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Home My WebLink AboutSite DewateringAmended Plan to-Monitor Dewatering Operations Four Seasons Resort — Vail, CO January 26, 2007 Layton Construction Dewatering will be monitored in the following ways at the site: Monitoring Activity #1 — Monitoring and settlement points will be established on each building on any adjacent properties, including the Scorpio Condominium Building and the 9 Vail Road Condominium Building. These points will be surveyed on a regular basis to determine if movement is taking place. These measurements will be done at regularly scheduled intervals, of every three days for the first three weeks of dewatering and then weekly if no significant movement has occurred. Significant movement shall be defined as any movement of more than one fourth of one inch. Monitoring Activity #2 - Monitoring of ground surface monuments on the outside of the shoring wall, as well as, monitoring points on the face of the shoring wall itself shall be established. Surveying of these points will take place on the same time schedule as surveying the settlement points on each building, see above. Monitoring Activity #3 — Four piezometers will be installed inside the proposed limits of excavation to measure the hydraulic head of groundwater. The actual location of the piezometers will be subject to approval by the developer and Town of Vail. These measurements will be done at regularly scheduled intervals, of once a day, unless results and/or conditions warrant more frequent testing. Monitoring Activity #4 — Upon completion of installation of the wells and the submersible pumps, the discharge from the wells will be checked by means of a Rossum Sand Tester. A port will be installed in all major discharge lines to allow the Rossum Sand Tester to be installed and moved from discharge line to discharge line. The port for the Rossum Sand Tester will be installed toward the end of each discharge header to monitor a group of wells based on one sample. According to the Environmental Health Office with the Town of Vail, Bill Carlson and as provided in the Groundwater discharge permit information, the required not to exceed measurements for discharge water into Spraddle Creek storm sewer system are as follows: Over any 7 day period, the average particulate measurement must be less than 45 mg/liter. - Over any 30 day period, the average particulate measurement must be less than 30 mg/liter. If the results exceed the aforementioned values, the Rossum Sand Testers will be moved to individual wells for further testing. Attached is the proposed dewatering well locations, discharge locations, and port locations for the Rossum Sand Tester and flowmeters. Final locations will be coordinated with the Town of Vail. Also, Rossum Sand Tester procedures and a typical cross section on how this device connects to the discharge header are attached hereto for reference. Notwithstanding the foregoing, for the wells connected to Discharge Header #2 and for Well #'s 1 and 2 on Discharge Header #1, measurements shall be taken at the discharge line of each well twice per day during the first three weeks of dewatering operations, and then once per day thereafter if no significant turbidity is detected in the discharged water. Significant turbidity shall mean particulate measurement of any sample exceeding 30 mg/l. If significant turbidity is encountered, then the affected well shall be immediately adjusted to reduce its pumping rate to a level such that the turbidity of the discharge water falls below 30mg/l. All test results for the Rossum Sand Tester shall be noted in a log to be maintained by well(s), discharge lines and date and time of test. In the event that any Rossum Sand Tester measurement exceeds aforementioned values, then the well or wells so affected shall be temporarily shut down and a plan of action will be implemented in