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Home My WebLink AboutCT 97-09; LA COSTA LUCKY SAV ON; Tentative Map (CT)Page 1 of 1 Meg Carroll From: OTP [gtp@ohill.com] Sent: Wednesday, October 15, 2003 2:56 PM To: Under, Mark Cc: Dierck, Jeff; Jan Castaneda; Meg C Subject: SDG&E Quitclaims Mark, I received the check today and sent it off to SDG&E. By early next week, we should have the quitclaim recorded for 8 of the 9 easements which Meg identified to be quitclaimed. The 9th easement is for gas transmission which was an easement which SDG&E had actually paid money to procure. They would not release this easement without appraising the easement area and being paid to do the appraisal and for the value of the easement as well. The easement is inside ofthe easement area covered by the 150" wide electrical transmission easement. This area cannot be built in anyway, so I recommended to Jeff that Albertson's not pay for an appraisal or a quitclaim at this time. It can always be bought later if the need arises, since the gas transmission facilities have been moved into El Camino Real. According to SDG&E there are no facilities in the easement at this time. Jeff agreed with my recommendation and that is why we aren't seeking a quitclaim for the gas easement at this time. i have attached the letter I sent to SDG&E requesting the quitclaim be recorded. Best Regards, Larry Tucker 10/16/2003 October 15, 2003 Michael J. Williams San Diego Gas & Electric Land Management Representative 8335 Century Park Court Suite 100 San Diego, CA 92123 Re: La Costa Plaza-SDG«&E Quitclaims Mike, Enclosed please find a clieck in the amoimt of $700 fi-om iUbertson's to SDG&E. In accordance with our agreement, please record the quitclaims of the 8 SDG&E easements and provide me with a conformed copy of the quitclaim (making sure the recording infonnation is shown on the face ofthe conformed copy). Thank you for your assistance in this matter. Best Regards, Larry Tucker cc: via email: Mark Linder Jeff Dierck Jan Castaneda Meg Carroll From: Tim Fennessy To: Jennifer Gowen CC: John Maashoff Date: 12/15/2006 8:29 AM Subject: Re: CT 97-09 La Costa Lucky Sav On All Inspedion items are completed. This projed: Is being held up due to a request from Frank Jimeno based on the refusal of Albertson's to execute water and storm drain easements to the city. This is the perfect example of why the easements should be dedicated prior to issuance of permit. Tim Fennessy Construction Inspector City of Carlsbad >>> Jennifer Gowen 12/15/06 8:22 AM >>> Ronald Kemp received a letter of inquiry from these guys with regards to their faithful performance bond. The drawing for the improvements is 379-9. They were as-built bacic in Feb. 2006. Do you know the status on this one? Ron Is waiting for a response from us... I don't find any paperwork on it anywhere, and neither Mary nor I ever prepared any acceptance and/or release paperwork... I know there Is some history out there w/the medians on ECR I think It Is, but I that's about all I remember!! GRANT TUCKER PROPERTIES STEVEN P. GRANT LARRY TUCKER August 22, 2003 Frank Jimeno City of Carlsbad 1635 Faraday Ave. Carlsbad, CA 92008 Re: La Costa Plaza, Easement to be Relinquished Dear Frank: As you know, Albertson's, Inc. and Grant Tucker Properties are nearing the end of the process of redeveloping La Costa Plaza (NEC El Camino Real and La Costa Avenue, Carlsbad, Ca). The first step in the process was demolishing the former development. That happened a few years ago. At that time, the need for utility service to the removed improvements, of course, became unnecessary. We would like to clean up the title of the Shopping Center by having the easement which was initially granted to serve water to the since demolished improvements, be relinquished/quitclaimed of record. Attached to this letter is a copy of the recorded easement of CMWD we would like quitclaimed. We would like to have the relinquishment/quitclaim recorded by the middle of September. Please advise us of any other information or documentation which is needed in order to accomplish the requested relinquishment/quitclaim. Thank you. Very truly yours, Larry Tucker cc: Jan Castaneda, Esq., Albertson's, Inc. Jeff Dierck, Albertson's, Inc. Mark Linder, Albertson's, Inc Steve Grant, Grant Tucker Properties Van Lynch One Upper Newport Plaza, P.O. Box 7974, Newport Beach, CA 92658 (949) 852-5800 (949) 752 0885 Fax \^<jt-%;DLJL- I rail o .SM mi SB? 23 '97 1S:54 I LASMIM owe 38* August?, 1997 DEPAF(TMQ<T OF PUBLIC WORKS §eHOVBKAIIDAVESM4M6«0.<iAUniiMM «ie9<IM6 ieOMTVaWMBit MianvciMewft SOU»«MlSR Hazard ideetificatioa Bnoch Mitigaxioa Duectocate WMiMMliqoQdfowicgacePiDOgram Federal BdajHSBoc^ Managq^^ Washinirtoia. DLC. 20472 DearMr. Sbanodis: RBVJSION QF ESCONDIDO CRB£ECHXX)DPLAIM/FLOOD msURANCBMAFS Tbe C«at^ of S«D Di(^ coDStnicted a oa diB Escondido Oedc in 1994. ll^MdisetijiittdowiuitiiMmoflbBlo^ The bridge aflb^iU tbe cunent BscoiKiido Ctodt Coooty flOOd^Ildn nuip in tlias yk»oity. TtecoroeotCotintyRsflondtdo<>»dkfl^^ 1974 KBC- laaaiysis. The ori^osl FEMA issued in I9&t vas taku direct TlieflfHanmifasiiinrapomtedia 1966. TlKCity^CouncybauiidaRyganerally&UGm^B^^ ofaeEtPwdidoCceekaooaBtoin. . • •. ••. 1: ..- Il»cuaeni.FIRM(eABetiveJane 19, IdST^ is based <Mdk61974 Coonty map in tb&u^^ ar» and the 1986 Noteeanidy. done fiyiCMA^ Noiis's cross sectioas arc inappioiqzsatefydwsanieloeatioaaKtlteGa^^ Tbe 1997 FIRM basislii^ diffez«it ikk)d water isurEK^e efevations in tbe CoQ^ la t992« die DMBtdnent of PubUc WodCS a>PW) lev^^ and the 1986 Nobe H£C-2 for Eacoadido Cmk from San £Ujo Lj^gjoon to upstream <tf Val Sonio (about 4 miles). DPW fouodinconsisteaci^iatsoiiic areas and devci^^ incoi^pOfal«sbadi studies and is ooBSisteat with die Coiinlyaood^)^^ 1984 FIRM. A coj^ of &e report on this study is enclosed (ACtadunentX), A consuttatit to tbe Ctiunty, Howard Qum^ lu» {XK^Mnsd an upd^e|dHB02 analysis that; reflects iheLaBj^ahddge. Dr. Chang also m the HEC-2 fbr die 1966 Kolte study and tbe Coui^^ of Eogineeis stud;^. Tbe hycicaiulic analysis covers about 1,5 miles of ^aaox^Sda Qeek (JS bUe doWOSOeamofdlBblidgetoiadlei^XStlBam). Dr. Oiaap's report. T^yriratilir, .^iiiirfy far FEMi^ t Iffff^ifT of Map Revision aCiMtt^ ftir Escondido iTmtk in .Satn nteyn O^mry, r»Kfnnna. May 199(7. is 09-23-1997 04:48PM 6197569460 P.02 Oi s^ue^insuoo Rea.O WOdJ WUt^TiBT A66T-S2-60 £0-d "lUlOl Mr.Sbanxxto '2-Angusc?, 1997 faadditJ(»»Aiiad«e«8landILlbefolldwingi»fe^^ flood^laio/Qoodwa^ isenclnsed: FEMA FIRM 1044P 1061F floodway in the viciniiy of UBa^ Mtej flood eiwatioiis for Loiiw Escondido Ceedc (AttadB^ Prafite sheets 83P. 84P. 8SP and 86P showing rewsed 100- eieyatsoQS (Alinob^QSDl WV 1. 2. i im4APtmMl,2.4,5«»d7(AltachineOlV), my not TtetmiiBdfkwdw^ surface dteVBiion^ . , die floodplain or floodway liBe.deli»««i<Htt on the 200-scaie Of 50U-scwc wy. T^Countyisde«gni«Bal^^«iJ-a«^ Ina»inn«ry.iti.Teq«ested&at.FEMAissoe.b^ | I. R^ FBM 1044F. 1061F, lO«l«li2^^^Sw^C«S ^ eievatioosinfeeCilyaiuiCoaBtyaiftea^^ should ^ used tor those portions <tf the Or«3t that aw ^ HEC-2anal3r^. i ffy<»h«veanyqu«aioas,ple«ec^ | I VetytEUtyyoui:^ DWKOTra SMTIH, Pep»»^ I»tector I>ep9Xtiaent of Public Works DGS:KH;daie ActBciQjnents ! 9492, Raneho Santa Fe. CA 92067; Manaxd Smith, DPW C«34«) 09-23-1997 04s5ePM £0'd f6808£t' 6197569460 P. 01 01 s^uB^Insuo^ fiea.O WOad WbST:0T A66T-S2-60 [~Frank Jimeno - Traffic Signal Plans__ Page 1 From: "jjtuckerl" <jjtucker1@cox.net> To: <bwojc@ci.carlsbad.ca.us> Date: 9/3/02 6:43AM Subject: Traffic Signal Plans Bob, The improvement plans for La Costa Plaza will hopefully be ready for final approval this week, with the likely exception of the traffic signal plans for the new signal at La Costa Ave and the project entrance. Frank released all of the on-site and off-site comments on Friday afternoon, and we expect, based upon what staff has told us, that these comments will be minor and easily and quickly addressed. O'Day has promised to turn around the corrections rapidly. Albertsons has advised me that the grading period will only be about a week and a half, since much of the grading was done before the work was stopped. This was a surprise to me. Albertsons could lawfully start the grading right away, but Albertsons does not want to be in a position to finish the grading and then have to wait for the improvement plans to be approved before moving on to other work on the site. The LCWD work will have to wait until at least 30 days after the grading is completed, per the soils consultant. Albertsons does not want to again be in a position for the public to see what appears to be work stopped on the site, once it starts. Until the improvement plans for both off-site and on-site work have been approved (including the traffic signal plans), that is possible. The grading could be complete, but nothing would be in a position to be worked on, absent the approved improvement plans. Albertsons doesn't want more bad press if it can at all be avoided. Frank just found out about the new requirement for the traffic signal hardware to be reviewed and updated, in turn we just heard about it on Wednesday afternoon (8/28). On Friday (8/30)multiple copies of the existing traffic signal plans were turned in for review by staff, but we don't know when that staff review will happen. It is our understanding that the only aspect of the traffic signal plans under review is the hardware (and not the location of such facilities). A further timing issue is that Albertsons traffic signal engineer was hired when the site was controlled by Lucky, which was based out of the Bay Area, so the traffic engineer is out of the Bay Area. We can see a delay if the project on-site and off-site approvals need to await the approval of new signal hardware. Based upon the above, Albertsons would like to bifurcate the traffic signal approvals from the rest of the on-site and off-site improvement plans. That way, Albertsons can know that it has all of the approvals for the improvement plans before it mobilizes the grading operation. We are quite some time from working on the traffic signal and the bifurcation will allow the remainder of the project to start within days. With the rainy season fast approaching, every day counts. The traffic signal plans v/ill be ready in due course and the City is at no risk in bifurcating the plans as requested. Thanks for your consideration of our request. If you respond to this email by a reply email, please send your reply to my office email at gtp@ohill.com. Best Regards, Larry Tucker (949) 251-2045 CC: <fjime@ci.carlsbad.ca.us>, <vlync@ci.carlsbad.ca.us>, "jeff dierck" <jeff.dierck@albertsons.com>, "Mark Linder" <mark.linder@albertsons.com>, "Mark Steinman" <mark.steinman@albertsons.com>, "Steve Grant" <sg-gtp@ohill.com>, <megc@odayconsultants.com> 30-03 12:38pm From-O'DAY mmxiurt V V V V 760-931-8680 T-301 P.02/02 F-530 S/AifO/V »VOAf6 ENGINBBBING September 29,2003 O'Day Consultants 2710 Uoker Avenue, Sute 100 Carisbad, CA 92008 Attention: Cam>ll SUBJECT: EL CAMfNO R6AL DRIVEWAY GUARDRAIL DETAILS Dear Ux%. Carroil: At you request, Simon Wong Engineering has reviewed the site conditions and tiie proposed details for the driveway entrance at a new Alliartsons near the Intersection'of El Camino Real and La Costa Avenue, We understand that this project ia currently under construction; however, the details for the metal beam guardrail connection to the existing El Camino Real Bridge over San Marcos Creek need to be reused. The existing bridge barrier consists of a r-3"± high concrete curb an approximately 2'± higli tubular metal railing. The end ot the bridge railing (mounted above the bridge wingwall) is approximately 15' trom the face of driveway curb. There are also existing eiectrical conduits behind the existing banier. Given these