Monitoring Scour Critical Bridges (2009)

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123 Table G1 contains a list of available plans, programs, guidelines, and manuals from survey respondents. Items followed by a super- script have been included in this appendix as samples. APPENDIX G Available Plans, Programs, Guidelines, and Manuals State Bridge Name Plans, Drawings, or Specifications Guidelines, Manuals, Plans of Action, Reports, etc. Alaska 20 bridges Plans Programs and Report California Santa Clara River No Plan of Action and Report I-10 over San Gorgonio River Yes Program Florida John's Pass Bridge No Programs, Plan of Action, and Report SR-105 and SR A1A No Programs and Plan of Action Georgia Four bridges No Report Indiana US-52 over Wabash River and SR-43 No Report (Purdue University) Maryland Woodrow Wilson Memorial Bridge Plans Guidelines, Manuals, and Plan of Action1 New York Wantagh Parkway over Goose Creek Plans and Specifications1 Manuals1, Plan of Action1, and Report Robert Moses Causeway over Fire Island Inlet Plans and Specifications Manuals1, Plan of Action, and Report NYS Thruway over Cattaraugus Creek No Programs and Report Nevada Four bridges No Program 1 Texas Five bridges No Yes Vermont Vt Route 5 over White River No Report 1. Samples have been included in this appendix. 2. References to the reports listed above may be found in the Bibliography or Reference section of this synthesis study. TABLE G1 AVAILABLE DRAWINGS, PLANS, GUIDELINES AND MANUALS

124 Plan of Action for Scour Monitoring of the Woodrow Wilson Bridge (March 2005 Update) 1. BACKGROUND At this time, March 2005, construction of the new Woodrow Wilson Bridge is well underway, and the construction schedule calls for shifting traffic from the existing bridge to the new bridge during autumn 2006. Until the traffic is shifted, the existing bridge will continue to be monitored for scour to assure that it remains in a safe operating condition for its remaining service life. Scour monitoring was initiated in 1999 and sonar devices were installed on five piers. Monitoring of these 5 piers (see table below) has continued up to the present time, and will continue until traffic is shifted off the bridge. There have been some gaps in the records due to technical problems with the meters and the remote communication system; however, the record to date indicates that measured scour is very small and has not represented a significant concern regarding the stability of the bridge. 2. MONITORING RESPONSIBILITIES The Office of Bridge Development (OBD) has primary responsibility for oversight of the monitoring system: The Structure Hydrology and Hydraulics Unit (H&H) will download the data from the bridge at least once per month. More frequent readings will be obtained in the event of a flood event, or if the scour plots indicate any significant change in the channel elevations. If there is a problem in downloading the data, H&H will contact Bea Hunt of the consultant firm of Hardesty & Hanover. There are additional contact names for Hardesty & Hanover listed in Section 5 of this document. Hardesty & Hanover will make remote checks to troubleshoot the electronic system. They may also contact the subcontractor, ETI Instrument Systems, Inc. to troubleshoot the system remotely. If a visit to the site is required, Hardesty & Hanover will make appropriate arrangements for repairs after receiving approval from OBD to make the field visit and carry out the repair work. H&H will work cooperatively with the Bridge Inspection and Remedial Engineering Unit to expeditiously authorize funds for any needed repair work. The firm of Whitman, Requardt and Associates (WRA) has the overall contract for maintaining the Woodrow Wilson Bridge. All funding transactions will be carried out through arrangements with WRA. 3. MONITORING DURING FLOOD EVENTS In the event of a flood event, the downloading of scour readings will be increased as necessary to assure continued safe operation of the bridge. Previous evaluation structure stability studies have been carried out for the purpose of determining alert depths, action depths, and failure depths as depicted in the table below. Action Plan Scour Critical Depths (Established in a 1999 Report by WRA entitled Pier Analysis and Target Scour Depths) Pier ID Number Channel Elevation Alert Depth Action Depth Failure Depth 1W – 34.7 – 45 ? 1E – 36 – 45 ? 25E – 10 – 13 – 23 – 32 27 E – 17 – 17 – 24 – 33 29 E – 16 – 17 – 24 – 29.4 V1 – 34.7 – 45 ? M1 – 36.2 – 45 ?

125 4. ALERT DEPTH If the “Alert Depth” elevations are recorded by the scour equipment, OBD will initiate a more intense monitoring program which may include: Confirm scour depths by on-site inspectors using portable scour equipment (This will be more easily accomplished for Piers 25E, 27E, and 29E; it may be more difficult for Piers 1E and 1W, the bascule piers for the existing bridge), Increased frequency of downloading scour data, Diving inspections of scoured piers, if conditions permit, Notification of appropriate agencies of the possible need for a traffic detour plan. The SHA Statewide Operations Center will coordinate with other jurisdictions in developing a plan for rerouting of traffic. The alert depth elevations for Piers 27E and 29E have occurred more or less continuously at various times during the monitoring period, and in fact were recorded during bridge inspections before the monitoring system was initiated. These alert depths were established in a very conservative manner. With the experience gained through the monitoring program, they are no longer considered to be critical values to trigger the “alert depth” actions noted above. However, any further lowering of the channel bed for these piers will be monitored at frequent intervals to determine whether a trend of increased scour is occurring and whether the “alert depth” program should be initiated. Please note that Piers V1 and M1 are the piers for the main bascule span for the new bridge and do not have scour meters. These piers will also be included in increased monitoring activities triggered by any “alert depth” actions. 5. ACTION DEPTH If scour proceeds to the “Action Depth” elevation, OBD will take immediate action to protect the bridge and ensure the safety of the public. Such actions may include: Placement of scour countermeasures (riprap) and/or Bridge closure and rerouting traffic in accordance with the plan established by the SHA Statewide Operations Center. 6. CONTACT PERSONNEL Name Work Number Cell Number Home Number SHA SHA SHA SHA SHA Statewide Operations Center Hardesty & Hanover Hardesty & Hanover Hardesty & Hanover Hardesty & Hanover Whitman Requardt and Associates (WRA) Director OBD

126 SCOUR MONITORING PROGRAM MANUAL Sonar Scour Monitoring System for Wantagh Parkway over Goose Creek Bridge & Robert Moses Causeway over Fire Island Inlet Prepared for: New York State Department of Transportation Region 10 Prepared by: New York, NY October 1998 Second Edition: July 2002 Third Edition: July 2006 Fourth Edition: August 2007

127 TABLE OF CONTENTS 1. Description of the System s........................................................................................................................…. 2. Installation of the System s.............................................................................................................................. 3. Progra mmi ng of the Syste ms .......................................................................................................................... 4. Benchm arks and Datum .............................................................................................................................…. 5. Data Acquisition............................................................................................................................................. 5.1 Com puter Set-Up........................................................................................................................... 5.2 Norm al Circum stances: Downloading of Data.............................................................................. 5.3 Alerting System s........................................................................................................................... 5.4 Special Flood Events..................................................................................................................... 5.5 Calling the System s....................................................................................................................... 6. Analysis of Data............................................................................................................................................. 7. Scour Cautionary and Critical Depths: Notifications..................................................................................... 8. Portable Sonar M onitoring Devices............................................................................................................... 9. Plan of Action................................................................................................................................................. 9.1 Closure of Bridges ....................................................................................................................... 9.2 Portable Sonar Scour M onitor Measurem ents ............................................................................. 9.3 Diving Inspections ....................................................................................................................... 10. Access........................................................................................................................................................... 11. Maintenance.................................................................................................................................................. 12. General Inspection........................................................................................................................................ 13. Underwater Inspection ................................................................................................................................ 14. Miscellaneous Construction Wo rk at the Bridges........................................................................................ 15. Syste m Malfunction..................................................................................................................................... 16. Contacts........................................................................................................................................................ 17. Revisions...................................................................................................................................................... 18. References.................................................................................................................................................... Appendices Index: Appendix A: As-Built Plans and Specifications Appendix B: Bridges in the Program and Downloading of Data Appendix C: Scour Cautionary and Critical Depths Appendix D: Contact Inform ation Appendix E: Sam ple Data Appendix F: Photographs Appendix G: Maintenance, General Inspection and Underwater Inspection Checklists Appendix H: Plan of Action Appendix I: Bridge Specific Access Appendix J: Revisions Note: This Manual is to be used in conjunction with Scour Tracker TM AS-3 Scour Monitoring System manuals by ETI Instrument Systems, Inc. They have provided a manual for each bridge that has a sonar scour monitoring system installation (see Appendix B).

