing list) to this office. Upon confirmation that record fee title owner(s) have been notified of the proposed case closure yo., ,ouy proceed with the proper destruction of all rnonitoling wells. Well destruction shall be lond.,.i"d under pennit Uy ttie San Luis Obispo County, Division of Envirorunental Health Services (DEHS) and by a C-57 licensed well driller uuder the supervision of a registered professional in accordance with California Department of Water Resources Bulletin No' 74-81 arfi74-90, Porler Cologne Water Quality Control Act Sections 13710 thlough I3755. Please submit the well destruction report to this office and DEHS bv November 30' 2005. The Water Boar.d needs the required well destruction report as a formal condition of case closule to document proper well destruction. You are required to submit this infonnation as the responsible purtylor this underground storage tank (UST) facility, We will issue a formal case cloiure ietter followilg receipt of a well destluction report docnmenting all rnonitoring wells have been properly destroYed, Califu r n io E nviro nm entul P rotectio rt Ag e n cy .Jg{t Reqtcl211 PnOn, Mr. Dana Thunnan a September' 7 ,2005 Water Board closure will end our regulatoly oversight of the subject site, but will not relieve yon of other agency's requirements, which may continue to have jurisdiction and require fuilher work, Generally, the San Luis Obispo File Department is the lead oversight agency for tank pennitting, inspection and removal, soil contamination and human health lelated issues. The Water Board is the lead agency for groundwater quality oversight. As with any real property, additional or previously uridentified contamination at the site may require additional investigation and cleanup. The site is cu-rently a gasoline service station, which operates one 1,000-gallon waste oil UST, one 20,000-gallon gasoline UST and two 10,000-gallon gasoline USTs. Failure to comply with these requirements will subject the responsible parly to enforcement action by the Water Board, including issuance of an order under Water Code Sections 13267 and/or 13304, and potential administrative civil liabilities. Please review and cornplete the enclosed Case Closure Summary fonl and provide additional required information as discussed with youl'consultant Mr. Todd Porter on September 6, 2005, and retum signed attestation page and Case Closure Surnmary, If you have any questions, please contact Corey Walsh at (805) 542-478I or via e-mail address at crvalshGlwatelboalcls.ca.gor'. Sincerely, Enclosure: Case Closure Summary S:\US'l-\l{egulated Sites\San Luis Obispo Co\San Luis Obispo\Santa Rosa St\l5l Santa Rosa\Wcll Destt'ttct Recl.doc cc: Mr. Todd Pofter / Ms. Arny Joy SECOR Intemational Inc. 3437 Enpressa Drive, Suite A San Luis Obispo, CA 93401-7355 Ms. Monica L. Aragon SECOR Intemational Inc. 11085 I(nott Avenue, Suite B Cypress, CA 90630 Mr. Roger Steiner Roger C. Steiner, Etal 1417 Bridgeway, Suite 4 Sausalito, Cl.94965 (Ploperty owner') Mr. I(euy Boyle San Luis Obispo City Fire Depadment 2160 Santa Barbara Avenue San Luis Obispo, CA. 93401-5240 Mr. Mark Matranga State Water Resoulces Control Board Underground Storage Tank Cleanup Frurd P.O. Box 944212 Sacranrento, C A 9 4244-2120 Mr. Aat'ou Labarre San Luis Obispo County Division of Environmental Health Services P.O. Box 1489 C alifu rniu Enviro nm entsl P rotectio n A g e n cy ?oq.J Req)cled PoPet' a Mr. Dana Thurman San Lnis Obispo, CA 93406 Mr. JeffM. Whitwofth Shell Oil Prodricts US 433 Town Center #496 Corle Madera, CA94925 Mr. Everett Ferguson Miller Brooks Environmental, Inc. 2124Main Street, Suite 200 Hnntington Beach, CA 92648-6450 -3-September 7,2005 Califumiu Environmental Protection Agen cy 170 e,J Recycled Paper n ,,.\ ,'\ t) CASE CLOSURE SUMMARY Leaking Underground Fuel Storage Tank Program lnformation ll. Case lnformation lll. Tank lnformation lV. Release and Site Characterization lnformation Address: 895 Aerovista Place, Suite 101Agency Name: RWQCB - Central Coast Region Phone: (BO5) 542-4781City/State/Zip: San Luis Obispo, CA 93401-7906 Title: Associate Engineering GeologistResponsible Staff person: Mr. Corey Walsh Site Facility Name: Chevron Service Station #9-1717 LUSTIS Case #: 884 Site FacilityAddress: 151 North Santa Rosa Street, San Luis Obispo Responsible Parties Address Phone Number Chevron Environmental Management Company Atin: Mr. Dana Thurman 6001 Bollinger Canyon Rd., K2236 San Ramon, CA 94583 (925) 842-9559 Property Owner Roger C. Steiner Etal 1417 Bridgeway, Suite 4, Sausalito, CA 94965 Tank #Size in Gallons Gontents Glosed in Place/Removed Date 1 10,000 Gasoline Removed 10125-26195 2 10,000 Gasoline Removed 10125-26195 3 10,000 Gasoline Removed 10125-26195 Gause and Type of Release: Piping and Dispenser leak Site Characterization Complete? Yes Date Approved by Oversight Agency: April 29, 2005 Monitoring Wells Installed? Yes Number:4 Proper Screened interval? Yes Highest GW Depth Below Ground Surface: 3.8 fi Lowest: 7.9 ft Flow Direction: South-southeast Most Sensitive Current GW Use: Municipal (Nearest municipal well, Mitchell Park Well, located approx. 