AWS 1500 October 19, Karen Maloney, Assistant Superintendent Novato Unified School District 1015 Seventh Street Novato, CA 94945

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1 AWS 1500 October 19, 2015 Karen Maloney, Assistant Superintendent Novato Unified School District 1015 Seventh Street Novato, CA RE: Surface Sampling Report-Novato Charter School 940 C Street, Novato, CA Dear Ms. Maloney, Pursuant to your direction, Air & Water SCIENCES (AWS) has prepared this report regarding our testing of surfaces at Novato Charter School for metals; lead (Pb), barium (Ba) and arsenic (As). This report includes the procedures and methodologies followed, analytical laboratory results, and applicable conclusions and recommendations for the site. Site Location The Novato Charter School (NCS) is located at 940 C Street in Hamilton Field, Novato, CA. The school site is approximately 2.8 acres in size and opened at the above address in The school serves grades K-8 and has approximately 267 students enrolled. The site houses 14 structures; all of which are portable units. Background In April 2015 the former gas station building was demolished at 970 C Street; which is located directly west from NCS. According to the contractors lead (Pb) and asbestos containing materials were removed from the building prior to the demolition, however, documents show that the restrooms could not be accessed during the assessment for testing. Due to the fact that these documents still have not been provided it is possible that the building was demolished without these materials being properly removed nd Street, Suite 210, Petaluma, CA

2 Karen Maloney, NUSD October 19, 2015 Page 2 of 6 In addition, earthwork was conducted at the 970 C Street site in April 2015 as part of the building demolition and also from the abandonment of environmental testing locations (wells, piezometers). This earthwork was performed in areas that may contain barium and arsenic above the residential screening levels (RSLs). Based on the fact that work that was performed in close proximity and directly upwind from NCS it was determined that surface testing at NCS should be performed to document that the levels of these contaminants of concern (COCs) are not present in levels above regulatory health based screening levels. Purpose and Scope of Work The purpose of the work was to collect surface samples of the metals that may have been released as part of the work that was done in April Generally, perimeter air testing would have been conducted during and/or immediately after the work, but because this was not done by the contractors, the alternative is to sample the surfaces for COCs that could have been deposited at NCS during the 970 C soil disturbance work. For this reason, AWS selected the heavier COCs which include the metals that were detected or suspected at the site that could have become airborne during the demolition/earthwork. These COCs include lead (Pb), barium (Ba), and arsenic (As). Testing Methodology Lead, barium and arsenic Three (3) surfaces at NCS and one (1) background sample were collected for lead, barium, and arsenic testing. AWS used ghost wipes to collect each sample from a one (1) square foot area. The sample locations were selected from horizontal surfaces that have a high probability of hand touch while also being within closest proximity to the 970 C Street site. The sampling locations are as follows: 1-MW (west play structure), 2-MW (northwest play structure), 3-MW (west picnic table), and 4-MW (background; play structure at Bolling St and Randolph Drive). The background sample is located approximately 0.25 miles south-southwest from NCS. The sampling locations are shown on Figure 1.

3 Karen Maloney, NUSD October 19, 2015 Page 3 of 6 Testing Results All four (4) of the surface wipe samples were submitted for analytical testing for lead, barium, and arsenic, as mentioned above. The samples were analyzed by Analytical Sciences in Petaluma, CA for the three metals using NIOSH method A copy of the lab report from Analytical Sciences is attached. Lead The analytical results for lead (Pb) were as follows: 1.5 μg/ft 2 (1-MW [west play structure]), 0.85 μg/ft 2 (2-MW [northwest play structure]), 1.6 μg/ft 2 (3-MW [west picnic table]), and 0.5 μg/ft 2 (4-MW [background]). The most conservative levels of lead detected on surfaces is set by various regulatory and oversight agencies. The Environmental Protections Agency Toxic Substances Control Act (EPA TSCA) Section 403 Standard (January 2001), California Title 17 Lead-contaminated dust (April 2008), and the Housing Urban Development (HUD) surface clearance criteria for lead (Pb) all state that level of lead on surfaces should be below 40 μg/ft² for interior floors. The clearance levels for soil and other surfaces are higher than 40 μg/ft². For instance, under California Title 17 Lead-contaminated dust (April 2008), for exterior floor and exterior horizontal surfaces the level is set at 400 μg/ft². The lead (Pb) levels found on surfaces at NCS ranged from 0.85 μg/ft 2 (2-MW [northwest play structure]) to 1.6 μg/ft 2 (3-MW [west picnic table]). Based on the above mentioned regulations the surfaces sampled were all well below the most stringent regulatory levels for surface concentrations of lead (Pb). Barium The analytical results for surface wipe samples collected from NCS and the background sample for barium (Ba) were as follows: 26 μg/ft 2 (1-MW [west play structure]), 20 μg/ft 2 (2-MW [northwest play structure]), 6.5 μg/ft 2 (3-MW [west picnic table]), and 15 μg/ft 2 (4-MW [background]). Unlike lead (Pb) there are no regulatory standards for barium on surfaces or in dust. There are occupational standards for barium in air and also standards for barium in drinking water. The Occupational Safety and Health Administration s (OSHA) permissible exposure limit (PEL) and the American Conference of Governmental Industrial Hygienist s (ACGIH) threshold limit value (time-weighted average) ((TLV [TWA]) for exposure to barium in air is 0.5 mg/m 3 ). Regarding barium in drinking water; the EPA s Maximum Contaminant Level (MCL) in drinking water is 2 mg/l (2000 μg/l).

