LONG TERM MONITORING AND MAINTENANCE REPORT 2012 TO PRESENT THOMAS PRINCE SCHOOL PRINCETON, MASSACHUSETTS

Transcription

1 LONG TERM MONITORING AND MAINTENANCE REPORT 2012 TO PRESENT THOMAS PRINCE SCHOOL PRINCETON, MASSACHUSETTS ATC PROJECT NO DOCUMENT NO SEPTEMBER 30, 2017 Prepared by: Prepared for: ATC Group Services LLC United States EPA 997 Millbury Street 5 Post Office Sq., Ste. 100 (OSRR07-2) Worcester, MA Boston, MA Phone: (508) Attn: Kimberley N. Tisa, PCB Coordinator Prepared on behalf of: Town of Princeton 6 Town Hall Drive Princeton, MA Nina Nazarian, Town Administrator

2 TABLE OF CONTENTS 1.0 INTRODUCTION BACKGROUND SCHOOL DESCRIPTION SOURCE AND EXTENT OF PCB S AND MITIGATION ACTIVITIES COMPLETED - SUMMARY ANNUAL MONITORING AND MAINTENANCE MARCH 22, ST POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND DECEMBER 28, ND POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND DECEMBER 23, RD POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND NOVEMBER 11, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND FEBRUARY 16, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND APRIL 19, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND FUTURE ANNUAL LONG TERM MONITORING AND MAINTENANCE ACTIVITIES - INDOOR AIR AND WIPE SAMPLING FIGURES: Figure 1 Figure 2 Site Locus Room ID Plan TABLES: Table 1: Table 2: Table 3: Table 4 Table 5 Table 6 Historical Indoor Air Analytical Results USEPA Method TO-10A Long Term Monitoring Wipe Sample Analytical Results for Porous Surfaces - since March, 2012 Analytical Results of Wipe Samples for the Epoxy Coated Non- Porous Surfaces of the Interior of the 100-Wing and 200-Wing Unit Ventilators Analytical Results of Wipe Samples for the Non-Porous Surfaces of the Motor Casings Within the 100-Wing and Unit Ventilators Analytical Results of Wipe Samples for the Non-Porous Surfaces of the Window Frames Within the 100-Wing Classrooms Analytical Results of Wipe Samples for the Non-Porous Surfaces of the Exterior Air Intake Louvers for the 200-Wing Classrooms

3 TABLE OF CONTENTS (CONTINUED) APPENDICES: Appendix A: Indoor Air Laboratory Analytical Certificates Appendix B: Annual Post-Mitigation Wipe Sample Laboratory Analytical Certificates for the Epoxy Coated Porous Surfaces - since March, 2012for Appendix C: Post-Mitigation Wipe Sample Laboratory Analytical Certificates for the Non-Porous Surfaces of the Interior of the 100-Wing and 200- Wing Unit Ventilators Appendix D: Post-Mitigation Wipe Sample Laboratory Analytical Certificates for the Non-Porous Surfaces of the Motor Casings Within the 100-Wing and Unit Ventilators Appendix E: Post-Mitigation Wipe Sample Laboratory Analytical Certificates for the Non-Porous Surfaces of the Window Frames Within the 100- Wing Classrooms Appendix F: Post-Mitigation Wipe Sample Laboratory Analytical Certificates for the Non-Porous Surfaces of the Exterior Air Intake Louvers for the 200-Wing Classrooms Appendix G: Photo Log of Interior/Exterior Epoxy Coated Porous Surfaces associated with the 200-Wing Classroom Windows March 2012 Appendix H: Photo Log of Interior/Exterior Epoxy Coated Porous Surfaces associated with the 200-Wing Classroom Windows and Applicable Visual Inspection and Maintenance Logs December 2013 Appendix I: Photo Log, Visual Inspection and Maintenance Logs of the Observed Minor Breaches in the Interior Epoxy Coated Porous Surfaces of Classrooms 207 and 209 April 2017 Appendix J: Timeline April 2011 August 2017

4 Abbreviations and Acronyms ACO ADD ADE ATSDR CERCLA cfm cm 2 CSF CSM DQA DQO DUE ELCR EPA ft GC/FID IAS in. HG ID IRIS kg m 3 MDL mg mg/g mg/m 3 mg/l Mod msl MW ND ng/m 3 NGVD NPL OD OSHA OSWER PARCSS PCB PUF PVC QAPP RAF's RBC RfD sf SOP SOW TAC TSCA ug/g ug/kg ug/l ug/m 3 USEPA UTM Administrative Consent Order Average Daily Dose Average Daily Exposure Agency for Toxic Substances and Disease Registry Comprehensive Environmental Response, Compensation and Liability Act Cubic feet per minute Square Centimeter Cancer Slope Factor Conceptual Site Model Data Qaulity Assessment Data Qaulity Objective Data Usability Evaluation Excess Lifetime Cancer Risk Environmental Protection Agency Foot Gas Chromatogram/Flame Ionization Detector Indoor Air Sample inches of mercury Inside Diameter Integrated Risk Information System Kilogram Cubic meter Method Detection Limit milligram milligrams per gram milligrams per cubic meter milligrams per liter Modification Mean Sea Level Monitoring Well Non-detect - not detected above laboratory reporting limit or instrument detection limit. Nanogram per cubic meter National Geodetic Vertical Datum National Priority List Outside Diameter Occupational Safety and Health Administration EPA Office of Solid Waste and Emergency Response Precision, Accuracy, Representativeness, Comparability, Completeness and Sensitivity Polychlorinated Biphenyl Polyurethane Foam Polyvinyl Chloride Quality Assessment Project Plan Relative Absorption Factors Risk Based Concentration Reference Dose Square Feet Standard Operating Procedures Scope-of-Work Target Indoor Air Concentration Toxic Substances Control Act micrograms per gram micrograms per kilogram micrograms per liter microgram per cubic meter United States Environmental Protection Agency Universal Transverse Mercator REGULATORY AGENCIES USEPA United States Environmental Protection Agency SUBCONTRACTORS ATC ECS ATC Group Services, LLC Environmental Compliance Services, Inc. 9/30/2017