128 SCOUR MONITORING PROGRAM Sonar Scour Monitoring Systems 1. DESCRIPTION OF THE SYSTEMS Fixed sonar scour monitoring systems have been installed at several bridges in Long Island. The scour monitoring systems employ transducers to take streambed elevation measurements at designated piers. The system at each bridge consists of one master control station, a remote station at each pier location being monitored, a water temperature sensor, a water stage sensor, and an automatic alerting system (see Appendix A, As-Built Scour Monitoring Plans). All the data gathered is transmitted to the master control station. A portable computer is set-up at the designated office to retrieve the data from the systems. The scour monitor electronics measure the lapsed time that an acoustic pulse takes to travel from the transducers to the streambed and back. These measurements are converted into distances using the velocity of sound, adjusted for temperature. The transducers are programmed to take measurements at specified intervals. The master control station contains the data acquisition module that communicates with the remote sensor stations, controls their operation, and collects and stores their data in the desired format. The data is transmitted via modem from the master control station to the portable computer at the designated base office. Each remote station includes a sonar transducer sensor, scour monitoring electronics, and a wireless data link communication with the master control station. Solar panels that maintain battery power have also been installed at non-movable bridges that do not have electric power to power the monitors. The number and locations of the current sonar scour monitoring sensors at each bridge may be found in Appendix B. To see photographs of currently installed scour monitor systems, refer to Appendix F. The Monitoring System Vendor, ETI Instrument Systems, Inc., has provided a manual with descriptions and drawings of the equipment, as-built locations, and instructions for programming and retrieving data using the operating software. This manual is entitled Scour TrackerTM AS-3 Scour Monitoring System and a copy has been provided for each bridge that has a scour monitoring installation (hereafter referred to as the AS-3 Manual). This scour monitoring program is state-of-the-art, using equipment and concepts recommended by the Federal Highway Administration and the Transportation Research Board. There are no guarantees that the program will provide complete notification of a scour failure. However, it does exceed all current inspection and monitoring programs currently established for scour. The program that follows is a guideline to establish a baseline for analyzing and reacting to various scour levels. 2. INSTALLATION OF THE SYSTEMS The systems were installed by independent Contractors. The sonar transducers at each pier location were installed at specified positions and elevations as shown on the Plans and as directed by the Engineer. The installations were supervised and calibrated by ETI Instrument Systems, Inc. The As-Built information may be found in the AS-3 Manual, and in Appendix A of this Manual. 3. PROGRAMMING OF THE SYSTEMS The data collection systems were programmed to take streambed measurements at specified intervals at each pier. Intervals have been set for each bridge currently in the system. For example, Goose Creek and Fire Island collect data every ½ hour. Instructions for programming the systems may be found in the AS-3 Manuals. The alerting system will activate should any scour sensor detect a decrease of two (2) feet or more from the baseline elevation. The baseline elevation is a measurement taken at the time of the installation of the monitors. A printout of the data will indicate that the system has been activated. The systems will automatically set a new baseline elevation when the alerting system is activated (see Section 5.3). Each sensor station contains a data logger that activates the sonar at the prescribed interval, processes the sonar measurement signals, and stores the data until requested by the master control station. This process includes taking a series of sonar soundings and eliminating those soundings that are out of tolerance. If the sonar sensor is unable to obtain a “lock” on the streambed, the depth recorded defaults to the initial streambed depth. The processing routines programmed into the data logger include: 1. Activation of the sonar device at specified intervals. 2. Computation of a streambed elevation (ten readings are taken, the highest and lowest values are discarded, and the result is the average of the remaining eight readings).

129 3. Recording of a “no lock” condition when an echo is not received. 4. Recording of an “outside limits” condition if an average depth cannot be computed within the programmed measurement time. The portable computer and software provided by the Monitoring System Vendor are used to program the scour monitoring electronics and to retrieve data. A time-stamped record of the streambed elevations, including the scour and backfill process, is recorded and can be retrieved from the base office for future analysis. Data is recorded in sequential data record format which can be analyzed and presented by spreadsheet or other means. Included with the portable PC software is presentation software, Visual Log, which displays historical data in both graphical and tabular format. To view sample data in both tabular and graphical form, see Appendix E. 4. BENCHMARKS AND DATUM Benchmarks were established during the installation of the scour monitors. The datum shall be National Geodetic Vertical Datum (N.G.V.D.) 1929, Elevation 0.0, which is also Mean Sea Level. This datum shall also be used in obtaining data with the portable scour monitors and during Diving Inspections and fathometer surveys. 5. DATA ACQUISITION 5.1 Computer Set-Up 1. The designated computer shall be connected to a telephone line, capable of receiving incoming telephone calls. This should be a voice line, not a data line. 2. The computer may be left on at all times to ensure immediate retrieval of data should a scour event occur. 3. To collect the data, the PC208W software shall be installed and properly set-up on a computer designated for the scour monitoring system. 4. In order to print the data, there shall be a color printer in the designated office. 5. The computer shall be properly secured against theft or damage. 5.2 Normal Circumstances: Downloading of Data The system may be programmed such that the data is automatically downloaded to the designated computer each night, or at any specified interval. If there is a concern and data is needed immediately or more frequently, the Department, the Scour Monitoring Consultant, or the Monitoring System Vendor may also retrieve the data at any time by calling the data collection system(s) using a computer that contains the appropriate software. Each bridge may also be called from any telephone. When this is done, a voice synthesized message will provide elevations from the latest readings (i.e. one elevation per monitoring location). See Appendix E for sample raw data output from bridges currently in the system. The procedure for downloading data is in Appendix B. The Department has requested that the Scour Monitoring Consultant install the computer in the Consultant’s office, receive the data, and analyze it. The Scour Monitoring Consultant will call and check the data as outlined in Appendix B of this Manual, or as directed by the Regional Structures Engineer. A report shall be submitted to the Department as outlined in Appendix B of this Manual, or as directed by the Regional Structures Engineer. This Manual shall be updated to reflect any changes in the scour monitoring program. To ensure accuracy, ground truth measurements shall be taken at installation and during Diving Inspections and/or Fathometric Surveys. A ground truth measurement is a measurement of the scour condition by some alternate technique to evaluate instrument performance. An example of an alternate method would be a tape measurement taken by a diver from the face of the transducer to the streambed. The measurements obtained with the scour monitoring devices should be within one foot of the ground-truth measurements. If the measurements are not within this limit, refer to System Malfunction for possible outcomes, Section 15 of this Manual.

