Paerto Rico Electric Power Authority Palo Seco Steam Plant Units 1, 2, 3 4 Emergency Structural Steel Assessment Report ISLAND STRUCTURES ENGINEERING, PC 319 SUNRISE HEGHWAY WEST ISLIP, NY 11795 August 25, 2017 Puerto Rico Electric Power Authority Palo Seco Steam Plant Units 1, 2, 3 4 Emergency Structural Steel Assessment Report Prepared for: Puerto Rico Electric Power Authority San Juan, PR 00936 Prepared by: Island Structures Engineering, PC 319 Sunrise Highway West Isltp, NY 11 795 ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST JSLIP. NY 11795 II IV. INDEX GENERAL OVERVIEW OBJECTIVES LIMITATIONS OF STUDY OBSERVATIONS RECOMMENDATIONS a. Remediation Required b. General Surface Preparation Coatings c. Recommendations for Additional Inspections APPENDIX A PHOTOS OF TYPICAL CONDITIONS ISLAND STRUCTURES ENGINEEIQING, PC 319 SUNRISE HIGHWAY WEST ISLIP, NY 11795 LEGAL NOTICE AND STATEMENT OF CONFIDENTIALITY The information contained in this report is intended for the exclusive use of PREPA and may contain con?dential or privileged information supplied by PREPA. This document was prepared by Island Structures Engineering, PC (Island) solely for the bene?t of PREPA. Neither Island, PREPA nor their parent corporations or af?liates, nor any person acting on their behalf makes any warranty, expressed or implied, with respect to the use of any information or methods disclosed in this document; or assumes any liability with respect to the use of any information or methods disclosed in this document. Any recipient of this document, by their acceptance or use of this document, releases Island, PREPA, their parent corporations and affiliates from any liability for direct, indirect, consequential, or special loss or damage whether arising in contract, warranty, express or implied, tort or otherwise, and irrespective of fault, negligence, and strict liability. Report Updates Island has no responsibility to update this report for any changes occurring subsequent to the issuance of this report. ISLAND STRUCTURES ENGINEEQING, PC 319 SUNRISE HIGHWAY WEST NY 11795 I. GENERAL OVERVIEW William Schlumpf and other staff of Island Structures Engineering, PC (Island), as a sub-consultant to Sigma Energy Solutions, previously performed a preliminary boiler building structural steel framing condition assessment at the Palo Seco Steam Plant Units 1, 2, 3 and 4 for the Puerto Rico Electric Power Authority (PREPA) in mid-September 2011. Sigma issued a Preliminary Structural Assessment report subsequent to that inspection and identi?ed several ?critical? structural conditions. Mr. Schlumpf and staff performed follow?up site visits in January, March and April 2012 for the purpose of performing a detailed structural inspection of the items identi?ed during the ?rst visit as ?critical? and in need of immediate remediation. Mr Schlumpf and staff subsequently performed yet more detailed inspections of the units in May and June of 2016 for the purpose of evaluating and updating serious defects in the structural framing that need to be addressed at once. Units 1, 2, 3 and 4 are oil ?red CE boilers with a capacity of approximately 75/75/200/200 MW respectively each, constructed in the late 1950?s and mid-1960?s. Each boiler structure is essentially unclad, structural steel, with top supported boilers, exposed to the elements. The units are located on the north side of the island of Puerto Rico, west of San Juan in the Palo Seco area. Puerto Rico experienced a magnitude 4.8 seismic event just north of San Juan on August?Q?, 2017. PREPA requested that ISEPC (as a sub- consultant to GE) perform an emergency inspection of Units 1?4 at Palo Seco to assess any damages resulting from the seismic event II. OBJECTIVES The purpose of this emergency effort is to provide a current updated assessment of the Units with specific attention to indications of damage from the seismic event. Additionally, PREPA requested that Island opine on the viability and safety of proceeding with the remediation efforts recommended in the June 2016 evaluation. Changes in conditions since both the 2012 and 2016 inspections were of particular concern to PREPA. Only limited repairs have been undertaken since the 2012 inspection report was issued. The scope of work includes the evaluation and ISLAND STRUCTURES PC 319 SUNRESE HIGHWAY WEST ISLIP, NY 11795 recommendations for remediation of corroded or otherwise compromised structural members throughout the units that require structural repair or replacement in order to remediate signi?cant and dangerous structural de?ciencies. This report includes the recommendations for the critical items that were identi?ed in the June 2016 Report, subsequent to this re?inspection. This emergency inspection revealed areas of signi?cant