5 Abbreviations and Acronyms Eurofins/Spectrum Eurofins/Spectrum Analytical, Inc., Agawam, MA 9/30/2017

6 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page INTRODUCTION On behalf of the Town of Princeton, the purpose of this report is to present the results of long term monitoring and maintenance activities that have been conducted at the Thomas Prince School since the completion of PCB remediation activities. Included within this report are results and summaries of all post-mitigation indoor air and wipe sampling events that have occurred since PCB mitigation activities were completed in As previously discussed during recent correspondence with EPA, the activities conducted in support of the monitoring and maintenance activities for this project are being submitted under single cover to streamline the reporting and review of these activities as this information was not previously provided to EPA. However, the information provided within this report has been provided as public information via the website of the Wachusett Regional School District in which the school resides. Refer to the acronym list which follows the Table of Contents for a listing of common acronyms utilized within this report. 1.1 BACKGROUND The Thomas Prince School is a public elementary school located in the Town of Princeton, Massachusetts. The school is operated by the Wachusett Regional School District (WRSD). The building and property are owned by the Town of Princeton. The school currently serves approximately 400 students in the grades of kindergarten through eight and approximately 60 fulltime/part time educators. The school is occupied for typical school session from late August through June between the hours of 8:30 AM to 3 PM on weekdays. School sponsored before and after care programming occurs for an additional 3.5 hours per day. Also, the school is used for childhood activities during the summer on a varying schedule. A locus map, showing the location of the school is presented as Figure 1. A plan showing the building and locations of rooms within the building is presented as Figure 2. In April 2011, during preparation for a window replacement project being performed as part of Green Repair Program administered under the Massachusetts School Building Authority, analysis of samples of window caulking and window glazing material collected from the school indicated the presence of PCB s in those building materials. Additional sampling, conducted in June 2011, confirmed the presence of PCB s in window caulking and indicated the presence of PCB s in structural joint caulking. PCB s in building materials is regulated under the Toxic Substances Control Act (TSCA, 40 CFR, Part 761). Use of PCB s in building materials is an unauthorized use under this act. Multiple rounds of indoor air sampling and analysis for PCB s, as well as surface wipe sampling and building materials sampling and associated analyses for PCB s, have been performed at the school. Much of this data has been presented in the reports previously submitted to the EPA titled Risk Based Site Cleanup and Disposal Plan - Revision 1, dated February 13, 2012 and Modification of Risk Based Site Cleanup and Disposal Plan, dated August 14, Based on conditional approvals by USEPA, PCB mitigation activities including the removal and/or disposal of PCB fluorescent light ballasts and stained fixtures, PCB Capacitors, PCB Bulk Product Waste (window and joint caulking), and PCB Remediation Waste (building substrate materials and soil) were performed. The PCB mitigation activity which has been completed that requires long term monitoring and maintenance includes the encapsulation of identified PCB contaminated porous surfaces with two layers of an epoxy coating. Refer to Appendix J for a bulletized timeline of the

7 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 2 events that have been conducted at the Thomas Prince School in relation to the assessment and remediation of PCB s. 1.2 SCHOOL DESCRIPTION The Thomas Prince School building is a slab-on-grade concrete block building with a brick façade that has a footprint of approximately 76,000 square feet (Figure 2). The northeast portion of the existing building, comprising approximately 32,000 square feet, was constructed in A large addition, comprising approximately 44,000 square feet, was constructed in 1991 west and south of the original structure. In 1991, at the time the addition was constructed, the library/media center, computer laboratory (Room 111), Room 113, and Classroom 112 were renovated. Ceilings in the hallways and in the administrative office area and the exterior façade at the administrative office area and Room 112 were also renovated at this time. Refer to Figure 2 for the school interior layout. 1.3 SOURCE AND EXTENT OF PCB S AND MITIGATION ACTIVITIES COMPLETED - SUMMARY Various potential sources of the detected PCB s to school indoor air and porous/non-porous surfaces were identified. These sources consisted of window caulking and structural joint caulking, window glazing, fluorescent light ballasts, and unit ventilator motor capacitors. As an initial response to the detection of PCB s in the indoor air, all fluorescent light fixtures were inspected for PCB containing ballasts or stained light fixture housings 1. PCB containing ballasts and/or residual staining from a previously ruptured ballast may provide the opportunity for volatilization of PCB s to indoor air, thus impacting the indoor air. As a result of the inspection, a total of 57 ballasts, 74 stained light fixture housings and 20 stained plastic light covers were removed and properly disposed. During the assessment and cleaning activities that were performed, it was confirmed that PCB s were primarily limited to the following: interior/exterior caulking associated with the framed windows of the 100-Wing and 200- Wing classrooms; exterior caulking associated with vertical expansion joints of the concrete pillars and window sills associated with the classroom windows; substrate material (i.e. interior concrete block and exterior concrete pillars, window sills and brick façade) in direct contact with the window caulking and expansion joint caulking; caulking and associated substrate material immediately surrounding the exterior air intake vents for the 100-Wing and 200-Wing classrooms, the cafeteria and the kitchen; Exterior caulking associated with the clerestory windows in the cafeteria and kitchen and the associated substrate material, and; Electrical capacitors associated with the motors of the Unit Ventilators for the 100-Wing and 200-Wing classrooms. Remediation of the identified PCB s associated with the 100-Wing and 200-Wing classrooms, the cafeteria and the kitchen was totally complete by November, In summary, the remediation activities essentially consisted of: 1 A light fixture housing stained with a brown/black tar like substance indicates that a prior ballast for the light had likely ruptured.

8 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 3 Removal and proper disposal of the framed window units of the 200-Wing classrooms and the complete removal of the associated interior/exterior window caulking; Removal and thorough cleaning of the framed window units of the 100-Wing classrooms, and the complete removal of the associated interior/exterior window caulking; Complete removal of exterior vertical expansion joint caulking associated with the concrete columns surrounding the windows of the 100-Wing and 200-Wing classrooms; Application of two coats of Sikagard-62 to the interior/exterior porous surfaces surrounding the 100-Wing and 200-Wing classroom windows, (i.e. CMU concrete block, concrete columns and adjacent brick façade); Complete removal of exterior caulking associated with the air intake vents and the application of two coats of Sikagard-62 to the exterior porous surfaces surrounding the air intake vents for the 100-Wing and 200-Wing classrooms; Removal and thorough cleaning of the exterior louvers from the air intake vents of the 200- Wing classrooms; Removal and proper disposal of the framed clerestory window units of the cafeteria and kitchen and the complete removal of the associated window caulking; Application of two coats of Sikagard-62 on the interior/exterior substrate material surrounding the windows for the cafeteria and the kitchen; Removal and proper disposal of the PCB containing electrical capacitors for the Unit Ventilator motors of the 100-Wing and 200-Wing classrooms; Thorough cleaning of the interior surfaces of the Unit Ventilators for the 100-Wing and 200-Wing classrooms; and, Thorough cleaning of the 100-Wing and 200-Wing classrooms, the cafeteria and the kitchen following completion of remedial actions in those areas.