constraints, the Caltrans standard details for bridge barrier protection with metal beam guardrail cannot be directly applied. We are not aware of any standards that address this condition. Your proposed details include extending the existing banier with a Caitrans Type 736B concrete rail and attaching a metal beam element along ttie curb return. You also have proposed a Callrans Standard end treatment Type SRT along the tangent portion of the driveway. Given the constraints noted above, we believe that the proposed details are an appropriate solution for the site conditions. The City of San Diego used a similar approach to the detailing of the Morena Boulevard end treatment design. While the proposed details reference Caitrans Standard Plans, tiie application is non-standard. As such, the details may be considered a "design exception" by the City of Carisbad. This was also true ofthe original plans approved fbr constmction. Please, contact us if you have any questions.' Sincerely, femes FfbsLlP.E. Simon Wong Engineering 9968 Hibert Street. Suite 202 • San Ulegd, CA 92131 • (858) 566-31 IS • FAX (858) 566-6844 tOIS HUMPHREYS President DAVID KUtCHlN Director ELAINE SULUVAN Director JUDY HANSON Director ALUNJULIUSSEN Oitedor TIMOTHY JOCHEM General Manager 4 111/ • V >^ I February 12, 1997 IVIeg Purviance O'Day Consultants Suite 204 7220 Avenida Encinas Carlsbad, California 92009 O'DAY Subject: Sewer availability for proposed Lucky's Drug/Grocery Store #121-283; La Costa Ave, Northeast corner of Ei Camino Real and La Costa Avenue. Dear Meg: The proposed project at the corner of La Costa Ave and La Costa Avenue is within the boundaries of the Leucadia County Water District. Sewer permits are currentiy being issued for new connections pursuant to District ordinances. It can reasonably be expected that service will be avail- able for the planed use of the above referenced property. This letter is valid for two years and is transferable to a new owner upon approval of the District. Cordially, LEUCADIA COUNTY WATER DISTRICT DAVE DOWNEY Administrative Aide District Office: I960 La Costa Avenue, Carlsbad, California 92009-6810 • (619) 753-0155 • FAX (619) 753-3094 Primed on recycled paper. & ASSOCIATES ineering. Corporate OflUr 619.942.5147 Environmental Sciences and 605 Third Street Fax 619.632.0164 Management Services Encinitas, California 92024 • A California Corporation June 9, 1997 /A''- '' 1228-55 Mr. Jeff Gibson Planner ; ; City of Carlsbad V 2075 Las Palmas Dr. \ Carlsbad, CA 92009-1576 Re: La Costa Lucky Sav-On Shopping Center #121-283 - GPA 97-02/ZC 97-02/SDP 97- 07ICT 97/09/SUP 97-03/CUP 97-03/PS 97-32 Dear Jeff, This letter is sent with regard to the potential etTect of the subject project on the Leucadia County Water District facilities (LCWD). We have received a copy of the Planning Director's letter of June 2, 1997 to American Stores Properties, Inc. (American Stores) and we noted that initial engineering comments have not yet been made. The attached information may be of interest in your continuing review. Informal discussions began between LCWD and American Stores Properties, Inc. (American Stores) around December 1996. A number of meetings between American Stores and LCWD have occurred since that time. American Stores has proposed a land swap and construction of a new reclaimed water storage tank to offset impacts of the proposed store on the LCWD site. As the contract LCWD District Engineer, Dudelc & Associates, Inc. (Dudelc), has assisted LCWD staff in discussions with the American Stores project proponents. LCWD will continue to discuss and negotiate the fmal terms of reimbursement for loss of LCWD property and facilities, as necessary. In the meantime, the following attached items may be of interest to the City with regard to flood control and groundwater contamination issues at this site: 1) Review comments on behalf of LCWD by West Environmental Hydrosciences regarding the preliminary HEC-2 study done for American Stores. 2) Dudek/HMMD letter of March 18, 1997 regarding status of groundwater cleanup at the former ARCO gas station site, which we understand is part of the proposed American Stores development. 3) Dudek/LCWD letter of October 15, 1996 also regarding the ARCO groundwater cleanup and our concern regarding potential impact on LCWD and Carlsbad MWD facilities. Please call, if you have any questions. Very truly yours, Dudek & Associates, Inc. Steve Deering, PE ^ LCWD District Engineer cc. Mr. Tim Jochem, LCWD General Manager Mr. Mike Bardin, LCWD Assistant General Manager ^ VES ENVIRONMENTAL HYDROSCIENCES A Joint Venture of WEST CONStJLTANTS, INC. and DUDEK & ASSOCIATES, INC. April 28, 1997 C J?- ATTN: Steve Deering, P.E. LCWD District Engineer " '"2 iQQy 605 Third Street O^Op.. Encinitas, CA 92024 ^ ^•^o^^ RE: Review of HEC-2 Study for Proposed Lucky/Savon Store, San Marcos Creek, Carlsbad, CA Dear Mr. Deering, WEST Environmental Hydrosciences has completed a technical review of the subject study as presented below. BACKGROTJND INFORMATTON A constructed fill is proposed for a Lucky/Savon Store (as shown on the Preliminary Grading and Drainage Plan submitted with the HEC-2 study) on the site adjacent to existing LCWD facilities. These facilities are located in the left overbank looking downstream within the 1 OO-year floodplain of San Marcos Creek. A detailed Flood Insurance Study has not been performed by FEMA (Federal Emergency Management Agency) for this section of San Marcos Creek. The current FIRM (Flood Insurance Rate Map) shows the subject reach in Zone A, which indicates that an approximate study has been performed. An approximate study implies that a regulatory floodway was not designated for this section of the creek. Development within floodways is not permitted per federal (FEMA) regulations. However, development within the floodplain fringe, the area between the regulatory floodway and the limits of the 100-year floodplain is permitted. Federal floodplain ordinances govern development in floodplains unless superseded by more sfringent local regulations. FEMA regulations allow no more than a foot ( 1.0' ) of rise in the base 100-year water surface elevation as a result of proposed development in the floodplain fi-inge. The width of the floodway does not have any effect on the base 100-year water surface elevation. In order to establish a regulatory floodway, an existing conditions model with the floodway defined using equal conveyance reduction in both overbanks is submitted to FEMA for approval. A FEMA approved existing conditions model provides a legal basis for the regulatory floodway. The City of Carlsbad is most likely the responsible agency other than FEMA, that would review changes or upgrades to current effective FIRM's because FEMA administers the NFIP (National Flood Insurance Program) through incorporated communities. Typically, a study to determine the effects of a proposed development would require a FEMA approved existing conditions model along with a proposed condidons model to show the relative effect of the proposed development on the 1 OO-year water surface elevation. It is pertinent to note that an existing conditions model without the proposed fill has not been submitted. The model submitted to WEST for review (Filename: SMC97.HEC) reflects proposed conditions with a proposed floodway. 2111 PALOMAR AIRPORT ROAD, SUITE 180 • CARLSBAD, CA 9.2009 • (tel) 619/431-8113 • (fax) 619/431-8220 Mr. Steve Deering April 28,1997 Leucadia County Water District Page 2 of 5 GENERAL OBSERVATIONS The submitted HEC-2 model for San Marcos Creek begins at Badquitos Lagoon approximately 670 feet dovrastream of El Camino Real at Cross-section 2.49 and extends up to Cross-section 2.93 located approximately 1559 feet upstream of El Camino Real. Cross-sections in the model appear to have been developed using City of Carlsbad aerial topographic maps (Scale 1"= 100'; Photo date 1988; 1929 MSL Dahmi) although not stated in the submitted report. Several cross- sections show interpolated spot elevation values between contours from the topographic map. Spot elevation checks indicate that the submitted Preliminary Grading and Drainage Plan is based on the same datum as the aerial topographic maps from which cross-sections were derived for the HEC-2 model. However, more information about the bench mark reference is needed before this can be verified conclusively. Channel and overbank reach lengths correspond to cross-sections drawn on City of Carlsbad aerial topographic maps included with the submitted study. Flow through the bridge at El Camino Real has been modeled using the Special Bridge option. The HEC-2 model consists of two profiles which include the I OO-year natural profile and the 100-year floodway profile. A discharge of 13,000 c.f.s was used through the entire reach. The slope-area method was used to determine the starting water surface elevation. The proposed Lucky/Savon store appears to be modeled in Cross-section 2.77 only. HEC-2 MODEL REVIEW AND COMMENTS The purpose of this review is to evaluate the modeling methodology used to show the effect of the proposed fill in the submitted HEC-2 model and to address flooding concems expressed by LCWD per your letter dated 4/3/97. We did not attempt to evaluate the adequacy of the model per FEMA requirements. The following narrative addresses the results of the review. Existing Condidons Model An existing conditions model has not been submitted. Therefore the study did not establish a basis for comparison to demonstrate the effect ofthe proposed fill. Hydrology 100-Year Discharge The study does not describe how the discharge of 13,000 cubic feet per second was derived. Therefore, this discharge is not verifiable. Available Flood Insurance Study information for San Marcos Creek indicates a FEMA conditions discharge of 14,700 cfs further upstream at Discovery Street. This may point to an attenuation of the flood wave due to San Marcos Lake located upstream. However, more information and further analyses would be required before any conclusions can be made. Mr. Steve Deering April 28,1997 Leucadia County Water District Page 3 of 5 Flood Storage/ Routing The hydrologic analysis performed to derive the discharge of 13,000 cfs in the submitted study will have to be fumished in order to address storage or flood routing considerations through the La Costa Golf Course and Batiquitos Lagoon. However, preliminary observations indicate that valley storage through La Costa Golf Course appears quite small relative to the expected 100-year discharge and would have a negligible effect on peak discharge and flood elevations. Floodway There is no evidence to show that equal conveyance reduction was used to define the floodway width and location. FEMA generally requires equal conveyance reduction be used to define floodways. More information or an explanation of the methodology used is required to evaluate the correctness of the floodway boundaries. The submitted model indicates that the floodway analysis was performed using Method 1. Method 1 is a user defined method to establish floodways and does not reduce conveyance equally in both overbanks. An arbitrary designation of the floodway could have adverse development implications for the owners of the property located on the opposite bank because development in floodways is not permitted by FEMA. The floodway model does not begin with a water surface elevation one foot ( 1.0' ) higher than the base lOO- year water surface elevation at Cross-section 2.49 (the first downstream cross-section in the model) which is standard procedure. This may be responsible for the negative surcharge of -0.5 feet at Cross-section 2.68, immediately upstream of El Camino Real. A negative surcharge could be caused by excessive encroachment, errors in bridge modeling or insufficient