structural risk that require immediate remediation. This Report emphasizes six speci?c areas identi?ed previously as posing such risk of imminent failure if subjected to substantially less than original design loads. They are identi?ed herein as items through f. While these are speci?cally identi?ed as ?critica this should not be construed to lessen the need for remediation of more general structural defects noted within the June 2016 Report and the associated remediation spread sheets and drawings. These other defects also have the potential for failure with consequential life safety and plant operation impacts and should also be addressed at once. LIMITATIONS OF STUDY The assessment is limited to the structural steel framing, including beams, girders, columns, bracing, connections and platform sub~framing. This assessment does not include the stacks themselves, or any ductwork. Small bore pipe supports were not examined in any detail, however are referred to in some of the repair details, where structural remediation affects them. IV. OBSERVATIONS Primary structural members of each unit were inspected visually, as well as with electronic or other probing tools where warranted, at each framing level and at each vertical bracing elevation. There are numerous instances of members with either signi?cant corrosion or perforation corrosion that will require either structural repairs or member replacement at each Unit. Members were previously assigned unique ?piece marks? on the drawings, and were given detail numbers on spread sheets that relate to the detail drawings indicating the particular remediation required. The required ISLAND STRUCTURES ENGINEERING, PC 319 SUNRISE HIGHWAY WEST NY 11795 structural repairs and replacements were indicated in the spread sheets included in the June 2016 Report. Each Unit was re?inspected on a level by level basis. Each boiler has multiple main framing levels above the ground (numbered 1 up to as high as 9), plus the main boiler hanging steel level above highest numbered level. Several levels are split, with raised platform elevations at partial areas, or have partial sub-levels immediately above or below. Additionally, each main framing line of the Units was detailed on Elevation view drawings, in order to depict the vertical framing and bracing system members and columns. These were inspected again for this assessment. Throughout this and prior reports, certain levels of corrosion are identi?ed using speci?c terminology. This terminology is consistent with that used in prior reports. The following de?nitions provide an understanding of the general condition of structural members so identi?ed: Surface Corrosion - Indicates coating defects and/or exposed bare steel requiring only limited surface preparation before recoating would be effective. Corrosion - Indicates coating failure and pitting of steel surface, with a pitted pro?le typically less than 1/16?. Corrosion at this level does not result in a severe enough loss of material to compromise the load carrying capacity of the member. Signi?cant Corrosion - Indicates surface coating failure and deep pitting and/or scaling with a corroded pro?le depth in excess of 1/16?, but not complete perforation of the member. Signi?cant corrosion has the potential for compromising the load carrying capacity of the member, particularly if located at a stress critical location of the member. Perforation Corrosion Indicates a complete loss of cross section of the member to the point where a portion of the web or ?ange under consideration is completely gone. This level of defect clearly compromises the member, and its structural integrity and load carrying capacity cannot be relied upon. Units 1 through 4 were speci?cally inspected for signs of overstress or damage resulting from the recent seismic event. Areas of particular concern included the vertical bracing systems that resist lateral loading. Such lateral loads typically are the result of wind or seismic events. Additionally, areas of interest included the steam drum hanger supports, large high-energy piping hangers, interconnecting bridges between boilers, interconnecting ISLAND STRUCTURES ENGINEERING, PC 319 SUNRISE HIGHWAY WEST NY 11795 bridges between boilers and stacks, as well as other areas that previously exhibited signi?cant and extensive perforation corrosion. Prior inspections revealed extensive corrosion at the bottom of the vertical bracing systems at all columns in Units 3 and 4, so these were given particular attention as well. Inspections did not reveal extensive damage from the recent seismic event on any of the units. Units 3 and 4, however, were observed to have sustained some buckling of the already weakened (due to corrosion) gusset plates between the base of the columns