1.25 miles SE) Are Drinking Water Wells Affected? No Aquifer Name: San Luis Obispo Creek Hydrologic Subarea 3-10.24 ls Surface Water Affected? No Nearest Suface Water: Stenner Creek 600 ft' east of site Off-site Beneficial Use lmpacts (addresses/locations): None ,-.-\l) CASE CLOSURE SUMMARY Leaking Underground Storage Tank Program add itional information Page 2 V. TreatmenUDis Methods Vl. Closure DateMaterialAmount (lnclude Units) Action (Treatment or Disposal Method) Removed & disposed off-site October 1995Tanks3 -'10,000 gal. USTs Removed & disposed off-site Ociober 1995PipingNA Product NA Excavated and disposed off-site December 1995Soil716 tons Not Applicable No remedial action for groundwater deemed necessary Groundwater Maximum Documented Contaminant Concentrations--Before and After Cleanup Water (pgiL)Soil (mg/kg)Water (pg/L)Soil(mg/kg) Before AfterAfterBeforeAfter Gontaminant Before After Contaminant Before NA NA NA1 500 <0.5 600 <50 1,2-DCA NATPH (Gas) Oil & Grease NA NA NA NANANANANATPH (Diesel) NA0.7 Lead NA NA NABenzene8.1 <0.005 4.6 530 3.0<0.005 <0.3 <0.5 MTBE NA NAToluene31 NA NA NA NA21<0.005 <0.3 0.8 HVOEthylbenzene NA2.0 Naphthalene NA NA NAXylenes120<0.005 <0.6 Gomments: Soil samples from the excavation boundaries (side walls and bottom) did not exhibit soil hydrocarbon concentrations exceeding action levels. Does completed corrective action protect existing beneficial uses per the Basin Plan? Yes Does completed corrective action protect potential beneficial uses per the Basin Plan? Yes Does corrective action protect public health for current land use? Yes Site Management Requirements: No Should corrective action be reviewed if land use changes? No Monitoring Wells Destroyed? No Number Destroyed: 4 pending Number Retained: None ".) CAS E CLOSURE SUMMARY Page 3 Leaking Underground Storage Tank Program List Enforcement Actions Taken: Conducted remedial excavation to remove petroleum hydrocarbon impacted soil Conducted semi-annualgroundwater monitoring following excavation activities (since September 1997). List Enforcement Actions Rescinded: None Vll. Local e resentative Data Vlll. AdditionalGomments lX. Regional Board Gertification Signature of Executive Officer Date p:\clients\chevrontexaco\chevron management iransfeAg-1717\closure request\case closure form for 9-17'17.doc 5t9t05 Address: 2160 Santa Barbara AvenueAgency Name: City of San Luis Obispo Fire Department Phone: (805) 78'1-7383City/State/Zip: San Luis Obispo, CA 9340'1 Title: Hazardous Waste CoordinatorResponsible Staff person: Mr. Kerry Boyle See Attached Request for Closure letier X. 1 ,) CASE CLOSURE SUMMARY PAgE 4 Leaking Underground Storage Tank Program Additional lnformation (to be attached to this repott) Listino of RePorts please include a list of all investigative reports, including reports prepared for financial institutions such as phase I Environmental Assessments, ail monitoring data, corrective action alternatives analyses, and other consultant reports. lf a report on the list has nbt been previously submitted to the Regional Board, pfrur" submit the ieport with this form. On or attached to the list must be the following statement, with in" o"t"o signature of the responsible party or his agent: "l attest, under penalty of perjury, in accordance *itn Wut"r bode section liz61, the following documents constitute the complete list of documents pertaining to waste discharged, hydrogeology and other information directly relevant to the characterization and cleanup of the waste discharged at the subject site'" Extent of Soil Contamination a)Maps showing the extent of soil degradation by chemicals of concern in excess of guidelines, before and after remediation. Geologic log of the most highly degraded soil boring or monitoring well showing sample points b) c) wiih a list of contaminant concentrations. Summary table of all historic soil sampling results ofG Water 2. 