encroachment at the downstream section. Proposed Fill / Building To establish a floodway, the base conditions model should not include any proposed conditions. To model the effect of the proposed fill for the Lucky/Savon store, an inadequate number of sections was used. A single section (Cross-section 2.77) depicts the proposed fill and does not reflect the total projected width of the proposed building. It is recommended that at least three sections be used to simulate the proposed fill. Cross- sections 2.77 and 2.72 could have been used with an additional cross-section inbetween to describe the proposed fill more accurately. This correction would raise the water surface elevation immediately upstream of the proposed building. Further analysis is required, along with the development of an existing conditions model, in order to determine the effect of the proposed fill on the 100-year water surface elevations. Starting Water Surface Elevation The model uses the slope-area method to establish a starting water surface elevation of 9.43 feet at Cross- section 2.49 located at the mouth of San Marcos Creek in Batiquitos Lagoon. The slope-area method computes the flow depth based on an estimated energy slope, geometry, discharge, and manning's roughness coefficients. FEMA requires that the MHHW (Mean Higher High Water) tide elevation be checked in this type of situation. The MHHW (Mean Higher High Water ) elevation, based on tidal datums in the Pacific ocean at the La Jolla tide station was checked and found to be 5.37 feet MLLW (Mean Lower Low Water) or 2.81 feet NGVD (1929 National Geodetic Vertical Datum) at the mouth of the lagoon. The influence, if any, of the tidal effect on the starting water surface elevation for the 100-year flood was not treated in the submitted study. Mr. Steve Deering April 28,1997 Leucadia County Water District Page 4 of 5 Contraction and Expansion Coefficients A contraction coefficient of 0.1 and an expansion coefficient of 0.2 has been used for the entire model. The higher the values of these coefficients, the greater is the energy loss resuhing fi'om the contraction and expansion of flow, and consequently, higher is the water surface elevation. These coefficients are selected based on the judgement of the modeler. These coefficients were not adjusted to reflect flow contraction and expansion through the bridge at El Camino Real and fiirther upstream from it. There is no explanation to justify the use of the same contraction and expansion coefficients throughout the entire reach. In our opinion, a contraction coefficient of 0.3 and an expansion coefficient of 0.5 should have been used through the bridge. A contraction coefficient of 0.1 and an expansion coefficient of 0.3 should have been used upstream of the bridge. This correction could result in an increase in the water surface elevation. Bridge Modeling It appears that flow through the bridge at El Camino Real has not been modeled adequately and may need more refinement. The model output shows a weir flow of 456 cfs over the road even though the 100-year floodplain delineated on the topographic map shows all the water going under the bridge. Since the model is inadequate, h is difficult to predict if the 100-year flood passes through the bridge without further analyses. Effective Flow Widths Effe tive flow widths between cross-sections 2.72 and 2.77 in the left overbank appear to have been set incorrectly based on field observations. This correction may also have a significant effect on the water surface elevations and increase the potential for flooding. Further analysis will be required before any definitive conclusions can be made. Manning's "N" Values Field evidence associated with the possible flow pattem mdicates that the flow conveyance is not representative of an "N" value of 0.035 in the left overbank upstream of El Camino Real at cross-sections 2.68, 2.72, and 2.77. Floodwater in this portion of the reach is not expected to be flowing effectively due to vegetation, elevated areas, and buildings immediately upstream of these cross-sections. Therefore the use of a higher "N" value would be more appropriate. This could also result in higher water surface elevations. CONCLUSIONS The relative effects of the proposed development (Lucky/Savon Store) in the floodplain of San Marcos Creek cannot be ascertained because of inadequacies in the submitted model. An existing conditions model has not been submitted. There are flaws in the submitted HEC-2 model that could have a significant effect on the lOO- year water surface elevations for existing conditions as well as proposed conditions. More information would have to be fumished and further analyses would be required in order to definitively address the effects of the proposed development on LCWD facilities. Mr. Steve Deering April 28,1997 Leucadia County Water District Page 5 of 5 RRCOMMENDATTONS Completion of an existing conditions model would assist in predicting potential impact of the proposed development during a 100 year flood on LCWD facilities. It is recommended that Lucky/Savon revise the flood analysis and address the following items: -Comply with FEMA modeling requirements -Meet all local, state, andfederal regulatory compliance requirements for flood control -Provide FEMA approved hydrologic study or other acceptable basis for establishing the 100-year discharge -Provide a legal regulatory definition of the existing base flood -water surface elevation and proposedfloodway -Confirm relationship of1929 datum versus datum used for proposed site development plan -Justify and/or correct the floodway analysis starting water surface elevation -Justify and/or correct the contraction and expansion coefficients -Justify and/or correct the El Camino Bridge modeling -Provide an adequate number of cross-sections to describe the proposed project -Justify and/or correct the effective flow widths -Justify and/or correct manning's "N" values The existing LCWD facilities are currently subject to 100-year flood inimdation based on the Flood Insurance Rate Maps published by FEMA. Some suggested precautions that LCWD can take to minimize or avoid flood damage to existing LCWD facilities are: the installation of a remote flood waming system based on measured rainfall and/or upstream stage, contacting FEMA for information regarding flood proofing, and checking to see if there are any contacts at Lake San Marcos located upstream, for information during storm events. Further studies beyond the scope of this review would be required to evaluate altemative flood protection measures under existing conditions. Further hydrologic and hydraulic analyses are required in order to recommend additional features to the proposed Lucky/Savon project to lower the 100-year flood elevation. The creek hydrology would have to be obtained and verified in addition to making corrections to the hydraulic analysis before any suggestions can be made. It has been a pleasure assisting you in this technical review. Please do not hesitate to call if you have any fiirther questions or if we can assist you in any other way. Sincerely, David T. Williams, Ph.D., P.E. Managing Partner WEST Environmental Hydrosciences DUDEK & ASSOCIATES A California Corporation Engineering, Environmental Sciences and Management Services Corporate Office: 605 Ttiird Street Encinitas, California 92024 619.942.5147 Fax 619.632.0164 March 18, 1997 1228-68 Mr. Nasser Sionit, Ph.D. Hazardous Materials Management Division County of San Diego P.O. Box 85261 San Diego, CA 92186-5261 RE: INVESTIGATION OF EXISTING DISTRICT'S FACIUTIES NEAR THE FORMER ARCO GAS STATION SITE Dear Dr. Sionit: The Leucadia County Water District (District) has been requested by the County's Hazardous Materials Management Division (HMMD) to provide additional infonnation regarding the District's facilities in the area of the former ARCO gas station at the H Camino Real/La Costa Avenue intersection. The District has expressed concemed that their facilities may have been impacted by the petroleum hydrocarbon releases at the former ARCO station. Existing Facilities Figure 1 shows the District's facilities in the immediate vicinity of the former ARCO gas station. Existing District facilities include the Leucadia 24" force main, the Failsafe 12" force main, and a 24" VCP gravity sewer. There is also an abandoned line (Vulcan Avenue 12" force main) which was broken during remediation excavation and was plugged with concrete. In addition, the District has a proposed Leucadia Parallel 24" force main which is currently in the design stage. The figure identifies record information for the top of pipe elevations for the force mains and the invert elevations of the gravity sewer and feet below ground surface (bgs) to the top of pipe for the force mains and to the invert of the gravity sewer. There is no readily available information for the abandoned 12" force main. Groundwater Elevations In a letter addressed to you dated August 1, 1996 fi-om Mr. Patrick A. McConnell, SECOR, indicates the depth to groundwater generally as being between 6 to 9 feet bgs. TTie ARCO Quarterly Report dated March 15, 1995 tabulated groundwater elevations in various monitoring wells. These data may be found in the attachments. MW-4 was located at the northwest comer of the remediation site slightly to the east between HA-17 and HA-29 (see Figure 4) and has since been destroyed. The groundwater elevations ranged from 11.01 feet mean sea level (msl) on 3/16/90 to 5.84 feet msl on 9/15/94. MW-10 is located approximately due north of the remediation site (see Figure 4). Groundwater elevations at MW-10 varied between 7.44 feet msl on 2/28/93 to 5.24 feet msl on 11/23/94. MW-7 is located approximately 110 feet east of El Camino Real adjacent to the gravity sewer. Groundwater elevations at MW-7 have varied from Dr. Nasser Sionit Hazardous Materials Manaj ment Division Page 2 March 18, 1997 5.39 feet msl to 9.97 feet msl. The approximate elevation of the gravity sewer invert at this location is 2.77 feet msl and becomes deeper toward the northeast end and the District's pump station. MW-13 is located approximately 5 feet fi'om the gravity sewer with an invert elevation of 3.14 feet msl. Groundwater levels in MW-4, M-7 and MW-10 indicate that the gravity sewer and the 24" force main have been submerged during the period of 3/90 to 3/95. SECOR indicated the general fiow of groundwater to be to the northwest towards Batiquitos Lagoon. Inspection of the data presented in attachments, however, indicate that the groundwater levels in MW-7 (located northeast of the site) are generally lower than the groundwater levels in MW-10 and MW-6. The data indicate the gravity sewer trench acts as a drain. The 10-inch abandoned force main which crosses the site also produces this type of fiow pattem. The abandoned force main lies between MW-9 and MW-8. The groundwater level in MW-9 on 3/10/95 is 5.83 feet msl, 7.6 feet msl in MW-6, and 8.92 feet msl in MW-8. Table 1 tabulates the depth bgs and elevations to the District's faciUties near the northwest comer of the former ARCO station. Based on the historic groundwater elevations and the elevation of the District's facilities, the District's Leucadia 24" force main. Failsafe 12" force main, and the 24" VCP gravity sewer have been submerged in groundwater. It is therefore likely that the peti-oleum hydrocaibons released at the former ARCO station were in contact witii these facilities for some period of time. TABLE 1 PIPELINE ELEVATIONS NEAR NORTHWEST CORNER OF FORMER ARCO STATION Pipeline Ground Surface Elevations Pipe Elevation* 24" VCP Sewer 13.0 feet msl 3.5 feet msl 9.5 feet bgs 12" Force Main 12.5 feet msl 8.6 feet msl 3.9 feet bgs 24" Force Main 12.4 feet msl 4.2 feet msl 8.2 feet bgs ' Pipe elevations to top of pipe for force mains and to invert for gravity sewers. Contamination In the aforementioned letter dated August 1, 1996, SECOR presented groundwater quality data for samples taken in June 1996 (see Figure 4). The data on HA-30, HA-23, HA-22, HA-20, and samples ID S100-6 and S101-7 clearly indicate contamination still exists off-site in the immediate vicinity of the District's facilities. The extent to which contamination has occurred in the area of the northwest of HA-23 and west of HA-25, we believe has not been fiilly explored. These levels represent contamination levels after remediation efforts at the site Dr. Nasser Sionit Hazardous Materials Management Division Page 3 March 18, 1997 including the excavation of oyer 5,000 cubic yards of soil. Prior to remediation, the concentration of petroleum hydrocarbons in the vicinity of the pipelines were much higher and once may have posed a greater threat to the Distiict's facilities (see Table 2) than current conditions. TABLE 2 SELECTED SITE ASSESSMENT Site ID Sampling Date Concentration TPH (ppm) Reference HA-21-5 2/10/93 10,279 1 HA-21-8 2/10/93 1,307 1 HA-22-5.5 11/12/93 259 1 HA-23-5.5 11/12/93 281 1 MW-11 6/12/95 9/12/95 1800 2 MW-11 6/17/96 <500 2 MW-12 6/12/95 970 2 MW-13 6/28/96 47,000 2 SPlOO-60 11/28/95 10,258 3 SPlOl-7 11/28/95 1,027 3 1. Additional Site Characterization Report, February 11, 1994. 