November 13, 2017 Hindu Temple, LTD 13010 Arbor Street Omaha, Nebraska 68144-0000 Attn: Subject: Srini Mallipudi / mallipudis@gmail.com Underground Utility Survey Report Hindu Temple - 13010 Arbor Street, Omaha, Nebraska To: Srini Mallipudi In accordance with your request and authorization, National Ground Penetrating Radar Service, Inc. (NGPRS) conducted a Ground Penetrating Radar (GPR), Electro-Magnetic Induction (EMI), and Global Positioning System (GPS) survey for the above referenced project. Our services included an underground survey, and report. Report data obtained at the site will be held for 3 years at which time data will be discarded. Please advise us in writing if you wish to have us retain them for a longer period. We appreciate the opportunity to have been of service on this project. If there are any questions regarding our review, please contact me Toll Free at (877) 556-4777. Sincerely, NATIONAL GROUND PENETRATING RADAR SERVICE, INC. Stan Liszka Certified Professional Geologist Jared Lampe President
SUBSURFACE UTILITY SURVEY REPORT Project Location: Hindu Temple 13010 Arbor Street Omaha, Nebraska Prepared for: Hindu Temple, LTD 13010 Arbor Street Omaha, Nebraska 68144-0000 Prepared by: National Ground Penetrating Radar Service, Inc. Midwest Divsion Headquarters 8400 Normandale Lake Blvd, Suite 920 Minneapolis, Minnesota 55437 (952) 445-9040 Project No. 178599 Report Date: November 13, 2017
Executive Summary National Ground Penetrating Radar Service, Inc. (NGPRS) was retained by Hindu Temple, LTD (HINDU) to perform a Ground Penetrating Radar (GPR), Electro-Magnetic Induction (EMI), and Global Positioning System (GPS) survey at 13010 Arbor Street in Omaha, Nebraska. The site is currently used for religous temple purposes, and the survey was conducted over a asphalt covered surface in an exterior area consisting of approximately 14,000 sq. ft. The purpose of the survey was to locate, mark and map underground utilities. Ryan Swartz (NGPRS) performed the field work on November 8, 2017. Three (3) energized electrical lines were located at depths ranging from 2-3 ft. below the surface. Electric lines are identified in red in Figure 3. One (1) potential water line was located at a depth ranging from 8 ft. below the surface. Entire line could not be traced as signal was lost due to poor conductivity of pipe connections. Water lines are identified in blue in Figure 3. Two (2) gas lines were located at a depth ranging from 2-3 ft. below the surface. Gas utilities are identified in yellow in Figure 3. No sewer line was located or identified within the survey area(s). Five (5) telecommunication lines were located at depths of 3 ft. below the surface. Telecommunication lines are identified in orange in Figure 3. No additional anomalies were located in the survey area using GPR. All target locations were memorialized using the WGS1984 latitude/longitude coordinate system with accuracy ranging from 23.5 to 53 inches horizontally. We recommend HINDU retain NGPRS to clear additional areas if excavation is to occur outside of the identified survey area. Based on the information presented in this report, we require the following: It is required to use soft dig techniques or hydro excavation if excavating within three (3) feet of any underground utility or anomaly.
TABLE OF CONTENTS 1.0 INTRODUCTION...................................................................... 1 1.1 Project Description.......................................................... 1 1.2 Site Conditions............................................................. 1 1.2.1 Location and Surface Conditions....................................... 1 1.2.2 Subsurface Soil Conditions............................................ 1 1.3 Scope of Work.............................................................. 1 2.0 SURVEY PROCEDURES............................................................... 2 2.1 Equipment................................................................. 2 2.1.1 Electro Magnetic Induction (EMI)...................................... 2 2.1.2 Ground Penetrating Radar (GPR)...................................... 2 2.1.3 Global Positioning System (GPS)....................................... 2 2.1.4 Software............................................................ 3 2.2 Field Approach............................................................. 3 3.0 RESULTS............................................................................... 4 3.1 Electro Magnetic Induction (EMI)............................................. 4 3.1.1 Electric............................................................. 4 3.1.2 Water.............................................................. 4 3.1.3 Gas................................................................ 4 3.1.4 Sewer.............................................................. 4 3.1.5 Telecommunication.................................................. 4 3.1.6 Unidentified......................................................... 4 3.2 Ground Penetrating Radar (GPR).............................................. 5 3.3 Global Positioning System (GPS).............................................. 5 4.0 RECOMMENDATIONS & REQUIREMENTS.......................................... 6 5.0 LIMITATIONS......................................................................... 7 5.1 Electro Magnetic Induction (EMI)............................................. 7 5.2 Ground Penetrating Radar (GPR).............................................. 7 5.3 Global Positioning System (GPS).............................................. 8 6.0 QUALIFICATIONS & DECLARATIONS............................................... 9 6.1 Declaration................................................................. 9 6.2 Qualifications of the Professional(s)............................................ 9 7.0 RECORD SOURCES................................................................... 10