and the diagonal bracing (see photo 0038). This is the likely initial failure mode of these connections when subjected to compression loads in excess of their current limited capacity. No other telltale signs of signi?cant seismic movement were observed at the steam drum and high-energy piping hangers and interconnecting bridges. It is important to note, however, that the recent magnitude 4.8 event was relatively small. For comparison, a magnitude 5.8 event, at the same location would be 10 times as severe. For reference, the Puerto Rico area experienced a magnitude 6.4 event several years ago, and several magnitude 5.4 events in 2010?11. Six speci?c areas of structural defects were identi?ed by Island during its prior inspections and were documented in its June 2016 Report. These areas pose the threat of imminent collapse or failure and pose a signi?cant threat to both personnel and to the equipment supported thereon. In the case of items listed below as d) and immediate and total restriction of personnel access should be placed on these areas. In the case of the item f) under the checkered ?oors at Unit 3), a restriction on loads other than from required maintenance personnel should be enforced. Item g) is a condition that warrants further investigation as noted. During this inspection, it was observed that PREPA had begun, but not completed, installing barriers to restrict access as recommended previously. These areas have now become more critical. Other structural defects that require immediate repair are addressed in sections and i. All areas of remediation are listed in the Spread Sheets that were included in Appendix of the June 2016 Report. Member identi?cation numbers used in those spread sheets are indicated on the drawings that were included as Appendix in the same report. The spread sheets were also highlighted in different colors, as indicated on the lead sheet, to identify more easily which repairs belong in each of the noted categories. In order to make recent revisions easy to detect, changes to the spread sheets since the Interim Report was ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST Isup. NY 11795 issued were identi?ed with red font (or white in the case of red highlighted areas). a. Unit 3 4 Column Bases and Lateral Bracing System (Photos 0054, 0057, 0063, 0064, 0067 and 0068) i. ii. Assessment: The column base connections of the lateral bracing systems for Units 3 4 are severely compromised. The original bracing systems were designed for loads considerably lower than current code requirements, and the degradation of these structural members further reduces the capacity of the main boiler structures to resist both wind and seismic loads. Loads in the diagonal members of the bracing system at this base level are on the order of over 220,000 in each brace. It is estimated that the capacity of the system in the north-south direction has been compromised to the point where it only has between 15% and 25% of its originally designed strength. The east-west direction is only marginally better. Photos 0063 and 0064 depict the center column bracing on the east side of Unit 3. Photos 0067 and 0068 depict the center column bracing on the west side. Photo 0054 shows the bracing at the center column on the east side of Unit 4. As these show, the gusset plate connections from the diagonal bracing to the bottom of the column are virtually completely corroded. Photo 0057 also shows the degradation of the high strength bolts at these connections. The corner columns at each boiler are similarly corroded, providing only limited lateral stability for the unit. The severity of the current condition is such that even relatively minor storms or seismic events, considerably lower than originally designed for, could result in GROSS failure of the units. As an example, if the original Units were designed for 120 winds, the optimistic range of the current capacity would be for only 60 winds. Remediation Details: The remediation work associated with these defects is identi?ed in the June 2016 spread sheets with blue highlighting. The column base repairs typically consist of chopping the surrounding concrete to expose the diagonal bracing connection plates, and the replacement or repair of those plates. Also included are several member replacements and several structural repairs. Replacement steel and all remediation details should be prime-painted and ?nish coated as speci?ed in Speci?cation 09900. Replacement members and replacement connection details noted as ?replacement in-kind? should be ?eld ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST ISLIP, NY 11795 detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. Replacement of the concrete and installation of replacement concrete piers