2. Letter firom P. McConnell, SECOR, to N. Soinit, HMMD, dated August 1, 1996. 3. Tank Removal and Excavation Report, dated February 22, 1996. Note that after remediation of the site, a groundwater sample (6/28/96) from MW-13 exhibited contamination levels of 47,000 /xg/l Total Petroleum Hydrocarbons, 8,200 /xg/1 Benzene, 2,500 /ig/1 Toluene, 2,200 /xg/1 EUiylene, and 6,900 ng/l Xylenes. As established previously, MW-13 is approximately 5 feet from the gravity sewer which is generally submerged in groundwater. This clearly indicates that the pipeline is still in contact witii contaminants migrating from the ARCO site. Conclusion and Recommendations This letter documents the findings of various studies performed at the former ARCO station. Based on these findings and the elevations of the existing District facilities, we believe these facilities have been in contact with petroleum hydrocarbons released at tiie site. The condition Dr. Nasser Sionit ^ ^ Page 4 Hazardous Materials Management Division March 18, 1997 of the gaskets and polyethylene encasement on the pipelines has not been investigated and these items may have deteriorated due to this contact. Furthermore groundwater level and water quality data indicate the migration of the contaminants beyond the immediate vicinity of the former ARCO station. This migration may have occurred preferentially along the pipelines due to the higher hydraulic transmissivity of pipe bedding in the pipeline trenches. We do not know the extent of such migration or the possible damage caused by this type of contact. As stated in our October 15, 1996 letter to Mr. Mike Bardin, Distiict Assistant General Manager, we recommend: Removal of all remaining contaminated materials up to, around, and beyond the existing pipelines, while by-passing or keeping these pipelines in service. Fill and recompact the area with clean granular materials. Inspect a portion of each force main and the sewer for possible deterioration of gasket and polyethylene encasement material. Immediately repair or replace any damaged District pipelines for the full length of past contamination impact. SECOR indicated that it was not "economic" to excavate soil under the sidewalk and driveway adjacent to the gravity sewer. There may well be an economic impact to the District due to past and present contact of contaminants with the District's pipelines. Perhaps in-situ enhanced bioremediation, sparging, or vapor extraction would be effective in expeditiously removing this ongoing impact to the District's facilities. If you have any questions regarding this letter, or need more information, please call me at (619) 942-5147. Very truly yours, DUDEK & ASSOCIATES, INC. /^teve Deering, Califoirfia P.E. 26514 LCWD Distiict Engineer Attachments cc: Mike Bardin, Leucadia County Water Distiict Denis Pollak, Leucadia County Water Distiict Larry Tucker, Grant Tucker Properties Steve Grant, Grant Tucker Properties Tom Hageman, Planning Systems Gail Masutani, Dudek & Associates Dr. Nasser Sionit ^ Page 5 Hazardous Materials Mana^nent Division ^ March 18, 1997 ATTACHMENTS 1. Figure 1 - Site Map With Pipeline Elevations 2. Figure 4 - TPH in Soil Reference: Letter from Mr. Patrick McConnell, SECOR to Mr. Nasser Soinit, HMMD, dated August 1, 1996. 3. Table 2 - Cumulative Water Elevations Reference: ARCO Quarterly Rqwrt, dated March 15, 1995. p 3 <10 5.5 <10 8 <10 ?f5y (rr^/i)) 4 <10 6 <10 n 4.5 OO tl <10 n 3 <10 5.5 281 n <10 4 <10 6 490 (mq/t) 4 <10 5 <10 7.5 <10 3 <10 5 <10 , rPH 3.5 <10 5 290 7 <10 X TPH mg/kg LEGEND HA-8 A HAND AUGER BORING MW-114- MONITORING WELL — S — SEWER LINE (6-9 ft. bgs\ —F— FIBER OPTIC LINE (MAX. 3 ft. bgs) ,\ TRAFFIC SIGNAL LINE (WAX. 3 ft. bgs) ELECTRICAL LINE (MAX. 3 ft. bgs) SOIL SAMPLE LOCATION TOTAL PETROLEUM HYDROCARBONS MILLIGRAMS PER KILOGRAM ESTIMATED AREAS OF REMAINING HYDROCARBONS ME BASE MAP, INCLUDING SITE DIMENSIONS ANO WEa/ BORING LOCATIONS. MODIRED fROH ALTON GEOSaENCE. 1994. REMAINING TPH IN SOIL PROJECT No.: SECOR FORMER ARCO FACIUTY #1939 80600-017-13 SECOR 7654 EL CAMINO REAL FIGURE: 4 1939TP4.DWG CARLSBAD. CALIFORNIA FIGURE: 4 0 TABLE 2 Cumulative Water Elevations WellTD. D2te Measured ^ Surveyed Well Elevation' rfeetl Depth la Water rreetl JLFH Thickness (reet> Groundwater Elevation^ MW-1 3/16/90 17.53 5.56 0 11.97 7/27/90 17.53 6.12 0 11.41 2/05/91 17.53 6.33 0 11.20 5/20/91 17.68 5.94 0 11.74 8/22/91 17.68 6.35 0 11.33 11/12/91 17.68 6.60 0 11.08 9/04/92 13.09 5.91 0 7.18 12/10/92 13.09 5.92 0 7.17 2/03/93 13.09 4.61 0 8.48 5/06/93 13.09 4.79 0 8.30 8/30/93 13.09 5.70 0 7.39 10/29/93 13.09 5.65 0 7.44 3/04/94 13.09 5.32 0 7.77 5/11/94 13.09 5.60 0 7.49 9/15/94 13.09 6.22 0 6.87 11/23/94 13.09 6.26 0 6.83 3/10/95 13.09 4.43 0 8.66 MW-2 3/16/90 18.00 0 1185 1800 6 79 0 11 Jll 2/05^1 18 00 7 13 0 10.«7 5/20/91 18.65 6.57 0 12.08 6/04/91 18.65 6.80 0 07 1!^ 8/22/91 18 65 6.93 0.03 n.74» 11/12/91 18.65 7.25 TRACL 11.40 9/04/92 13.86 6.50 0 ' 7J6 11/04/92 i3.86 6.73 TRACE 7.13 12/10/92 13.86 6.63 TRACE 7.23 1/07/93 13.86 6.06 TRACE 7.80 2/03/93 13.86 5.15 TRACE 8.71 3/16/93 13 86 , 5.47 .08 8 45' 4/08/93 13.86 5.53 .05 8J7» 5/06/93 13.86 5.80 ,03 SJ)8» 6/17/93 13.86 5.83 0 2.03 «/30/93 13.86 6.28 0 7.58 10/29/93 13.86 6.25 0 7.61 3/04/94 13.86 6.03 0 7.83 5/11/94 13.86 6.33 0 7,53 9/15/94 13.86 6.88 0 6.98 11/23/94 13.86 7.04 0 6.82 3/10/95 13.86 5.22 0 8.64 C-VwpSlbcr>vu\ar19)904 ( TABLE 2 (Continued) Wril T.P. I "Hate Measured Surveyed WeU •Klevah'on' ffeet> Depth to Water ^reet> LPHThlc]mes& Groundwater Elevation' MW-3 3/16/90 7/27/90 2/05/91 5/20/91 8/22/91 11/12/91 9/04/92 12/10/92 2/03/93 5/06/93 8/30/93 10/29/93 3/04/94 5/11/94 9/15/94 11/23/94 3/10/95 15.66 15.66 15.66 16.46 16.46 16.46 11.97 11.97 11.97 11.97 11.97 11.97 11.97 11.97 11.97 11.97 11.97 5.18 4.95 5.00 5.27 5.67 5.93 5.30 5.33 3.89 4.40 5.14 5.01 5.43 5.61 5.65 5.54 3.98 10.48 10.71 10.66 11.19 10.79 10.53 6.67 6.64 8.08 7.57 6.83 6.96 6.54 6.36 6.32 6.43 7.99 MW-4 3/J6W 7/27/90 2/05/91 5/20/91 6/04/91 8/22/91 nnn9\ 9/04/92 12/10/92 2/03/93 5/06/93 8/30/93 10/29/93 3/04/94 5/11/94 ^/15/94 11/23/94 3/10/95 14.66 3.65 14.66 4.38 14.66 4.35 15.21 4.55 15.21 4.75 15.Z1 5.00 15.21 5.25 10.65 10.65 10.65 10.65 10.65 10.65 10.65 ia65 10.65 10.65 10.65 4.34 4.72 2.81 3.60 4.19 4.18 3.70 409 4 81 4.66 2.98 0 T 11.01 10.28 10.31 10.66 10.46 10.21 9.96 6.31 5.93 7.84 7.05 6.46 6 47 6.95 6,56 5.84 5.99 7.67 c:\wrvSIUe^»*M^»'t9)•X>*.fT» c ( TABLE 2 (Continued) WeU T.D. Date Measured Sun-eyed WeU •FleratJon' ffeet^ Depth to Water rreet> jUPHIhickaess freel> Groundwater Elevatfori* MW-5 3/16/90 16.43 5.55 0 10.88 7/27/90 16.43 6.19 0 10.24 2/05/91 16.43 6.28 0 10.15 5/20/91 16.73 6.32 TRACE 10.41 6/04/91 16.73 6.47 TRACE 10.26 8/22/91 16.73 6.85 .30 10.11» 11/12/91 16.73 6.95 TRACE 9.78 9/04/92 12.57 6.41 .18 6.30" 11/04/92 12.57 6.57 .12 6.09' 12/10/92 12.57 6.26 TRACE 6.31 1/07/93 12.57 5.56 TRACE 7.01 2/03/93 12.57 5.73 1.07 7.64' 3/16/93 12.57 5.87 .96 7.42' 4/08/93 12.57 5.87 .80 7.30* 5/06/93 12.57 6.38 1.13 7.04' 6/17/93 12.57 6.25 .99 7.06' 8/30/93 12.57 5.94 .24 6.81' 10/29/93 12.57 6.85 1.15 6.58' 3/04/94 12.57 5.95 .38 6.91' 5/11/94 12.57 6.00 .27 6.77' 9/15/94 12.57 6.62 .02 5.97' 11/23/94 12.57 6.69 .01 5.89' 3/10/95 12.57 5.22 0 7.35 MW.6 8/22/91 17.37 6.80 0 1057 11/12/91 17.37 7.20 0 10.17 9/04/92 12.78 6.47 0 6.31 12/10/92 12.78 6.42 0 6.36 2/03/93 12.78 5.11 0 7.67 5/06/93 12.78 5.49 0 7.29 8/30/93 12,78 • 5.94 0 6.84 10/29/93 12.78 S3\ 0 6.87 3/04/94 12.78 5.70 0 7,08 5/11/94 12.78 5.60 0 7.18 9/15/94 12.78 6.60 0 6.18 11/23/94 12.78 6.70 0 6.08 3/10/95 12.78 5.18 0 7.60 c:\»TSl\inw«i\«H 93904.rr* TABLE 2 (Continued) ( Well T D Dale Measured Surveyed Well Elevation' ffeet) Depth to Water {feet) LPH Thickness ffeert Groundwater Elevation' MV/-7 8/22/91 17.67 7.70 0 9.97 11/12/91 17.67 7.70 0 9.97 9/04/92 12.94 7.17 0 5.77 12/10/92 12.94 7.21 0 5.73 2/03/93 12.94 5.77 0 7.17 5/06/93 12.94 6.49 0 6.45 8/30/93 12.94 6.85 0 6.09 10/29/93 12.94 6.81 0 6.13 3/04/94 12.94 6.52 0 6.42 5/11/94 12.94 6.50 0 6.44 9/15/94 12.94 7.54 0 5.40 11/23/94 12.94 755 0 5.39 3/10/95 12.94 5.81 0 7.13 MW-S 9/04/92 15.41 7.66 0 7.75 ::|i:||||3^iq|^|||i 15 41 7 80 0 7.61 2/03/93 • 6 41 0 9.00 0 8 35 8/30/93 iiiii?;rs*^ill?i 7.46 7.95 10/29/93 7 41 8.00 3/04/94 15,41 7.41 0 8.00 5/11/94 ii5li;M?iills:i 0 7.98 9/15/94 IjSiX^iJJjrjO:*;!:! 7.31 7.11 3/10/95 :s;:;f;g*l5i4rvr^-^ •^••:mpf^;6^mW'.'''-8.92 MW-9 9/04/92 13.79 6.81 0 6.98 12/10/92 13.79 7.12 0 6.67 2/03/93 13.79 5.81 0 7.98 5/06/93 13.79 6.14 0 7.65 8/30/93 13.79 6.62 0 7.17 10/29/93 13.79 6.82 0 6.97 3/04/94 13.79 6.50 0 7.29 5/11/94 13.79 6.48 0 7.31 9/15/94 13.79 7.28 0 6.51 11/23/94 13.79 7.46 0 6.33 3/10/95 13.79 7.96 0 5.83 ( ( TABLE 2 (Continued) WeU T D. Dafe Measured Surveyed WeU Elevation' ffeet) Depth to Water /reef* LFH Thickness ffeetl Groundwater Elevation' MW.IO 9/04/92 11 98 . . 6.05 0 5.93 12/10/92 It 98 625 0 5.73 2/03/93 11.98 454 0 7.44 5/06/93 1L98 5.41 0 6.57 sno/93 11.98 S.92 6.06 10/29/93 11,98 5.84-P 6,M iliii3/o^^ 11.98 |p|;|p|53||«|:i D 6.45 5/li/94 11-98 556 6.42 9/15/94 H.98 651 5.47 11/23/94 11,98 6.74 0 5,24 3/10/95 11,98 4.57 liiiliiiliilii 7.41 Survey elevation and depth to water measurements prior to 9/15/94 summariied ftom Alton Geoscience Reports Notes: 'Elevations are in feet above mean sea level. 