9 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page ANNUAL MONITORING AND MAINTENANCE Data obtained during annual monitoring and maintenance activities that have been performed at the Thomas Prince School, as well as other documents related to the PCB assessment and remediation, have been provided to the general public via posting on the WRSD website at The following tables present all data obtained from wipe sampling and analysis that has been conducted at the school since March 22, Table 1 presents a summary of all indoor air sampling analytical results that have been obtained at the school as part of pre/post PCB assessment and remedial mitigation activities. The laboratory certificates of analysis associated with the indoor air sampling activities discussed within this report (dates of service range from 12/28/2012 to 04/19/2017) are included in Appendix A. Table 2 presents a summary of the post-remedial, epoxy coated, porous surface wipe sample analytical results that have been obtained as part of the annual wipe sampling since March 22, 2012 from the 100-Wing and 200-Wing classrooms, Cafeteria and Kitchen. The laboratory certificates of analysis associated with the wipe sample results presented in Table 2 are included in Appendix B. Table 3 presents a summary of the post-remedial wipe sample results that have been obtained from the non-porous surfaces within the interiors of the unit ventilators for the 100-Wing and 200-Wing classrooms. The laboratory certificates of analysis associated with the wipe sample results presented in Table 3 are included in Appendix B & C. Table 4 presents a summary of the post-remedial wipe sample results that have been obtained from the non-porous surfaces of the outer sides of the motor casings of the 100- Wing classroom unit ventilators. The laboratory certificates of analysis associated with the wipe sample results presented in Table 4 are included in Appendix D & E. Table 5 presents a summary of the post-remedial wipe sample results that have been obtained from the non-porous surfaces of the aluminum window frames in the 100-Wing classrooms. The laboratory certificates of analysis associated with the wipe sample results presented in Table 5 are included in Appendix D & E. Table 6 presents a summary of the representative post-remedial wipe sample results that have been obtained from the non-porous surfaces of the inner sides of the exterior air intake louvers of the 200-Wing classrooms. The laboratory certificates of analysis associated with the wipe sample results presented in Table 6 are included in Appendix F. As part of the long term monitoring activities completed at the school, indoor air samples were collected in conformance with EPA Method TO-10A 2, using low flow air sampling pumps and polyurethane foam traps. The samples were typically collected over a duration of approximately 6 hours and 40 minutes at a flow rate of approximately 5 liters per minute (for a total sample volume of air of approximately 2 cubic meters). The air samples were submitted for laboratory analysis of PCB Homolog s via EPA Method 680. The results are compared to the current 2 USEPA. (1999). Compendium of methods for the determination of toxic organic compounds in ambient air. Second Edition. Compendium Method TO-10A. Determination of pesticides and polychlorinated biphenyls in ambient air using low volume polyurethane foam (PUF) sampling followed by gas chromatographic /multi-detector detection. USEPA Office of Research and Development, Center for Environmental Research Information. Cincinnati, OH January, 1999.

10 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 5 calculated EPA Exposure Levels for Evaluating PCB s in Indoor School Air (EPA guidance values) presented in Table 1. All wipe samples collected as part of long term monitoring activities were done so in conformance with the methods recommended by USEPA 3. The wipe samples were collected using hexane doused cotton gauze wipes over a 100 cm 2 area. The samples were extracted per EPA Method 3540C and analyzed for PCB s via EPA Method The results are compared to the EPA guideline for the cleanup of PCBs on surfaces in schools of 1 ug/100 cm 2. PCB mitigation activities were completed at Thomas Prince School during two events as summarized below: Risk Based Cleanup and Disposal Plan (revision 1 - February 13, 2012) - The primary areas remediated during the initial mitigation event included the 200-Wing classrooms, the kitchen windows and the cafeteria windows. Verbal approval for the mitigation activities were obtained from EPA on February 21, The mitigation activities were performed from February 22, 2012 to March 19, 2012). The remedial activities primarily consisted of the following: the removal/disposal of windows and associated PCB window caulk and glazing; the removal of exterior louvered air intake vents and removal/disposal of associated PCB caulk; the removal/disposal of caulk around the doorways of the 200-Wing classrooms; the cleaning of all surfaces, including unit ventilators, in the 200-Wing classrooms; encapsulation, via two coats of an epoxy coating, of interior and exterior PCBcontaminated porous surfaces; and, the temporary encapsulation, via two coats of an epoxy coating, of exterior PCB caulk located in vertical joints along the building facing side of pre-cast concrete columns and adjacent brick (note that this PCB caulk was removed during subsequent remedial activities). Modification: Risk Based Cleanup and Disposal Plan (August 14, 2012) - The primary areas remediated during this modification to the initial mitigation event included the 100-Wing classrooms and some additional activities associated with the 200-Wing classrooms. Written approval for the mitigation activities were obtained from EPA on September 17, The mitigation activities were performed from October 15, 2012 to November 5, The remedial activities primarily consisted of the following: the removal/disposal of PCB window caulk associated with the 100-Wing classrooms; the removal/disposal of PCB caulk around exterior air vent intakes for the 100-Wing classrooms; the removal/disposal of PCB caulk from the exterior vertical structural joints associated with the pre-cast concrete columns of the 100-Wing and 200-Wing classrooms; 3 Smith, John H. (1987). Wipe sampling and double wash/rinse cleanup as recommended by the Environmental Protection Agency PCB Spill Cleanup Policy. USEPA. June 23, 1987 (revised and clarified on April 18, 1991) and information presented in 40 CFR , Definition of Standard wipe test.

11 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 6 the decontamination of non-porous surfaces (i.e. 100-Wing window frames) to achieve the clean-up standard of 1ug/100cm 2 ; the decontamination of non-porous surfaces (i.e. 200-Wing air intake louvered vent covers) to achieve the clean-up standard of 1ug/100cm 2 ; encapsulation, via two coats of an epoxy coating, of interior and exterior PCBcontaminated porous surfaces; and, the removal/disposal of identified or potential PCB capacitors that are present within the unit ventilators of classrooms 100, 102, 104, 106, 108 & 110. Following completion of the initial mitigation activities on March 19, 2012, indoor air samples and wipe samples were collected on March 22, Summaries of the air sample results are presented in Table 1. Summaries of the wipe sample results are presented in Tables 2-6. Five additional rounds of indoor air sampling and wipe sampling have been completed to date since the final mitigation activities were completed at the school on November 5, These sampling events occurred on the dates of: December 28,2012; December 23, 2013; November 11, 2014; February 16, 2016; and, April 19, MARCH 22, ST POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND This initial post-remedial sampling round occurred following the completion of the initial PCB mitigation at the school which primarily included indoor air sampling from all 200-Wing classrooms, two, 100-Wing classrooms, the cafeteria and the kitchen. Surface wipe samples were primarily collected from the 200-Wing classrooms. Indoor Air Samples March 22, 2012 The 1 st round of post-mitigation indoor air sampling included the collection of indoor air samples from classrooms 201, 203, 205, 207, 209, 211, the cafeteria, the kitchen, and classrooms 100 and 106 on March 22, The air samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. The results of the analytical testing were favorable (i.e. the results were below the EPA calculated exposure level of 300 ng/m 3 for the age group of 6-12 years) for all rooms except classroom 209. No PCB s were detected above laboratory PQL s or EPA guidance values in the sample collected from the cafeteria. Concentrations of PCB s were detected in the indoor air of all of the other rooms that were sampled during this event at concentrations ranging from 3.86 ng/m 3 (library) to ng/m 3 (classroom 209), refer to Table 1. Surface Wipe Samples March 22, 2012 Since the only PCB remediation that had occurred up to this point was focused on the 200-Wing classrooms, the cafeteria and the kitchen, no wipe samples were collected from the 100-Wing