130 5.3 Alerting Systems The alerting system of the scour monitors may be programmed to call Region 10's INFORM Group in Hauppauge, New York. This station is staffed 24 hours/day, seven days/week. The scour monitor alert system may be programmed to automatically dial the INFORM group should two (2) feet of scour occur from a set baseline at a monitoring location. Note: at the time of publication of this Manual, this feature had not been activated. Below are the instructions for this Group should this procedure be used. The outgoing message from the scour monitoring system works as follows: The system dials the telephone number that has been programmed into it. When the programmed telephone is answered, a synthesized voice says: “Press the pound key (#) to hear call back message 1.” The command will repeat until the pound key is pressed. When the # key is pressed, the message will provide the following: “Scour monitor warning from bridge (number) ______. The current streambed elevation at Pier _____ is at the alarm level of ______ feet.” The INFORM group should receive proper training on what to do in the event of a scour monitor warning. The person at the INFORM center shall immediately call and relay this information to the following persons from Region 10, in the order listed below, until a person is reached: 1. Regional Structures Engineer 2. Bridge Management Engineer 3. Hydraulic Engineer 4. Assistant Bridge Management Engineer 5. Regional Design Engineer 6. Deputy Regional Design Engineer (Note: This does not include answering machines. If calls to beepers are not answered within 20 minutes, the next person on the list should be contacted.) The names and telephone and beeper numbers may be found in Appendix D. Appendix D, Contact Information, provides the bridge telephone number for the bridges being monitored as well as the office and home telephone numbers of those responsible for implementing this program. This Appendix is included in the Manuals of those responsible for implementing this program. Should two (2) feet of scour occur, the system may be programmed to automatically download the data to the designated computer. (See Section 6, Analysis of Data, should this occur.) The Regional Structures Engineer may also instruct the Scour Monitoring Consultant to download the data manually rather than use the automatic system. 5.4 Special Flood Events The Regional Structures Engineer or a specified designee shall be responsible for the following actions during and following special flood events: 1. In the event of a tropical storm watch or hurricane watch, the streambed readings shall be retrieved within four (4) hours of the initiation of the watch, and shall continue to be checked every four (4) hours throughout the storm and every twelve hours for three (3) days after the termination of the storm watch. 2. If a tropical storm warning or hurricane warning is issued, the streambed readings shall be checked every two (2) hours, until such time as the warning is lifted, and then as described under storm watch. 3. If a high tide event occurs, actions must be taken in response to the following high tides: a) After tides are two (2) feet or more above high tide for a period of six (6) hours, the streambed readings shall be checked every four (4) hours, and continue for four (4) hours after normal tides return. b) When tides are four (4) feet or more above high tide for any duration, the streambed readings shall be checked every two (2) hours, and continue for six (6) hours after normal tides return.

131 The Regional Structures Engineer shall (a) determine when a storm watch or warning has been issued, (b) determine when a high tide event has occurred, and (c) contact those responsible for retrieving and analyzing the data. The monitoring system may be called from any telephone using the procedure described in Section 5.5 below. For interpretation of the data, see Sections 6, 7 and 9. 5.5 Calling the Systems The monitoring systems may be dialed from the designated computer or from any telephone at most times; however, service will be unavailable when the transducer is taking or transferring data once every 30 minutes. This occurs on the hour and half hour at each bridge. In order to allow for the transfer of data, it is recommended that the bridges not be called during the time interval between 0–15 minutes and 30–45 minutes past the hour. The telephone numbers for the bridges may be found in Appendix D, Contact Information. This Appendix is included in the Manuals of those responsible for implementing this program. The outgoing message from the scour monitoring system when the telephone numbers are dialed, works as follows: “Streambed elevation at Pier ____ is ____ feet. Pier ____ elevation is _____ feet…” This message continues until all the elevations at all the piers at that particular bridge have been reported. The message then continues and offers the following three options: “Press pound (#) to hear again” “Enter security code and then press the pound (#) key” “Press star (*) to disconnect” The security code provides access to the area in which one can change the operating parameters. In order to avoid making unintentional changes to the system, the Monitoring System Vendor shall make all required changes to the system. Contact ETI Instrument Systems, the Monitoring System Vendor, to request any changes in the operating parameters. If no key is pressed, the message terminates with: “Good-bye.” 6. ANALYSIS OF DATA The actions described in Section 7 shall be implemented if certain streambed elevations are obtained. For specific criteria for scour notifications for each bridge, see Appendix C. If any of these events occur, the condition should be treated as a CAUTIONARY or a CRITICAL SCOUR NOTIFICATION. The following persons shall be notified, in the order listed, until one is reached: (Note: This does not include answering machines. If calls to beepers are not answered within 20 minutes, contact the next person on the list.) 1. NYSDOT Region 10, Structures Unit: Regional Structures Engineer Bridge Management Engineer Hydraulic Engineer Assistant Bridge Management Engineer Regional Design Engineer

132 Senior Structural Engineer Project Engineer Electrical Engineer The office numbers listed in Appendix D, Contact Information, are for use on working days between the hours of 8:00 a.m. and 4:10 p.m. for NYSDOT, and 8:45 a.m. to 5:00 p.m. for STV. Appendix D, also lists home and cell telephone numbers that may be used during other times. This Appendix is included in the Manuals of those responsible for implementing this program. See Section 7 for existing streambed elevations and a discussion of CAUTIONARY and CRITICAL SCOUR NOTIFICATIONS. See Section 9 for the Plan of Action. 7. SCOUR CAUTIONARY AND CRITICAL DEPTHS: NOTIFICATIONS If the streambed reaches the depths listed under CRITICAL SCOUR NOTIFICATION in the tables in Appendix C, the Department shall review the data and consider the necessary steps, if any, to be taken. The Region may alert the authorities so that the public is diverted from using the bridge. The Plan of Action in Section 9 and Appendix H shall be followed. If any of the depths listed under CAUTIONARY SCOUR NOTIFICATION in the tables in Appendix C are reported at the bridge, the Department shall immediately convene a meeting to discuss the installation of scour countermeasures. Interim mitigation measures may be taken, which may include the following: 1. Check the scour monitoring data every hour for a period of 12 hours. After that time, the data shall be checked every 12 hours for the next 72 hours. 2. Confirm these scour depths with alternate methodologies. 3. Implement or increase the frequency of the land field monitoring of the piers. 4. Conduct a Diving Inspection of the problem pier(s) and adjacent piers. Consideration should be given to increasing the frequency of Diving Inspections and underwater surveys. 5. Consider the addition of pier protection. 6. Consider the addition of pier strengthening. If there are no cautionary or critical notifications in a given month, the Scour Monitoring Consultant Hydraulic Engineer shall call the Regional Structures Engineer to discuss the data and the condition of the systems every three months. 8. PORTABLE SONAR MONITORING DEVICES Region 10 shall be responsible for the operation and maintenance of the portable sonar scour monitors. The Department may take streambed readings with the portable devices following major storm events and/or should a large drop occur in the streambed elevations. Additional readings are required during an emergency (see Plan of Action, Section 9 and Appendix H). The Department currently owns two portable devices which are located in the Region 10 Structures Office. 9. PLAN OF ACTION Since 1988, the FHWA, in conjunction with state departments of transportation, has committed resources to coordinate and conduct a National Bridge Scour Evaluation Program. This program has helped bridge owners to rate the bridges in the National Bridge Inventory (NBI) using rating codes for Item 113—Scour Critical Bridges. Item 113 identifies bridges as “low risk, scour susceptible, or scour critical.” A “scour critical” bridge is one whose foundation has been determined to be unstable for the calculated or observed scour conditions. An unstable foundation exists when: (a) scour reaches the threshold limits of footings or piles, or (b) scour reaches below spread footings or pile tips. 2. STV Incorporated: Senior Hydraulic Engineer/Project Manager