'Elevations adjusted by adding (0.75 x LPH thickness) to measured water elevations. c:V*T\51 Wcr»*uW 193904.tr« fineering, Corporate Offi^ 619.942.5147 Environmental Sciences and 605 Third Street Fax 619.632.0164 Management Services Encinitas, California 92024 .A California Corporation October 15, 1996 196269-12 Mr. Mike Bardin Assistant General Manager 1960 La Costa Avenue Carlsbad, CA 92009 RE: ARCO Station Contamination Impacts on LCWD FacUities Dear Mike: The Leucadia County Water District (District) has expressed concern that the District's pipelines in the vicinity of the La Costa Avenue and El Camino Real intersection may have been impacted by the petroleum hydrocarbon release at the former ARCO station. In this regard, Dudek & Associates, Inc. has performed preliminary investigation of the status of the contamination problem at the former ARCO Station through review of the County of San Diego's Hazardous Materials Management Division (HMMD) files on this site. There is concern regarding impact on the pipelines since petroleum hydrocarbons can permeate the polyethylene encasement on the force mains and many types of joint gasket rubber. The extent to which the contamination has impacted the force mains (polyethylene lined, gaskets), and the sewer pipe (gaskets (and pipeline, if PVC)) is unknown. Furthermore, there exists the possibility that the petroleum hydrocarbons may have traveled down pipeline trenches due to the higher hydraulic conductivity ofthe pipe bedding material. Presented below is a review of our findings. SITE BACKGROUND In 1985 the steel underground storage tanks (UST) at the ARCO station at 7654 El Camino Real were removed. At that time, liquid phase hydrocarbons (LPH) were observed on the groundwater beneath and adjacent to the removed gasoline USTs. Approximately 6,000 gallons of LPH and water were pumped prior to the installation of four new fiberglass reinforced USTs. Since 1991, HMMD has received quarterly ground water quality monitoring reports for the site. Between 1988 and 1985, approximately 31 soil boreholes and 12 groundwater monitoring wells were installed on and off-site. A variety of information on groundwater levels, monitoring well locations, and contaminate concentrations exist in the HMMD file. In July 1995, the USTs were removed from the site. In an attempt to remediate the site, over 5,000 cubic yards of soil was excavated from the former ARCO facility in November, 1995. Due to adjacent utilities, sidewalks, and driveways, some hydrocarbon-impacted soils with concentrations above 1,000 milligrams per kilogram (mg/kg) were not removed in two locations - one on the west sidewalk (along El Camino Real) and one on the north sidewalk (adjacent to the La Costa Plaza driveway). Mr. Mike Bardin Page 2 Leucadia County Water District October 15, 1996 A review of the information in the HMMD files indicates the flow of groundwater to generally be in a north, north-west direction towards Batiquitos Lagoon. Most of the remaining contamination is at the west and north boundaries of the former ARCO station. A review of the fluctuating groundwater level information indicates that at times the groundwater could have been above the bottom of the existing District pipelines in the area. There are four District pipelines which may be impacted: 24" Leucadia Force Main, 12" Failsafe Line, 18" gravity sewer and ttie 12" abandoned Vulcan Avenue Force Main. It does not appear from a review of the data that contamination from the ARCO site will impact the proposed new 24" Parallel Leucadia Force Main alignment south of the ARCO station on La Costa Avenue. CURRENT STATUS With the removal of most of the contaminated soil at the site, the concentrations of total petroleum hydrocarbons (TPH) have been decreasing. Figure 1 depicts the current levels of contamination as of August 1996. In an August 1, 1996 letter to Mr. Nasser Soinit ofthe HMMD, SECOR International Inc. (SECOR), on behalf of ARCO Products Company (ARCO) requested closure of the site due to the reduction in contamination levels. HMMD staff indicated in a conversation with Dudek that the site will not be closed until contamination levels are reduced ftirther. The SECOR letter of August 1, 1996 indicates that the force mains and sewer lines "could be impacted by hydrocarbons dissolved in groundwater," but that the District did not report hydrocarbon odors or impact in the lines or the line trenches. Furthermore, the letter states: "Additional assessment in the area of MW-13 would be limited because of the sewer lines. The Leucadia Water District has already demonstrated their resistance to assessment adjacent to the sewer lines, therefore it is anticipated that permission to perform additional assessment or excavation of a small volume of hydrocarbon impacted soil is unlikely." Dudek understands from discussions with District staff that, in fact, the District has been cooperative with SECOR's efforts to assess the contamination close to the District's facilities. To our knowledge there has been no resistance to further assessment adjacent to the sewer, in fact, the District should insist on additional assessment and excavation. RECOMMENDATIONS We believe that SECOR has not satisfactorily proven that the District's force mains and sewer line were not impacted by the contamination at the former ARCO site. The lack of the District reporting of odors or problems with the lines does not indicate that the District's lines were not impacted. There may be contamination in the old trench (beyond the edge of the ARCO site) of the abandoned 12" force main which diagonally crosses the site. In fact, there may be contamination within the abandoned pipeline which we understand was broken open during remediation excavation and then plugged with concrete. Mr. Mike Bardin Page 3 Leucadia County Water District October 15, 1996 We recommend that HMMD be requested to direct SECOR to propose methods and a schedule for the approval of the District for SECOR to: Remove all remaining contaminated materials up to, around, and beyond the existing pipelines, while by-passing or keeping those pipelines in service. Fill and recompact the area with clean granular materials. Further inspect a portion of each force main and the sewer for possible deterioration of gasket and polyethylene encasement material. Immediately repair or replace any damaged LCWD pipelines for the full length of past contamination impact. We recommend that the District forward a copy of this letter to Mr. Nasser Soinit, HMMD, regarding the District's concerns and recommendations for further contamination removal and utility inspection and repair or replacement. We recommend that a copy of this letter also be forwarded by District staff to Mr. Dwight Worden, District Attorney, for information and possible ftiture action. Because waterlines are generally installed shallower than sewer lines as indicated in the SECOR report, adjacent waterlines may not have been affected. However, we recommend that a copy of this letter and attachments also be forwarded by District staff to Mr. Bob Greaney, City of Carlsbad, for his possible action with regard to potential impact on Carlsbad Municipal Water District waterlines. If you have any questions, please call me at 942-5147. Very truly yours, DUDEK & ASSOCIATES, INC. 26514 LCWD District Engineer Attachments: List of Figures with References Letter from Ms. Patricia McConnell, SECOR to Mr. Nasser Soinit, HMMD dated August 1. 1996 Mr. Mike Bardin Page 4 Leucadia County Water District October 15, 1996 LIST OF FIGURES Figure 3a Borings, Monitoring Wells, Cross-Section Lines, and Approximate Extent of Hydrocarbon- Affected Soil Reference: Alton Geoscience, Site Assessment Report, date March 11, 1993 Figure 7 Estimated Lateral Extent of Free Product and Benzene Plumes, and Ground Water Laboratory Results (September 4, 1992) Reference: Alton Geoscience, Site Assessment Report, date March 11, 1993 Figure 4 Remaining THP in Soil Note: This figure does not show existing water lines (Dudek, 10/08/96). Reference: Letter from Ms. Patricia McConnell, SECOR to Mr. Nasser Soinit, HMMD dated August 1, 1996 MW-4 DISPENSER PUMP ISLANDS — P HA-7 ^ . LEGEND HA-8 /K Hand Augor Bof Ing Hand Auger Slant Boring B-5 © Boring Monitoring Well A A" Cross-Section Line Affected Interval 2to4fl>g Qstoyfbg w>*: MM «M* Product Une (approximate location) BORINGS, MONITORING WELLS, CROSS-SECTION LINES, AND APPROXIMATE EXTENT OF HYDROCARBON-AFFECTED SOIL ALTON GEOSCIENCE 5764 PACIFIC CENTER BLVD. SUrrE 101 SAN DIEGO, CA92121 NOTES: Figure redrawn (rom 1991 maps by EA Engineering, Science, and Technology. All structure, txsring, and well locations are estimated, ppm > parts per million. TPH e total petroleum hydrocarbons. Approximate , extent o( adsorbed-phase plume based on 100 ppm TPH. Interval depths are in ieet below grade. See Figures ^ 5^or cross-sections. ARCO Station 1939 7654 El Camino Real Carlsbad, California FIGURE 3a 6OO130-2O-SC2 9-30-92 DRIVEWAY MW-10 TPH ND B ND • T ND E ND X ND MW-7 TPH NO B 0.0095 T 0.0549 E 0.2002 X 0.9608 MW-4 TPH ND B ND T ND E NO X ND .-J < Ui ir o z < o UJ /•^i ^ ? MW-3 TPH ND B NO T ND E ND x 0.0262 * DISPENSER . PUMP ' / ISLANDS / Mfth / I (0.18)*/ I ^-•». STATION BUILOING MW-2 TPH 22.650 B 1.8339 T i3007 E 0.4092 X 1.6368 MW-2 1.8339' MW-S (0.18)* MW.2 TPH 22.150 B T 2.X07 E 0.4O«2 X 1.UM LEGEND Monitoring Well wtth Benzene Concentration In mg/1 Monitoring Weil with Free Product thickness In F^t Estimated Lateral Extent of Free Product Plume Estimated Lateral Extent of Benzene Plume Greater than 0.001 mg/1 Product Une (approximate location) DIssolved-Phase Hydrocartx>n Concentrations In mg/1 MW-1 TPH ND B ND T ND E NO X NO MW-6 TPH NO B ND T 0.0059 E 0.0216 X 0.169 1 MW-9 TPH ND B NO T ND E ND x ND -1 MW-8 TPH ND B ND T NO E ND x ND ESTIMATED LATERAL EXTENT OF FREE PRODUCT AND BENZENE PLUMES, AND GROUND WATER LABORATORY RESULTS ALTON GEOSCIENCE 5764 PACIRC CENTER BLVD. SUPTEIOI SANDIEGO, CA92121 NOTES: Extent of plumes is interpretivo based on data collected September 4,1992; mg/1 = milligrams per liter; B = benzene; T •= toJuene; E = eaiy1benzer>e; X = totai xylenes; NO ^ below detection limits slated in official Laboratory Reports. For additional laboratory results, refer to the Table. * = free product thickness in feet Scale(Feet) 15 30 September 4,1992 ARCO Station 1939 7654 El Camino Real Carlsbad, California FIGURE? 600130-20-SC2 10-6-92 (mq/kg) 3 <10 5.5 <10 8 <10 N (rr^/ikq) 4 <10 6 <10 (mg%) 4.5 <1Q n <10 3 <10 5.5 281 n (mo/kq) 4 <10 5 <10 7.5 <10 (nJg%) 1 2 <10 4 <10 6 490 1 1 \^ (mg)kg) 1 4 <10 1 5 <10 (mqjilq) 3 <!0 5 <10 (mqAg) 3.5 <10 5 290 7 <10 X TPH mg/kg LEGEND HA-8 A HAND .AUGER BORING MW-11-^ MONITORING WELL — S — F— TRAFFIC SIGNAL LINE (MAX. 5^ ft. ELECTRICAL LINE (MAX. 3 ft. bgs) SOIL SAMPLE LOCATION TOTAL PEJROLEUM HYDROCARBONS MILLIGRAMS PER KILOGRAM SEWER LINE (6-9 ft. bgs\ FIBER OPTIC LINE (MAX. 3 ft. bgs) '"^^ bgs) <^ ESTIMATED AREAS OF REMAINING HYDROCARBONS mL BASE MAP. INCLUDING SITE DIMENSIONS ANO WELL/ BORING LOCATIONS, MGDIRED FROM ALTON GEOSatNCE. 1994. APPROXIMATE SCALE IN FEET NOTE: ALL LOCAIIONS AND DIMENSIONS ARE APPROXIMATE BASED ON AVAILABLE DATA. REMAINING TPH IN SOIL PROJECT No.: SECOR FORMER ARCO FACILITY #1939 80600-017-13 SECOR 7654 EL CAMINO REAL FIGURE: 4 1939TP4.DWG CARLSBAD. CALIFORNIA FIGURE: 4 SECOR Jiitcnicilioiial /iicor/xjralL'cl August 1, 1996 Project #80600-017-13 AUG V ii. JO Mr. Nasser Sionit County of San Diego, Site Assessment and Mitigation Division P.O. Box 85261 San Diego. CA 92186-5261 Subject: Well Installation Report and Request for Closure Former ARCO Facility #1939 7654 El Camino Real Carlsbad, Califomia 92009 jJ / Dear Mr. Sionit: H/3 I This report summarizes additional site assessment activities requested by the County of San Diego, Site Assessment and Mitigation Division (SAM) and completed for ARCO Products Company (ARCO) by SECOR Intemational Incorporated (SECOR) at the subject site (Figure 1). Following the SAM'S review of the Tank Removal and Excavation Report (dated Febmary 22, 1996), the SAM required the installation of one monitoring well north of the former imderground storage tank (UST) excavation to assess the potential presence of hydrocarbons in groundwater and soil. In addition. The SAM required a review of utility maps for the site vicinity to assess potential hydrocarbon migration pathways. BACKGROUND In 1985, one 500-gallon waste-oil, two 4,000-gaIlon, and two 6,000-gallon gasoline single-walled steel USTs were removed from the site. The USTs were replaced with one 550-gallon waste oil and three 12,Q00-gallon gasoline double-walled plastasteel USTs in the same locations. Between 1988 and 1995, consultants for ARCO commissioned 31 soil boreholes and the installation of 12 groundwater monitoring wells on and off-site. Total Petroleum Hydrocarbons as gasoline (TPHg) concentrations in soil samples collected during these assessments are summarized in a SECOR report tided "Additional Site Assessment, ARCO FacUity 1939," dated November 3, 1995. Quarterly groundwater sampling has been performed at the site since 1991. No TPHg or BTEX concentrations were reported for wells MW-1, MW-3, MW-4, MW-6, MW-7, MW-8, and MW-9 since 1993. Liquid-phase hydrocarbons (LPH) were reported in wells MW-2 and MW-5 from the time of installation imtil destmction of the wells in 1991 (SECOR, Quarterly Groundwater Monitoring Report, July 16, 1996). In July 1995, SECOR supervised the removal of one waste oil UST and three gasoline USTs, and the demolition ofthe service station. In August 1995, wells MW-1, MW-2, MW-3, MW-4, MW-5, and MW-12 were destroyed prior to beginning remedial excavation. 