12 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 7 classrooms. Surface wipe samples were collected from both interior (12 samples) and exterior (6 samples) epoxy coated porous surfaces associated with the 200-Wing classrooms. Two interior surface wipe samples were collected from epoxy coated porous surfaces of the cafeteria. All of the epoxy coatings appeared intact with no peeling, chipping or flaking observed. The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. No PCB s were detected in these post mitigation samples above 1 ug/100cm 2 (Table 2). Refer to the Photograph log provided in Appendix G for representative photos of the interior and exterior epoxy coated porous surfaces associated with the windows of the 200-Wing classrooms. 2.2 DECEMBER 28, ND POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND This post-remedial sampling round occurred following the completion of final PCB mitigation at the school and included indoor air and surface wipe samples collected from the 100-Wing and 200-Wing classrooms. Indoor Air Samples December 28, 2012 The 2 nd round of indoor air sampling performed following the completion of final PCB mitigation activities included the collection of indoor air samples from classrooms 100, 102, 104, 106, 108, 110, 201, 203, 205, 207, 209, and 211 on December 28, The air samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. The results of the analytical testing were favorable. No PCB s were detected above laboratory PQL s or EPA guidance values in any of the samples. Surface Wipe Samples December 28, 2012 Post mitigation surface wipe samples were collected from the epoxy coated porous surfaces of classrooms 100, 102, 104, 106, 108 and 110 on December 28, A total of 15 surface wipe samples were collected from both interior and exterior epoxy coated porous surfaces. All of the epoxy coatings appeared intact with no peeling, chipping or flaking observed. The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. No PCB s were detected in these post mitigation samples above the laboratory reporting limit of 0.2 ug/100cm 2 (Table 2). Thirty-one pre/post remedial surface wipe samples were also collected from the non-porous surfaces of classroom related items including the surfaces of the existing painted aluminum window frames of the 100-Wing classrooms, interior surfaces of unit ventilators of the 100-Wing and 200-Wing classrooms, exterior surfaces of motors for the unit ventilator fans of the 100-Wing classrooms and the exterior air intake louvers for the 200-Wing classrooms. The surface wipe samples were collected during the performance of mitigation activities and the cleaning of the subject items between March 22, 2012 through November 5, The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. Surfaces where PCB s had initially been detected 4 above 1 ug/100cm 2 had been re-cleaned such that the final resultant PCB concentration remaining on the surface was <1 ug/100cm 2 (Tables 3-6). In March and April, 2012, surface wipe samples had also been collected from the epoxy coated surfaces which had previously been applied to the surface of the PCB-contaminated caulk that was 4 The results of these initial pre-mitigation analyses are not presented within this report

13 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 8 present within the exterior vertical expansion joints associated with the concrete window columns of the 200-Wing classrooms as well as the horizontal and vertical joints surrounding the exterior air intake louvers. These samples were also analyzed by Pace Analytical Services, Inc. Concentrations of PCB s above 1 ug/100cm 2 were detected in several of the samples (Table 2). During mitigation activities completed later in the year, the PCB-contaminated caulk was removed and two coats of epoxy encapsulant were applied to all previously epoxy coated porous surfaces associated with the subject caulk joints. 2.3 DECEMBER 23, RD POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND Indoor Air Samples December 23, 2013 The third round of post mitigation indoor air samples were collected from classrooms 100, 106, 110, 201, 205, 209, Cafeteria and Library on December 23, The air samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. The results of the analytical testing were favorable. No PCB s were detected above laboratory PQL s or EPA guidance values in any of the samples. Surface Wipe Samples December 23, 2013 The 3 rd round of post mitigation surface wipe samples were collected from classrooms 100, 106, 108, 110, 201, 203, 205, 207, 209 and 211 on December 23, A total of 19 surface wipe samples were collected from both interior and exterior epoxy coated porous surfaces. The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. PCB s were not detected above 1 ug/100 cm 2 in 16 of the samples collected as part of the December, 2013 surface wipe sampling event. Concentrations of PCB s above 1 ug/100cm 2 were detected in three samples at the following concentrations (Table 2): 1.21 ug/100cm 2 interior classroom 201; 1.1 ug/100cm 2 interior classroom 203; and, 1.7 ug/100cm 2 interior classroom 205. Resample - Surface Wipe Samples January 24, 2014 On January 24, 2014 surface wipe sampling was performed to confirm the December, 2013 results. The January samples were split between two independent laboratories (Pace Analytical Services, Inc. of Schenectady, NY and Spectrum Analytical Services, Inc. of Agawam, MA) as a quality control measure. Similarly labeled samples were collected adjacent to one another such that each laboratory essentially received the same sample sets 5. The newer results for classroom 205 confirmed the December results. The newer results from classrooms 201 and 203 were lower than but similar to the December results though the samples from classroom 203 did not exhibit PCB concentrations above 1 ug/100 cm 2. 5 The January 2014 wipe samples were collected from adjacent areas on the concrete block wall face, at similar locations (but not identical) to the samples collected in December 2013.