TABLE OF APPENDICES Figure 1 - Vicinity Location Map Figure 2 - Survey Area Site Map Figure 3 - Results Site Plan Map Appendix A - United States Department of Agriculture - GPR Soil Suitability Map Appendix B - Electro Magnetic Induction (EMI) Equipment Settings Appendix C - Ground Penetrating Radar (GPR) Equipment Settings Appendix D - Global Positioning System (GPS) Equipment Settings Appendix E - Photographs Appendix F - Certification of Professional(s)
1.0 INTRODUCTION National Ground Penetrating Radar Service, Inc. (NGPRS) was retained by Hindu Temple, LTD (HINDU) to perform a Ground Penetrating Radar (GPR), Electro-Magnetic Induction (EMI), and Global Positioning System (GPS) survey at 13010 Arbor Street in Omaha, Nebraska. 1.1 Project Description The purpose of the purpose of the project was to locate, mark and map underground utilities. Vicinity Location Map is shown in Figure 1. A 1.2 Site Conditions 1.2.1 Location and Surface Conditions The site is located in a rural community north of Arbor Street between S. 132nd Street and S. 130th Circle. The site is currently used for religous gathering purposes. The survey was conducted in an exterior parking lot area on the north end of the building. The subsurface survey was conducted over asphalt covered areas totaling approximately 14,000 sq. ft. No physical limitations to access were encountered in the performance of this subsurface survey. A Survey Area Site Map of the area surveyed is shown in Figure 2. The survey area boundary is outlined using dashed white lines. 1.2.2 Subsurface Soil Conditions The United States Department of Agriculture GPR Soil Suitability map for Douglas County, Nebraska is shown in Appendix A. The map indicates a GPR survey should produce Low results in native soils. Taking into consideration engineered soil conditions, we anticipated the maximum GPR survey depth to be approximately 4-6 feet. 1.3 Scope of Work Our Scope of Work (SOW) was to perform the following: 1. Perform and underground survey in an exterior, 14,000 sq. ft. area. 2. Use EMI to locate and mark energized underground utilities to a depth of 15 feet below ground surface (bgs). 3. Use GPR to locate and mark non-energized anomalies to a requested survey depth of 9-12 feet bgs. 4. Use GPS to map subsurface target locations. 5. Submit a written report of findings. 1
2.0 SURVEY PROCEDURES 2.1 Equipment 2.1.1 Electro Magnetic Induction (EMI) The EMI survey was conducted using a precision electromagnetic pipe and cable locator, Ridgid SR-20 series. The SR-20 series consists of separate transmitter and receiver. The receiver can be used in "passive" and "active" modes to locate buried pipes by detecting electromagnetic signals carried by the pipes. In the "passive" mode, only the receiver unit is used to detect signals carried by the pipe from nearby power lines, live signals transmitted along underground power cables, or very low frequency radio signals resulting from long wave radio transmissions that flow along buried conductors. In the "active" mode of operation, the transmitter is used to induce a signal on a target pipe, and the receiver is used to trace the signal along the length of the pipe. Our system uses a 5W or 10W transmitter. Equipment and settings are shown in Appendix B. 2.1.2 Ground Penetrating Radar (GPR) The GPR survey was conducted using a Geophysical Survey Systems, Inc. system (Model SIR3000) using an antenna with central frequency of 400 MHz and a 100 ns time window. The system includes a survey wheel that triggers the recording of the data at fixed intervals, thereby increasing the accuracy of the locations of features detected along the survey lines. GPR uses a high-frequency electromagnetic pulse (referred to herein as radar signal ) transmitted from a radar antenna to probe the subsurface. The transmitted radar signals are reflected from subsurface interfaces of materials with contrasting electrical properties. The travel times of the radar signal can be converted to approximate depth below the surface by correlation with targets of known depths, including stratigraphic horizons, pipes, cables, and other utilities, or by using handbook values of velocities for the materials in the subsurface. The acquisition of GPR data was monitored in the field on a graphic recorder and the real time images were immediately available for field use. The GPR data were also recorded digitally for subsequent processing. Interpretation of the records is based on the nature and intensity of the reflected signals and on the resulting patterns. Equipment and settings are shown in Appendix C. 2.1.3 Global Positioning System (GPS) The GPS survey was conducted using a Trimble (c) GPS (Model R1) antenna system. The GNSS Bluetooth antenna is designed for mobile devices with WAAS correction. The peripheral GNSS 2