2655 Qiiiuiio Del Kio A'.. Siiilc'302. .San Dicf-u. CA 92J0S-I6.ii ((>!')) 2'X>-(>I<)5 (619) 2%-6n)9 /M.V Mr. Nasser Sionit Project No. 80600-017-13 August 1, 1996 Page 2 In November 1995, SECOR supervised the remedial excavation of over 5,000 yd^ of soil from former ARCO Facility #1939. Due to utility locations, sidewalks, and driveways, hydrocarbon-impacted soils with concentrations above 1,000 milligrams per kilogram (mg/kg) were allowed to remain in two locations-one on the west sidewall (along El Camino Real) and one on the north sidewall (adjacent to the La Costa Plaza Driveway). Because soils in these areas were not economically accessible and soil samples collected adjacent to these areas contained TPH concentrations below 100 mg/kg, no additional excavation was performed. Based on field and laboratory data, the combined volume of hydrocarbon- impacted soil above 1,000 mg/kg in these areas was estimated at 15 to 20 yd'. GEOLOGIC AND HYDROGEOLOGIC SETTING The site is underlain by sands, silts, and clays of Quatemary Age. These Quatemary deposits overlie marine and lagoonal deposits of the Eocene Del Mar and Friars Formations (Kennedy, 1975). Soil types encountered during drilling included silty to clayey sands from grade to five to sue feet bgs, underlain by silt, clay, and sandy clay to 15 feet bgs. Localized sand lenses arc present in the clay at depths greater than 6 feet bgs. The site is in the Carlsbad Hydrographic Unit (HU 4.00) in the San Marcos Hydrologic Area (HA 4.50). According to the Califomia Regional Water Quality Control Board (CRWQCB, 1994), groundwater in the San Marcos HA has no beneficial uses for areas which drain into Encinitas Creek. The site is approximately 150 feet east and southeast of Encinitas Creek, and drains into the creek. Therefore, groundwater beneath the site is designated as non-beneficial. Based on a review of a map at the San Diego RWQCB, the site is not located within a sensitive aquifer boundary. Batiquitos Lagoon is located approximately 1,000 feet west and northwest of the site. Depth to water (DTW) on-site ranges between sbc and nine feet bgs. The groimdwater flow direction is generally toward the north and northwest. PRE-FIELD ACTIVITIES Based on SAM correspondence, SECOR prepared and subinitted a work plan and pennit application for the installation of one groundwater monitoring well (Attachment A). Local public utUities were notified of the scheduled subsurface activity through Underground Service Alert (USA). Utility company representatives marked public utility lines in the site vicinity prior to drilling. FIELD ACl'lVn iES On June 24, 1996, SECOR personnel supervised the drilling and installation of monitoring well MW-13 using a CME 75 drill rig equipped with 10-inch diameter hollow stem augers (Figure 2). The location of MW-13 was selected in accordance with the SAM's request to locate a well north of the excavation sidewall containing the highest remaining TPHg coiKentration. During drilling, soU samples were collected from approximately 6, 11, and 15 feet bgs using a modified Califomia split spoon sampler lined with three clean 6-inch brass liners. At each sample interval, the bottom liner was removed from the sampler, sealed with Teflon sheets and plastic caps, properly labeled, and placed in an ice cooled chest. A measured portion of soil collected from each sample point was placed in a resealable plastic bag. Hydrocsbbon vapors from the soil sample were allowed to volatilize into the headspace for several minutes prior to performing measurements. Headspace vapors were measured by inserting the prot>e of Mr. Nasser Sionit Project No. 80600-017-13 August 1, 1996 Page 3 an organic vapor analyzer (OVA) into a small hole punctured in the bag. The OVA measurements were recorded on each borehole log (Attachment B). Soil samples were selected for analysis based on field OVA measurements and the depth of sample collection. The sample from 6 feet bgs was analyzed to assess hydrocarbon impact in a 1-foot thick sand lens that had been sampled during the excavation. The sample from 15 feet bgs was analyzed to assess if hydrocarbons had migrated vertically. Soil samples were transported in an insulated storage chest cooled with ice to a Califomia state-certified and ARCO-approved laboratory for chemical analysis. The sampler and liners were washed in a dilute Alconox solution and rinsed with tap and distilled water prior to collecting each sample. Soil cuttings were logged by a SECOR geologist using the Unified Soil Classification System (USCS). Lithologic classifications are provided on the borehole logs in Attachment B. Following drilling of the borehole for MW-13, 4-inch flush-threaded PVC blank and 0.02-inch slotted casing were installed. A filter pack of pre-washed #3 Monterey sand was placed in the annular space surrounding the screened casing to approximately two feet above the slotted section. The remaining annular space was sealed with bentonite and concrete. A locking well cap was placed over the casing top. A traffic rated monitoring well cover was installed slighdy above the existing grade to protect the wellhead and to minimize infiltration of surface water. Well construction details are provided on the borehole logs (Attachment B). Following placement of the sand filter pack, and prior to installation of the bentonite seal, the well was developed using a surge block and purged using a baDer. The purpose of development was to remove any fme formational and filter pack material present and to increase flow of formational water into the well. Approximately 15 gallons of water were removed from the well. Field data pertaining to the purging and sampling of the monitoring wells are provided in Attachment C. On June 28, 1996, depth to water was measured in MW-13. Approximately 1.5 well volumes of water were purged from the well using a hand bailer. Conductivity, pH, and temperature measurements were recorded during purging to determine when groimdwater conditions were stable. Groundwater samples were collected in a clean disposable bailer, and transferred to 40 milliliter VOAs. Samples were stored in an insulated storage chest cooled with ice until delivery to a Califomia state-approved laboratory for chemical analysis. Soil cuttings, decontamination water, well development water, and purged groimdwater generated during drilling activities were placed in separate 55-gallon drums, labeled, and left on the ARCO site pending the results of laboratory analyses. Based on laboratory results, Ihe soil drums were transported as non- hazardous waste by Belshire Environmental, Inc. (Belshire), and delivered to TPS Technologies in Adelanto, Califomia for treatment. The water drums were transported by Belshire for treatment and disposal at DeMenno Kerdoon in Compton, Clalifomia. Disposal manifests are included as Attachment D. CHEMICAL ANALYSES Chemical analyses of select soil and groimdwater samples wa^ performed by Columbia Analytical Services (CAS), a state-certified and ARCO-approved laboratory located in Canoga Park, Califomia. Selected soil samples were analyzed for TPHg by Modified EPA Method 8015 (DOHS Method). The soil sample with the highest TPHg concentration was analyzed for benzene, toluene, ethylbenzene, and total INwu>WI«],]0.,p, Mr. Nasser Sionit Project No. 80600-017-13 August 1, 1996 Page 4 xylenes (BTEX) by EPA Method 8020. The groundwater samples were analyzed for TPHg and BTEX by Modified EPA Methods 8015 POHS Method) and 8020, respectively. UTILITY LINE REVIEW SECOR obtained utility line and subsurface stracture maps for the site vicinity to determine if potential hydrocarbon migration pathways exist. There are existing gas, water, electrical, sewer, and telephone lines, and storm drain systems in the vicinity of the site. The locations of the utility lines are illustrated on Figure 3. Utilities immediately adjacent to the site are detailed below. Electrical An electrical line trench is located parallel to the westem property line of the site beneath the El Camino Real sidewalk. San Diego Gas and Electric (SDG&E) persoimel indicated that buried electrical lines are generally within three feet of the surface. It is unlikely that the line trench could provide a migration pathway for hydrocarbons in groundwater based on the expected shallow depth of the tirench compared to the depth to groundwater (6 to 9 feet bgs). Traffic Signals A traffic signal line trench is located parallel to the westem property line of the site beneath the El Camino Real sidewalk. City of Carisbad personnel indicated that traffic signal lines are generally within one to two feet of the surface. It is unlikely that the line trench could provide a migration pathway for hydrocarbons in soil or groundwater based on the expected shallow depth of the trench. Natiu^ Gas There is a 30-inch high pressure namral gas line located beneath the southbound traffic lanes of El Camino Real. Based on the distance from the site (approximately 100 feet west of the westem property line), it is unlikely that hydrocarbons would migrate in soil or groundwater to this utility trench. Telephone A fiber optic telephone line is located approximately 10 to 15 feet from the westem property line, beneath the bike lane on the east side of El Camino Real. AT&T personnel indicated that buried fiber optic cables are generally within three feet of the surface. Based on the location and depth of the line, the potential for hydrocarbon migration in soil or groundwater in the fiber optic line trench is unlikely. Water There are two water lines in the vicinity of the site. One line is located approximately 20 feet from the westem property line beneath El Camino Real. The second line mns east/west beneath La Costa Avenue, approximately 15 feet south of the southem property line and intersects the first line beneath the La Costa Avenue/El Camino Real intersection. According to maps obtained from the Leucadia Water District and the City of Carlsbad, the water lines are installed at approximately 4 feet bgs. Because the groundwater elevation is below the water lines, the potential for hydrocarbon migration in groundwater is unlikely. Mr. Nasser Sionit Project No. 80600-017-13 August 1. 