cooperation with the Town of Vail before such wells shall be reactivated. Monitoring Activity #5 - Monitoring of the nearby ground surface will also take place. Visual inspection to spot any ground movement will take place twice a day during the first three weeks of dewatering and then such inspection shall be, once a day, unless conditions warrant more frequent visual inspection. If substantial settlement of the adjacent ground surface is observed using any of the above monitoring methods, the dewatering process will be fully and/or partially stopped and a plan of action will be implemented in cooperation with the Town of Vail to deal with the situation prior to the stopped dewatering activities being resumed. S . (YVAT(: ASS 0 C I ATE S I N C. March 21, 2007 Mr. Douglas G. Hipskind Vail Development, LLC 50 South Sixth Street, Suite 1480 Minneapolis, MN 55402 RE: Proposal for Groundwater Monitoring 13 Vail Road and 28 South Frontage Road Vail, Colorado ATC Proposal Number: 35 -07- 0051 -E Dear Mr. Hipskind: 8985 East Nichols Avenue, Suite 350 Centennial, Colorado 80112 www.atcassociates.com Phone 303.799.6100 Fax 303.799.3441 ATC Associates Inc. (ATC) is pleased to respond to your request for a proposal to perform groundwater monitoring services during the dewatering of the construction site at the above - referenced property. ATC understands that Layton Construction Company, Inc. will be performing the dewatering and excavation work at the site and that dewatering at the site is required for approximately nine months. ATC will oversee groundwater monitoring through the dewatering process to ensure regulatory compliance with applicable regulations. This proposal will include a brief summary of scope -of -work issues, followed by a fee proposal estimate. Scope of Work The purpose of groundwater monitoring is to monitor dewatering activities at the construction site. ATC project monitoring services will generally consist of maintaining communication with a client representative and the onsite contractor; assessing discharge water quality and dewatering progress; work to maintain compliance with the federal, state, and local discharge regulations as well as maintain the project schedule. Specific project activities are described below in detail. ATC anticipates a total of 13 sampling events throughout the course of the dewatering process. Initial sampling will be conducted at the outset of site dewatering and re- implemented weekly for the first month of discharge. Additional sampling will be conducted on a monthly basis until the conclusion of the dewatering process at the site. Other unanticipated sampling events may occur if onsite conditions warrant an increase in sampling frequency due to changing site conditions or if elevated concentrations of regulated hydrocarbon compounds are identified in the discharge. • ATC will collect groundwater discharge samples to determine hydrocarbon concentrations at the initiation of and throughout the dewatering process. The samples will be analyzed by SPL, Inc. laboratories for Benzene, Toluene, Ethylbenzene, and Total Xylenes (BTEX) and Methyl tert- Butyl . Ether (MTBE) by EPA Method 8260 and Gasoline Range Organics (GRO) and Diesel Range Organics (DRO) by EPA Method 8015. ATC will visually inspect the discharge at each sampling event for evidence of hydrocarbon impact (sheen and/or visible free product) and monitor for odor and/or vapor with a Photo - Ionization Detector (PID). S. Vail Development, LLC March 21, 2007 Groundwater Monitoring Proposal • ATC will provide on -site monitoring and groundwater sampling on a regular basis to establish and confirm discharge compliance. ATC will record field activities and observations and provide a summary of field data in a summary report. ATC will respond to changes in site conditions if notified by appropriate onsite representatives by scheduling mid -term sampling