4 Karen Maloney, NUSD October 19, 2015 Page 4 of 6 As mentioned above, screening levels for barium have been established by a few agencies, but regulatory levels do not exist. The World Trade Center Indoor Air Task Force Working Group set a screening level for barium on surfaces at 1,025 μg/ft 2 ( μg/m 2 ) (WTCIATFWG, 2003). The U.S. Army Center For Health Promotion and Preventive Medicine established a surface wipe screening level at 5,204 μg/ft 2 (560 μg/100cm 2 ) (USACHPPM, 2009) and the North Carolina Department of Environment and Natural Resources (NCDENR) Air Toxics Analytical Support Team (ATAST) published a screening level of 10,223 μg/ft 2 (1100 μg/100cm 2 ) (NCDENR, 2006) for barium on exterior surface wipes. The highest level detected of barium found on a surface at NCS was 26 μg/ft 2 (1-MW [west play structure]) with the lowest being 6.5 μg/ft 2 (3-MW [west picnic table]). The background sample was measured at 15 μg/ft 2 was collected from a play structure located approximately 0.25 miles south-southwest. Based on the above, the levels detected at the school are far below the established screening levels for barium on surfaces and may be reflective of background concentrations. Arsenic The analytical results for surface wipe samples collected from NCS and the background sample for arsenic (As) were as follows: 0.45 μg/ft 2 (1-MW [west play structure]), 0.27 μg/ft 2 (2-MW [northwest play structure]), sample 3-MW (west picnic table) was non-detect (<0.25 μg/ft 2 ), and 0.30 μg/ft 2 was found for 4-MW (background), which was also collected from the play structure located 0.25 miles from the NCS in the south-southwest direction. Similar to barium, the same agencies established screening levels for arsenic, but regulatory levels for surfaces do not exist. The regulations that do exist for arsenic exposure pertain to air and drinking water and these are as follows: the OSHA s PEL and the ACGIH (TLV [TWA]) for exposure to arsenic in air is 10 μg/m 3 and the National Institute for Occupational Safety and Health sets a recommended exposure limit (REL) of 2 μg/m 3 for exposure to airborne arsenic. Regarding arsenic in drinking water; the EPA s MCL in drinking water is mg/l (10 μg/l). The World Trade Center Indoor Air Task Force Working Group sets a screening level for arsenic on surfaces at μg/ft 2 (387 μg/m 2 ) (WTCIATFWG, 2003). The U.S. Army Center For Health Promotion and Preventive Medicine established a surface wipe screening level at μg/ft 2 (2.0 μg/100cm 2 ) (USACHPPM, 2009) and the North Carolina Department of Environment and Natural Resources, Division of Air Quality, Toxics Protection Branch (NCDENR), Air Toxics Analytical Support Team (ATAST) published a screening level of μg/ft 2 (3.87 μg/100cm 2 ) (NCDENR, 2006) for arsenic on exterior surface wipes.

5 Karen Maloney, NUSD October 19, 2015 Page 5 of 6 The highest level detected of arsenic found on a surface at NCS was 0.45 μg/ft 2 (1-MW [west play structure]) with the lowest being non-detect (<0.25 μg/ft 2 ) from 3-MW (west picnic table). The background sample was measured at 0.30 μg/ft 2 from a play structure located approximately 0.25 miles south-southwest. Based on the above, the levels detected at the school are far below the established screening levels for arsenic on surfaces. Conclusions and Recommendations Three (3) surface samples were collected from horizontal surface areas at NCS which were closest to the 970 C Street site and also most likely to be touched by NCS students. These samples were analyzed for lead (Pb), barium (Ba), and arsenic (As) and the results were compared against regulatory or screening levels for these chemicals of concern (COCs). The results of the testing indicate that all of the samples collected fell far below any established regulatory or screening level for surface wipe samples. Based on the results no further testing for lead (Pb), barium (Ba) or arsenic (As) is recommended at this time. The results obtained can be used as background levels for any upcoming remediation work at the adjacent site. As mentioned in the AWS Report of Recommendations for 970 C Street Remediation Work dated September 10, 2015 additional testing for these COCs is warranted during or at the completion of the remedial work at the 970 C Street site. Limitations The conclusions and results contained herein are based solely on the information presented in this report. Additional information or contamination that was hidden, undiscovered, inaccessible, or are not a part of the finding presented herein, would result in the modification of the conclusions and recommendations of this report. Any remediation guidelines are minimum general guidelines based solely on the findings contained herein. The guidelines are presented as a courtesy and are not to be considered a complete or detailed set of remediation specifications. AWS is not responsible for the accuracy of information provided by others, or for conditions or consequences arising from relevant facts that were withheld, concealed, undiscovered or not fully disclosed. AWS is not qualified to present medical advice. If any present or future health issues are in question, it is recommended that the findings in this report be presented to a

