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HomeMy WebLinkAboutR-25-19VILLAGE OF DEERFIELD RESOLUTION NO. 2025- R-25-19 A RESOLUTION APPROVING A CONTRACT FOR ELECTRIC RESISTIVITY IMAGING SURVEY WHEREAS, the Village of Deerfield ("Village's is a home rule municipality in accordance with Article VII, Section 6 of the Constitution of the State of Illinois of 1970; and WHEREAS, the Village has identified the need to procure electrical resistivity imaging ("ERP) surveys of the historic Deerfield Cemetery to help staff identify available grave sites for future burials ("Services'); and WHEREAS, Carolyn Streiff ("Contractor') has previously provided ERI surveys of the Deerfield Cemetery for the Village and proposes to provide the Services for the not -to - exceed amount of $39,240; and WHEREAS, the Village has been satisfied with the services provided by Contractor and desires to enter into a contract with Contractor for the Services ("Contract'); and WHEREAS, the Services require a high degree of professional skill and are exempt from the Village's competitive bidding requirements; and WHEREAS, the Mayor and Board of Trustees have determined that entering into the Contract with Contractor will serve and be in the best interest of the Village and its residents; NOW, THEREFORE, BE IT RESOLVED BY THE VILLAGE BOARD OF DEERFIELD, LAKE AND COOK COUNTIES, ILLINOIS, as follows: SECTION 1: RECITALS. The Village Board hereby adopts the foregoing recitals as its findings, as if fully set forth herein. SECTION 2: APPROVAL OF CONTRACT. The Contract by and between the Village and Contractor is hereby approved in substantially the form attached to this Resolution as Exhibit A, and in a final form and substance acceptable to the Village Manager and the Village Attorney. SECTION 3: AUTHORIZATION TO EXECUTE CONTRACT. The Mayor and the Village Clerk are hereby authorized and directed to execute and attest, on behalf of the Village, the final Contract upon receipt by the Village Clerk of at least one original copy of the final Contract executed by Contractor; provided, however, that if the executed copy of the final Contract is not received by the Village Clerk within 60 days after the effective date of this Resolution, then this authority to execute and attest will, at the option of the Mayor and Board of Trustees, be null and void. SECTION 4: EFFECTIVE DATE. This Resolution shall be in full force and effect from and after its passage and approval by two-thirds of the Village Board according to law. 4911-8720-2848, v. 1 AYES: Berg, Goldstone, Jacoby, Oppenheim NAYS: None ABSTAIN: None ABSENT: Benton, Metts-Childers PASSED: March 3, 2025 APPROVED: March 3, 2025 RESOLUTION NO: R-25-19 ATTEST: Kent k Street, Vill e Clerk Daniel C. Shapiro, Mayor OF Oq,1 .A,.ccQ� O• SEAL co • . �F�EL D--\\- :�1,. 4911-8720-2848, v. 1 EXHIBIT A CONTRACT 4911-8720-2848, v. 1 Proposal for Ground Penetrating Radar (GPR) Survey at Deerfield Cemetery 2025 Previous Work: Electrical Resistivity Imaging (ERI) was used for ground surveys in the southeast corner of Deerfield Cemetery during the summers of 2021-2024. The ERI method images burials by finding resistivity differences in the ground using an electrical current. Although effective for locating burials, the ERI method takes more time to conduct a survey. Once the equipment is at the survey site, it takes about 30 mins to measure and set up the first survey line. Depending on the ground type, data is collected for about 45 mins a line. When one survey line is complete, it must be moved to the next location and set up again. The ERI method is effective at locating burials and, additionally, can provide detailed information, such as: age of the burial, casket/vault composition, and stability of the burial and ground. However, at Deerfield Cemetery, checking the current burial records is our focus, so this additional information isn't necessary. The main concern with using the ERI method here is the longer amount of time it takes to collect data and interpret it. It took 4 years to survey the southeastern part of the cemetery, which leaves the SW, NW, NE, and fence lines left to do. The entire cemetery will likely take longer than a decade of additional work to complete using the ERI as the only method of data collection and interpretation. ERI is best for detailed imaging of smaller areas than for imaging entire properties, like the cemetery. Ground -Penetrating Radar (GPR): For larger survey areas, GPR is an effective tool because of its speed and accuracy. This method is also less sensitive to electrical interference from powerlines and electrical boxes, which is a concern on the southern and eastern borders of the cemetery. Once the equipment is at the survey site, it takes about 30 mins