should be done such that storm and/or operational water will no longer pool next to the steel, but rather will be conveyed by sloping concrete away from the steel. Remediation work details for the column base repairs are indicated on Detail Sheet (Details 43 through 49) in the June 2016 Report. Due to their extreme weakened condition, it is recommended that the initial column base/bracing repairs begin with the center columns on the east and west sides of the Unit 3 boiler columns 13-1044 and 13- 1256). Only one column on each side should be worked on at a time. The center columns at Unit 4 should be simultaneously with those at Unit 3, or immediately after. If wind loads are expected to exceed 50 mph, the work should be stabilized to the extent possible, and personnel should leave the area until such time as the winds abate. Once at least two columns on each side of the boilers are repaired, personnel may remain in the area with winds up to 75 mph. Concrete repairs need not be completed before moving to the next set of columns. b. Unit 1 Soot Blower Platform Framing at Elevation 82??0? and 94?-8? (Photo DSFC-2101) i. Assessment: On the east side of Level 4 (soot blower elev. 82?- 0? and sections of platform framing have corrosion so severe that the platforms are unsafe for any use (see photo These sections of platform should be immediately cordoned off to prevent any usage, until such time as a detailed repair/replacement can be implemented. The area affected is east of column line 3 2/3. This will preclude the ability to perform periodic maintenance of the soot blowers in those areas. ii. Remediation Details: The remediation work associated with these defects is identi?ed in the spread sheets with yellow highlighting. The repairs include several member replacements and several structural repairs. Replacement steel and all remediation details should be prime-painted and ?nish coated as speci?ed in Speci?cation 09900. Replacement members and replacement connection details noted as ?replacement in-kind? should be ?eld detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. ISLAND STRUCTURES PC 319 SUNRESE HIGHWAY WEST ISLIP, NY 11795 0. Unit 1 Deaerator Tank Upper Platform Framing (Photo 836 and DSFC- 2101) i. ii. Assessment: The structural framing supporting the upper level of the Unit 1 deaerator tank access platform has deteriorated to the point where it is in danger of collapse under normal platform loading, and perhaps under its own weight. This area should be restricted from any personnel access until it is replaced. The corrosion is pervasive to the point where complete replacement of the entire platform is warranted. This replacement work was previously detailed in the drawings and spread sheets developed in 2012, as well as in 2016. Remediation Details: The remediation work associated with these defects is identi?ed in the spread sheets with deep purple highlighting. The repairs include the complete member replacement of this platform level. Replacement steel and all remediation details should be prime-painted and ?nish coated as speci?ed in Specification 09900. Replacement members and replacement connection details noted as ?replacement in-kind? should be ?eld detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. d. Unit 1 Level 1 Platform Framing Over Electrical Building Roof (Photo DSFC-2 1 09) i. ii. Several members supporting the Level 1 platform over the Electrical Building roof (Elevation 39??4? south of column line E) have deteriorated to the point that they pose imminent threat of collapse under their own equipment and dead load. The southernmost W14 spandrel beam is already failing with noticeable de?ection (see photo DSFC-2109). This area requires immediate member replacement and/or supplemental support. Until such remedial work is completed, access to this platform should be prohibited. This will preclude the ability to monitor and maintain the unit-critical equipment located thereon. Remediation Details: The remediation work associated with these defects is identi?ed in the spread sheets with deep orange highlighting. The repairs include several member replacements, several structural repairs, and the installation of a new member under the main spandrel beam to provide additional support to that failed member, while limiting the associated plant equipment ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST lsup, NY 11795 impacts. Replacement steel and all remediation details should be prime-painted and ?nish coated as speci?ed in Speci?cation 09900. Replacement members and replacement connection details noted as ?replacement inukind? should be ?eld detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. e. Unit 3 4 Elevator Area Framing (Photos 0040, 0041, 0042 and 