133 Standards (NBIS) regulation, 23 CFR 650.313.e.3, requires DOTs to prepare a POA to monitor known and potential deficiencies and to address critical findings for bridges identified as scour critical. On March 29, 2005, the FHWA issued a memorandum titled: “Compliance with the National Bridge Inspection Standards—Plan of Action for Scour Critical Bridges.” This states that the NBIS was enacted on January 13, 2005 and one of the immediate actions that require attention is the rule that pertains to the preparation of a POA for a bridge identified as scour critical during the national bridge scour evaluation program. The POA outlines important information about the bridge, scour critical conditions, contact information, and scour countermeasure alternatives. The POA makes information readily available should the bridge scour reach the point of critical depth and require immediate attention. The bascule piers of the Wantagh Parkway Bridge over Goose Creek have been identified as scour critical from observed and calculated scour conditions and through a pier stability analysis. Scour has been observed and potential scour has been computed for the Robert Moses Causeway over Fire Island Inlet; however, a pier stability analysis must be performed prior to determining a scour critical rating for the Causeway. The FHWA POA template dated June 2006 was modified to include several additional items from the NYSDOT POA template. It was completed for each bridge and is included in Appendix H. 9.1 Closure of the Bridges If a bridge closure is recommended, NYSDOT forces shall be responsible for a complete shutdown of the roadways as per NYSDOT procedures. In the event of closure, the following persons at the Transportation Maintenance group shall be notified to implement the closure plan. These persons shall be notified in the order listed below until one person is reached. (Note: This does not include answering machines. If calls to beepers are not answered within 20 minutes, contact the next person on the list.) 1. Res. 06 Resident Engineer 2. Bridge Maintenance Engineer 3. Regional Transportation Maintenance Engineer Appendix D, Contact Information, provides office, cell, and home telephone numbers and is included in the Manuals of those responsible for implementing this program. Once a bridge closure has occurred, it shall be necessary to confirm the measurements of the devices as outlined in Sections 9.2 and 9.3. 9.2 Portable Sonar Scour Monitor Measurements Region 10 shall insure that the Department sends engineers to the bridge(s) for a visual inspection as soon as it is deemed safe to do so to confirm the measurements taken by the fixed sonar monitoring devices. When there are emergency conditions, both portable devices, owned by the Department, shall be taken to the site. If the portable devices confirm the scour critical measurements that were taken by the fixed devices, the bridge shall remain closed and a Diving Inspection shall be conducted. If the portable devices indicate streambed elevations that are higher those reported by the fixed devices, the elevations shall be reported to the Department, and a decision shall be made regarding the necessity of a Diving Inspection. 9.3 Diving Inspections A Diving Inspection may be required after the report of a critical scour depth. The Diving Inspection shall include the inspection requirements outlined in Section 13. Particular details shall be noted and manual measurements taken of the streambed elevations at the pier directly beneath the sonar monitor. The Diving Consultant for the emergency Diving Inspection contract shall do this work. If there is an event that requires a Diving Inspection, the Diving Consultant Project Manager shall be contacted. In addition, the Bridge Management Engineer may be contacted. If neither is available, the INFORM Group shall be contacted for the purpose of contacting Regional Structures Unit personnel. Appendix D, Contact Information, provides office, cell, and home telephone numbers and is included in the Manuals of those responsible for implementing this program. While continuing to encourage DOTs to complete their scour screening and evaluations, the FHWA formally moved into the next phase of the scour program as documented in their July 24, 2003 memorandum, which encourages bridge owners to develop and implement a Plan of Action (POA) for each bridge coded scour critical as defined by NBI Item 113 of the FHWA’s Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation's Bridges. The updated National Bridge Inspection

134 10. ACCESS Often, access to the scour monitoring systems is limited. General guidelines for consideration are listed below. Bridge-specific access limitations may be found Appendix I. It is recommended that the items listed below, as well as those listed in Appendix I are considered before performing maintenance, repairs or inspections. Keys may be required to open instrumentation boxes or doors. A boat, ladder, and/or manlift may be required to access instrumentation mounted on piers, fenders, or abutments, or under the bridge deck. Security clearance may be required to access parts or all of the bridge. Contact the appropriate authorities and notify them when and where the work is scheduled to take place. Lane closures may be required. Proper maintenance and protection of traffic as well as inspection/repair crew safety will be needed. 11. MAINTENANCE The Regional Structures Engineer shall be responsible for notifying the appropriate NYSDOT Bridge Maintenance group for the routine maintenance of the fixed sonar monitoring devices. The following items are included as maintenance requirements for the bridge: Appendix D “Contact Information” shall be updated annually (i.e. January 31st) to ensure that all names, addresses, and contact numbers are current. The Group responsible for this update shall contact all the individuals listed in Appendix D to make them aware or remind them of their responsibilities regarding the Scour Monitoring Program. Indoor instrument boxes and electrical conduit shall be visually inspected for corrosion, overheating, insects, moisture, etc. The thermostat reading or temperature reading shall be recorded for areas containing instruments. The desiccants in the instrument boxes shall be replaced as necessary. The desiccants are heavy brown paper bags filled with silica gel. The Department has been supplied with a second set of desiccants to replace those at the bridges. The desiccants that are removed are reusable, and may be dried in an oven at 200 degrees for 12 hours and stored for future use. A Scour Monitoring Maintenance Checklist has been included in Appendix G. The electronic version of this form may be obtained from the Regional Hydraulic Engineer or the Scour Monitoring Consultant. This form shall be completed after all routine maintenance, and kept on file in the Regional Structural Engineer’s office. The Monitoring System Vendor, ETI Instrument Systems, conducted several trainings seminars at Region 10 and at the bridge sites since the installation of the systems. The Scour Monitoring Consultant and/or the Monitoring System Vendor may be contacted should there be any questions with regard to maintenance of the system. The contact names, telephone numbers, and e-mails may be found in Appendix D. 12. GENERAL INSPECTION The Regional Structures Engineer shall be responsible for notifying the appropriate group for the inspection of the fixed sonar monitoring devices. This work shall be performed by the appropriate Bridge Maintenance Group or the Consultant retained for the biennial inspection of the bridge. The following items are included in the list of required work: Inspect all outdoor instruments boxes for corrosion, damage, vandalism, leaks, etc. Inspect the outdoor/above water conduit and cable for corrosion, damage, vandalism, leaks, etc. Remove any spiders, mice nests, bird droppings, etc. from all outdoor instrument boxes. Check the door gasket and/or seal. Check and clean the solar panels (if applicable).

135 A Scour Monitoring General Inspection Checklist has been included in Appendix G. The electronic version of this form may be obtained from the Regional Hydraulic Engineer or the Scour Monitoring Consultant. This form shall be completed after all general inspections and kept on file in the Regional Structural Engineer’s office. The Scour Monitoring Consultant and/or the Monitoring System Vendor may be contacted should there be any questions with regard to the general inspection of the system. The contact names, telephone numbers, and e-mails may be found in Appendix D. If the general inspection reveals that the system requires maintenance and/or repair, this work shall be performed by an Electrical Contractor or other appropriate group. The Monitoring System Vendor may need to be retained for repairs or new components, and the Scour Monitoring Consultant may be required for repairs or design of new countermeasures. This work shall be as directed by the Regional Structures Engineer. 13. UNDERWATER INSPECTION Diving Inspections and fathometer surveys shall be conducted at the frequency established by the Regional Structures Engineer for each bridge. Additional Diving Inspections may be required after a major storm event. The datum and benchmarks to be used shall be as described in Section 4. The following items shall be included as part of the Diving Inspection/Fathometric Survey: If the location being monitored is in close proximity to bridge dolphins, special care should be taken to ensure accurate streambed elevations. Estimations and/or interpolating should not be used in this area. The scour monitors shall be inspected during each Diving Inspection. This includes the annual inspections and any interim inspections following floods. The inspectors shall obtain depth measurements at the location of each scour monitor with the instrumentation they are using for the underwater inspection, and these shall be compared to the sensor readings. Removal of debris or moss buildup - debris may collect on the transducer or the conduit leading up to the bridge deck. If the debris is on the transducer, or is bending or crushing the pipe, it should be removed. Any algae or marine organisms must be removed from the transducer face. Remove all submerged, waterlogged debris that may potentially sink beneath a transducer. Re-coat the transducer with anti-fouling paint, as needed. The paint shall be transducer anti-fouling paint that is available at most marine supply stores. Replace zinc anodes (if applicable). A Scour Monitoring Underwater Inspection Checklist has been included in Appendix G. The electronic version of this form may be obtained from the Regional Hydraulic Engineer or the Scour Monitoring Consultant. The form shall be completed after all underwater inspections and kept on file in the Regional Structural Engineer’s office. The Scour Monitoring Consultant and/or the Monitoring System Vendor may be contacted should there be any questions with regard to the underwater inspection of the system. The contact names, telephone numbers and e-mails may be found in Appendix D. The Regional Structures Engineer may request that the Scour Monitoring Consultant and/or Monitoring System Vendor provide inspection support services to the Diving Consultant. If the Diving Inspection/Fathometric Survey reveals that the system requires maintenance or repair, this work shall be performed by an Underwater Contractor. The Monitoring System Vendor may need to be retained for repairs or new components, and the Scour Monitoring Consultant may be required for repairs or design of new countermeasures. This work shall be determined by the Regional Structures Engineer. 14. MISCELLANEOUS CONSTRUCTION WORK AT THE BRIDGES If any construction work is done near the fixed scour monitors, including work unrelated to the bridge, provisions shall be made to protect the sonar monitoring system. Upon completion of the work, the monitors shall be checked to ensure the monitors had not been damaged. If they are damaged, they shall be repaired at the expense of the Contractor. In the event that stone fill, riprap, or any type of armor protection is placed near or around piers or abutments with fixed monitoring devices, the Contractor shall exercise reasonable care to avoid damaging these devices. The monitors shall be checked after the conclusion of the placement of the armor protection.