14 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 9 Maintenance Activities Surface Re-Coating with Sikagard 62 In February 2014, due to the detection of PCB s in December, 2013, ECS re-applied two coats of epoxy sealant (Sikagard 62 ) to the entire concrete block surface areas surrounding the windows in rooms 201, 203 & 205 to which it had previously been applied. An area where a chip in the epoxy coating had been observed in classroom 209 was also re-encapsulated with epoxy (two coats). ECS re-sampled the epoxy coated concrete block in room 205 on February 24, 2014 and no PCB s were detected above the laboratory reporting limit of 0.1 ug/100 cm 2 (as compared with the EPA exposure limit guideline value for unrestricted use in schools of 1 ug/100 cm 2 ). Refer to the Photograph Log, the Visual Inspection Log and the Maintenance Log Forms provided in Appendix H. 2.4 NOVEMBER 11, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND Indoor Air Samples November 11, 2014 The 4 th round of post mitigation indoor air samples were collected from classrooms 102, 104, 203, 207, 211 and the Cafeteria an on November 11, The air samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. The results of the analytical testing were favorable. No PCB s were detected above laboratory PQL s or EPA guidance values in any of the samples. Surface Wipe Samples November 11, 2014 The 4 th round of post mitigation surface wipe samples were collected from the epoxy coated porous surfaces of classrooms 100, 102, 104, 106, 108, 110, 201, 203, 205, 207, 209 and 211 on November 11, All of the epoxy coatings appeared intact with no peeling, chipping or flaking observed. The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. A total of 19 surface wipe samples were collected from both interior and exterior epoxy coated porous surfaces. PCB s were not detected above the laboratory reporting limit of 0.5 ug/100 cm 2 in any of the samples. 2.5 FEBRUARY 16, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND Indoor Air Samples February 16, 2016 The 5 th round of post mitigation indoor air samples were collected from classrooms 106, 108, 201, 205, 209 and the Cafeteria an on February 16, The air samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. The results of the analytical testing were favorable. No PCB s were detected above laboratory PQL s or EPA guidance values in any of the samples. Surface Wipe Samples February 16, 2016 The 5 th round of post mitigation surface wipe samples were collected from the epoxy coated porous surfaces of classrooms 100, 102, 104, 106, 108, 110, 201, 203, 205, 207, 209 and 211 on February 16, All of the epoxy coatings appeared intact with no peeling, chipping or flaking observed. The wipe samples were analyzed by Pace Analytical Services, Inc. of Schenectady, NY. A total

15 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 10 of 20 surface wipe samples were collected from both interior and exterior epoxy coated surfaces. PCB s were not detected above the laboratory reporting limit of 0.1 ug/100 cm 2 in any of the samples. 2.6 APRIL 19, TH POST-MITIGATION INDOOR AIR AND SURFACE WIPE SAMPLING ROUND Indoor Air Samples April 19, 2017 The 6 th round of post mitigation indoor air samples were collected from classrooms 100, 104, 110, 201, 205, 211 and the Cafeteria on April 19, The air samples were analyzed by Alpha Analytical, Inc. of Westborough, MA. The results of the analytical testing were favorable. No PCB s were detected above laboratory PQL s or EPA guidance values in the samples collected from classrooms 104, 110, 201 and the Cafeteria. Low levels of PCB s were detected in indoor air samples collected from classrooms 100 (4.98 ng/m 3 ), 205 (19.18 ng/m 3 in the duplicate sample for 205 but not detected above the laboratory reporting limit in the primary sample) and 211 (12.38 ng/m 3 ), all values being well below the lowest EPA guidance value for children aged 1-3 years. Surface Wipe Samples April 19, 2017 The 6 th round of post mitigation surface wipe samples were collected from epoxy coated porous surfaces of classrooms 100, 102, 104, 106, 108, 110, 201, 203, 205, 207, 209 and 211 on April 19, The wipe samples were analyzed by Eurofins Spectrum Analytical of Agawam, MA (Spectrum). A total of 20 surface wipe samples were collected from both interior and exterior epoxy coated porous surfaces. PCB s were not detected above the laboratory reporting limit of 0.2 ug/100 cm 2 in 19 of the samples. One exterior surface wipe sample, collected from the parallel face of the concrete column located between the windows for classrooms 100/102, was found to contain 4.47 ug/100 cm 2. Resample - Surface Wipe Samples July 27, 2017 On July 27, 2017, six surface wipe samples were collected from various portions of the subject epoxy coated concrete column to confirm that PCB s were present. The July samples were analyzed by Spectrum and confirmed that PCB s were present on the surface of the middle of the epoxy coated column.

16 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page 11 Maintenance Activities Surface Re-Coating with Sikagard 62 In August 2017, ATC re-applied one coat of epoxy sealant (Sikagard 62 ) to the entire length of the parallel face of the concrete column present between the windows for classrooms 100/102. A surface wipe sample of the epoxy coated surface was collected on August 31, 2017 (in the same location as the highest previously detected PCB concentration) and a PCB concentration of 0.25 ug/100 cm 2 was detected, just above the laboratory reporting limit of 0.2 ug/100 cm 2 but below the EPA exposure limit guideline value for unrestricted use in schools of 1 ug/100 cm 2. Minor flaking of the epoxy coating of three small areas on the concrete block in classrooms 207 (two areas) and 209 (1 area) were also re-encapsulated with epoxy (two coats). Refer to the Photograph Log, the Visual Inspection Log and the Maintenance Log Forms provided in Appendix I.

17 Annual MMIP Report Project No /Document No Thomas Prince School September 30, 2017 Princeton, Massachusetts Page FUTURE ANNUAL LONG TERM MONITORING AND MAINTENANCE ACTIVITIES - INDOOR AIR AND WIPE SAMPLING Future Long Term Monitoring and Maintenance Activities are expected to be conducted at varying times of the year for evaluation under different weather conditions on an annual basis. Per the requirements of the EPA approvals, these activities shall be conducted until such time that EPA, determines in writing, that such activities are no longer necessary.

18 FIGURES

19 Thomas Prince School 170 Sterling Street Princeton, MA ATC Group Services LLC 997 Millbury Street, Unit 6 Worcester, MA Phone Fax Figure 1: SITE LOCUS Base Map: U.S. Geological Survey; Quadrangle Location: Sterling, MA Lat/Lon: 42 26' 33" NORTH, 71 50' 38" WEST - UTM Coordinates: EAST / NORTH Generated By: Rick Starodoj

20 Concrete Asphalt BUS PICKUP / DROP OFF Corridor Custodian Kindergarten SR ER Boiler Room SR Corridor 302 Outdoor Courtyard 203 SL Kitchen Serving BR BR BR Corridor Cafeteria Corridor Stage PLAYGROUND T 306 T Corridor Teach Teach Gud Outdoor Courtyard 207 BR SR BR Corridor SR SR 113 SR BR Computers 111 Library Media Center SR BR Comp 17 SR Corridor BR BR SR Office Parent - Pickup / Drop Off Corridor 400 Gym Science Room 402 Green House Art & Industry Room 404 Corridor Legend Storage BR - Bathroom SR - Storage Room ER - Electrical Room SL - Staff Lounge - Fire Door PLAYGROUND Building Constructed 1962 Un-hatched sections were constructed in 1991 Room ID Plan