0043) i. ii. Assessment: The area in the vicinity of the original common Unit 3 4 elevator shaft platform framing is extremely critical. The main platform framing girders in these areas typically have severe perforation corrosion at the penetration of the siding to the elevator shaft (see photos 0040, 0041, 0042 and 0043) where the girders and beams attach to the elevator shaft columns. At some levels this is so severe as to provide no visible means of support to these main framing members. The member in photo 0042 is already starting fail under its own weight. It also noted that many of these platform areas support soot blowers. These areas should be immediately cordoned off to prohibit any personnel from walking on or below them, as the pose an imminent threat of collapse even under current equipment and dead weight alone. This restriction will preclude the ability to perfrom routine maintenance on the soot blower located thereon. The situation exists at multiple levels (from level 1 through 9). Remediation Details: The remediation work associated with these defects is identi?ed in the spread sheets with green highlighting. The repairs include the installation of structural connection ?seats? at many of the beam connections to the elevator shaft columns (See Details 41 and 42, Drawing 900?4). These ?seats? can be installed without complete removal of the deteriorated structural members. Additionally, some member replacements and several structural repairs are required. The situation exists at multiple levels (from level 1 through 9), precluding the possibility of temporary posting from the level immediately above or below. As such it is recommended that level?one repairs be performed ?rst, using manlift equipment. Subsequently, the upper levels should be temporarily shored down to this level. Remediation details for this area were previously indicated on Drawings through RE-629-374-3 and in details ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST NY 11795 shown on Drawings through 4. Replacement members and replacement connection details noted as ?replacement in-kind? should be ?eld detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. Replacement steel and all remediation details should be prime?painted and ?nish coated as speci?ed in Speci?cation 09900. Additional repairs, particularly at bracing connections have also now been identi?ed and are included in the remediation details. f. Unit 3 4 Level 2 Framing Beneath Checkered Plate (Photo 809) i- ii. Assessment: The framing on the south side of Units 3 4 at Level 2 (Elevation 605-11?) 13 mostly covered with checkered plate (instead of open grating). The checkered plate has allowed moisture to be retained between the plate and the top ?ange of these members, resulting is signi?cant pervasive corrosion of many of the top ?anges. This area will require removal of the checkered plate during remediation and re?inspection is recommended at that time to verify the condition of these top ?anges. Until such time as that is completed, it is recommended that only critical personnel loading no equipment or tools or unnecessary transit) be permitted on these areas. Remediation Details: The remediation work associated with these defects is identi?ed in the spread sheets with red highlighting. The repairs include member replacements and structural repairs. There may be additional repairs required, after a re?inspection is performed subsequent to the checkered plate removal. Replacement steel and all remediation details should be prime-painted and ?nish coated as speci?ed in Speci?cation 09900. Replacement members and replacement connection details noted as ?replacement in-kind? should be ?eld detailed for fabrication. All new bolts (typically 7/8? diameter A325N) should be used for connections. Most of the steel in this area has poor coating condition. Proper cleaning and recoating will be required for much of the area once the plate is removed. g. Unit 3 Deaerator Platform Pipe Support Hanger Beam 1. Assessment: It was observed during the June 2016 re- inspection that the beam running along the south side of the deaerator had signi?cant de?ection in it. This beam does not support the ISLAND STRUCTURES PC 319 SUNRISE WEST Isup, NY 11795 deaerator directly, but rather is loaded by substantial pipe hangers supporting the steam lines. The de?ection indicates overstressing of the member. It could not be determined if this is a current condition or one that had occurred previously with the plastic deformation remaining. It is our recommendation that the pipe hanger loads in this area be established and veri?ed against the intended design conditions. ii. Remediation Details: The remediation work associated with this issue is identi?ed in the spread sheets as Member 3-30227 (Unit 3 4, Level #3 El. The noted de?ection may have been the result of prior overstress or perhaps even the result of high temperature during a prior ?re. Once the current pipe hanger loading is established, a further review to establish if repairs or replacement are needed can be made. h. Unit 1 2 General Structural Framing Defects i. Assessment. Since the completion of the ?nal assessment ?ve years ago, and even since the June 2016 re-? inspection Units 1 and 2 have experienced additional corrosion. This was determined by comparing the previous pictures to the existing condition. Both units require the original speci?ed uncompleted repairs (in some cases with those repairs modi?ed to accommodate worsened conditions as noted in June 2016). Additional corrosion may have an effect on some of the previously noted repairs; however it is our recommendation that a full re?inspection not be performed at this time to update these. Rather, it is suggested that any conditions which appear to exceed the bounds of the previously indicated repairs be reported to Island and we will provide the necessary revisions. Periodic oversight of the work should also be included in the overall effort to ensure that such it the case. ii. Remediation Details: Of the general repairs or replacements required for Units 1 2, some have been identi?ed as more urgent. These have been highlighted on the spread sheets with a light orange color where complete replacement is necessary, and with pink highlighting where Detail 15 top ?ange. /kick plate repairs are necessary. Other important remediation requirements have been left un?highlighted. i. Unit 3 4 General Structural Framing Defects ISLAND STRUCTURES PG 319 SUNRISE HIGHWAY WEST ISLIP, NY 11795 i. Assessment: Since the completion of the ?nal assessment ?ve years ago, and even since the June 2016 re-inspection, Units 3 and 4 have experienced additional corrosion. This was determined by comparing the original pictures and repairs to the existing condition. Both units require the original speci?ed uncompleted repairs (in some cases with those repairs modi?ed to accommodate worsened conditions as noted in June 2016. Additional corrosion may have an effect on some of the previously noted repairs; however it is our recommendation that a full re-inspection not be performed at this time to update these. Rather, it is suggested that any conditions which appear to exceed the bounds of the previously indicated repairs be reported to Island and we will provide the necessary revisions. Periodic oversight of the work should also be included in the overall effort to ensure that such it the case. ii. Remediation Details: Of the general repairs or replacements required for Units 3 4, some have been identi?ed as more urgent. These have been highlighted on the spread sheets with a light purple color where complete replacement is necessary. Other important remediation requirements have been left un- highlighted. VI. RECOMMENDATIONS a. Remediation Required The results of this emergency assessment con?rm the need for the critical repair of work to ensure life safety and the safety of the boilers and balance of plant. Many of the defects observed were identi?ed in the prior reports issued in 2012 and 2016. These have, in many cases, worsened. The severity of many of these defects is such that they are of critical importance and pose a current imminent threat to the safety of personnel using the areas, as well as posing a potential threat of damage to critical boiler equipment such as soot blowers that are supported thereon or even gross failure of the structures. The Unit 3 and 4 lateral bracing systems pose a real threat of gross structural failure for the units. The corrosion is pervasive to the point of rendering the units potentially incapable of resisting relatively frequent loading conditions, far below their original design capacity. Other speci?c critical areas identi?ed during our June 2016 re?Visit consist of the Unit 1 Level and Level 2 east side soot blower platforms, the Unit 1 upper deaerator platform, the ISLAND STRUCTURES ENGINEERING, PC 319 SUNRISE HIGHWAY WEST NY 11795 Unit 1 Level 1 platform over the Electrical Building, and the platform framing around the Unit 3 and 4 elevator. All of the aforementioned areas should be prohibited from all access, including even routine maintenance activities. The Unit 3 4 Level 2 ?oor framing under the checkered plate requires limitation of loading to critical personnel loading only. These areas should be the ?rst priority in performing the remediation work to the Units. Nevertheless, ALL speci?ed remediation work should be completed to ensure the continuing viability and safety of the structures. b. General Surface Preparation Coatings In general it was