activities. Field observations of such events by Vail Development, LLC or Layton Construction Company representatives shall be forwarded to ATC representatives for consultation and evaluation. If site conditions change significantly that warrant mid -term sampling, ATC will conduct additional sampling activities at the same rate as described for regularly scheduled sampling and analyses. Mid -term sampling activities will be conducted only upon authorization by Vail Development, LLC representatives. The cost for additional sampling activities is not included in this estimate. • ATC will prepare a summary report which will include: a brief description of the dewatering activity; historic groundwater discharge sampling results over the course of the dewatering activities; any corrective action required at the site; and recommendations. Two copies of the final report will be provided within 30 days after receipt of the final laboratory data sheets. Fee Proposal for Groundwater Monitoring SERVICE UNITS RATE FEE Project Geologist/Scientist 104 Hours 8 hours /event $75.00/hour $7,800.00 Project Management 13 Hours (1 hour /event) $115.00/hour $1,495.00 Project Adminstration 13 Hours (1 hour /event ) $35.00/hour $455.00 Vehicle 13 events $85.00 /event $1,105.00 Mileage 3,000 total miles (230 miles /event) $0.48.5/mile $1,455.00 Laboratory 13 — submittals (standard TAT) $180.00 /event $2,340.00 Groundwater Monitoring Subtotal $14,650.00 This estimated total is based on the time and materials costs itemized above. If there are any additional charges necessary Vail Development, LLC will be immediately informed. No additional work will be performed without Vail Development, LLC prior approval. Authorization In order for ATC to proceed, please complete and sign the attached Proposal Acceptance Agreement included below indicating proper billing instructions and return the signed authorization copy to us. Please review the attached Terms and Conditions that are considered an integral part of this proposal. ATC Associates Inc. Page 2 Vail Development, LLC March 21, 2007 Groundwater Monitoring Proposal Schedule Site dewatering activities are tentatively scheduled to begin in the fourth week of March, 2007. ATC will coordinate appropriate field activities with onsite representatives to collect initial groundwater discharge samples for the site. Groundwater samples will be collected weekly for the first month of dewatering and then monthly thereafter, with the final sampling event occurring near the end of December, 2007. The project will be coordinated and managed out of ATC's office in Centennial, Colorado. We will coordinate field activities, prepare data summaries, and perform quality control review on laboratory analyses for the samples collected at the site. ATC will provide verbal updates upon receipt of final laboratory data, periodic written data summaries of field observations and sample results, and a final written report summarizing observations and results at the conclusion of the dewatering activities at the site. ATC is pleased to have this opportunity to work with Vail Development, LLC on this project. If you have any questions regarding this proposal, please contact me at (303) 799 -6100. Sincerely, ATC Associates Inc. Christopher A Woods Senior Project Manager Attachments: Terms and Conditions Proposal Acceptance and Agreement ATC Associates Inc. Page 3 David Offermann Branch Manager rage i or i Mike Ellis From: Chris Woods [woods35 @atcassociates.comj Sent: Tuesday, April 10, 2007 7:02 AM To: Doug Hipskind Cc: Mike Ellis; David Offermann Subject: Preliminary Laboratory Results for 4/3/2007 Discharge Attachments: Prelim disc lab 07040135.pdf Gentlemen: Attached are the preliminary results for the discharge sample collected 4/3/2007 at the Vail site. The samples were collected from the culvert (Dis -C) as it discharged into a small stream and at the point of