3 a) b) c) d) e) Maps showing the extent of ground water degradation in excess of detection limits for chemicals of concern, before and after remediation' Geologic logs, including construction, for all wells' Representative geologic log identifying all aquifers' Two intersecting cross-sections of the site' Summary table of all historic ground water analyses and water levels' 1'l CASE CLOSURE SUMMARY Leaking Underground Storage Tank Program Page 5 I attest, under penalty of perjury, in accordance with Section 13267 of the Galifornia Water Gode, the following documentJ constiiute the complete list of documents pedaining to waste discharged, hydrogeology and other information directly relevant to the character and cleanup of the waste discharged at the subject site. Signature of Responsible Parly (or Designated Agent's)Date Signed Print Name lU SECOR sEcoR. INTERNATIONAL INCORPORATED www5ecor.com 3437 Empresa Drive San Luis Obispo, CA 93401 805 546-0455 rer 805 546-0583 eu October 25,2005 Mr. Roger C. Steiner and Barry J. Steiner 1417 Bridgeway, Suite 4 Sausalito, CA. 94965 SUBJECT:Notice of the Proposed Site Glosure Chevron Service Station Number 9-1717 151 North Santa Rosa, San Luis Obispo, Galifornia RWQCB Gase No.884. Dear Mr. R. Steiner and B. Steiner: SECOR lnternational lncorporated (SECOR), on behalf of Chevron Environmental Management Company (CEMC), has prepared this notice of proposed site closure for the fee title owner of the subject site listed above as required in the Health and Safety Code $ 25297.15 & 25299.37 (Figure 1). ln a letter dated September 7,20A5, the California Regional Water Quality Control Board - Central Coast Region (RWQCB), recommended site closure based on current site conditions (Attachment A). Should you have questions or comments regarding the proposed site closure, please contact either Monica L. Aragon at (714) 379-3366 or Amy Joy at (805) 546-0455. Sincerely, SEGOR International lncorporated ,/l/tu4/W Ryan LaPorte Project Scientist L P Project Hydrogeologist Attachments: Figure 1 - Site Map Attachment A - Regulatory Letter cc:Mr. Dana Thurman, Chevron Environmental Management Company Mr. Corey Walsh, Central Coast RegionalWater Quality Control Board Mr. Kerry Boyle, San Luis Obispo Fire Department Ms. Monica L. Aragon, Secor lnternational lnc. (Orange County) P:\Clients\ChewonTexaco\Chewon Management Transfer\9-1717\Closure Request9-1717 Close ltr owner.doc California Regional Water Quality Control Board Central Coast Region Alan C. Lloyd Ph. D. Agenqt Secretary Arnold Schwarzenegger GovernorIntemet Address: htF://www.waterboards.ca.gov/centralcoast 895 Aerovista Place, Suite 101, San Luis Obispo, Califomia 93401-7906 Phone (805) s49-3147'FAX (805) 5434397 May 2,2005 Mr. Dana Thurman Chevron Environmental Management Company 6001 Bollinger Canyon Road P.O. Box 6004 San Ramon, CA 94583-2324 Dear Mr. Titur::nan: UST: 151 SAI\TA ROSA STREET' SAN LUIS OBISPO; CHEVRON SERVICE STATION NO. 9-1717; CASE CLOSURE REVIEW (RB CASE NO. 884) Central Coast Water Board (Water Board) staff has reviewed SECOR International, Inc.'s (SECOR) April 20, 2005, First Quarter 2005 Groundwater Monitoring Report Thank you for submitting ihis repon, which describes the groundwater monitoring results. Groundwater sampling-results from January 26, 2005, indicate methyl tertiary-butyl ether (MTBE) "ott".nttutions have decreased from a maximum of 530 micrograms per liter (pglt ) in September 1997 to l0 p{L currently. Total petroleum hydrocarbons reported as gasoline (TPH-g) and benzene concentrations are below detection limits in all four monitoring wells. Groundwater sample results also indicate groundwater pollution remains at concentrations greater than Water Board cleanup goals for methyl tertiary-butyl ether (MTBF). Th_e site lies iritttitt the San Luis Obispo Creek Hydrologic Subarea (3-10.24) of the Estero Bay Hydrologic Unit. The "Water Quality Control Plan, Central Coast Region" (Basin Plan) designates groundwater beneficial uses to be domestic and municipal supply, agncultural supply,- and i-ndustrial supply. Therefore, the groundwater cleanup goals for common petroleum hydrocarbons are as follows: 1,000 LLglLtotal petroleum hydrocarbons (TPH), 1.0 pgll- benzene, and 5.0 1tg/L for MTBE. The TPH and MTBE cleanup goals have been established based on - taste and odor thresholds, not health risks; the benzene goal is based on the Califorrua Primary Maximum Contaminant Level (MCL) which is based on health effects data, but also contains other information relating to technical and economic feasibility of attainment in a' waiter::qe distribution system. The groundwater plume extent has been characteized and is contracting or declining in size and conclntration, the contaminant mass has been removed from the site to the extent practical, and historical monitoring data indicate the MTBE concentrations are expected to continue to decrease with time. Confirmation sampling and analysis is required during the second quarter 2005. Upon review and based on the results, Water Board staff will formally recommend the case for closure to our Board. ia Environmental Protection AgencyCaliforn I Reqcled Paper