observed that the coatings on the south and east sides of the structures were in considerably worse condition than the north (stack side) and west side. This is the result of prevailing southeast winds and the more direct exposure to the shoreline. All of the steel requires adequate pressure wash cleaning prior to any recoating activity. It is critical to remove all contaminants and salts prior to any further surface preparation. Additionally, most of the steel will require at least a moderate amount of hand and/or power tool cleaning to remove surface corrosion and to provide an adequate surface profile. Much of the steel, particular where noted in the spread sheets as requiring ?Detail 3, Heavy Cleaning Required?, will require more than a super?cial hand or power tool cleaning. This notation is not to be considered exclusive, in that portions of many other beams may also require more than limited hand tool cleaning, particularly in isolated areas. Rather it is a general indication of those members that have more extensive surface preparation needs and may be concealing additional signi?cant defects. In all cases, the steel shall be provided with suf?cient surface preparation to ensure its suitability with the specified coating system. Normally, a blasting surface preparation would be desired, however, the limitations on such blasting at the facility necessitate the use of heavier power tool cleaning to remove failed coatings, deeper corrosion and to expose sound metal. It is strongly suggested that the surface preparation and recoating be performed on a limited area basis, proceeding from the upper levels downward. Properly prepared steel on an upper level should be recoated as soon as possible, before proceeding to the level below. Much of the structural steel has grating over its top ?ange. Grating must be removed prior to implementing surface preparation and coating ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST ISLIP, NY 11795 activities. This work is not to be done with the grating in place. Gratings should be replaced using galvanized saddle clip fasteners upon completion of the recoating effort. The coating speci?cation includes Island?s recommendation for recoating products including primer and top coat. All structural and miscellaneous steel shall be recoated, with primer application required over any new bare steel and wherever surface preparation has penetrated existing sound coatings. PREPA has previously indicated that it would con?rm the present coating system material (through testing) so that it can be properly established that the proposed coating system is compatible. Furthermore, testing of the existing coatings will also con?rm whether any special measures must be taken to account for any possible presence of lead. c. Recommendations for Additional Inspections Island recommends a level of inspection during the execution of the remediation work. Additionally, the re-inspection is now over a year old, and as such conditions have worsened. In many cases the repair speci?cations were such that they will cover such additional defect areas. As noted above, however, diligence on the part of the Contractor should be made to identify to Island any areas of corrosion that will not be accommodated by the previously speci?ed repair. As the work progresses and existing steel is cleaned and exposed, there will be locations that require additional or modi?ed remediation measures. Some speci?c areas and members have also been identi?ed in the remediation spread sheets as requiring further inspection once cleaned. As much of the steel was heavily coated, with inadequate surface preparation prior to the initial 2012 inspections, there will also be additional defects found when properly cleaning those areas. This work can be accomplished as either a sub-consultant to the Contractor. Historically, the staff of Island has been involved through the steel remediation contractor. Site visits approximately once per month (or more frequent if the work progresses rapidly), during the execution of the work would be a reasonable level of effort to consider, with somewhat more frequent visits initially and when substantial levels of contractor resources are applied. ISLAND STRUCTURES PC 319 SUNRISE WEST NY 11795 APPENDIX A PHOTOS ASSOCIATED WITH EMERGENCY INSPECTION ASSESSMENT ISLAND STRUCTURES Fe 319 HIGHWAY WEST ISLEP, NY 11795 mm: >2 .n?ww 5m; 2220?: me22m 0, 5 0n. .02_mmuz_02m nz2 .mjw? wwEZDm On? n24.5? N25 mm in RKWm?z?af, Kimw?w A . . g? a WEST ISLEP, NY 11795 319 HIGHWAY ISLAND STRUCTURES PC 372?; 0057 7f2-33/28 0063 ISLAND STRUCTURES PC 319 SUNRISE HIGHWAY WEST ESLIP, NY 11795 owwq .wr>zu .5 n: mczwam 1.0153 Emma z< A 38 I Nvaaxgg" 551%? I A 0068 ISLAND STRUCTURES PC 319 HIGHWAY WEST ISLIP, NY 11795