6 Karen Maloney, NUSD October 19, 2015 Page 6 of 6 qualified medical professional for evaluation. AWS is not a law firm and, therefore, makes no representations regarding any potential liability of any person or entity for site conditions. If you should have any questions or would like to discuss the contents of this report, please do not hesitate to contact us at (707) Respectfully submitted, Air & Water SCIENCES Chip Prokop, PE, BCEE, CIEC, CAC Principal Heidi Bauer, PG Senior Project Manager REFERENCES North Carolina Department of Environment and Natural Resources, Division of Air Quality, Toxics Protection Branch (NCDENR), November 2006, ATAST Response # 06020, Exterior Wipe Sampling Screening Program. U.S. Army Center For Health Promotion And Preventive Medicine (USACHPPM), June 2009, Health Risk Assessment Methods and Screening Levels for Evaluating Office, Worker Exposures to Contaminants on Indoor Surfaces Using, Surface Wipe Data- Technical Guide 312. Committee of the World Trade Center Indoor Air Task Force Working Group (WTCIATFWG), May 2003, World Trade Center Indoor Environment Assessment: Selecting Contaminants of Potential Concern and Setting Health-Based Benchmarks.

7 2-MW 1-MW 3-MW 4-MW NOVATO CHARTER SCHOOL 940 C ST NOVATO, CA FIGURE 1 METAL SAMPLING LOCATIONS Air & Water Sciences PROJECT NO nd Street., Ste. 210 Petaluma, CA (707) / Fax (707) DATE: SEPTEMBER 30, 2015

8 Analytical Sciences Report Date: October 13, 2015 Laboratory Report Chip Prokop AW Sciences 625 2nd Street, Suite 210 Petaluma, CA Project Name: Lab Project Number: AWS 1500/Hamilton AWS 1500/Hamilton This 5 page report of analytical data has been reviewed and approved for release. Mark A. Valentini, Ph.D. Laboratory Director P.O. Box Petaluma, CA Telephone: (707) Liberty Street Petaluma, CA 94952

9 Wipe Metals Lab# Sample ID Compound Name Result (µg/square foot) RDL (µg/square foot) MW Lead (Pb) Arsenic (As) Barium (Ba) Date Sampled: Date Analyzed: 10/09/15 QC Batch: B Date Received: Method: NIOSH 9100 Wipe Metals Lab# Sample ID Compound Name Result (µg/square foot) RDL (µg/square foot) MW Lead (Pb) Arsenic (As) Barium (Ba) Date Sampled: Date Analyzed: 10/09/15 QC Batch: B Date Received: Method: NIOSH 9100 Wipe Metals Lab# Sample ID Compound Name Result (µg/square foot) RDL (µg/square foot) MW Lead (Pb) Arsenic (As) ND 0.25 Barium (Ba) Date Sampled: Date Analyzed: 10/09/15 QC Batch: B Date Received: Method: NIOSH 9100 Lab Project#: Page 2 of 5 CA Lab Accreditation #: 2303

10 Wipe Metals Lab# Sample ID Compound Name Result (µg/square foot) RDL (µg/square foot) MW Lead (Pb) Arsenic (As) Barium (Ba) Date Sampled: Date Analyzed: 10/09/15 QC Batch: B Date Received: Method: NIOSH 9100 Lab Project#: Page 3 of 5 CA Lab Accreditation #: 2303

11 Quality Assurance Report Wipe Metals Analyte Result Reporting Limit Units Spike Level Source Result %REC %REC Limits RPD RPD Limit Notes Batch B NI0SH 9100 Blank (B BLK1) Prepared: 10/07/15 Analyzed: 10/09/15 Lead (Pb) ND 0.25 µg/square foot Arsenic (As) ND 0.25 µg/square foot Barium (Ba) ND 2.5 µg/square foot Lab Project#: Page 4 of 5 CA Lab Accreditation #: 2303

12 Notes and Definitions RDL ND RPD NR Reporting Detection Limit Analyte NOT DETECTED at or above the reporting detection limit (RDL) Relative Percent Difference Not Reported Lab Project#: Page 5 of 5 CA Lab Accreditation #: 2303

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