receiver pairs with mobile devices such as smart phones, tablets, and other devices. Survey points were recorded using the WGS1984 latitude/longitude coordinate system with sub-meter accuracy. Equipment and settings are shown in Appendix D. 2.1.4 Software Post processing of any saved GPR data was completed using Geophysical Survey Systems, Inc. RAdar Data ANalyzer (RADAN) software (Version 7.3). GPS data was processed using a Trimble Insphere cloud platform. 2.2 Field Approach Ryan Swartz (NGPRS) performed the field work on November 8, 2017. The EMI survey was used to identify, and trace energized utilities in the survey area. GPR was used to verify EMI locations/ depths and determine if any non-energized anomalies were present. Multiple parallel GPR transects were taken in a bi-directional grid pattern using five (5) foot interval spacing. All located utilities were marked on the ground surface using aerosol spray paint and/or flags. 3
3.0 RESULTS A Results Site Plan Map and legend is shown in attached Figure 3. 3.1 Electro Magnetic Induction (EMI) A maximum allowable EMI depth of fifteen (15) feet bgs was achieved at this site using multiple frequencies. 3.1.1 Electric Three (3) energized electrical lines were located at depths ranging from 2-3 ft. below the surface. Electric lines are identified in red in Figure 3. 3.1.2 Water One (1) potential water line was located at a depth ranging from 8 ft. below the surface. Entire line could not be traced as signal was lost due to poor conductivity of pipe connections. Water lines are identified in blue in Figure 3. 3.1.3 Gas Two (2) gas lines were located at a depth ranging from 2-3 ft. below the surface. Gas utilities are identified in yellow in Figure 3. 3.1.4 Sewer No sewer line was located or identified within the survey area(s). 3.1.5 Telecommunication Five (5) telecommunication lines were located at depths of 3 ft. below the surface. Telecommunication lines are identified in orange in Figure 3. 3.1.6 Unidentified No sewer utility was located or identified within the survey area(s). 4
3.2 Ground Penetrating Radar (GPR) A maximum allowable GPR signal penetration depth of four (4) feet was achieved at this site using the 400 MHz antenna. No anomalies were located in the survey area(s). 3.3 Global Positioning System (GPS) Results of the GPS survey are provided in Google Earth (.kmz) and AutoCAD (.dxf) formats. To download the files, please visit: (LINK TO BE PROVIDED UPON PAYMENT OF FINAL INVOICE). Horizontal accuracy ranged from 23.5 to 53 inches. Geotagged digital photographs are visible in the Google Earth format by left clicking on each survey point. Photographs are also shown in Appendix E. 5
4.0 RECOMMENDATIONS & REQUIREMENTS We recommend HINDU retain NGPRS to clear any additional areas if excavation is to occur outside of the identified survey area. Based on the information presented in this report, we require the following: It is required to use soft dig techniques or hydro excavation if excavating within three (3) feet of any underground utility or anomaly. 6
5.0 LIMITATIONS NATIONAL GROUND PENETRATING RADAR SERVICE, INC. (NGPRS) MAKES NO GUARANTEE THAT ALL SUBSURFACE TARGETS OF INTEREST WERE DETECTED IN THIS SURVEY. NGPRS IS NOT RESPONSIBLE FOR DETECTING SUBSURFACE TARGETS THAT NORMALLY CANNOT BE DETECTED BY THE METHODS EMPLOYED OR THAT CANNOT BE DETECTED BECAUSE OF SITE CONDITIONS. GPR SIGNAL PENETRATION MAY NOT BE DEEP ENOUGH TO DETECT SOME TARGETS. NGPRS IS NOT RESPONSIBLE FOR MAINTAINING FIELD MARKOUTS AFTER LEAVING THE WORK AREA. HINDUUNDERSTANDS THAT MARK-OUTS MADE DURING INCLEMENT WEATHER OR IN AREAS OF HIGH PEDESTRIAN OR VEHICULAR TRAFFIC MAY NOT LAST. Field mark-outs. Utilities detected by the EMI method at the time of the survey are marked in the field, and the operator makes every attempt, field conditions permitting, to detect and mark as many utilities as possible at the time of survey. Adverse weather and site conditions (rain, snow, snow and soil piles, uneven surfaces, high traffic, etc.) can hamper in-field interpretation. Utility mark-outs made on wet pavement, snow, snow piles, gravel surfaces, or in active construction zones may not last. NGPRS is not responsible for maintaining utility mark-outs after leaving the work area. 5.1 Electro Magnetic Induction (EMI) The EMI equipment cannot detect non-metallic utilities, such as pipes constructed of vitrified clay, plastic, PVC, fiberglass, and unreinforced concrete, when used in passive mode alone. Such pipes can be detected if a wire tracer is installed with access to such tracer for transmission of a signal or where access (such as floor drains and clean-outs) permits insertion of a device on which a signal can be transmitted. In some, but not all, cases, the subsurface utility designation equipment cannot detect metal utilities reliably under reinforced concrete because the signal couples onto the metal reinforcing in the concrete. Similarly, the method commonly cannot be used adjacent to grounded metal structures such as chain link fences and metal guardrails. In congested areas, where several utilities are bundled or located within a short distance, the signal transmitted on one utility can couple onto adjacent utilities, and the accuracy of the location indicated by the instrument decreases. 5.2 Ground Penetrating Radar (GPR) There are limitations of the GPR technique as used to detect and/or locate targets such as those of the objectives of this survey: (1) surface conditions, (2) electrical conductivity of the ground, (3) contrast 7