21 TABLES

22 Thomas Prince School 170 Sterling Road Princeton, Massachusetts Table 1 INDOOR AIR SAMPLING RESULTS USEPA Method TO-10A Indoor Air USEPA Method TO-10A/680/8082 Polychlorinated Biphenyls Method Aroclor (EPA Method 8082) Homolog's (EPA Method 680) Sample Location Sampling Date Aroclor (8082) Homolog's (680) Notes Sample Designation Total Aroclor Total Homolog's Monochlorobiphenyl Dichlorobiphenyl Trichlorobiphenyl Tetrachlorobiphenyl Pentachlorobiphenyl Hexachlorobiphenyl Heptachlorobiphenyl Octachlorobiphenyl Nonachlorobiphenyl Decachlorobiphenyl 8/20/2011 x x < 47.8 < 47.8 < < 23.9 < 23.9 < 23.9 < 35.9 < 35.9 < 59.8 < /22/2012 x < <4.94 <4.94 <4.94 <7.40 <7.40 <12.3 <12.3 Classroom /28/2012 x RM ND <2.17 <2.17 <2.17 <4.33 <4.33 <4.33 <6.49 <6.49 <10.8 <10.8 Classroom 102 Classroom 104 Classroom 106 Classroom 108 Classroom /23/2013 x 0 ND <2.45 <2.45 <2.45 <4.89 <4.89 <4.89 <7.34 <7.34 <12.2 <12.2 4/19/2017 x <4.61 <4.61 <4.61 < <4.61 <4.61 <4.61 <4.61 <4.61 8/20/2011 x RM < 48 < 48 12/28/2012 x RM ND <2.16 <2.16 <2.16 <4.31 <4.31 <4.31 <6.47 <6.47 <10.8 < /11/2014 x RM 102 ND <2.50 <2.50 <2.50 <5.01 <5.01 <5.01 <7.51 <7.51 <12.5 <12.5 8/20/2011 x RM < 48 < 48 12/28/2012 x RM ND <2.16 <2.16 <2.16 <4.31 <4.31 <4.31 <6.47 <6.47 <10.8 < /11/2014 x RM 104 ND <2.65 <2.65 <2.65 <5.30 <5.30 <5.30 <7.95 <7.95 <13.3 <13.3 4/19/2017 x RM 104 ND <4.56 <4.56 <4.56 <4.56 <4.56 <4.56 <4.56 <4.56 <4.56 <4.56 8/20/2011 x RM < 47.9 < /22/2011 x RM < < 4.93 < 7.39 < 7.39 < 12.3 < /22/2012 x RM < <4.94 <4.94 <4.94 <7.41 <7.41 <12.4 < /28/2012 x RM ND <2.14 <2.14 <2.14 <4.27 <4.27 <4.27 <6.41 <6.41 <10.7 < /23/2013 x RM ND <2.40 <2.40 <2.40 <4.80 <4.80 <4.80 <7.20 <7.20 <12.0 <12.0 2/16/2016 x RM 108 "B" 0 ND <2.22 <2.22 <2.22 <4.80 <4.44 <4.44 <6.66 <6.66 <11.1 <11.1 8/20/2011 x RM < 48.7 < /20/2011 x RM 108A < 49.9 < /8/2011 x RM < <5 <5 <5 <7.5 <7.5 <12.5 < /28/2012 x RM ND <2.37 <2.37 <2.37 <4.74 <4.74 <4.74 <7.11 <7.11 <11.8 <11.8 2/16/2016 x RM 108 "A" 0 ND <2.22 <2.22 <2.22 <4.44 <4.44 <4.44 <6.66 <6.66 <11.1 <11.1 8/20/2011 x RM < 49.2 < /28/2012 x RM ND <2.43 <2.43 <2.43 <4.85 <4.85 <4.85 <7.28 <7.28 <12.1 < /23/2013 x RM ND <2.43 <2.43 <2.43 <4.87 <4.87 <4.87 <7.30 <7.30 <12.2 <12.2 4/19/2017 x RM ND <4.53 <4.53 <4.53 <4.53 <4.53 <4.53 <4.53 <4.53 <4.53 <4.53 Page 1 of 4 9/30/2017