entry into Gore Creek (Dic -GC). The results indicate non - detect (ND) for all parameters tested, including 1,1,2,2 Tetrachloroethane (less than 0.53 ugl). Please call or email with any questions. Sincerely, Christopher A Woods Senior Project Manager ATC Associates Inc 8985 E. Nichols Ave., Suite 350 Centennial, CO 80112 Phone(303)799 -6100 Fax(303)799 -3441 Mobile (303) 570 -2035 woods35@atc-enviro.com 'C�A /�eaNrWwt SoGrtlanf 4/10/2007 H 1 M K Pr 2 0 0 �P'A i!Nx� HOUSTON LABORATORY 88W INTERCHANGE DRIVE HOUSTON, Tx 77054 (713) 660 -0901 Client Sample ID DISC Collected: 04103 /2007 13:50 SPL Sample 10: 07040135-01 Site: Vail, Colorado Analyses /Method Result QUAL MDL Rep.Limit Dll. Factor Date Analyzed Analyst Seq. 1F Diesel Range Organics, C11- C28 ND 0.041 1 1 04/04/0717.49 CU 3760708 Surr. n- Pentacosane 82.0 0 % 21 -130 1 04104/0717:49 CU 3760708 111= 71.'�1�1,4� 1� � : ;- ' F � iL,�,: ' F • i ry � D'Anna Stelly Project Manager Qualiflam: ND/U - Not Detected at the Method Detection Limit >MCL - Result Over Maximum Contamination Umit(MCL) J - Estimated Value between MDL and PQL D - Surrogate Recovery Unreportable due to Dilution MI - Matrix Interference ' - Surrogate Recovery Outside Advisable QC Limits TNTC - Too numerous to count E - Concentrations exceeding Calibration range of Instrument 07040135 Page 2 B - Analyte detected In the associated Method Blank above Rep.Limit 49C=325ZPM P �Pr' M�X� HOUSTON LABORATORY 8880 INTERCHANGE DRIVE HOUSTON, TX 77054 (713) 660 -0901 Client Sample ID DISC Collected: 04 /03/2007 13:50 SPL Sample ID: 07040135 -01 Site: Vail, Colorado Analyses /Method Result QUAL MDL Rep.Limit DII. Factor Date Analyzed Analyst Seq. # VOLATILE ORGANICS BY METHOD 8260B MCL SW8260B Units: uglL 1,1,2,2- Tetrachloroethane ND 0.53 5 1 04/06/0717:02 D_R 3763579 Benzene ND 0.17 5 1 04/06/0717:02 D R 3763579 Ethylbenzene ND 0.31 5 1 04/06/0717:02 D R 3763579 Gasoline Range Organics ND 5.7 50 1 04/06/07 17:02 D R 3763579 Methyl tert-butyl ether ND 0.85 5 1 04/06/07 17:02 D_R 3763579 Toluene ND 0.28 5 1 04/06/0717:02 D_R 3763579 m,p- Xylene ND 0.47 5 1 04/06/0717:02 D_R 3763579 o- Xylene ND 0.18 5 1 04/06/0717:02 D_R 3763579 Xylenes,Total ND 0.18 5 1 04/06/0717:02 D_R 3763579 Surr:1,2- Dichloroethane -d4 96.7 0 % 71 -140 1 04/06/0717:02 D_R 3763579 Surr:4- Bromofluorobenzene 98.4 0 % 70 -130 1 04/06/0717:02 D_R 3763579 Surr: Toluene -d8 94.2 0 % 61 -121 1 04/06/07 17:02 D_R 3763579 D'Anna Stelly Project Manager Qualifiers: ND/U - Not Detected at the Method Detection Limit J - Estimated Value between MDL and PQL >MCL - Result Over Maximum Contamination Limit(MCL) D - Surrogate Recovery Unreportable due to Dilution MI - Matrix Interference ' - Surrogate Recovery Outside Advisable QC Limits TNTC - Too numerous to count E - Concentrations exceeding Calibration range of Instrument 07040135 Page 3 B - Analyte detected in the associated Method Blank above Rep.Limit 4s2W 32525 PM O HOUSTON LABORATORY 8880 INTERCHANGE DRIVE HOUSTON, TX 77054 (713) 660 -0901 Client Sample ID DIS-GC Collected: 04 /03/2007 14:10 SPL Sample ID: 07040135 -02 Site: Vail, Colorado Analyses /Method Result QUAL MDL Rep.Limit DII. Factor Date Analyzed Analyst Seq. S DIESEL RANGE ORGANICS MCL CO DRO Units: mg/L Diesel Range Organics, C11- C28 NO 0.041 1 1 04/04/07 18:12 Cu 3760709 Surr: n- Pentacosane 74.8 0 % 21 -130 1 04/04/07 18:12 Cu 3760709 1PreD Math lPreD Date 1Prep In" Is 1Prep Factor 1 0C 104/04/2007 12:15 IN M 11.00 D'Anna Steffy Project Manager Qualifiers: ND/U - Not Detected at the Method Detection Limit >MCL - Result Over Maximum Contamination Limit(MCL) J - Estimated Value between MDL and PQL D - Surrogate Recovery Unreportable due to Dilution MI - Matrix interference - Surrogate Recovery Outside Advisable QC Limits TNTC - Too numerous to count E - Concentrations exceeding Calibration range of Instrument 07040135 Page 4 B - Analyte detected in the associated Method