1996 Page 5 Sewer A main sewer line is located beneath tiie La Costa Plaza driveway, approximately 5 feet north of tiie southem curb line of tiie driveway. Two sewer force mains, also located beneatii tiie driveway, are north and adjacent to the main line. These lines intersect otiier sewer lines beneath El Camino Real, which parallels the westem property line of the site. Based on maps provided by the Leucadia Water District and discussions witii Leucadia personnel, the main sewer line is approximately 5 to 7 feet bgs, and the force mains are approximately 6 to 9 feet bgs. Because deptii to water ranges from 6 to 9 feet bgs, these sewer lines could be impacted by hydrocarbons dissolved in groundwater. However, Leucadia Water District has not reported hydrocarbon odors or impact in tiie lines or tiie line trenches. Additional assessment in the vicinity of tiie sewer lines would be limited by the presence of tiie lines. Storm Drains Storm drain grates are located north of the site on the east side of El Camino Real, and soutii of the site on the nortii and soutii sides of La Costa Avenue. The main drain line is routed north beneath El Camino Real toward an effluent drain into Encinitas and San Marcos Creeks. Storm drains are generally shallow, and tiie potential for hydrocarbon migration in the storm drains or trenches is considered to be unlikely. SOIL SAMPLE ANALYTICAl. RESULTS Soil laboratory analytical results are summarized in Table 1. A copy of the laboratory report, including chain-of-custody documentation, is included in Attachment E. Figure 4 summarizes hydrocarbon concentrations in soil for this investigation, and for boreholes, monitoring wells, and excavation verification samples from previous assessment work. GROUNDWATER SAMPLE ANALYTICAL RESULTS Groimdwater sample analytical results are summarized in Table 2, and are illustrated in Figure 5. A copy of the laboratory report, including chain-of-custody documentation, is included in Attachment E. DISCUSSION SoU SoU containing TPHg concentrations greater than 1,000 mg/kg has been removed from the site except as described in tiie background. Approximately 4,500 yd' (6,735 tons) of hydrocarbon-impacted soU were transported from tiie site for disposal at TPS Technologies. SoUs containing hydrocarbon concentrations above 1,000 mg/kg remain in two locations (Figure 4). One area is along the westem property boundary near El Camino Real. The limits of hydrocarbon-impacted soil are relatively well defined by tiie adjacent sidewall, bottom, and soil borehole samples. The utility lines in this area consist of an electrical line, traffic signal lines, and a fiber optic telephone cable. These lines are installed at depths rauging from approximately 2 to 4 feet bgs, and the potential for hydrocarbon impact in the line trenches is considered to be low. Additional assessment and/or excavation in this area would be limited by the utility lines, sidewalk, and El Camino Real. Mr. Nasser Sionit Project No. 80600-017-13 August 1, 1996 Page 6 The second area of remaining hydrocarbon-impacted soil is along the north side of the former excavation, near the driveway of La Costa Plaza (Figure 4). The limits of hydrocarbon-impacted soU are relatively well defmed by tiie adjacent sidewall, bottom, and soil borehole samples. In MW-13, a TPHg concentration of 600 mg/kg was reported in a sample collected at 6 feet bgs (MW13-6). TPHg concenti^tions were below reporting limits •(< 10 mg/kg) in a sample collected from 15 feet bgs (MW13- 15). A benzene concentration of 3.3 mg/kg was reported for sample MW13-6. Hydrocarbons in this area are contained in a sand lens that is approximately one foot thick, located at approximately 6 to 7 feel bgs. Further excavation or assessment in this area is not recommended due to the presence of tiie driveway and the sewer main and force mains located beneatii the driveway. SoU sample analytical results for wells and boreholes which remain following excavation are summarized in Figure 4. Groimdwater The majority of the source for additional hydrocarbon impact to groundwater appears to have been removed during the remedial excavation. Hydrocarbon concentrations, in groundwater would be expected to degrade naturally because the source has been removed. The site is located in a non-beneficial groundwater use area. Groundwater samples collected from four of tiie six remaining monitoring wells, on-site wells MW-6, MW-8, and MW-9, and off-site well MW-7, have been below reporting limits for TPHg and BTEX for a minimum of 15 quarters. In off-site well MW-10, TPHg and benzene concentrations in groimdwater samples have decreased between 1992 and 1995. Analytical results for the remaining wells are summarized in Table 2. Well MW-13 is downgradient from the area of the highest TPHg concentration remaining in the former excavation. The groundwater sample from well MW13 contained TPHg and benzene concentrations of 47,000 and 8.200 micrograms per liter, respectively. SECOR anticipates tiiat tiie dissolved hydrocarbon concentrations in wells MW-11 and MW-13 wUI decrease based on source (hydrocarbon-impacted soil) removal. Additional assessment in the area of MW-13 would be limited because of the sewer lines. The Leucadia [ i - Water District has already demonstrated their resistance to assessment adjacent to the sewer lines, ' f therefore it is anticipated that permission to p>erform additional assessment or excavation of a small volume \ of hydrocarbon impacted soU is unlikely. REQUEST FOR CLOSURE SECOR, on behalf of ARCO Products Company, requests closure for ARCO Facility 1939, based on the following: • The source area for additional hydrocarbon impact to groundwater has been excavated. Existing dissolved hydrocarbons are expected to degrade namrally. • The sile is located in a non-beneficial groundwater use area. Groundwater in wells MW- 6, MW-7, MW-8. and MW-9 has been below reporting limits for TPHg and BTEX for a minimum of IS^quarters. Dissolved hydrocarbon concentrations reported in MW-11 have i:Ws*,inJ«.(K*n.vWI9)9X).rpi Mr. Nasser Sionit Project No. 80600-017-13 August 1. 1996 Page 7 shown a reduction with time, and are anticipated to continue decreasing. Hydrocarbon concentrations in MW-13 are anticipated to attenuate and degrade naturally over time. • Based on the laboratory results of verification :soU samples coUected from the excavation sidewalls and bottom, and the laboratory results from the soU boreholes and wells, the vertical and lateral limits of hydrocarbon-impacted soils above the regulatory action level (1,000 mg/kg) appear to have been assessed (SECOR. 1996). • The volume of hydrocarbon-impacted soU greater tiian 1,000 mg/kg TPH which remains in place is estimated to be 20 yd'. Further excavation and/or assessment is not recommended due to tiie presence of utUity lines, sidewalks, or streets. If you have any questions regarding the contents of this letter, please contact tiie undersigned at your convenience. Sincerely, SECOR International Incorporated Patrick A. McConnell Project Geologist Marci J. Ri<ihards Associate Geologist David W. Varco, RG #6191 Registered Geologist PAM\MJR\DWV:clk Enclosures: Figure 1, 2, 3, 4 and 5 Tables 1 and 2 Attachment 1 Well Pennit Attachment 2 Borehole/WeU Log and Legend Attachment 3 Groundwater Sampling and Purging Log Attachment 4 Waste Disposal Manifests Attachment 5 Laboratory Reports & Chain of Custody Record REFERENCES Alton Geoscience, February 11, 1994, Additional Site Characterizfltion Report for ARCO Station 1939. Alton Geoscience, March 11, 1993. Site Assessment Report. ARCO Station 1939. Alton Geoscience, September 12. 1991. Site Investigation Report, ARCO Station 1939. Califomia Regional Water Quality Conti-ol Board (CRWQCB), San Diego, 1994. Waier QuaUty Control Plan, San Diego Basin (9). EA Engineering. Science and Technology, Inc., April 1990, Phase II Subsurface Investigation at ARCO Station No. 1939. EA Engineering, Science and Technology, Inc.. September 1991, Site Investigation II, ARCO Station No. 1939. Groundwater Technology, June 2, 1993, Removal of Oil Water Separator/Clarifier and Surrounding Soil, ARCO Facility ttl939. Kennedy, M.P., 1975, Geology of tfie San Diego Metropolitan Area, Califomia, Section A, Califomia, Division of Mines and Geology, Bulletin 200, Sacramento, Califomia. SECOR Intemational Incorporated, September 8, 1995, Remediation Worlc Plan and Community Health and Safety Plan, ARCO Facility HI939 SECOR Intemational Incorporated, November 3, 1995, Site Assessment Report, ARCO Facility #7959 SECOR Intemational Incoiporated, February 22, 1996, Tank Removal and Excavation Report, ARCO Facility if 1939 Testing Engineers-San Diego, December 7, 1988, Laboratory Test Results, Walt's ARCO Service Station. U.S. Geological Survey, Encinitas, Califomia, 7.5-Minute Topographic Quadrangle, 1968. Photorevised 1975. i:\MF<M)rd6.0U(cuWt«]9}0.rpi FIGURES 20CX) 2000 REFERENCE: U.S.G.S. TOPOGRAPHIC MAP 7.5 MINUTE SERIES ENCINITAS QUADRANGLE DATED 1958 PHOTOREVISED 1975. SCALE IN FEET SECOR INTERNATIONAL INCORPORATED 2655 CAMiNO OQ. RIO N.. SUITE 302 r SAN DIEGO, CA. 92108 SITE LOCATION MAP FORMER ARCO FACIUTY /1939 7654 a CAMINO REAL CARSBAD. (>UFORNIA PROJECT No.: 80600-017-13 FIGURE: 1 > HIGH VOLTAGE ELECTRICAL VAULTS S — MW-13 r MW-11 1^ < LlJ < o LEGEND: MW-6 MONITORING WELL MW-LO DESTROYED MONITORING WELL - - — SEWER LINE NOTE: MODIFIED FROM ALTON GEOSCIENCE FIGURE. 1994 30 APPROXIMATE SCALE IN FEET NOTE: AU LOCATIONS AND DUCKSONS AK AP(>1!0X1UATC SECOR 1939SP1B.DWG SITE PIAN . FORMER ARCO FACILfTY <(1939 7654 EL CAMINO REAL CARLSBAD, CALIFORNIA PROJECT No.: 80600-017-13 SECOR 1939SP1B.DWG SITE PIAN . FORMER ARCO FACILfTY <(1939 7654 EL CAMINO REAL CARLSBAD, CALIFORNIA FIGURE: 2 ' 5 — r •< u O z LEGEND: inr-64- . . _9_ . . F rob = i:-: MONITORING WELL PROPERTY UNE SEWER UNE HBER OPTIC TELEPHONE UNE TRAFFIC SIGNAL UNE EUCTRICAL UNE WATER LINE STORM DRAIN 40 80 APPROXIMATE SCALE IN FED USE; B«S£ W. KIUIMC sit DM>6»6 MO MU/ uxAToie, uxns ntou AUON ccoscsa, im HJTF' Mi UKiTtXS MO DUCKSONS MiC APPROXIUTC B^SED ON iVNtABU MIA SECOR INTERNATIONAL INCORPORATED 2655 CAMINO DEL RIO N., SUITE 302 SAN DIEGO, CA 92108 19J9Da.DWG UTILITY LOCATION MAP FORMER ARCO FACILITY #1939 7654 CAMINO REAL CARLSBAD, CAUFORNIA PROJECT No.: 80600-017-13 SECOR INTERNATIONAL INCORPORATED 2655 CAMINO DEL RIO N., SUITE 302 SAN DIEGO, CA 92108 19J9Da.DWG UTILITY LOCATION MAP FORMER ARCO FACILITY #1939 7654 CAMINO REAL CARLSBAD, CAUFORNIA FIGURE: 3 m (""9%) 3 <10 5.5 <10 8 <10 Tm 4 <10 6 <10 m (m9%) 4.5 <10 11 <10 ft 3 <10 " 5.5 281 (mgX) 2 <10 4 <10 6 490 OO^HIGH VOLTAGE ELECTRICAL VAULTS 3 <10 5.5 <10 8 <10 (mq/'ilg) 2.5 <10 4 <10 6 <10 (rngXij) 6 600 15 <10 4 <rlO 5 <10 7.5 <10 (iilg)i<9) 3 <10 5 <10 , TPH 3.5 <10 5 290 7 <10 X TPH mg/kg LEGEND HA-8 A h'^ND AUGER BORING MW-11-^ MONITORING WELL — S — SEWER LINE (6-9 ft bgs F— FIBER OPTIC LINE (h —?— TRAFFIC SIGNAL LINE (WAX. 3^ft. bgs) ELECTRICAL LINE (MAX. 3 ft. bgs) SOIL SAMPLE LOCATION TOTAL PETROLEUM HYDROCARBONS MILLIGRAMS PER KILOGRAM ESTIMATED AREAS OF REMAINING HYDROCARBONS ML BASE MAP, WaUDIMG STIE DIMENSIONS AND nil/ BORING LOCATIONS, HOOinED FROM ALTON GEOSCIENCE, 1994. APPROXIMATE SCALE IN FEET NOTE: Aa LOaTlOHS AND DIMENSIONS ARE APPROXIMATE BASED ON AVAILABLE DATA REMAINING T.PH IN SOIL PROJECT No.: SECOR FORMER ARCO FACILITY |1939 80600-017-13 SECOR 7654 EL CAMiNO REAL FIGURE: 4 1939TP4.DWG CARLSBAD. CALIFORNIA FIGURE: 4 D^HIGH VOLTAGE ELECTRICAL VAULTS r < LU o < CJ TPH= 47.000 B= 10,000 J, TPH= <500 B= 3.2 TPH= <500 B= 1.6 MW-12 MW-4 L—... MW-5 MW-6 TPH= B= <500 <0.5 MW-9 4- MW-3 TPH= <500 B= <0.5 MW-1 .O Q MW-2 LEGEND MW-6 MONITORING WELL MW-1G DESTROYED MONITORING WELL - -S- - SEWER LINE TPH= ^-snn TOTAL PETROLEUM HYDROCARBON CONCENTRATIONS -"^^ IN MICROGRAMS PER LITER (ug/L) B= 3.2 BENZENE CONCENTRATIONS IN ug/L. <0.5 BELOW LABORATORY DETECTION LIMIT NS NOT SAMPLED (SEE TABLE 2) NOTE: MODIFIED FROU ALTON GEOSCIENCE FIGURE, 1994. WELLS TPH= B= <500 <0.5 •i 0 30 APPROXIMATE SCALE IN FEET NOTE: ALL LOCATIONS AND DIMENSIONS ARE APPROXIMATE SECOR 1939GW3B.DWG HYDROCARBON CONCENTRATIONS IN GROUNDWATER. JUNE 1996 FORMER ARCO FACILITY i'l939 7654 EL CAMINO REAL CARLSBAD, CALIFORNIA PROJECT No.: 80600-017-13 SECOR 1939GW3B.DWG HYDROCARBON CONCENTRATIONS IN GROUNDWATER. JUNE 1996 FORMER ARCO FACILITY i'l939 7654 EL CAMINO REAL CARLSBAD, CALIFORNIA FIGURE: 5 TABLES TABLE 1 SUMMARY OF SOIL SAMPLE ANALYTICAL RESULTS ARCO Fadlity #1939 (Ail Results Reported in mg/kg) ' Sample HiOcation Depth ^ (ft) ' TPH B. E X MW13-6 6/24/96 6 600 3.3 8.9 11 33 MW13-15 6/24/96 15 <10 NA NA. NA NA Notes: mg/kg = milligrams per kilogram TPH = Total Petroleum Hydrocarbons (EPA Method 8015) B = Benzene (EPA Method 8020) T = Toluene (EPA Method 8020) E = Ethylbenzene (EPA Method 8020) X = Total Xylenes (EPA Method 8020) NA = Not Analyzed <# = Below Reporting Limits <: >MU««fM. (NwTwW 19 ] no. ffa TABLE 2 W CUMULATIVE GROUNDWATER SAMPLE ANALYSES AJRCO Fadlity #1939 (All Results Reported in fig/l) Well No. Sampling I>ate TPHg' ii;f"'--Tli||^^^^^^ llflilPlliil X Total Lead: MW-I 3/16/90 ND ND ND ND ND - 7/27/90 ND ND ND ND ND - 2/05/91 ND ND NI) ND ND — 5/20/91 ND ND ND ND ND — ' 8/22/91. ND ND ND ND ND — 11/12/91 ND ND ND ND ND — 1 9/04/92 ND ND ND ND ND — 1 12/10/92 ND ND ND ND ND — 1 2/03/93 ND ND ND ND ND — II 5/06/93 ND ND ND • ND ND — 1 8/30/93 ND ND ND ND ND — n 10/29/93 ND ND ND ND ND — \ 3/04/94 ND ND ND ND ND — \ 5/11/94 ND ND ND ND ND — 1 9/15/94 <50 <0.50 <0.50 <0.50 <1.0 — 1 11/23/94 <50 <0.50 <0.50 <0.50 <1.0 - \ 3/10/95 <50 <0.30 <0.30 <0.30 <0.60 — \ 5/12/95 Not Sampled | 8/95 Well Destroyed i MW-2 3/16/90 16,000 2,100 760i^S; :;.:.