23 Thomas Prince School 170 Sterling Road Princeton, Massachusetts Table 1 INDOOR AIR SAMPLING RESULTS USEPA Method TO-10A Indoor Air USEPA Method TO-10A/680/8082 Polychlorinated Biphenyls Method Aroclor (EPA Method 8082) Homolog's (EPA Method 680) Sample Location Sampling Date Aroclor (8082) Homolog's (680) Notes Sample Designation Total Aroclor Total Homolog's Monochlorobiphenyl Dichlorobiphenyl Trichlorobiphenyl Tetrachlorobiphenyl Pentachlorobiphenyl Hexachlorobiphenyl Heptachlorobiphenyl Octachlorobiphenyl Nonachlorobiphenyl Decachlorobiphenyl Classroom 201 8/1/2011 x < /22/2012 x < <4.92 <7.38 <7.38 <12.3 < /28/2012 x 0 ND <2.36 <2.36 <2.36 <4.72 <4.72 <4.72 <7.08 <7.08 <11.8 <11.8 RM /23/2013 x 0 ND <2.42 <2.42 <2.42 <4.83 <4.83 <4.83 <7.25 <7.25 <12.1 <12.1 2/16/2016 x 0 ND <2.36 <2.36 <2.36 <4.72 <4.72 <4.72 <7.08 <7.08 <11.8 <11.8 4/19/2017 x 0 ND <4.60 <4.60 <4.60 <4.60 <4.60 <4.60 <4.60 <4.60 <4.60 <4.60 8/1/2011 x < /22/2012 x < <4.99 <7.49 <7.49 <12.5 <12.5 Classroom 203 RM /28/2012 x 0 ND <2.32 <2.32 <2.32 <4.63 <4.63 <4.63 <6.94 <6.94 <11.6 <11.6 Classroom 205 Classroom 209 Classroom /11/2014 x ND <2.48 <2.48 <2.48 <4.96 <4.96 <4.96 <7.43 <7.43 <12.4 <12.4 8/1/2011 x < /22/2012 x < < <4.88 <7.31 <7.31 <12.2 < /28/2012 x 0 ND <2.35 <2.35 <2.35 <4.70 <4.70 <4.70 <7.04 <7.04 <11.7 < /23/2013 x 0 ND <2.47 <2.47 <2.47 <4.94 <4.94 <4.94 <7.40 <7.40 <12.3 <12.3 2/16/2016 x 0 ND <2.35 <2.35 <2.35 <4.70 <4.70 <4.70 <7.04 <7.04 <11.7 <11.7 4/19/2017 x 0 ND <2.35 <2.35 <2.35 <4.70 <4.70 <4.70 <7.04 <7.04 <11.7 <11.7 4/19/2017 x DUP <4.62 <4.62 < <4.62 <4.62 <4.62 <4.62 <4.62 8/1/2011 x < /22/2012 x < <4.98 <7.47 <7.47 <12.4 <12.4 RM /28/2012 x 0 ND <2.32 <2.32 <2.32 <4.63 <4.63 <4.63 <6.94 <6.94 <11.6 < /11/2014 x ND <2.47 <2.47 <2.47 <4.94 <4.94 <4.94 <7.41 <7.41 <12.3 < /11/2014 x 1 RM 207 DUP ND <2.54 <2.54 <2.54 <5.07 <5.07 <5.07 <7.61 <7.61 <12.7 <12.7 8/1/2011 x < /22/2011 x RM < 7.45 < 7.45 < 12.4 < /8/2011 x RM <7.5 <7.5 <12.5 <12.5 3/22/2012 x RM < <7.31 <7.31 <12.2 <12.2 3/22/2012 x 1 RM 209 DUP < <4.9 <7.35 <7.35 <12.2 < /28/2012 x RM ND <2.30 <2.30 <2.30 <4.61 <4.61 <4.61 <6.91 <6.91 <11.5 < /28/2012 x 1 RM 209 DUPLICATE 0 ND <2.30 <2.30 <2.30 <4.61 <4.61 <4.61 <6.91 <6.91 <11.5 < /23/2013 x RM ND <2.40 <2.40 <2.40 <4.81 <4.81 <4.81 <7.21 <7.21 <12.0 < /23/2013 x 1 RM 209 DUPLICATE 0 ND <2.41 <2.41 <2.41 <4.81 <4.81 <4.81 <7.22 <7.22 <12.0 <12.0 2/16/2016 x RM ND <2.37 <2.37 <2.37 <4.74 <4.74 <4.74 <7.10 <7.10 <11.8 <11.8 2/16/2016 x 1 RM 209 DUPLICATE 0 ND <2.44 <2.44 <2.44 <4.89 <4.89 <4.89 <7.33 <7.33 <12.2 <12.2 8/1/2011 x < /22/2012 x < <4.86 <7.29 <7.29 <12.2 <12.2 Classroom /28/2012 x ND <2.28 <2.28 <2.28 <4.57 <4.57 <4.57 <6.85 <6.85 <11.4 < /11/2014 x ND <2.46 <2.46 <2.46 <4.92 <4.92 <4.92 <7.38 <7.38 <12.3 <12.3 4/19/2017 x <4.65 <4.65 <4.65 < <4.65 <4.65 <4.65 <4.65 <4.65 Page 2 of 4 9/30/2017

24 Thomas Prince School 170 Sterling Road Princeton, Massachusetts Table 1 INDOOR AIR SAMPLING RESULTS USEPA Method TO-10A Indoor Air USEPA Method TO-10A/680/8082 Polychlorinated Biphenyls Method Aroclor (EPA Method 8082) Homolog's (EPA Method 680) Sample Location Sampling Date Aroclor (8082) Homolog's (680) Notes Sample Designation Total Aroclor Total Homolog's Monochlorobiphenyl Dichlorobiphenyl Trichlorobiphenyl Tetrachlorobiphenyl Pentachlorobiphenyl Hexachlorobiphenyl Heptachlorobiphenyl Octachlorobiphenyl Nonachlorobiphenyl Decachlorobiphenyl Kitchen Library Computer Lab 111 Home Economics 112 Off Library 113 Cafeteria Office Common Area 13 8/20/2011 x CAF/AUD A < 44.3 < /20/2011 x CAF/AUD B < 48.4 < /20/2011 x 1 CAF/AUD DUP < 48.4 < /22/2011 x CAF/AUD < 2.51 < < 5.01 < 5.01 < 5.01 < 7.52 < 7.52 < 12.5 < /22/2011 x 1 CAF/AUD DUP < 2.4 < < 4.81 < 4.81 < 7.21 < 7.21 < 12 < 12 3/22/2012 x Cafeteria 0 ND <2.48 <2.48 <2.48 <4.95 <4.95 <4.95 <7.43 <7.43 <12.4 < /23/2013 x Cafeteria 0 ND <2.51 <2.51 <2.51 <5.03 <5.03 <5.03 <7.54 <7.54 <12.6 < /11/2014 x RM-Caf ND <2.47 <2.47 <2.47 <4.94 <4.94 <4.94 <7.40 <7.40 <12.3 <12.3 2/16/2016 x Cafeteria ND <2.43 <2.43 <2.43 <4.87 <4.87 <4.87 <7.30 <7.30 <12.22 < /19/2017 x Cafeteria ND <4.55 <4.55 <4.55 <4.55 <4.55 <4.55 <4.55 <4.55 <4.55 <4.55 8/20/2011 x KITCHEN < 47.9 < /22/2011 x KITCHEN < < 4.95 < 4.95 < 7.42 < 7.42 < 12.3 < /22/2012 x KITCHEN < <2.41 <4.82 <4.82 <4.82 <7.23 <7.23 <12.0 <12.0 8/20/2011 x LIBRARY A < 47.5 < /20/2011 x LIBRARY B < 49.7 < /22/2011 x LIBRARY < < 4.88 < 4.88 < 4.88 < 7.32 < 7.32 < 12.2 < /22/2012 x LIBRARY <2.48 < <4.96 <4.96 <4.96 <7.44 <7.44 <12.4 < /23/2013 x LIBRARY 0 ND <2.44 <2.44 <2.44 <4.88 <4.88 <4.88 <7.31 <7.31 <12.2 <12.2 8/20/2011 x RM < 49.6 < /22/2011 x RM < 4.97 < 4.97 < 7.45 < 7.45 < 12.4 < /20/2011 x x RM ND 24.8 <48.9 < 48.9 < 48.9 < 12.2 < 12.2 < 12.2 < 24.4 < 24.4 < 24.4 < 36.7 < 36.7 < 61.1 < /20/2011 x 1 RM 112 (DUP) ND 0 <66.9 <66.9 < 66.9 < /20/2011 x RM < 50.3 < /22/2011 x RM < < 4.93 < 4.93 < 7.39 < 7.39 < 12.3 < /20/2011 x x RM < 49.3 < 49.3 < < 12.3 < 24.6 < 24.6 < 24.6 < 37 < 37 < 61.6 < /22/2011 x RM < 2.45 < < 4.91 < 4.91 < 4.91 < 7.36 < 7.36 < 12.3 < 12.3 Stage Area 8/20/2011 x STAGE < 48.8 < 48.8 Staff Lounge -- Off Kitchen 8/20/2011 x T LOUNGE < 48.4 < 48.4 Electrical Room 8/20/2011 x ELEC ROOM < 48.1 < Corridor North 100 Corridor South 8/20/2011 x 100 COR A < 47.7 < /22/2011 x 100 COR N < 4.93 < 7.4 < 7.4 < 12.3 < /20/2011 x 100 COR B < 49.6 < /22/2011 x 100 COR S < < 4.96 < 4.96 < 7.44 < 7.44 < 12.4 < 12.4 Central Corridor West 8/20/2011 x MID COR A ND 0 < 49 < 49 < 49 < 49 Central Corridor East 200 Corridor North 9/22/2011 x CENTRAL COR MID < 4.93 < 7.4 < 7.4 < 12.3 < /20/2011 x MID COR B < 49.9 < /22/2011 x CENTRAL COR E < < 5.03 < 5.03 < 5.03 < 7.55 < 7.55 < 12.6 < /20/2011 x 200 COR A < 50.1 < 50.1 Page 3 of 4 9/30/2017