of the electrical properties of the target and the surrounding soil, and (4) spacing of the traverses. Of these restrictions, only the last is controllable by us. The condition of the ground surface can affect the quality of the GPR data and the depth of penetration of the GPR signal. Sites covered with snow piles, high grass, bushes, landscape structures, debris, obstacles, soil mounds, etc. limit the survey access and the coupling of the GPR antenna with the ground. In many cases, the GPR signal will not penetrate below concrete pavement, especially inside buildings, and a target may not be detectable. The electrical conductivity of the ground determines the attenuation of the GPR signals, and thereby limits the maximum depth of exploration. For example, the GPR signal does not penetrate clay-rich soils, and targets buried in clay might not be detected. A definite contrast in the electrical conductivities of the surrounding ground and the target material is required to obtain a reflection of the GPR signal. If the contrast is too small, possibly due to construction details or deeply corroded metal in the target, then the reflection may be too weak to recognize and the target can be missed. In many cases, plastic, clay, asbestos concrete (transite), brick-lined, stone-lined, and other non-metallic utilities are extremely difficult to detect. Spacing of the transects is limited by access at many sites, but where flexibility of transect spacing is possible, the spacing is adjusted to the size of the target. The GPR operator controls the spacing between lines, and the design of the survey is based on the dimensions of the smallest feature of interest, and budgetary controls. GPR surveys typically require one (1) inch diameter of target for every one (1) inch of survey depth to be detectable. 5.3 Global Positioning System (GPS) Information regarding GPS limitations is provided on the National Oceanic and Atmospheric Administration website at http://www.gps.gov/systems/gps/performance/accuracy/. 8
6.0 QUALIFICATIONS & DECLARATIONS 6.1 Declaration The conclusions in the report are predicated on observation and testing of the earthwork and/or construction of the foundation under the direction of the Certified Individual of record. Opinions are based on data assumed representative of the site. We do not warranty conditions below the depth of equipment readings. Recommendations represented in this report should be verified and approved by a designated engineer of record. We declare that, to the best of our professional knowledge and belief, we have performed the GPR survey in accordance with American Society of Testing and Material (ASTM) D-6432-99 Guide for Using the Surface Ground Penetrating Radar Method for Subsurface Investigation, and the GPR & EMI survey in accordance with American Society of Civil Engineers (ASCE) 38-02 Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data Quality Level B results, and we have the specific qualifications based on education, training, and experience to perform a project of the nature, history, and setting of the Site. 6.2 Qualifications of the Professional(s) The site survey was conducted by Ryan Swartz who is a certified GPR operator. Stan Liszka, CPG assisted in the preparation of this report, and Jared Lampe, President reviewed the contents of this report. Staff certification qualifications are shown in attached Appendix F. 9
7.0 RECORD SOURCES Imagery displayed on the Figures was obtained through 2017 Google Earth a computer application that renders a 3D representation of Earth based on satellite imagery. All imagery and/ or maps used by NGPRS used in this report conforms with the attribution guidelines for Google Maps and Google Earth explained at the following website https://www.google.com/permissions/ geoguidelines/attr-guide.html. 10
Figure 1 - Vicinity Location Map
Figure 2 - Survey Area Site Map
Figure 3 - Results Site Plan Map
Appendix A - United States Department of Agriculture - GPR Soil Suitability Map
Appendix B - Electro Magnetic Induction (EMI) Equipment Settings
Appendix C - Ground Penetrating Radar (GPR) Equipment Settings
Appendix D - Global Positioning System (GPS) Equipment Settings
Appendix E - Photographs
1 : Photo 2 : Photo 3 : Photo 4 : Photo
5 : Photo 6 : Photo 7 : Photo 8 : Photo
9 : Photo 10 : Photo 11 : Photo 12 : Photo
13 : Photo 14 : Photo
Appendix F - Certification of Professional(s)
Ryan Swartz 2008