>.- — . . \ 7/27/90 8,100 :.:••^"^l.266#^t» |:-v •64i;iiiri 260 — \ 2/05/91 :V-:;::v:-l,800.;&. :.:;i:...J::430:;ii:s|| ;;;::•;:. 13.::t::?|5i . : 41 ^ — \ 5/20/91 .••.•if(H.' j'?:;-, ..,_;.::::::;::;|;i|.;;:; yfifMili^^$MM, 6/04/91 • • ••:>.\:::S:;?.:,: . ••.:i!i}^'i^&!M', :w&:* : ' 8/22/91 « !::•'.:: • * : ;;v ;;^:i::;::::" 1 11/12/91 • j::.'.- • : • :V;:-;|S:^:j;:: • • 9/04/92 22.650 18,339' 23,007 ;-:-:r^^4,092^:::;::-::^ 16,368 ' ' 11704/92 * • 12/10/92 • * • 1/07/93 • * ' » • 2/03/93: » m • ' 3/16/93 * • • • • 4/08/93' * * * * 5/06/93 ; * • • . '6/17/93 — — 33.000 ' . 4,700 8,500 1300 400 .v 10/29/93 55.000 4,600 ' 11,000 '• 1.600 6300 — 3/04/94 17.000 2400 . 2,5<X) 900 2,800* - . 5/11/94 25,000 2.500 6.300^ 1300 4,200 — 9/15/94 19.000 1,400 3,500 1.000 3.100 - 11/23/94 7.100 ' - 680 720 , 320 880 3/10/95 , 11,000 . 1.600 1.200 '710 ' •' 2.000 ' - 5/12/95 * « 8/95 Well Destroyed TABLE 2 (continued) CUMULATIVE GROUNDWATER SAMPLE ANALYSES ARCO Fadlity #1939 (All results reported in /jg/1) Well No. MW-3 Sampling Date : |||TEHgi» iiiiiiilHI -liiiiii ::lH^&|f|if Total Lead 3/16/90 2.300 160 200 69 250 _ 7/27/90 300 5.5 ND 2.6 1.5 — 2/05/91 ND ND ND ND ND — 5/20/91 53 1.2 ND ND ND — 8/22/91 ND 1.4 ND .89 .82 — 11/12/91 ND ND ND ND ND — 9/04/92 ND ND ND ND 26.2 — 12/10/92 ND ND ND ND ND — 2/03/93 ND ND ND ND ND — 5/06/93 ND ND ND ND ND — 8/30/93 ND ND ND ND ND — 10/29/93 ND ND ND ND ^^) — 3/04/94 ND ND ND ND ND — 5/11/94 ND ND ND ND ND — 9/15/94 <50 <0.50 <0.50 <0.50 <1.0 - 11/23/94 <50 <0.50 <0.50 <0.50 <1.0 3/10/95 <50 <0.30 <0.30 <0.30 <0.60 — 5/12/95 <500 <0.5 <0.5 <0.5 <1.5 — 8/95 Well Destroyed 3/16/90 • lOO:; -••.•"::.21 •••*.:t •^::*;^5;:':K:^-•••••":• •:v;3.2:^s:::::":.:. •':••'— 7/27/90 •::*;:;•:<:.• m.iMi-:i-; & : . Nliiiii: ND ND w-^ •:i^: 2/05/91 : •::>::•:. ND>: .x-: •: ND ND ND ::':•;#;:::• OT>i#«::' 5/20/91 ND ND ND 6/04/91 ND ND ND ND ND — 8/22/91 ;::;:;:.;•• ND:;vt:^:; ND ND ND ••::::^;-:hrol^lPis • ~ 11/12/91 ND ND ND ND ND 9/04/92 ND ND ' ND ND ND — ' 12/10/92 ND ND ND ND ND —' 2/03/93 ND ND ND ND ^ ND — 5/06/93 iiliiNDilii :iisS:i3liiii 3 ND ND — 8/30/93 ND ND ND ND ND — 10/29/93 ND ND ND ND " — 3/04/94 ND. ND-ND ' • ^ND ND ^ - — ' 5/11/94 ND ND Nl> m >ID '9/ <50 ' <0.50 <0.5Q '<0.50 ' <1.0 = 11/23/94 <50 ::;:iiil5Siii <0.50' <0.5D <1.0 . — '3/10/95 <0.30 <030 <030 <0.60 — 5/12/95 ' Not Sampled Well Destroyed " MW-4 : TABLE 2 (continued) CUMULATIVE GROUNDWATER SAMPLE ANALYSES ARCO FadUty #1939 (All results reported in ngfl) Well No. MW-5 Sampling Date TPHg B T E j X j Total Lcad^ 3/16/90 17.000 1.800 1.700 230 1.120 - [ 7/27/90 42,000-1,200 170 150 350 2A)5/91 13.000 160 ND 21 11 - 5/20/91 21.000 1,700 • 1,300 260 980 - 6/04/91 • • • • • • 8/22/91 • • • • • • 11/12/91 * • • • • j 9/04/92 • • • • ! 11/04/92 • • • 1 12/10/92 • • • 1 1/07/93 • • 1 2/03/93 • • • • • 3/16/93 • • • • • • 4/08/93 • • • • 5/06/93 • • • • • 6/17/93 • • • • 8/30/93 • • • • 10/29/93 » • • • • • 3/04/94 • • • • • 5/11/94 • • • • • 9/15/94 * • • • • 11/23/94 • • • • 3/10/95 73.000 4,700 800 1,900 2,100 - 5/12/95 Not Sampled 8/95 Well Destroyed 1 8/22/91 ND ND ND ND ND 11/12/91 .300 ND ND ND ND - 9/04/92 " ND ND 5.9 21.6 169 ' ND 12/10/92 ND ' ND ND -ND ND • - -2A)3/93 'ND ND ND ND • ND - 5/06/93 ND .4 ,4 ND ND — 8/30/93 , ND ND ND ND - ' 10/29/93 ND ND ND ND ND - 3/04/94 •' ND ND ND ND ND — 5/11/94 ' . ND ' • ND ND - ND . ND ' — ' 9/15/94 <50 <0.50 <:o.50 <0.50 <1.0 - 11/23/94 ' <5Q <0.50 <0J0 <0.50 <1.0 — 3/10/95 ' <50 <0.30 <0,30 <0.30 <0.60 - 5/12/95 <500 <0.5 <0.5 <{).5 - <1.5 9/12/95 Not Sampled 12/20/95 <500 <0.5 <0.t> <0.5 -<L5 - 3/25/96 <50 <0.3 <0.3 •'<Q.^ ' ' <0.6 - 6/17/96 *<500 <0.5 <0.5 <03 <1.5 1 MW-6 TABLE 2 (continued) CUMULATIVE GROUNDWATER SAMPLE ANALYSES ARCO Fadlity #1939 (All results reported in ;tg/I) 1 Well No. Sampling Date T ;Pf;i3li|: Total Lead MW-7 8/22/91 .43 .5 ND ND 11/12/91 770 ND ND ND ND — 9/04/92 ND 9.5 54.9 200.2 960.8 — 12/10/92 ND ND ND ND ND — 2/03/93 ND ND • ND ND ND — 5/06/93 ND ND ND ND ND — 8/30/93 ND ND ND ND ND — 10/29/93 ND ND ND ND ND — 3/04/94 ND ND ND ND ND — 5/11/94 ND ND ND ND ND — 9/15/94 <50 <0.50 <0.50 <0.50 <1.0 — 11/23/94 <50 <0.50 <0.50 <0.50 <1.0 — 3/10/95 <50 <0.30 <0.30 <0.30 <0.60 — 5/12/95 <500 <0.5 <().5 <0.5 <1.5 — 9/12/95 <500 <0.5 <0.5 <0.5 <1.5 — 12i^/95 <500 <0.5 <0.5 <0.5 <1.5 3/25/96 <50 <0.3 <0.3 <0.3 <0.6 - 6/17/96 <500 1.6 <0.5 <0.5 <1.5 MW-8 9/04/92 ND •:.::S;*;^:::ND ^-t:::!^ 12/10/92 ND :.:-: :.-ND,.:-.--:::5-" ^--.:r:-::ij>ni:::-v:;fii^-^ ::::;::|:;;::ij::I.;:.,:;. :x::.-::. 2/03/93 ND ND ;:|||«:::p; :::'K 5/06/93 ND ND >^''yMD>'A 8/30/93 ND ND ND iifSpii ¥;::•?:;::::•;:; 10/29/93 >ro ND |:||||:;gi::!5;';:i:;;:w 3/04/94 mMytiiMim ND • ND liliroiii:? liilsip?-:^::!::::? 5/11/94 ND • ND ND ND •:g;:f|::::2S>.:-.!:7^ 9/15/94 • <0 50 <0.50 <0.50 11/23/94 <50 : <0 50 <0.50 ;||:|s|;Op:v::::.::;. 3/10/95 <0.30 <D.30 <0.30 — 5/12/95 iiliisdt^iiil <0.5 <0.5 <0.5 - :s:i;:-a;:;;:::ft^^^^^^^ 9/12/95 <0.5 <0.5 <0.5 iiiilisiil iSii-'#s:-'P^ 12/20/95 |SI<5®p:: <0.5 <0.5 l:W^;isiiii liBiisiil — 3/25/96 <50 <0.3 <0.3 <0.3 <0.6 — 6/17/96 <0.5 <0.5 <0:5 — TABLE 2 (continued) CUMULATIVE GROUNDWATER SAMPLE ANALYSES ARCO Facility #1939 WeU No. Sampling Date ; ;: JPHg B T E X Total Lead 12/10/92 ND ND ^•1D ND ND — 2/03/93 ND ND i«ro ND ND - 5/06/93 ND ND I'lD ND ND - 8/30/93 ND ND I'lD ND - ND - 10/29/93 ND ND ND ND ND - 3/04/94 ND ND m ND ND - 5/11/94 • ND ND ]<D ND ND - 9/15/94 <50 <0.50 <0.50 <0.50 <1.0 - 11/23/94 <50 <0.50 <0.50 <0.50 <1.0 - 3/10/95 <50 <0.30 <0.30 <0.30 <0.60 - 5/12/95 Not Sampled 9/12/95 Not Sampled 12/20/95 <500 <0.5 <:0.5 <0.5 <1.5 - 3/25/96 <50 <0.3 <:0.3 <0.3 <0.6 - 6/17/96 <500 <0.5 <0.5 <0.5 <1.5 - MW-10' 9/04/92 ND x,:^ ;.:•••• Nb-:^ : " ;llP::'Nriiili;: M> ND -MW-10' 12/10/92 ND ND-, ND ND - 2rt)3/93 ND lliililiil ND ND - 5/06/93 ND iiiiiiiiii ND ND 8/30/93 84 .92 ND ND - 1 10/29/93 ND ND ND ND liM:M#:;| _ 3/04/94 54 1.9 ND .65 ND - 5/11/94 62 .55 ND ' ND ND - 9/15/94 89 2.8 <.0J0 <0.50 <1.0 - 11/23/94 <50 <0.50 <0.50 <a.50 <1.0 - 3/10/95 140 3.1 <:0.30 <0.30 0.95 - 5/12/95 <500 • 1.4 <0J <0J <1.5 - 9/12/95 <500 13 <0.5 <0.5 <1.5 ::;:|:;:;?:;:;:;r;:;:|:::J;;:::;:v^^^^^^ 12/20/95 Not Sampled^ 3/25/96 Not Sampled' - ' 6/17/96 Not Sampled' MW-11 6/12/95 1.800 21 18 86 310 -MW-11 9/12/95 1,800 46 9.6 180 25 - 12/20/95 <500 11 <0.5 22 2.8 - 3/25/96 66 4.1 <0.3 1.6 <0.6 - 6/17/96 <500 3.2 <0.5 0.6 <1.5 • -MW-12 6/12/95 970 120 20 29 46 MW-12 8/95 Well Destroyed Data in this table prior to 9/15/94 summarized from Alton Geoscietxx Reports Notes TPHg = Total Petroleum Hydrocarbons as gasoline B = Benzene T = Toluene E = Ethylbenzene X = Xylenes — = Aiialysis Not Perfonned • = Well Not Sampled. LPH Present ND = Not Detected (Laboratory results are below the detection limit) Not Sampled = Indicates well has been removed from quarterly sampling program Not Sampled' = Unable to locate (AwHiM.CKwcv^ar 193918.rpi TABLE 2 (continued) CUMULATIVE GROUNDWATER SAMPLE ANALYSES ARCO FaciUty #1939 (All results reported in fig/l) Well No. Sampling Date TPHg B T E X Total Lead MW-9 9/04/92 ND ND ND tm ND 12/10/92 ND ND ND ND ND — 2/03/93 ND ND ND im • ND — 5/06/93 ND ND ND ND ND — 8/30/93 ND ND ND ND ND — 10/29/93 ND ND ND ND ND — 3/04/94 ND ND ND ND ND — 5/11/94 ND ND ND ND ND — 9/15/94 <50 <0.50 <0.50 <0.50 <1.0 — 11/23/94 <50 <0.50 <0.50 <0.50 <1.0 — 3/10/95 <50 <0.30 <0.30 <0.30 <0.60 — 5/12/95 Not Sampled 9/12/95 Not Sampled 12/20/95 <500 <0.5 <0.5 <0.5 <1.5 — 3/25/96 <50 <0.3 <0.3 <0.3 <0.6 — 6/17/96 <500 <0.5 <0.5 <0.5 <1.5 _ MW-10 9/04/92 'l:::-;:7,^^ND:-i:i?:;:' ;-p- • ND •:::.:• ND ND 12/10/92 '••'':''''t''imiT"Z'^ ^•'''-:''-:Wi0':'-". -•^{:- tm ND ND 2/03/93 ND:S:i:-i^^ ND ND 5/06/93 5:;:-:-;ND^6:t?---:' - ND- • ND ND • —• 8/30/93 :?;:K.S;;;84:lip:i: :S;.;.-;.-ND:v:-:::::.^:; ND ND , :"'::;;.•,, :7?:?;lCra9/^#::-m:-S;.itDMmM; M •. ND.-:;;:::'.:-ND ND •• 3/04/94 |s::;-:.:-NI)r^f? ::•:•••:• .65 ND '— 5/11/94 ND ND' — 9/15/94 •<a50:•.;^• <0.50 <1.0 — 11/23/94 l;: .•<o:50:;^*.:? <0 50 <1.0 3/10/95 • 140 i <0:30::-:j;V::: <0.30 0.95 — 5/12W <500 <0.5 <1.5 — ' 9/12/95 ' <500 1.3 lP:-;;v;<6:5l:.X:; <D.5 <1.5 — 12/20/95 Not Sampled '3/25/96 Not Sampled 6/17/96 ^ Not Sampled MW-11 6/12/95 • 1.800 21 18 86 310 — 9/12/95 1,800 46 9.6 180 25 — 12/20/95 <500 11 <0.5 22 2.8 — 3/25/96 66 4.1 <0.3 1.6 <0.6 — 6/17/96 <500 3.2 <0.5 0.6 <1.5 - lyIW-12 6/12/95, ' 970 120 20 29 46 — «/95 V/ell Destroyed MW.13 6/28/96 47,000 8,200 2,500 2,200 6,900 Data in this table prior to 9/15/94 summarized from Alton Geoscience Reports Notes: TPHg = Total Petroleum Hydrocarbons as gasoline * B = Benzene o ND T = Toluene E = Ethylbenzene Not X = Xylenes — = Analysb Not Performed Not Sampled Sampled = Well Not Sampled. LPH Present = Not Detected (Laboratory results are bdow the detection limit) = Indicates well has been removed from quarterly sampling program = Unable to locate Fehr & Peers Associates, Inc. Transportation Consultants 3685 Mt Diablo Blvd Suite 301 Lafayette, CA 94549 510 284-3200 FAX 510 284-2691 MEMORANDUM flUQ j j ,337 Date: August 11, 1997 To: Penny Milton, Fortney Associates From: Matthew Manjarrez Subject: Supplemental Carlsbad Lucky Store Traffic Study La Costa Avenue Operational Analysis Carlsbad Lucky Store #121-283 (971-1006) As requested, Fehr & Peers Associates performed an operational analysis of La Costa Avenue between El Camino Real and the project driveway to refine the recommendations contained in our April 25,1997 fmal traffic study report. Vehicle queuing, signal timing, signal phasing were evaluated using the Corsim micro- simulation software package. The La Costa Avenue intersections with El Camino Real and the project driveway were simulated for the "Year 2000 plus Project" scenario. The two intersections were assumed to be fully actuated and coordinated. Figure 1 summarizes the operational analysis. Figure 1 also shows the recommended striping on La Costa Avenue. The operational analysis results in the following key findings: • To reduce vehicle queues, the project driveway intersection shouid be operated as a "half-cycle" of 60 seconds. Therefore, the El Camino Real intersection shouid be operated with a 120 second cycle. • A 100 foot long left-tum bay should be provided on eastbotmd La Costa Avenue for vehicles entering the project driveway. The left-turn bay will provide adequate storage for the 95th percentile vehicle queue length. • The westbound left-tum bay at El Camino Real must be shortened to 185 feet to provide a 100 foot long left-tum bay at the project driveway. The shortened left-tum bay exceeds the 95th percentile vehicle queue length. Carlsbad Lucky Store Traffic Study July 1997 La Costa / El Camino 19 sec. 15 sec. 22 sec. 1^ M \ 19 sec. 4 sec. 41 sec. Offset = 42 sec. Cycle Length = 120 sec. La Costa / Project Access 8 sec. 15 sec. 27 sec. 10 sec. Offset = 40 sec. Cycle Length = 60 sec. 1"=50' Figure 1 Fehr & Peers Associates LA COSTA AVENUE MODIFICATIONS