25 Thomas Prince School 170 Sterling Road Princeton, Massachusetts Table 1 INDOOR AIR SAMPLING RESULTS USEPA Method TO-10A Indoor Air USEPA Method TO-10A/680/8082 Polychlorinated Biphenyls Method Aroclor (EPA Method 8082) Homolog's (EPA Method 680) Sample Location Sampling Date Aroclor (8082) Homolog's (680) Notes Sample Designation Total Aroclor Total Homolog's Monochlorobiphenyl Dichlorobiphenyl Trichlorobiphenyl Tetrachlorobiphenyl Pentachlorobiphenyl Hexachlorobiphenyl Heptachlorobiphenyl Octachlorobiphenyl Nonachlorobiphenyl Decachlorobiphenyl 200 Corridor North 9/22/2011 x 200 COR N < 4.9 < 4.9 < 7.36 < 7.36 < 12.3 < Corridor South 8/20/2011 x 200 COR B < /22/2011 x 200 COR S < 4.9 < 7.34 < 7.34 < 12.2 < 12.2 Storage Room Opposite 211 8/20/2011 x RM < South Corridor West 8/20/2011 x SOUTH COR A < 49.2 < 49.2 < 49.2 South Corridor East 8/20/2011 x SOUTH COR B < 49.4 < 49.4 < /20/2011 x x RM 300 ND ND < 50.1 < 50.1 < 50.1 < 50.1 < 12.5 < 12.5 < 12.5 < 25.1 < 25.1 < 25.1 < 37.6 < 37.6 < 62.6 < 62.6 Kindergarten x x RM ND 20.1 < 49.5 < 49.5 < 49.5 < 12.4 < 12.4 < 12.4 < 24.8 < 24.8 < 24.8 < 37.1 < 37.1 < 61.9 < /20/2011 x RM 302 DUP < 48.5 < 48.5 < Corridor North 8/20/2011 x 300 COR A ND 0 < 49.7 < 49.7 < 49.7 < Corridor South 8/20/2011 x 300 COR B ND 0 <49.9 < 49.9 < 49.9 < 49.9 North Corridor West 8/20/2011 x ENT COR B < 50.1 < 50.1 < 50.1 North Corridor East 8/20/2011 x ENT COR A ND 0 <50.3 < 50.3 < 50.3 < 50.3 Classroom 303 8/20/2011 x x RM ND 20.8 < 49.8 < 49.8 < 49.8 < 12.4 < 12.4 < 12.4 < 24.9 < 24.9 < 24.9 < 37.3 < 37.3 < 62.2 < 62.2 Classroom 308 8/20/2011 x x RM 308 ND ND < 49 < 49 < 49 < 49 < 12.3 < 12.3 < 12.3 < 24.5 < 24.5 < 24.5 < 36.8 < 36.8 < 61.3 < 61.3 Gymnasium West 8/20/2011 x GYM A < 48.4 < 48.4 < 48.4 Gymnasium East 8/20/2011 x x GYM B 37.1 ND 37.1 < 48.9 < 48.9 < 48.9 < 12.2 < 12.2 < 12.2 < 24.5 < 24.5 < 24.5 < 36.7 < 36.7 < 61.2 < 61.2 Science Room 8/20/2011 x x RM 402 ND ND < 50.5 < 50.5 < 50.5 < 50.5 < 12.6 < 12.6 < 12.6 < 25.2 < 25.2 < 25.2 < 37.8 < 37.8 < 63.1 < 63.1 Art & Industry Room 8/20/2011 x x RM 404 ND ND < 48.7 < 48.7 < 48.7 < 48.7 < 12.2 < 12.2 < 12.2 < 24.4 < 24.4 < 24.4 < 36.5 < 36.5 < 60.9 < 60.9 Outside (NW Cnr. of Bldg.) 8/20/2011 x OUTSIDE A ND 0 < 51.7 < 51.7 < 51.7 < 51.7 Outside (S. Courtyard) 8/20/2011 x OUTSIDE B ND 0 < 48.6 < 48.6 < 48.6 < /22/2011 x OUTSIDE S COURTYARD 0 ND < 2.42 < 2.42 < 2.42 < 4.84 < 4.84 < 4.84 < 7.26 < 7.26 < 12.1 < 12.1 Notes: Concentrations in nanograms (billionth of a gram) per cubic meter (ng/m3). 08/01/11 - Initial IAS round - limited to 200-wing classrooms "<" or "ND" denotes = Not Detected at laboratory reporting limit. 08/20/11-2nd IAS round - comprehensive round throughout building Yellow shading denotes most recent indoor air sampling results 09/22/11-3rd IAS round - targeted to show effects of initial "cleaning". 1 = Denotes sample dulicate. 11/08/11-4th IAS round - Limited to classrooms 209 & 108. EPA Calculated Exposure Levels for Evaluating PCB's in School Indoor Air (ng/m 3 ), Health Protective GUIDANCE Values 3/22/12-5th IAS Round - Post Mitigation 200-Wing, Cafeteria & Kitchen Age (years) ng/m 3 12/28/12-6th IAS Round - Post Final Complete Mitigation at school 1-< /23/13-7th IAS Round - 1 year following completed Mitigation 2-< /11/14-8th IAS Round - 2 years following completed Mitigation 3-< /16/16-9th IAS Round - 3 years following completed Mitigation 6-< Elementary School 4/19/17-10th IAS Round - 4 years following completed Mitigation 12-< Middle School 15-< High School Adult Post Abatement Indoor Air Sample Results - Blue Highlight Page 4 of 4 9/30/2017