Blank above Rep.Limit 492W73:2528 PM HOUSTON LABORATORY 8880 INTERCHANGE DRIVE HOUSTON, TX 77054 (713) 660 -0901 Client Sample ID DIS-GC Collected: 04 /03/2007 14:10 SPL Sample ID: 07040135 -02 Site: Vail, Colorado Analyses /Method Result QUAL MDL Rep.Limit Dil. Factor Date Analyzed Analyst Seq. # VOLATILE ORGANICS BY METHOD 8260B MCL SW8260B Units: ug/L 1,1,2,2- Tetrachloroethane ND 0.53 5 1 04/06/0717:24 D R 3763580 Benzene ND 0.17 5 1 04/06/0717:24 D R 3763580 Ethylbenzene NO 0.31 5 1 04/06/0717:24 D R 3763580 Gasoline Range Organics ND 5.7 50 1 04/06/07 17:24 D_R 3763580 Methyl tert-butyl ether ND 0.85 5 1 04/06/0717:24 D_R 3763580 Toluene ND 0.28 5 1 04/06/0717:24 D_R 3763580 m,p- Xylene ND 0.47 5 1 04/06/0717:24 D_R 3763580 o- Xylene ND 0.18 5 1 04/06/0717:24 D_R 3763580 Xylenes,Total ND 0.18 5 1 04/06/0717:24 D_R 3763580 Surr: 1,2- Dichloroethane -d4 95.2 0 % 71 -140 1 04/06/0717:24 D R 3763580 Surr:4- Bromofluorobenzene 102 0 % 70 -130 1 04/06/0717:24 D_R 3763580 Surr: Toluene -d8 98.9 0 % 61 -121 1 04/06/07 17:24 D R 3763580 D'Anna Steliy Project Manager Qualifiers: ND/U - Not Detected at the Method Detection Limn J - Estimated Value between MDL and PQL >MCL - Result Over Maximum Contamination Umit(MCL) D - Surrogate Recovery Unreportable due to Dilution MI - Matrix Interference - Surrogate Recovery Outside Advisable QC Limits TNTC - Too numerous to count E - Concentrations exceeding Calibration range of instrument 07040135 Page 5 B - Analyte detected in the associated Method Blank above Rep.Limlt 4AQ W 32526 PM Dewatering Monitoring Tracking Sheet Date Time ediment (Parts per Million) Well #1 Well #2 1 Well #24 Well #25 Well #26 Well #27 Well 928 Well N291 Well #30 Well #31 Well #32 Well #33 Well #34 Well #35 Well #36 Discharge Line 1 Discharge Line 2 Tuesday, April 03, 2007 Wednesday, April 04, 2007 Wednesday, April 04, 2007 Thursday,Apol04,2007 Thursday,Apol 04,2007 Friday,April 05,2007 Friday,April 05,2007 Monday,April 09,2007 Monday,April 09,2007 Tuesday,April 10,2007 Tuesday,April 10,2007 Wednesday,Apol 11,2007 Wednesday,April11,2007 2:00 PM 10:00 AM 2:00 PM 10AM 2PM 10AM 2PM 8:00 AM 2:00 PM 10AM 2PM 10AM 2PM NM NM NM NM NM NM NM turned off turned off turned off turned off NM NM NM NM turned off turned off turned off turned off turned off turned off turned off turned off turned off turned off turned off NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM turned off wells on 1 NM NM NM NM NM NM NM NM NM NM NM NM NM NM Note: NM = Not Measurable. This note indicates that the amount of soil found In the test is less than 0.1 (the smalles measurable amount using this testing system). The legal amount of soil in the test sample is 1.0. Anything over 1.0 is a failing test. Dewatering Monitoring Tracking Sheet Date Time Sediment (Parts per Million) Well #1 Well #2 Well #24 Well #25 Well 926 Well #27 Well #28 Well #29 Well #30 Well #31 Well #32 Well #33 Well #34 Well #35 Well #36 Discharge Line 1 Discharge Line 2 Tuesday, Apri103, 2007 Wednesday, April 04, 2007 Wednesday, April 04, 2007 Thursday,April04,2007 Thursday,April 04,2007 Friday,Apol 05,2007 Friday,April 05,2007 Monday,April 09,2007 Monday,April 09,2007 Tuesday,April 10,2007 Tuesday,April 10,2007 Wednesday,April 11,2007 Wednesday,April 11,2007 2:00 PM 10:00 AM 2:00 PM 10AM 2PM 10AM 2PM 8:00 AM 2:00 PM 10AM 2PM 10AM 2PM NM NM NM NM NM NM NM turned off turned off turned off turned off NM NM NM NM turned off turned off turned off turned off turned off turned off turned off turned off turned off turned off turned off NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM NM turned off wells on 1 NM NM NM NM NM NM NM NM NM NM NM NM NM NM Note: NM = Not Measurable. This note indicates that the amount of soil found in the test is less than 0.1 (the smalles measurable amount using this testing system). The legal amount of soil in the test sample is 1.0. Anything over 1.0 is a failing test.