to set up the instrument and set computer parameters. The GPR technician walks along previously determined survey lines to collect images of the ground. The location of each burial is electronically marked as the technician sees them on the computer screen while walking. These burial locations can be digitally saved as GPS points for use in Google Earth and other programs. Burials can also be physically marked on -site in the cemetery with flags. Once ground images are collected, they can be annotated on a computer to clearly show burial locations. Instead of taking over a decade to complete, the entire cemetery should be done in 1-2 days on -site. Further image creation, processing, and annotation will take longer, but an initial Google Earth file should take only a few days. Proposed Cemetery GPR Survev Plan: Dom: The first day on -site at the cemetery will be used to plan out where the survey lines will be located. A physical grid will be set up for the technician (myself) to follow as data is collected the next day. The grid will primarily be north- south over the burials. There will be a few west - east survey lines, as well as survey lines next to each fence. Day 2-3: Two days should be scheduled for GPR image collection, GPS coordinate recording, and on -site physical burial marking. As I walk each survey line with the GPR unit, my field assistant will mark with flags each time I see a burial in the real-time data. I'll simultaneously mark each burial electronically to record its GPS location for Google Earth file export. An image of the ground will be saved as I walk, as well. I'll supply the field assistant. Office Work: GPS locations of each burial will be exported from every survey line. These points will be put into a file format for Google Earth. These GPS points can also be provided in other file formats. Each survey line ground image will be processed for clarity to create an image for the cemetery records. These images will have each burial marked clearly. This may take several weeks to several months, depending on the character of the ground and how clearly the graves can be imaged. From this work, annotated aerial images of the cemetery burial locations will be made. What You Will Receive From Me: The final report will include these items: • Aerial images of all the cemetery sections with burials marked • Underground GPR images with burials marked • Burial GPS coordinates • Raw GPR data files. Due to the size of these files, this might be given on an external storage device. Ease of future burial look -up and information reference will be the focus of this final report. Cost: I provided a quote from Geophysical Survey Systems, Inc (GSSI). This company is headquartered in Nashua, NH, and is the industry standard for GPR equipment. The total cost of this survey is: $39,240. If only ERI was used, it could take 12 years to complete the other three quarters of the cemetery. An additional 2-4 years would be needed for the fence lines, with power possibly needing to be cut off for about an hour a line on the south and east sides. At current pace, a full ERI survey of the entire cemetery has an estimated additional cost of $49,000 to $80,000. Additionally, GPR surveys from other companies can cost much more if the technicians and equipment must be brought from another city or state. Travel costs alone for other companies can run well over $10,000. I don't have a travel cost for this survey. _Quality of My GPR Survey: Most GPR technicians from other companies only place physical flags on the ground at burial locations. It could possibly be the job of Deerfield to record these flag locations. Technicians rarely have a GPS unit attached to the GPR instrument. It's not common for GPS coordinates to be given to the survey client, especially in easy -to -use file format. I'll be able to provide GPS coordinates for each burial. These coordinates can be opened in Google Earth for future use. Other technicians may not save ground images of each survey line for future review. With some companies, this may not be available even upon request. I'll save each survey line and provide it as an annotated ima e for the cemeteW records. Each grave will be marked in these images. With some GPR companies, processed and annotated survey images can be requested by clients, but cost more money because of the time it takes to generate these images and interpretations. With my academic and professional background in waveform data analysis, data interpretation, and GPR, I strive for high quality data with high confidence in my data interpretations. I not only want the best quality information for The Village of Deerfield now, but I want this GPR data to be easily accessible and understandable for generations to come.