136 15. SYSTEM MALFUNCTION In the event of a scour monitoring system malfunction, the Regional Structures Engineer shall be responsible for notifying the appropriate groups for troubleshooting of the fixed sonar monitoring devices. This work may be done by the Transportation Maintenance Group, Region 10, an Underwater Contractor, or an Electrical Contractor. The AS-3 Manual shall be used as a reference when troubleshooting. If the system cannot be repaired using the suggestions outlined below, the Regional Structures Engineer shall contact the Scour Monitoring Consultant and/or the Monitoring System Vendor (see Appendix D). If the problem cannot be resolved via instructions given by telephone, arrangements should be made for the Scour Monitoring Consultant and/or the Monitoring System Vendor to visit the site. Most of this information is taken from National Cooperative Highway Research Program, Project 21-3, Installation, Operation, and Fabrication Manual, Sonar Scour Monitor (see Section 18). Additional site-specific items have been added, where applicable. 1. If the sonar instrument does not turn on at the scheduled sample intervals: Check the battery voltage and all power connections. Review the past data and look for anomalies in the daily battery voltages. If there are anomalies, see if there have been any events (i.e., a power outage or damage to the system) that might have caused the problem. If the battery voltage is less than 12.2 volts, this is an indication that there is a problem. If the battery voltage is low (less than 11 volts), check the output of the solar panel, if applicable, with the sun shining, and make sure it is producing at least 15 volts before the regulator and about 13.5 volts after the regulator. If the solar panel is functioning properly, either (1) the battery is faulty or was drawn down by lack of solar energy for recharging (e.g., an extended period of overcast weather), or (2) the data logger is leaving the sonar on for too long, or cycling too frequently, either from an error in programming or a faulty data logger. In either case, replace the battery with a fully charged battery and evaluate the data logger functioning for a short sample interval (e.g., 5 minutes). If the data logger appears to be functioning properly, re-program for the regular sample interval and periodically check the battery voltage (e.g. every week) to insure proper operation. If the data logger appears to be malfunctioning, check the programming and/or follow the troubleshooting instructions from the manufacturer. 2. If the sonar readings are erratic: Check for high (14.0+ volts) battery readings. Check to make sure the charger is functioning properly. Check for debris under the transducer. Remove debris as required. Check for algae or marine organisms on the transducer. Clean and/or add anti-fouling paint as required. 3. If the sonar readings remain fixed at a single elevation for a prolonged period of time: Check the battery voltage and all power connections (see Item 1). Check the transducer to ensure that it is still securely connected to the bracket. Check all wiring. 4. If a call to the automated telephone service results in a busy signal, no dial tone, or if it ring but there is no answer: Contact the local telephone provider’s service department. Ask the telephone service representative to check the line to determine whether it is an internal or external problem. A technician will be sent to the site if the problem is external. The service is provided free of charge. The contact number for the telephone provider is listed in Appendix D, Contact Information, under “Bridge Telephone Numbers.” If it is determined that it is a problem with an outside line, schedule a repair. If it is determined that it is a problem with an inside line, check connections with the telephone line and modem. 5. If a call to the automated telephone service results in “0” elevation readings: Wait a few minutes and try again. The system may have been in the process of downloading data.

137 16. CONTACTS Each bridge location with a scour monitoring system should have a list of contacts as outlined below. All contact information for current bridge locations may be found in Appendix D. 16.1 NYSDOT Region Regional Structures Engineer Bridge Management Engineer Hydraulic Engineer Regional Design Engineer Assistant Bridge Management Engineer INFORM Group 16.2 Scour Monitoring Consultant Project Manager / Senior Hydraulic Engineer Senior Structural Engineer Project Engineer Electrical Engineer 16.3 Monitoring System Vendor President Engineering Manager 16.4 Underwater Inspection Consultant Inspection Consultant 17. REVISIONS This document shall be revised to reflect any changes resulting from field conditions, new information obtained with future testing or analyses, and/or new technology. A distribution list shall be compiled of the contact person at each agency/company who received this document and is responsible for its distribution. That person shall be sent all future revisions. This list shall be added to this document as Appendix J and shall be updated once a year by January 31st to reflect any changes. 18. REFERENCES Butch, G.K., Evaluation of Selected Instruments for Monitoring Scour at Bridges in New York, ASCE North American Water and Environment Congress, 1996. ETI Instrument Systems, Inc., Scour Tracker™ AS-3 Scour Monitoring System (Configured for Robert Moses Causeway Over Fire Island Bridge), December 2000. ETI Instrument Systems, Inc., Scour Tracker™ AS-3 Scour Monitoring System (Configured for Wantagh Parkway Bridges), September 1998. Hunt, B.E., “Establishing a Scour Monitoring Program,” Proceedings of the GSP 135 Erosion of Soils and Scour of Foundations ASCE Geo-Frontiers Conference, Austin, Texas, Jan. 2005, pp. 1–11. Hunt, B.E., “Pier Pressure,” Bridge Design & Engineering, Issue No. 30, First Quarter 2003. Hunt, B.E. and G.R. Price, “Scour Monitoring—Lessons Learned,” Proceedings from the 2nd International Conference on Scour and Erosion, Nanyang Technological University, Meritus Mandarin, Singapore, Nov. 14–17, 2004, pp. 69–84. Hunt, B.E., L.N. Triandafilou, P.A. Carreras, D.A. LaBella, and G.R. Price, “Scour Monitoring of the Woodrow Wilson Bridge,” Proceedings of the ASCE Water Resources Engineering International Water Resources Conference, Vol. 1, Memphis, Tenn., 1998, pp. 57–62.

138 Lagasse, P.F., E.V. Richardson, J.D. Schall, and G.R. Price, NCHRP Report 396: Instrumentation for Measuring Scour at Bridge Piers and Abutments, Transportation Research Board, National Research Council, Washington, D.C., 1997. Lagasse, P.F., J.D. Schall, F. Johnson, E.V. Richardson, J.R. Richardson, and F. Chang, Stream Stability at Highway Structures, Hydraulic Engineering Circular 20, 3rd ed., FHWA, Washington, D.C., 2001. Lagasse, P.F., L.W. Zevenbergen, J.D. Schall, and P.E. Clopper, Bridge Scour and Stream Instability Countermeasures— Experience, Selection, and Design Guidelines, Hydraulic Engineering Circular 23, 2nd ed., FHWA, Washington, D.C., 2001. Richardson, E.V. and S.R. Davis, Evaluating Scour at Bridges, Hydraulic Engineering Circular 18, 4th ed., FHWA, Washington, D.C., 2001. Schall, J.D., G.A. Fisher, and G.R. Price, Scour Monitoring at Johns Pass and Nassau Sound, Florida, ASCE North American Water and Environment Congress, 1996. Schall, J.D., G.R. Price, G.A. Fisher, P.F. Lagasse, and E.V. Richardson, NCHRP Report 397A: Sonar Scour Monitor— Installation, Operation, and Fabrication Manual, Transportation Research Board, National Research Council, Washington, D.C., 1997. Zevenbergen, L.W., P.F. Lagasse, and B.L. Edge, Tidal Hydrology, Hydraulics and Scour at Bridges, Hydraulic Engineering Circular 25, 1st Ed., Federal Highway Administration, Washington, D.C., 168 pp., 2004.

139 Nevada Department of Transportation GENERAL SCOUR MONITORING DEVICE OPERATION SONAR Will take readings every hour. Data will be downloaded to HQ computer once a day (between ±2:30 a.m. and ±4:30 p.m.). Sonar data received by the computer will be as described below. Sonar will record elevations for depth readings between 3 feet and 40 feet (if less than 3, no elevation recorded; if more than 40, elevation at 40 will be recorded). To trigger a call to the pager group and computer, the transducer must be submerged (float switch activated) and the elevation reading must be below the pre-programmed elevation at the time the hourly reading is taken. Once a call has been triggered by a given elevation, another call will not be triggered until the next lower elevation has been reached. Equipment can be programmed to make calls at a series of elevations (e.g., when scour depth reaches 5', 10', 12', etc.). When a call is made, the pagers will be called twice (one minute between calls) before the computer is called. The message received by the pagers will be the numeric bridge number followed by the name of the Wash that the bridge spans (i.e., "420, Piute Wash" for B-420, "571, Toquop Wash" for B-571N, "839, California Wash" for B-839S, and "1805, Red Rock Wash" for B-1805). The pagers will be called repeatedly as each successive pre-programmed elevation is reached, but only hourly as readings are taken. The message received by the HQ computer will be as described below. The computer will be called repeatedly as each successive pre-programmed elevation is reached, but only hourly as readings are taken. Element Description 1 Array ID = 1 for Sonar Hourly Readings, = 2 for Scour Event 2 Year 3 Day (Julian) 4 Time (Military) 5 Elevation of the stream bed as determined by the average of 10 sonar readings (this is not meaningful data unless water level switch is underwater) 6 Minimum elevation measured over 10 consecutive soundings 7 Maximum elevation measured over 10 consecutive soundings 8 Water level switch status; 0 = inactive, 1= active (underwater) 9 Battery voltage (Replace battery if voltage falls below 12.2)

140 FLOAT-OUTS No signals will be sent until a float-out is released by a scour event. The bridge phone will call the pager group (twice) and the computer for each float-out as it is released. Message received by pagers will be the name of the Wash that the bridge spans (i.e., "Piute Wash" for B-420, "Toquop Wash" for B-571N, "California Wash" for B-839S, and "Red Rock Wash" for B-1805). Pagers will be called immediately as each individual float-out is released. Message received by HQ computer will be as described below: Element Description 1 Array ID = 3 (to indicate float-out signal) 2 Year 3 Day (Julian) 4 Time (Military) 5 Float-out number (channel) 1 status (1 = active, 0 = inactive) 6 Float-out number (channel) 2 status (1 = active, 0 = inactive) NOTES: The pagers may occasionally receive false alarm calls (e.g., if the group page number is accidentally dialed as a wrong number). These calls can be identified as false alarms because the bridge number portion of the message will either not be there or will be a different number. As described above, messages received by pagers will be the same whether the signal is from the sonar or from a float-out. System modifications may be made in the future to make pager calls from sonar and float-outs distinguishable. A “window” will exist each day from 9:15 a.m. to 9:30 a.m. During this time, the bridge can be called for the purposes of reprogramming system parameters, etc. (ETI can also call the bridge at this time). B-420 SCOUR MONITORING DEVICE DATA Location: Bridge B-420, US 95 at Piute Wash Bridge Phone #: 702-720-3038 (3039?) Sonar installed on upstream nose of southernmost pier. One channel 1 float-out installed 3 feet below bottom of 6 foot riprap layer at downstream end of each abutment wall. One channel 2 float-out installed 3 feet below bottom of 6 foot riprap layer at upstream nose of each of three northernmost piers. Elevation data from contract 1904 and field measurements during installations: Piers and Abutment Walls (Stem walls with Piles) bottom of bridge = top of pier cap: 2499.3 bottom of stem wall: 2488.6 pile tip (steel H-piles): 2470.8 Sonar (This data is programmed in the monitoring equipment) sonar transducer elevation: 2494.3 ground elevation (riprap) referenced by sonar at time of installation: 2492.0 elevation readings that trigger successive pager/computer calls: 2489.0, 2486.0, 2480.0 Pier and Abutment Float-Outs ground (riprap) elevation at float-out locations at time of installation: 2492.0 float-out elevation: 2483.0

141 B-420 SCOUR RESPONSE PLAN Location: Bridge B-420, US 95 at Piute Wash Scour Event Pager Message: "420, Piute Wash” [false alarm if 420 is missing or different] Pager Group Members: Phone # Cell Phone # Maintenance Supervisor 1 Maintenance Supervisor 2 Maintenance Superintendent District Maintenance Engineer Principal Bridge Maintenance Engineer Responses to Sonar Calls: First call at elevation reading of 2489.0 Scour Location: Midpoint of 6.0' riprap layer (scour depth = 3.0') Response: Mobilize to monitor and potentially close bridge Second call at elevation reading of 2486.0 Scour Location: Bottom of 6.0' riprap layer (scour depth = 6.0') Response: Close bridge Third call at elevation reading of 2480.0 Scour Location: Midpoint of piles (scour depth = 12.0') Response: Bridge already closed Responses to Float-Out Calls: First call from channel 1 float-out Scour Location: Downstream end of abutment 3.0' below bottom of 6.0' riprap layer (scour depth = 9.0') Response: Close bridge First call from channel 2 float-out Scour Location: Upstream nose of pier 3.0' below bottom of 6.0' riprap layer (scour depth = 9.0') Response: Close bridge Subsequent float-out calls Scour Location: See above Response: Bridge already closed B-571N SCOUR MONITORING DEVICE DATA Location: Bridge B-571N, I-15 at Toquop Wash Bridge Phone #: 702-720-3036 Sonar installed on upstream nose of east channel pier (pier 3). One channel 1 float-out installed under concrete slope paving at upstream nose of east channel pier (pier 3). One channel 2 float-out installed under concrete slope paving at upstream nose of west channel pier (pier 2). Elevation data from contract 905 and field measurements during installations: Piers top of pier walls (upstream nose): 1546.2 (pier 2), 1545.4 (pier 3) top of spread footings: 1506.7 (pier 2), 1505.9 (pier 3) bottom of spread footings: 1503.7 (pier 2), 1502.9 (pier 3)

142 Sonar (This data is programmed in the monitoring equipment) sonar transducer elevation: 1515.4 ground elevation referenced by sonar at time of installation: 1512.4 elevation readings that trigger successive pager/computer calls: 1512.0, 1510.0, 1506.0, 1503.0 Float-Outs ground elevation at float-out locations at time of installation: 1512.5± top of concrete slope paving: 1512.0± float-out elevation: 1510.5± B-571N SCOUR RESPONSE PLAN Location: Bridge B-571N, I-15 at Toquop Wash Scour Event Pager Message: "571, Toquop Wash” [false alarm if 571 is missing or different] Pager Group Members: Phone # Cell Phone # Maintenance Supervisor 1 Maintenance Supervisor 2 Maintenance Superintendent District Maintenance Engineer Principal Bridge Maintenance Engineer Responses to Sonar Calls: First call at elevation reading of 1512.0 Scour Location: Minimal scour. Call indicates that large flow event is taking place. Response: Mobilize to monitor and potentially close bridge Second call at elevation reading of 1510.0 Scour Location: 2.0' below concrete slope paving (scour depth = 2.0') Response: Close bridge Third call at elevation reading of 1506.0 Scour Location: Top of spread footing (scour depth = 6.0') Response: Bridge already closed Fourth call at elevation reading of 1503.0 Scour Location: Bottom of spread footing (scour depth = 9.0') Response: Bridge already closed Responses to Float-Out Calls: First call from channel 1 float-out Scour Location: Upstream nose of east pier beneath concrete slope paving (scour depth = 2.0') Response: Close bridge First call from channel 2 float-out Scour Location: Upstream nose of west pier beneath concrete slope paving (scour depth = 2.0') Response: Close bridge

143 Sonar installed on upstream nose of easternmost pier (pier 4). One channel 1 float-out installed 3 feet deep in 6 foot riprap layer at upstream nose of easternmost pier (pier 4). One channel 2 float-out installed 3 feet deep in 6 foot riprap layer at each upstream nose of center pier (pier 3) and westernmost pier (pier 2). Elevation data from contract 1108 and field measurements during installations: Piers bottom of bridge: 1818.7± top of pier walls (upstream nose): 1818.3 (pier 2), 1817.9 (pier 3), 1817.6 (pier 4) top of spread footings: 1806.3 (piers 2 & 4), 1806.7 (pier 3) bottom of spread footings: 1805.0 Sonar (This data is programmed in the monitoring equipment) sonar transducer elevation: 1812.0 ground elevation (riprap) referenced by sonar at time of installation: 1810.0± elevation readings that trigger successive pager/computer calls: 1808.0, 1805.0 Float-Outs ground (riprap) elevation at float-out locations at time of installation: 1810.0± float-out elevation: 1807.0± B-839S SCOUR RESPONSE PLAN Location: Bridge B-839S, I-15 at California Wash Scour Event Pager Message: "839, California Wash” [false alarm if 839 is missing or different] Pager Group Members: Phone # Cell Phone # Maintenance Supervisor 1 Maintenance Supervisor 2 Maintenance Superintendent District Maintenance Engineer Principal Bridge Maintenance Engineer Responses to Sonar Calls: First call at elevation reading of 1808.0 Scour Location: 2.0' into 6.0' riprap layer (scour depth = 2.0') Response: Mobilize to monitor and potentially close bridge Second call at elevation reading of 1805.0 Scour Location: Bottom of spread footing (scour depth = 5.0') Response: Close bridge Responses to Float-Out Calls: First call from channel 1 float-out Scour Location: Nose of east pier at midpoint of 6.0' riprap layer (scour depth = 3.0') Response: Mobilize to monitor and potentially close bridge First call from channel 2 float-out Scour Location: Nose of center or west pier at midpoint of 6.0' riprap layer (scour depth = 3.0') Response: Mobilize to monitor and potentially close bridge B-839S SCOUR MONITORING DEVICE DATA Location: Bridge B-839S, I-15 at California Wash Bridge Phone #: 702-720-3037

144 Second call from channel 2 float-out Scour Location: Nose of center or west pier at midpoint of 6.0' riprap layer (scour depth = 3.0') Response: Mobilize to monitor and potentially close bridge B-1805 SCOUR MONITORING DEVICE DATA Location: Bridge B-1805, FAS 159 (W. Charleston Blvd.) at Red Rock Wash Bridge Phone #: 702-720-3039 (3038?) Sonar installed on upstream nose of pier. Two channel 1 float-outs installed just downstream of pier. Two channel 2 float-outs installed just downstream of bridge ±15 ft. from north abutment toe. Elevation data from contract 2103 and field measurements during installations: Pier bottom of bridge at pier: 3217.2 top of pier pile cap: 3194.5 bottom of pier pile cap: 3191.0 pier pile tip (cast in drilled hole concrete pile): 3179.0 North Abutment bottom of bridge at abutment: 3216.9 top of abutment pile cap: 3212.5 bottom of abutment pile cap: 3210.3 abutment pile tip (cast in drilled hole concrete pile): 3186.0 Sonar (This data is programmed in the monitoring equipment) sonar transducer elevation: 3209.9 ground elevation (in riprap mound) referenced by sonar at time of installation: 3207.5 elevation readings that trigger successive pager/computer calls: 3195.0, 3185.0 Pier Float-Outs ground elevation at pier float out location at time of installation: 3205.2 upper pier float-out elevation: 3195.2 lower pier float-out elevation: 3185.2 Abutment Float-Outs ground elevation at abutment float out location at time of installation: 3202.3 upper abutment float-out elevation: 3192.3 lower abutment float-out elevation: 3185.3 B-1805 SCOUR RESPONSE PLAN Location: Bridge B-1805, FAS 159 (W. Charleston Blvd.) at Red Rock Wash Scour Event Pager Message: "1805, Red Rock Wash" [false alarm if 1805 is missing or different] Pager Group Members: Phone # Cell Phone # Maintenance Supervisor 1 Maintenance Supervisor 2 Maintenance Superintendent District Maintenance Engineer Principal Bridge Maintenance Engineer

145 Responses to Sonar Calls: First call at elevation reading of 3195.0 Scour Location: Top of pier pile cap (scour depth = 10.0') Response: Mobilize to monitor and potentially close bridge Second call at elevation reading of 3185.0 Scour Location: Midpoint of pier piles (scour depth = 20.0') Response: Close bridge Responses to Float-Out Calls: First call from channel 1 float-out Scour Location: Downstream end of pier at top of pile cap (scour depth = 10.0') Response: Mobilize to monitor and potentially close bridge First call from channel 2 float-out Scour Location: Downstream end of NE abutment (scour depth = 10.0') Response: Mobilize to monitor and potentially close bridge Second call from channel 1 float-out Scour Location: Downstream end of pier at midpoint of piles (scour depth = 20.0') Response: Close bridge Second call from channel 2 float-out Scour Location: Downstream end of NE abutment (scour depth = 20.0') Response: Close bridge

146 SCOUR CRITICAL BRIDGE - PLAN OF ACTION 1. GENERAL INFORMATION Structure number: 1-05850-9 City, County, State: Wantagh, Nassau County, NY Waterway: Goose Creek Structure name: Wantagh Parkway Bridge over Goose Creek State highway or facility carried: Wantagh Parkway Owner: NYSDOT Year built: 1929 Year rebuilt: N/A Bridge replacement plans (if scheduled): 2007Anticipated opening date: 2008 Structure type: Bridge Culvert Structure size and description: Double leaf bascule bridge; 109.7m (360 ft) in length; 28.3m (93 foot) bascule span; concrete pile bents. Number of spans: 9 Continuous over pier (Y, N, N/A): N Redundant (Y/N): N Over tidal waters? (Y/N): Y Foundations: Known, type: Piles Depth: EL. -12.2 m (-40.0 ft) – for scour critical bascule piers Unknown Abutment foundation type (piles, spread footing, unknown): Piles Pier(s) foundation type (piles, spread footing, unknown): Piles Subsurface soil information (check all that apply): Non-cohesive Cohesive Rock Streambed material (rock, boulders, cobbles, glacial till, alluvium): Sand/Riprap Bridge ADT: 12,597 Year/ADT: 2002 % Trucks: <10 Does the bridge provide service to emergency facilities and/or an evacuation route (Y/N)? Y If so, describe: Evacuation 2. RESPONSIBILITY FOR POA Author(s) of POA (name, title, agency/organization, telephone, pager, email): NYSDOT Region 10 and Hardesty & Hanover, LLP Date: July 2006 Date of last update: January 2006 Concurrences on POA (name, title, agency/organization, telephone, pager, email): NYSDOT Region 10, Structures Unit – Regional Structures Engineer and Regional Hydraulic Engineer POA to be updated every 12 months Date of next update: January 2007 3. SCOUR VULNERABILITY a. Current Item 113 Rating: 3 2 1 Other: ____ b. Source of Scour Critical Rating: Observed Assessment Calculated Other: Assigned by the Region (R) c. Scour Evaluation Summary: A scour analysis in support of an emergency bridge design and replacement was completed in May 1998. In 2000, a "South Shore Hydraulic & Scour Analysis" was conducted This consisted of a 2-D hydraulic model and scour analyses of 19 bridges, including Wantagh Parkway over Goose Creek Bridge. The results of both analyses indicated that the calculated scour was below the bottom of the existing pile tips elevations for the bascule piers, therefore a foundation structural analysis was required. NYSDOT Geotechnical Engineering Bureau conducted this analysis and the results may be found in this Manual, Appendix C.1.1. Both hydraulic studies are on file in NYSDOT Region 10, Structures Unit. d. Scour History: In April 1998 Wantagh Parkway over Goose Creek was closed due to a partial pier failure. It was found that the streambed at one pier had experienced approximately 8.8m (29 feet) of localized scour since it was built in 1929. This resulted in the downward movement of two piles and the fracturing of the pile cap above them. The outermost pile of this bent was left with 0.37m (1.2 feet) of embedment in the sand. NYSDOT decided to immediately replace the bridge approach spans, but the bascule piers would remain in service for about nine years. A hydraulic and scour analysis indicated that the potential scour at the bascule piers was below the pile tip elevations. The bridge was assigned an NBIS rating of Item 113, Code 3. e. NYSDOT Hydraulic Vulnerability Assessment Program Classification Score: N/A

147 4. RECOMMENDED ACTION(S) (see Sections 6 and 7) Recommended Implemented a. Increased Inspection Frequency Yes No Yes No b. Fixed Monitoring Device(s) Yes No Yes No c. Flood Monitoring Program Yes No Yes No d. Hydraulic/Structural Countermeasures Yes No Yes No 5. NBIS CODING INFORMATION . Current Previous Inspection date (these were General Inspections): 05/27/05 06/08/04 Item 113 Scour Critical 3 3 Item 60 Substructure 7 7 Item 61 Channel & Channel Protection 7 7 Item 71 Waterway Adequacy 6 6 Comments: (drift, scour holes, etc. - depict in sketches in Section 10) See Attachment D 6. MONITORING PROGRAM Regular Inspection Program w/surveyed cross sections Items to Watch: Bascule Pier movements, settlement Increased Inspection Frequency of ____ mo. TBD by the Regional Structures Engineer w/surveyed cross sections Items to Watch: Same as above Underwater Inspection Required Items to Watch: Scour holes in the vicinity of the bascule piers; See Manual, Section 13 and POA Attachment D Increased Underwater Inspection Frequency of 12 mo. and after major storms, TBD by the Regional Structures Engineer Items to Watch: Same as above Note for Underwater Inspections: All diving inspection and fathometer surveys are on file with the Regional Hydraulic Engineer Fathometer Survey Fixed Monitoring Device(s) Type of Instrument: Sonar scour monitors Installation location(s): Bascule Piers (one each on ebb and flood sides) Sample Interval: 30 min. 1 hr. 6 hrs. 12 hrs. Other: Frequency of data download and review: Daily Weekly Monthly Other 3x/week Scour watch elevation(s) for each pier/abutment: -27 ft (-8.2 m) Scour critical elevations(s) for each pier/abutment: -35 ft (-10.7 m) Survey ties: MSL, NGVD 1929 Flood Monitoring Program Type: Visual inspection Instrument (check all that apply): Note: Fixed sonar monitors with remote monitoring Portable Geophysical Sonar Other: Flood monitoring required: Yes No Note: A Coastal Flood Program has been established for 19 bridges in Region 10, including Wantagh Parkway Bridge over Goose Creek. This program includes the inspection of each bridge after major hurricanes or storms. It is a visual inspection of each bridge for any displacement, movement and/or cracks which may be indicative of larger problems from storm wind and/or water forces. The inspection is conducted as soon as post storm weather permits. The flood watch is activated any time a tropical storm, hurricane or high tide event occurs as described in the Manual, Section 5.4.

148 Frequency of post-flood monitoring: Daily Weekly Monthly Other: Varies, See Manual, Section 5.4 Criteria for termination of flood monitoring: Varies, See Manual, Section 5.4 Criteria for termination of post-flood monitoring: Varies, See Manual, Section 5.4 Scour watch elevation(s) for each pier/abutment: -27 ft (-8.2 m) Scour critical elevation(s) for each pier/abutment: -35 ft (-10.7 m) Note: Additional details for action(s) required may be included in Section 8. Action(s) required if scour watch elevation detected (include notification and closure procedures): See Manual, Sections 5.4 and 6 to 10. Action(s) required if scour critical elevation detected (include notification and closure procedures): See Section 8 and Attachment E. Agency and department responsible for monitoring: Scour Monitoring Consultant Contact person (include name, title, telephone, pager, e-mail): (1) Senior Hydraulics Engineer; (2) Hydraulics Engineer 7. COUNTERMEASURE RECOMMENDATIONS Prioritize alternatives below. Include information on any hydraulic, structural or monitoring countermeasures. Only monitoring required (see Section 6) Scour countermeasures considered (see Section 10, Attachment F): Priority Ranking Estimated cost (1) Riprap $ N/A (2) $ (3) $ (4) $ (5) $ Basis for the selection of the preferred scour countermeasure: Bridge to be replaced; scour mechanism was determined to be mostly degradation and thus riprap or armoring would entail armoring of the entire channel Countermeasure implementation project type: Proposed Construction Project Maintenance Project Programmed Construction - Project Lead Agency: Bridge Bureau Road Design Other Emergency Contract Agency and department responsible for countermeasure program (if different from Section 6 contact for monitoring): NYSDOT Region 10, Structures Unit Contact person (include name, title, telephone, pager, e-mail): Regional Structures Engineer Target design completion date: Dec 2006 Target construction completion date: Dec. 2008 Countermeasures already completed: Sonar scour monitors installed in Aug. 1998; ongoing scour monitoring program since installation 8. BRIDGE CLOSURE PLAN Scour monitoring criteria for consideration of bridge closure: Water surface elevation reaches at Flood monitoring event defined by (check all that apply): Discharge Stage See Manual, Section 5.4 Elev. measured from Rainfall (in/mm) per (hour) Flood forecasting information: See Manual, Section 5.4 Flood warning system: See Manual, Section 5.4 Frequency of flood monitoring: 1 hr. 3 hrs. 6 hrs. Other: See Manual, Section 5.4 Post-flood monitoring required: No Yes, within days Overtopping road or structure Scour measurement results / Monitoring device (See Section 6) Observed structure movement / Settlement Discharge: cfs/cms Flood forecast: Other: Debris accumulation Movement of riprap/other armor protection Loss of road embankment

149 Emergency repair plans (include source(s), contact(s), cost, installation directions): TBD by Regional Structures Engineer, See Manual, Section 7 Agency and department responsible for closure: NYSDOT, Region 10, Transportation Maintenance Group Contact persons (name, title, agency/organization, telephone, pager, email): (1) Regional Transportation Maintenance Engineer, (2) Res. 06 Resident Engineer, (3) Bridge Maintenance Engineer, See Manual, Appendix D Criteria for re-opening the bridge: To be determined by the Regional Structures Engineer pending results of diving inspection of Bascule Piers Agency and person responsible for re-opening the bridge after inspection: (1) Regional Transportation Maintenance Engineer, (2) Res. 06 Resident Engineer, (3) Bridge Maintenance Engineer 9. DETOUR ROUTE Detour route description (route number, from/to, distance from bridge, etc.) - Include map in Section 10, Attachment E. Bridges on Detour Route: Bridge Number Waterway Sufficiency Rating/ Load Limitations Item 113 Code 1059159 False Channel 79 6 1059149 Fundy Channel 82 6 1059129 Sloop Channel 47 – R-posted 6 Traffic control equipment (detour signing and barriers) and location(s): See POA, Attachment E Additional considerations or critical issues (susceptibility to overtopping, limited waterway adequacy, lane restrictions, etc.) : None News release, other public notice (include authorized person(s), information to be provided and limitations): Office of the Regional Director, Region 10, NYSDOT 10. ATTACHMENTS Please indicate which materials are being submitted with this POA: Attachment A: Boring logs and/or other subsurface information Attachment B: Cross sections from current and previous inspection reports Attachment C: Bridge elevation showing existing streambed, foundation depth(s) and observed and/or calculated scour depths Attachment D: Plan view showing location of scour holes, debris, etc. Attachment E: Map showing detour route(s) Attachment F: Supporting documentation, calculations, estimates and conceptual designs for scour countermeasures. – See Manual, Appendix A Attachment G: Photos – See Manual, Appendix F Attachment H: Other information: